merchant

Merchant backend to process payments, run by merchants
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commit f6633b5cb3567046f73d6cf4de0ab5b2eb4d217b
parent 5acd586004bd7281e6dcf14217e3fee316716804
Author: Christian Grothoff <christian@grothoff.org>
Date:   Sat,  2 Nov 2019 23:09:52 +0100

simplify structure

Diffstat:

Msrc/lib/Makefile.am | 13++++++++-----


Dsrc/lib/testing_api_cmd_refund.c | 636-------------------------------------------------------------------------------


Asrc/lib/testing_api_cmd_refund_increase.c | 234+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++


Dsrc/lib/testing_api_cmd_tip.c | 1205-------------------------------------------------------------------------------


Asrc/lib/testing_api_cmd_tip_authorize.c | 375+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++


Asrc/lib/testing_api_cmd_tip_pickup.c | 598+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++


Asrc/lib/testing_api_cmd_tip_query.c | 297+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++


7 files changed, 1512 insertions(+), 1846 deletions(-)

diff --git a/src/lib/Makefile.am b/src/lib/Makefile.am
@@ -42,14 +42,17 @@ libtalermerchant_la_LIBADD = \
   $(XLIB)
 
 libtalermerchanttesting_la_SOURCES = \
-  testing_api_cmd_proposal.c \
+  testing_api_cmd_history.c \
   testing_api_cmd_pay.c \
-  testing_api_cmd_refund.c \
-  testing_api_cmd_tip.c \
+  testing_api_cmd_proposal.c \
+  testing_api_cmd_refund_increase.c \
+  testing_api_cmd_refund_lookup.c \
+  testing_api_cmd_rewind.c \
+  testing_api_cmd_tip_authorize.c \
+  testing_api_cmd_tip_pickup.c \
+  testing_api_cmd_tip_query.c \
   testing_api_cmd_track_transaction.c \
   testing_api_cmd_track_transfer.c \
-  testing_api_cmd_history.c \
-  testing_api_cmd_rewind.c \
   testing_api_helpers.c \
   testing_api_trait_merchant_sig.c \
   testing_api_trait_string.c \
diff --git a/src/lib/testing_api_cmd_refund.c b/src/lib/testing_api_cmd_refund.c
@@ -1,636 +0,0 @@
-/*
-  This file is part of TALER
-  Copyright (C) 2014-2018 Taler Systems SA
-
-  TALER is free software; you can redistribute it and/or modify
-  it under the terms of the GNU General Public License as
-  published by the Free Software Foundation; either version 3, or
-  (at your option) any later version.
-
-  TALER is distributed in the hope that it will be useful, but
-  WITHOUT ANY WARRANTY; without even the implied warranty of
-  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-  GNU General Public License for more details.
-
-  You should have received a copy of the GNU General Public
-  License along with TALER; see the file COPYING.  If not, see
-  <http://www.gnu.org/licenses/>
-*/
-
-/**
- * @file lib/testing_api_cmd_refund.c
- * @brief command to test refunds.
- * @author Marcello Stanisci
- */
-
-#include "platform.h"
-#include <taler/taler_exchange_service.h>
-#include <taler/taler_testing_lib.h>
-#include "taler_merchant_service.h"
-#include "taler_merchant_testing_lib.h"
-
-
-/**
- * State for a "refund increase" CMD.
- */
-struct RefundIncreaseState
-{
-  /**
-   * Operation handle for a POST /refund request.
-   */
-  struct TALER_MERCHANT_RefundIncreaseOperation *rio;
-
-  /**
-   * Base URL of the merchant serving the request.
-   */
-  const char *merchant_url;
-
-  /**
-   * Order id of the contract to refund.
-   */
-  const char *order_id;
-
-  /**
-   * The amount to refund.
-   */
-  const char *refund_amount;
-
-  /**
-   * Refund fee.
-   */
-  const char *refund_fee;
-
-  /**
-   * Human-readable justification for the refund.
-   */
-  const char *reason;
-
-  /**
-   * Interpreter state.
-   */
-  struct TALER_TESTING_Interpreter *is;
-
-  /**
-   * Expected HTTP response code.
-   */
-  unsigned int http_code;
-};
-
-
-/**
- * State for a "refund lookup" CMD.
- */
-struct RefundLookupState
-{
-  /**
-   * Operation handle for a GET /public/refund request.
-   */
-  struct TALER_MERCHANT_RefundLookupOperation *rlo;
-
-  /**
-   * Base URL of the merchant serving the request.
-   */
-  const char *merchant_url;
-
-  /**
-   * Order id to look up.
-   */
-  const char *order_id;
-
-  /**
-   * Reference to a "pay" CMD, used to double-check if
-   * refunded coins were actually spent:
-   */
-  const char *pay_reference;
-
-  /**
-   * Reference to a "refund increase" CMD that offer
-   * the expected amount to be refunded; can be NULL.
-   */
-  const char *increase_reference;
-
-  /**
-   * Expected HTTP response code.
-   */
-  unsigned int http_code;
-
-  /**
-   * Interpreter state.
-   */
-  struct TALER_TESTING_Interpreter *is;
-
-  /**
-   * Explicit amount to be refunded, must be defined if @a
-   * increase_reference is NULL.
-   */
-  const char *refund_amount;
-};
-
-
-/**
- * Free the state of a "refund increase" CMD, and
- * possibly cancel a pending "refund increase" operation.
- *
- * @param cls closure
- * @param cmd command currently being freed.
- */
-static void
-refund_increase_cleanup (void *cls,
-                         const struct TALER_TESTING_Command *cmd)
-{
-  struct RefundIncreaseState *ris = cls;
-
-  if (NULL != ris->rio)
-  {
-    TALER_LOG_WARNING ("Refund-increase operation"
-                       " did not complete\n");
-    TALER_MERCHANT_refund_increase_cancel (ris->rio);
-  }
-  GNUNET_free (ris);
-}
-
-
-/**
- * Free the state of a "refund lookup" CMD, and
- * possibly cancel a pending "refund lookup" operation.
- *
- * @param cls closure
- * @param cmd command currently being freed.
- */
-static void
-refund_lookup_cleanup (void *cls,
-                       const struct TALER_TESTING_Command *cmd)
-{
-  struct RefundLookupState *rls = cls;
-
-  if (NULL != rls->rlo)
-  {
-    TALER_LOG_WARNING ("Refund-lookup operation"
-                       " did not complete\n");
-    TALER_MERCHANT_refund_lookup_cancel (rls->rlo);
-  }
-  GNUNET_free (rls);
-}
-
-
-/**
- * Process POST /refund (increase) response; just checking
- * if the HTTP response code is the one expected.
- *
- * @param cls closure
- * @param http_status HTTP status code
- * @param ec taler-specific error object
- * @param obj response body; is NULL on success.
- */
-static void
-refund_increase_cb (void *cls,
-                    unsigned int http_status,
-                    enum TALER_ErrorCode ec,
-                    const json_t *obj)
-{
-  struct RefundIncreaseState *ris = cls;
-
-  ris->rio = NULL;
-  if (ris->http_code != http_status)
-    TALER_TESTING_FAIL (ris->is);
-
-  TALER_TESTING_interpreter_next (ris->is);
-}
-
-
-/**
- * Run the "refund increase" CMD.
- *
- * @param cls closure.
- * @param cmd command currently being run.
- * @param is the interpreter state.
- */
-static void
-refund_increase_run (void *cls,
-                     const struct TALER_TESTING_Command *cmd,
-                     struct TALER_TESTING_Interpreter *is)
-{
-  struct RefundIncreaseState *ris = cls;
-  struct TALER_Amount refund_amount;
-
-  ris->is = is;
-  if (GNUNET_OK != TALER_string_to_amount (ris->refund_amount,
-                                           &refund_amount))
-    TALER_TESTING_FAIL (is);
-  ris->rio = TALER_MERCHANT_refund_increase (is->ctx,
-                                             ris->merchant_url,
-                                             ris->order_id,
-                                             &refund_amount,
-                                             ris->reason,
-                                             &refund_increase_cb,
-                                             ris);
-  GNUNET_assert (NULL != ris->rio);
-}
-
-
-/**
- * Callback that frees all the elements in the hashmap
- *
- * @param cls closure, NULL
- * @param key current key
- * @param value a `struct TALER_Amount`
- *
- * @return always #GNUNET_YES (continue to iterate)
- */
-static int
-hashmap_free (void *cls,
-              const struct GNUNET_HashCode *key,
-              void *value)
-{
-  struct TALER_Amount *refund_amount = value;
-
-  GNUNET_free (refund_amount);
-  return GNUNET_YES;
-}
-
-
-/**
- * Process "GET /public/refund" (lookup) response;
- * mainly checking if the refunded amount matches the
- * expectation.
- *
- * @param cls closure
- * @param http_status HTTP status code
- * @param ec taler-specific error object
- * @param obj response body; is NULL on error.
- */
-static void
-refund_lookup_cb (void *cls,
-                  unsigned int http_status,
-                  enum TALER_ErrorCode ec,
-                  const json_t *obj)
-{
-  struct RefundLookupState *rls = cls;
-  struct GNUNET_CONTAINER_MultiHashMap *map;
-  size_t index;
-  json_t *elem;
-  const char *error_name;
-  unsigned int error_line;
-  struct GNUNET_HashCode h_coin_pub;
-  const char *coin_reference;
-  char *coin_reference_dup;
-  const char *icoin_reference;
-  const struct TALER_TESTING_Command *pay_cmd;
-  const struct TALER_TESTING_Command *increase_cmd;
-  const char *refund_amount;
-  struct TALER_Amount acc;
-  struct TALER_Amount ra;
-  const json_t *arr;
-
-  rls->rlo = NULL;
-  if (rls->http_code != http_status)
-    TALER_TESTING_FAIL (rls->is);
-
-  arr = json_object_get (obj, "refund_permissions");
-  if (NULL == arr)
-  {
-    GNUNET_log (GNUNET_ERROR_TYPE_INFO,
-                "Tolerating a refund permission not found\n");
-    TALER_TESTING_interpreter_next (rls->is);
-    return;
-  }
-  map = GNUNET_CONTAINER_multihashmap_create (1, GNUNET_NO);
-
-  /* Put in array every refunded coin.  */
-  json_array_foreach (arr, index, elem)
-  {
-    struct TALER_CoinSpendPublicKeyP coin_pub;
-    struct TALER_Amount *irefund_amount = GNUNET_new
-                                            (struct TALER_Amount);
-    struct GNUNET_JSON_Specification spec[] = {
-      GNUNET_JSON_spec_fixed_auto ("coin_pub", &coin_pub),
-      TALER_JSON_spec_amount ("refund_amount", irefund_amount),
-      GNUNET_JSON_spec_end ()
-    };
-
-    GNUNET_assert (GNUNET_OK == GNUNET_JSON_parse (elem,
-                                                   spec,
-                                                   &error_name,
-                                                   &error_line));
-    GNUNET_CRYPTO_hash (&coin_pub,
-                        sizeof (struct TALER_CoinSpendPublicKeyP),
-                        &h_coin_pub);
-    GNUNET_assert (GNUNET_OK == GNUNET_CONTAINER_multihashmap_put
-                     (map,
-                     &h_coin_pub, // which
-                     irefund_amount, // how much
-                     GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
-  };
-
-  /* Compare spent coins with refunded, and if they match,
-   * increase an accumulator.  */
-  if (NULL ==
-      (pay_cmd = TALER_TESTING_interpreter_lookup_command
-                   (rls->is, rls->pay_reference)))
-    TALER_TESTING_FAIL (rls->is);
-
-  if (GNUNET_OK != TALER_TESTING_get_trait_coin_reference
-        (pay_cmd, 0, &coin_reference))
-    TALER_TESTING_FAIL (rls->is);
-
-  GNUNET_assert (GNUNET_OK == TALER_amount_get_zero ("EUR",
-                                                     &acc));
-  coin_reference_dup = GNUNET_strdup (coin_reference);
-  for (icoin_reference = strtok (coin_reference_dup, ";");
-       NULL != icoin_reference;
-       icoin_reference = strtok (NULL, ";"))
-  {
-    const struct TALER_CoinSpendPrivateKeyP *icoin_priv;
-    struct TALER_CoinSpendPublicKeyP icoin_pub;
-    struct GNUNET_HashCode h_icoin_pub;
-    struct TALER_Amount *iamount;
-    const struct TALER_TESTING_Command *icoin_cmd;
-
-    if (NULL ==
-        (icoin_cmd = TALER_TESTING_interpreter_lookup_command
-                       (rls->is, icoin_reference)) )
-    {
-      GNUNET_break (0);
-      TALER_LOG_ERROR ("Bad reference `%s'\n",
-                       icoin_reference);
-      TALER_TESTING_interpreter_fail (rls->is);
-      GNUNET_CONTAINER_multihashmap_destroy (map);
-      return;
-    }
-
-    if (GNUNET_OK != TALER_TESTING_get_trait_coin_priv
-          (icoin_cmd, 0, &icoin_priv))
-    {
-      GNUNET_break (0);
-      TALER_LOG_ERROR ("Command `%s' failed to give coin"
-                       " priv trait\n",
-                       icoin_reference);
-      TALER_TESTING_interpreter_fail (rls->is);
-      GNUNET_CONTAINER_multihashmap_destroy (map);
-      return;
-    }
-
-    GNUNET_CRYPTO_eddsa_key_get_public (&icoin_priv->eddsa_priv,
-                                        &icoin_pub.eddsa_pub);
-    GNUNET_CRYPTO_hash (&icoin_pub,
-                        sizeof (struct TALER_CoinSpendPublicKeyP),
-                        &h_icoin_pub);
-
-    iamount = GNUNET_CONTAINER_multihashmap_get
-                (map, &h_icoin_pub);
-
-    /* Can be NULL: not all coins are involved in refund */
-    if (NULL == iamount)
-      continue;
-
-    GNUNET_assert (GNUNET_OK == TALER_amount_add (&acc,
-                                                  &acc,
-                                                  iamount));
-  }
-
-  GNUNET_free (coin_reference_dup);
-
-  if (NULL !=
-      (increase_cmd = TALER_TESTING_interpreter_lookup_command
-                        (rls->is, rls->increase_reference)))
-  {
-    if (GNUNET_OK != TALER_TESTING_get_trait_amount
-          (increase_cmd, 0, &refund_amount))
-      TALER_TESTING_FAIL (rls->is);
-
-    if (GNUNET_OK != TALER_string_to_amount
-          (refund_amount, &ra))
-      TALER_TESTING_FAIL (rls->is);
-  }
-  else
-  {
-    GNUNET_assert (NULL != rls->refund_amount);
-
-    if (GNUNET_OK != TALER_string_to_amount
-          (rls->refund_amount, &ra))
-      TALER_TESTING_FAIL (rls->is);
-  }
-
-  GNUNET_CONTAINER_multihashmap_iterate (map,
-                                         &hashmap_free,
-                                         NULL);
-  GNUNET_CONTAINER_multihashmap_destroy (map);
-
-  /* Check that what the backend claims to have been refunded
-   * actually matches _our_ refund expectation.  */
-  if (0 != TALER_amount_cmp (&acc,
-                             &ra))
-  {
-    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
-                "Incomplete refund: expected '%s', got '%s'\n",
-                TALER_amount_to_string (&ra),
-                TALER_amount_to_string (&acc));
-    TALER_TESTING_interpreter_fail (rls->is);
-    return;
-  }
-
-  TALER_TESTING_interpreter_next (rls->is);
-}
-
-
-/**
- * Run the "refund lookup" CMD.
- *
- * @param cls closure.
- * @param cmd command being currently run.
- * @param is interpreter state.
- */
-static void
-refund_lookup_run (void *cls,
-                   const struct TALER_TESTING_Command *cmd,
-                   struct TALER_TESTING_Interpreter *is)
-{
-  struct RefundLookupState *rls = cls;
-
-  rls->is = is;
-  rls->rlo = TALER_MERCHANT_refund_lookup (is->ctx,
-                                           rls->merchant_url,
-                                           rls->order_id,
-                                           &refund_lookup_cb,
-                                           rls);
-  GNUNET_assert (NULL != rls->rlo);
-}
-
-
-/**
- * Offer internal data from the "refund increase" CMD
- * state to other commands.
- *
- * @param cls closure
- * @param ret[out] result (could be anything)
- * @param trait name of the trait
- * @param index index number of the object to extract.
- * @return #GNUNET_OK on success
- */
-static int
-refund_increase_traits (void *cls,
-                        const void **ret,
-                        const char *trait,
-                        unsigned int index)
-{
-  struct RefundIncreaseState *ris = cls;
-
-  struct TALER_TESTING_Trait traits[] = {
-    TALER_TESTING_make_trait_amount (0, ris->refund_amount),
-    TALER_TESTING_trait_end ()
-  };
-
-  return TALER_TESTING_get_trait (traits,
-                                  ret,
-                                  trait,
-                                  index);
-
-  return GNUNET_SYSERR;
-}
-
-
-/**
- * Define a "refund increase" CMD.
- *
- * @param label command label.
- * @param merchant_url base URL of the backend serving the
- *        "refund increase" request.
- * @param reason refund justification, human-readable.
- * @param order_id order id of the contract to refund.
- * @param refund_amount amount to be refund-increased.
- * @param refund_fee refund fee.
- * @param http_code expected HTTP response code.
- *
- * @return the command.
- */
-struct TALER_TESTING_Command
-TALER_TESTING_cmd_refund_increase
-  (const char *label,
-  const char *merchant_url,
-  const char *reason,
-  const char *order_id,
-  const char *refund_amount,
-  const char *refund_fee,
-  unsigned int http_code)
-{
-  struct RefundIncreaseState *ris;
-
-  ris = GNUNET_new (struct RefundIncreaseState);
-  ris->merchant_url = merchant_url;
-  ris->order_id = order_id;
-  ris->refund_amount = refund_amount;
-  ris->refund_fee = refund_fee;
-  ris->reason = reason;
-  ris->http_code = http_code;
-
-  struct TALER_TESTING_Command cmd = {
-    .cls = ris,
-    .label = label,
-    .run = &refund_increase_run,
-    .cleanup = &refund_increase_cleanup,
-    .traits = &refund_increase_traits
-  };
-
-  return cmd;
-}
-
-
-/**
- * Define a "refund lookup" CMD.
- *
- * @param label command label.
- * @param merchant_url base URL of the merchant serving the
- *        "refund lookup" request.
- * @param increase_reference reference to a "refund increase" CMD
- *        that will offer the amount to check the looked up refund
- *        against.  Must NOT be NULL.
- * @param pay_reference reference to the "pay" CMD whose coins got
- *        refunded.  It is used to double-check if the refunded
- *        coins were actually spent in the first place.
- * @param order_id order id whose refund status is to be looked up.
- * @param http_code expected HTTP response code.
- *
- * @return the command.
- */
-struct TALER_TESTING_Command
-TALER_TESTING_cmd_refund_lookup
-  (const char *label,
-  const char *merchant_url,
-  const char *increase_reference,
-  const char *pay_reference,
-  const char *order_id,
-  unsigned int http_code)
-{
-  struct RefundLookupState *rls;
-
-  rls = GNUNET_new (struct RefundLookupState);
-  rls->merchant_url = merchant_url;
-  rls->order_id = order_id;
-  rls->pay_reference = pay_reference;
-  rls->increase_reference = increase_reference;
-  rls->http_code = http_code;
-
-  struct TALER_TESTING_Command cmd = {
-    .cls = rls,
-    .label = label,
-    .run = &refund_lookup_run,
-    .cleanup = &refund_lookup_cleanup
-  };
-
-  return cmd;
-}
-
-
-/**
- * Define a "refund lookup" CMD, equipped with a expected refund
- * amount.
- *
- * @param label command label.
- * @param merchant_url base URL of the merchant serving the
- *        "refund lookup" request.
- * @param increase_reference reference to a "refund increase" CMD
- *        that will offer the amount to check the looked up refund
- *        against.  Can be NULL, takes precedence over @a
- *        refund_amount.
- * @param pay_reference reference to the "pay" CMD whose coins got
- *        refunded.  It is used to double-check if the refunded
- *        coins were actually spent in the first place.
- * @param order_id order id whose refund status is to be looked up.
- * @param http_code expected HTTP response code.
- * @param refund_amount expected refund amount.  Must be defined
- *        if @a increase_reference is NULL.
- *
- * @return the command.
- */
-struct TALER_TESTING_Command
-TALER_TESTING_cmd_refund_lookup_with_amount
-  (const char *label,
-  const char *merchant_url,
-  const char *increase_reference,
-  const char *pay_reference,
-  const char *order_id,
-  unsigned int http_code,
-  const char *refund_amount)
-{
-  struct RefundLookupState *rls;
-
-  rls = GNUNET_new (struct RefundLookupState);
-  rls->merchant_url = merchant_url;
-  rls->order_id = order_id;
-  rls->pay_reference = pay_reference;
-  rls->increase_reference = increase_reference;
-  rls->http_code = http_code;
-  rls->refund_amount = refund_amount;
-
-  struct TALER_TESTING_Command cmd = {
-    .cls = rls,
-    .label = label,
-    .run = &refund_lookup_run,
-    .cleanup = &refund_lookup_cleanup
-  };
-
-  return cmd;
-}
-
-
-/* end of testing_api_cmd_refund.c */
diff --git a/src/lib/testing_api_cmd_refund_increase.c b/src/lib/testing_api_cmd_refund_increase.c
@@ -0,0 +1,234 @@
+/*
+  This file is part of TALER
+  Copyright (C) 2014-2018 Taler Systems SA
+
+  TALER is free software; you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as
+  published by the Free Software Foundation; either version 3, or
+  (at your option) any later version.
+
+  TALER is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public
+  License along with TALER; see the file COPYING.  If not, see
+  <http://www.gnu.org/licenses/>
+*/
+
+/**
+ * @file lib/testing_api_cmd_refund_increase.c
+ * @brief command to test refunds.
+ * @author Marcello Stanisci
+ */
+
+#include "platform.h"
+#include <taler/taler_exchange_service.h>
+#include <taler/taler_testing_lib.h>
+#include "taler_merchant_service.h"
+#include "taler_merchant_testing_lib.h"
+
+
+/**
+ * State for a "refund increase" CMD.
+ */
+struct RefundIncreaseState
+{
+  /**
+   * Operation handle for a POST /refund request.
+   */
+  struct TALER_MERCHANT_RefundIncreaseOperation *rio;
+
+  /**
+   * Base URL of the merchant serving the request.
+   */
+  const char *merchant_url;
+
+  /**
+   * Order id of the contract to refund.
+   */
+  const char *order_id;
+
+  /**
+   * The amount to refund.
+   */
+  const char *refund_amount;
+
+  /**
+   * Refund fee.
+   */
+  const char *refund_fee;
+
+  /**
+   * Human-readable justification for the refund.
+   */
+  const char *reason;
+
+  /**
+   * Interpreter state.
+   */
+  struct TALER_TESTING_Interpreter *is;
+
+  /**
+   * Expected HTTP response code.
+   */
+  unsigned int http_code;
+};
+
+
+/**
+ * Free the state of a "refund increase" CMD, and
+ * possibly cancel a pending "refund increase" operation.
+ *
+ * @param cls closure
+ * @param cmd command currently being freed.
+ */
+static void
+refund_increase_cleanup (void *cls,
+                         const struct TALER_TESTING_Command *cmd)
+{
+  struct RefundIncreaseState *ris = cls;
+
+  if (NULL != ris->rio)
+  {
+    TALER_LOG_WARNING ("Refund-increase operation"
+                       " did not complete\n");
+    TALER_MERCHANT_refund_increase_cancel (ris->rio);
+  }
+  GNUNET_free (ris);
+}
+
+
+/**
+ * Process POST /refund (increase) response; just checking
+ * if the HTTP response code is the one expected.
+ *
+ * @param cls closure
+ * @param http_status HTTP status code
+ * @param ec taler-specific error object
+ * @param obj response body; is NULL on success.
+ */
+static void
+refund_increase_cb (void *cls,
+                    unsigned int http_status,
+                    enum TALER_ErrorCode ec,
+                    const json_t *obj)
+{
+  struct RefundIncreaseState *ris = cls;
+
+  ris->rio = NULL;
+  if (ris->http_code != http_status)
+    TALER_TESTING_FAIL (ris->is);
+
+  TALER_TESTING_interpreter_next (ris->is);
+}
+
+
+/**
+ * Run the "refund increase" CMD.
+ *
+ * @param cls closure.
+ * @param cmd command currently being run.
+ * @param is the interpreter state.
+ */
+static void
+refund_increase_run (void *cls,
+                     const struct TALER_TESTING_Command *cmd,
+                     struct TALER_TESTING_Interpreter *is)
+{
+  struct RefundIncreaseState *ris = cls;
+  struct TALER_Amount refund_amount;
+
+  ris->is = is;
+  if (GNUNET_OK != TALER_string_to_amount (ris->refund_amount,
+                                           &refund_amount))
+    TALER_TESTING_FAIL (is);
+  ris->rio = TALER_MERCHANT_refund_increase (is->ctx,
+                                             ris->merchant_url,
+                                             ris->order_id,
+                                             &refund_amount,
+                                             ris->reason,
+                                             &refund_increase_cb,
+                                             ris);
+  GNUNET_assert (NULL != ris->rio);
+}
+
+
+/**
+ * Offer internal data from the "refund increase" CMD
+ * state to other commands.
+ *
+ * @param cls closure
+ * @param ret[out] result (could be anything)
+ * @param trait name of the trait
+ * @param index index number of the object to extract.
+ * @return #GNUNET_OK on success
+ */
+static int
+refund_increase_traits (void *cls,
+                        const void **ret,
+                        const char *trait,
+                        unsigned int index)
+{
+  struct RefundIncreaseState *ris = cls;
+  struct TALER_TESTING_Trait traits[] = {
+    TALER_TESTING_make_trait_amount (0, ris->refund_amount),
+    TALER_TESTING_trait_end ()
+  };
+
+  return TALER_TESTING_get_trait (traits,
+                                  ret,
+                                  trait,
+                                  index);
+}
+
+
+/**
+ * Define a "refund increase" CMD.
+ *
+ * @param label command label.
+ * @param merchant_url base URL of the backend serving the
+ *        "refund increase" request.
+ * @param reason refund justification, human-readable.
+ * @param order_id order id of the contract to refund.
+ * @param refund_amount amount to be refund-increased.
+ * @param refund_fee refund fee.
+ * @param http_code expected HTTP response code.
+ *
+ * @return the command.
+ */
+struct TALER_TESTING_Command
+TALER_TESTING_cmd_refund_increase
+  (const char *label,
+  const char *merchant_url,
+  const char *reason,
+  const char *order_id,
+  const char *refund_amount,
+  const char *refund_fee,
+  unsigned int http_code)
+{
+  struct RefundIncreaseState *ris;
+
+  ris = GNUNET_new (struct RefundIncreaseState);
+  ris->merchant_url = merchant_url;
+  ris->order_id = order_id;
+  ris->refund_amount = refund_amount;
+  ris->refund_fee = refund_fee;
+  ris->reason = reason;
+  ris->http_code = http_code;
+  {
+    struct TALER_TESTING_Command cmd = {
+      .cls = ris,
+      .label = label,
+      .run = &refund_increase_run,
+      .cleanup = &refund_increase_cleanup,
+      .traits = &refund_increase_traits
+    };
+
+    return cmd;
+  }
+}
+
+
+/* end of testing_api_cmd_refund_increase.c */
diff --git a/src/lib/testing_api_cmd_tip.c b/src/lib/testing_api_cmd_tip.c
@@ -1,1205 +0,0 @@
-/*
-  This file is part of TALER
-  Copyright (C) 2014-2018 Taler Systems SA
-
-  TALER is free software; you can redistribute it and/or modify
-  it under the terms of the GNU General Public License as
-  published by the Free Software Foundation; either version 3, or
-  (at your option) any later version.
-
-  TALER is distributed in the hope that it will be useful, but
-  WITHOUT ANY WARRANTY; without even the implied warranty of
-  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-  GNU General Public License for more details.
-
-  You should have received a copy of the GNU General Public
-  License along with TALER; see the file COPYING.  If not, see
-  <http://www.gnu.org/licenses/>
-*/
-
-/**
- * @file lib/testing_api_cmd_tip.c
- * @brief command to test the tipping.
- * @author Marcello Stanisci
- */
-
-#include "platform.h"
-#include <taler/taler_exchange_service.h>
-#include <taler/taler_testing_lib.h>
-#include "taler_merchant_service.h"
-#include "taler_merchant_testing_lib.h"
-
-/**
- * State for a /tip-pickup CMD.
- */
-struct TipPickupState
-{
-  /**
-   * Merchant base URL.
-   */
-  const char *merchant_url;
-
-  /**
-   * Exchange base URL.
-   */
-  const char *exchange_url;
-
-  /**
-   * Expected HTTP response code.
-   */
-  unsigned int http_status;
-
-  /**
-   * Reference to a /tip/authorize CMD.  This will be used to
-   * get the tip id to make the request with.
-   */
-  const char *authorize_reference;
-
-  /**
-   * If set to non NULL, it references another pickup CMD
-   * that will provide all the data which is needed to issue
-   * the request (like planchet secrets, denomination keys..).
-   */
-  const char *replay_reference;
-
-  /**
-   * Handle to a on-going /tip/pickup request.
-   */
-  struct TALER_MERCHANT_TipPickupOperation *tpo;
-
-  /**
-   * The interpreter state.
-   */
-  struct TALER_TESTING_Interpreter *is;
-
-  /**
-   * An array of string-defined amounts that indicates
-   * which denominations are going to be used to receive
-   * tips.
-   */
-  const char **amounts;
-
-  /**
-   * The object version of the above @a amounts.
-   */
-  struct TALER_Amount *amounts_obj;
-
-  /**
-   * How many coins are involved in the tipping operation.
-   */
-  unsigned int num_coins;
-
-  /**
-   * The array of denomination keys, in the same order of @a
-   * amounts.
-   */
-  const struct TALER_EXCHANGE_DenomPublicKey **dks;
-
-
-  /**
-   * The array of planchet secrets, in the same order of @a
-   * amounts.
-   */
-  struct TALER_PlanchetSecretsP *psa;
-
-  /**
-   * Temporary data structure of @e num_coins entries for the
-   * withdraw operations.
-   */
-  struct WithdrawHandle *withdraws;
-
-  /**
-   * Set (by the interpreter) to an array of @a num_coins
-   * signatures created from the (successful) tip operation.
-   */
-  struct TALER_DenominationSignature *sigs;
-
-  /**
-   * Expected Taler error code (NOTE: this is NOT the HTTP
-   * response code).
-   */
-  enum TALER_ErrorCode expected_ec;
-};
-
-
-/**
- * State for a /tip-query CMD.
- */
-struct TipQueryState
-{
-
-  /**
-   * The merchant base URL.
-   */
-  const char *merchant_url;
-
-  /**
-   * Expected HTTP response code for this CMD.
-   */
-  unsigned int http_status;
-
-  /**
-   * The handle to the current /tip-query request.
-   */
-  struct TALER_MERCHANT_TipQueryOperation *tqo;
-
-  /**
-   * The interpreter state.
-   */
-  struct TALER_TESTING_Interpreter *is;
-
-  /**
-   * Expected amount to be picked up.
-   */
-  const char *expected_amount_picked_up;
-
-  /**
-   * Expected amount to be tip-authorized.
-   */
-  const char *expected_amount_authorized;
-
-  /**
-   * Amount that is expected to be still available
-   * from the tip reserve.
-   */
-  const char *expected_amount_available;
-};
-
-
-/**
- * State for a /tip-authorize CMD.
- */
-struct TipAuthorizeState
-{
-
-  /**
-   * Merchant base URL.
-   */
-  const char *merchant_url;
-
-  /**
-   * Expected HTTP response code.
-   */
-  unsigned int http_status;
-
-  /**
-   * Human-readable justification for the
-   * tip authorization carried on by this CMD.
-   */
-  const char *justification;
-
-  /**
-   * Amount that should be authorized for tipping.
-   */
-  const char *amount;
-
-  /**
-   * Expected Taler error code for this CMD.
-   */
-  enum TALER_ErrorCode expected_ec;
-
-  /**
-   * Tip taler:// URI.
-   */
-  const char *tip_uri;
-
-  /**
-   * The tip id; set when the CMD succeeds.
-   */
-  struct GNUNET_HashCode tip_id;
-
-  /**
-   * Expiration date for this tip.
-   */
-  struct GNUNET_TIME_Absolute tip_expiration;
-
-  /**
-   * Handle to the on-going /tip-authorize request.
-   */
-  struct TALER_MERCHANT_TipAuthorizeOperation *tao;
-
-  /**
-   * The interpreter state.
-   */
-  struct TALER_TESTING_Interpreter *is;
-};
-
-/**
- * Callback for a /tip-authorize request.  Set into the state
- * what was returned from the backend (@a tip_id and @a
- * tip_expiration).
- *
- * @param cls closure
- * @param http_status HTTP status returned by the merchant backend
- * @param ec taler-specific error code
- * @param taler_tip_uri URI to let the wallet know about the tip
- * @param tip_id unique identifier for the tip
- */
-static void
-tip_authorize_cb (void *cls,
-                  unsigned int http_status,
-                  enum TALER_ErrorCode ec,
-                  const char *taler_tip_uri,
-                  struct GNUNET_HashCode *tip_id)
-{
-  struct TipAuthorizeState *tas = cls;
-
-  tas->tao = NULL;
-  if (tas->http_status != http_status)
-  {
-    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
-                "Unexpected response code %u (%d)"
-                " to command %s\n",
-                http_status,
-                ec,
-                TALER_TESTING_interpreter_get_current_label
-                  (tas->is));
-
-    TALER_TESTING_interpreter_fail (tas->is);
-    return;
-  }
-
-  if (tas->expected_ec != ec)
-  {
-    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
-                "Unexpected error code %d (%u) to command %s\n",
-                ec,
-                http_status,
-                TALER_TESTING_interpreter_get_current_label
-                  (tas->is));
-    TALER_TESTING_interpreter_fail (tas->is);
-    return;
-  }
-  if ( (MHD_HTTP_OK == http_status) &&
-       (TALER_EC_NONE == ec) )
-  {
-    tas->tip_uri = strdup (taler_tip_uri);
-    tas->tip_id = *tip_id;
-  }
-
-  TALER_TESTING_interpreter_next (tas->is);
-}
-
-
-/**
- * Offers information from the /tip-authorize CMD state to other
- * commands.
- *
- * @param cls closure
- * @param ret[out] result (could be anything)
- * @param trait name of the trait
- * @param index index number of the object to extract.
- * @return #GNUNET_OK on success
- */
-static int
-tip_authorize_traits (void *cls,
-                      const void **ret,
-                      const char *trait,
-                      unsigned int index)
-{
-  struct TipAuthorizeState *tas = cls;
-  struct TALER_TESTING_Trait traits[] = {
-    TALER_TESTING_make_trait_tip_id (0, &tas->tip_id),
-    TALER_TESTING_trait_end (),
-  };
-
-  return TALER_TESTING_get_trait (traits,
-                                  ret,
-                                  trait,
-                                  index);
-}
-
-
-/**
- * Runs the /tip-authorize CMD
- *
- * @param cls closure
- * @param cmd the CMD representing _this_ command
- * @param is interpreter state
- */
-static void
-tip_authorize_run (void *cls,
-                   const struct TALER_TESTING_Command *cmd,
-                   struct TALER_TESTING_Interpreter *is)
-{
-  struct TipAuthorizeState *tas = cls;
-  struct TALER_Amount amount;
-
-  tas->is = is;
-  if (GNUNET_OK != TALER_string_to_amount (tas->amount,
-                                           &amount))
-    TALER_TESTING_FAIL (is);
-
-  tas->tao = TALER_MERCHANT_tip_authorize
-               (is->ctx,
-               tas->merchant_url,
-               "http://merchant.com/pickup",
-               "http://merchant.com/continue",
-               &amount,
-               tas->justification,
-               tip_authorize_cb,
-               tas);
-
-  GNUNET_assert (NULL != tas->tao);
-}
-
-
-/**
- * Run the /tip-authorize CMD, the "fake" version of it.
- *
- * @param cls closure
- * @param cmd the CMD representing _this_ command
- * @param is interpreter state *
- */
-static void
-tip_authorize_fake_run (void *cls,
-                        const struct TALER_TESTING_Command *cmd,
-                        struct TALER_TESTING_Interpreter *is)
-{
-  struct TipAuthorizeState *tas = cls;
-
-  /* Make up a tip id.  */
-  GNUNET_CRYPTO_random_block (GNUNET_CRYPTO_QUALITY_WEAK,
-                              &tas->tip_id,
-                              sizeof (struct GNUNET_HashCode));
-
-  TALER_TESTING_interpreter_next (is);
-}
-
-
-/**
- * Free the state from a /tip-authorize CMD, and possibly
- * cancel any pending operation.
- *
- * @param cls closure
- * @param cmd the /tip-authorize CMD that is about to be freed.
- */
-static void
-tip_authorize_cleanup (void *cls,
-                       const struct TALER_TESTING_Command *cmd)
-{
-  struct TipAuthorizeState *tas = cls;
-
-  if (NULL != tas->tao)
-  {
-    TALER_LOG_WARNING ("Tip-autorize operation"
-                       " did not complete\n");
-    TALER_MERCHANT_tip_authorize_cancel (tas->tao);
-  }
-  GNUNET_free (tas);
-}
-
-
-/**
- * Create a /tip-authorize CMD, specifying the Taler error code
- * that is expected to be returned by the backend.
- *
- * @param label this command label
- * @param merchant_url the base URL of the merchant that will
- *        serve the /tip-authorize request.
- * @param exchange_url the base URL of the exchange that owns
- *        the reserve from which the tip is going to be gotten.
- * @param http_status the HTTP response code which is expected
- *        for this operation.
- * @param justification human-readable justification for this
- *        tip authorization.
- * @param amount the amount to authorize for tipping.
- * @param ec expected Taler-defined error code.
- */
-struct TALER_TESTING_Command
-TALER_TESTING_cmd_tip_authorize_with_ec
-  (const char *label,
-  const char *merchant_url,
-  const char *exchange_url,
-  unsigned int http_status,
-  const char *justification,
-  const char *amount,
-  enum TALER_ErrorCode ec)
-{
-  struct TipAuthorizeState *tas;
-
-  tas = GNUNET_new (struct TipAuthorizeState);
-  tas->merchant_url = merchant_url;
-  tas->justification = justification;
-  tas->amount = amount;
-  tas->http_status = http_status;
-  tas->expected_ec = ec;
-
-  struct TALER_TESTING_Command cmd = {
-    .label = label,
-    .cls = tas,
-    .run = &tip_authorize_run,
-    .cleanup = &tip_authorize_cleanup,
-    .traits = &tip_authorize_traits
-  };
-
-  return cmd;
-}
-
-
-/**
- * Create a /tip-authorize CMD.
- *
- * @param label this command label
- * @param merchant_url the base URL of the merchant that will
- *        serve the /tip-authorize request.
- * @param exchange_url the base URL of the exchange that owns
- *        the reserve from which the tip is going to be gotten.
- * @param http_status the HTTP response code which is expected
- *        for this operation.
- * @param justification human-readable justification for this
- *        tip authorization.
- * @param amount the amount to authorize for tipping.
- */
-struct TALER_TESTING_Command
-TALER_TESTING_cmd_tip_authorize (const char *label,
-                                 const char *merchant_url,
-                                 const char *exchange_url,
-                                 unsigned int http_status,
-                                 const char *justification,
-                                 const char *amount)
-{
-  struct TipAuthorizeState *tas;
-
-  tas = GNUNET_new (struct TipAuthorizeState);
-  tas->merchant_url = merchant_url;
-  tas->justification = justification;
-  tas->amount = amount;
-  tas->http_status = http_status;
-
-  struct TALER_TESTING_Command cmd = {
-    .label = label,
-    .cls = tas,
-    .run = &tip_authorize_run,
-    .cleanup = &tip_authorize_cleanup,
-    .traits = &tip_authorize_traits
-  };
-
-  return cmd;
-}
-
-
-/**
- * Callback to process a GET /tip-query request, it mainly
- * checks that what the backend returned matches the command's
- * expectations.
- *
- * @param cls closure
- * @param http_status HTTP status code for this request
- * @param ec Taler-specific error code
- * @param raw raw response body
- * @param reserve_expiration when the tip reserve will expire
- * @param reserve_pub tip reserve public key
- * @param amount_authorized total amount authorized on tip reserve
- * @param amount_available total amount still available on
- *        tip reserve
- * @param amount_picked_up total amount picked up from tip reserve
- */
-static void
-tip_query_cb (void *cls,
-              unsigned int http_status,
-              enum TALER_ErrorCode ec,
-              const json_t *raw,
-              struct GNUNET_TIME_Absolute reserve_expiration,
-              struct TALER_ReservePublicKeyP *reserve_pub,
-              struct TALER_Amount *amount_authorized,
-              struct TALER_Amount *amount_available,
-              struct TALER_Amount *amount_picked_up)
-{
-  struct TipQueryState *tqs = cls;
-  struct TALER_Amount a;
-
-  tqs->tqo = NULL;
-  GNUNET_log (GNUNET_ERROR_TYPE_INFO,
-              "Tip query callback at command `%s'\n",
-              TALER_TESTING_interpreter_get_current_label
-                (tqs->is));
-
-  GNUNET_assert (NULL != reserve_pub);
-  GNUNET_assert (NULL != amount_authorized);
-  GNUNET_assert (NULL != amount_available);
-  GNUNET_assert (NULL != amount_picked_up);
-
-  if (tqs->expected_amount_available)
-  {
-    GNUNET_assert (GNUNET_OK == TALER_string_to_amount
-                     (tqs->expected_amount_available, &a));
-    {
-      char *str;
-
-      str = TALER_amount_to_string (amount_available);
-      TALER_LOG_INFO ("expected available %s, actual %s\n",
-                      TALER_amount2s (&a),
-                      str);
-      GNUNET_free (str);
-    }
-    if (0 != TALER_amount_cmp (amount_available, &a))
-      TALER_TESTING_FAIL (tqs->is);
-  }
-
-  if (tqs->expected_amount_authorized)
-  {
-    GNUNET_assert (GNUNET_OK == TALER_string_to_amount
-                     (tqs->expected_amount_authorized, &a));
-    {
-      char *str;
-
-      str = TALER_amount_to_string (amount_authorized);
-      TALER_LOG_INFO ("expected authorized %s, actual %s\n",
-                      TALER_amount2s (&a),
-                      str);
-      GNUNET_free (str);
-    }
-    if (0 != TALER_amount_cmp (amount_authorized, &a))
-      TALER_TESTING_FAIL (tqs->is);
-  }
-
-  if (tqs->expected_amount_picked_up)
-  {
-    GNUNET_assert (GNUNET_OK == TALER_string_to_amount
-                     (tqs->expected_amount_picked_up, &a));
-    {
-      char *str;
-      str = TALER_amount_to_string (amount_picked_up);
-      TALER_LOG_INFO ("expected picked_up %s, actual %s\n",
-                      TALER_amount2s (&a),
-                      str);
-      GNUNET_free (str);
-    }
-    if (0 != TALER_amount_cmp (amount_picked_up, &a))
-      TALER_TESTING_FAIL (tqs->is);
-  }
-
-  if (tqs->http_status != http_status)
-    TALER_TESTING_FAIL (tqs->is);
-
-  TALER_TESTING_interpreter_next (tqs->is);
-}
-
-
-/**
- * Free the state from a /tip-query CMD, and possibly cancel
- * a pending /tip-query request.
- *
- * @param cls closure.
- * @param cmd the /tip-query CMD to free.
- */
-static void
-tip_query_cleanup (void *cls,
-                   const struct TALER_TESTING_Command *cmd)
-{
-  struct TipQueryState *tqs = cls;
-
-  if (NULL != tqs->tqo)
-  {
-    TALER_LOG_WARNING ("Tip-query operation"
-                       " did not complete\n");
-    TALER_MERCHANT_tip_query_cancel (tqs->tqo);
-  }
-  GNUNET_free (tqs);
-}
-
-
-/**
- * Run a /tip-query CMD.
- *
- * @param cls closure.
- * @param cmd the current /tip-query CMD.
- * @param is the interpreter state.
- */
-static void
-tip_query_run (void *cls,
-               const struct TALER_TESTING_Command *cmd,
-               struct TALER_TESTING_Interpreter *is)
-{
-  struct TipQueryState *tqs = cls;
-
-  tqs->is = is;
-  tqs->tqo = TALER_MERCHANT_tip_query (is->ctx,
-                                       tqs->merchant_url,
-                                       &tip_query_cb,
-                                       tqs);
-  GNUNET_assert (NULL != tqs->tqo);
-}
-
-
-/**
- * Define a /tip-query CMD equipped with a expected amount.
- *
- * @param label the command label
- * @param merchant_url base URL of the merchant which will
- *        server the /tip-query request.
- * @param http_status expected HTTP response code for the
- *        /tip-query request.
- * @param expected_amount_picked_up expected amount already
- *        picked up.
- * @param expected_amount_authorized expected amount that was
- *        authorized in the first place.
- * @param expected_amount_available expected amount which is
- *        still available from the tip reserve
- * @return the command
- */
-struct TALER_TESTING_Command
-TALER_TESTING_cmd_tip_query_with_amounts
-  (const char *label,
-  const char *merchant_url,
-  unsigned int http_status,
-  const char *expected_amount_picked_up,
-  const char *expected_amount_authorized,
-  const char *expected_amount_available)
-{
-  struct TipQueryState *tqs;
-
-  tqs = GNUNET_new (struct TipQueryState);
-  tqs->merchant_url = merchant_url;
-  tqs->http_status = http_status;
-  tqs->expected_amount_picked_up = expected_amount_picked_up;
-  tqs->expected_amount_authorized = expected_amount_authorized;
-  tqs->expected_amount_available = expected_amount_available;
-
-  struct TALER_TESTING_Command cmd = {
-    .cls = tqs,
-    .label = label,
-    .run = &tip_query_run,
-    .cleanup = &tip_query_cleanup
-  };
-
-  return cmd;
-}
-
-
-/**
- * Define a /tip-query CMD.
- *
- * @param label the command label
- * @param merchant_url base URL of the merchant which will
- *        server the /tip-query request.
- * @param http_status expected HTTP response code for the
- *        /tip-query request.
- */
-struct TALER_TESTING_Command
-TALER_TESTING_cmd_tip_query (const char *label,
-                             const char *merchant_url,
-                             unsigned int http_status)
-{
-  struct TipQueryState *tqs;
-
-  tqs = GNUNET_new (struct TipQueryState);
-  tqs->merchant_url = merchant_url;
-  tqs->http_status = http_status;
-
-  struct TALER_TESTING_Command cmd = {
-    .cls = tqs,
-    .label = label,
-    .run = &tip_query_run,
-    .cleanup = &tip_query_cleanup
-  };
-
-  return cmd;
-}
-
-
-/**
- * Internal withdraw handle used when withdrawing tips.
- */
-struct WithdrawHandle
-{
-  /**
-   * Withdraw operation this handle represents.
-   */
-  struct TALER_EXCHANGE_ReserveWithdrawHandle *wsh;
-
-  /**
-   * Interpreter state.
-   */
-  struct TALER_TESTING_Interpreter *is;
-
-  /**
-   * Offset of this withdraw operation in the current
-   * @e is command.
-   */
-  unsigned int off;
-
-
-  /**
-   * Internal state of the "pickup" CMD.
-   */
-  struct TipPickupState *tps;
-};
-
-/**
- * This callback handles the response of a withdraw operation
- * from the exchange, that is the final step in getting the tip.
- *
- * @param cls closure, a `struct WithdrawHandle *`
- * @param http_status HTTP response code, #MHD_HTTP_OK (200)
- *        for successful status request, 0 if the exchange's
- *        reply is bogus (fails to follow the protocol)
- * @param ec taler-specific error code, #TALER_EC_NONE on success
- * @param sig signature over the coin, NULL on error
- * @param full_response full response from the exchange
- *        (for logging, in case of errors)
- */
-static void
-pickup_withdraw_cb (void *cls,
-                    unsigned int http_status,
-                    enum TALER_ErrorCode ec,
-                    const struct TALER_DenominationSignature *sig,
-                    const json_t *full_response)
-{
-  struct WithdrawHandle *wh = cls;
-  struct TALER_TESTING_Interpreter *is = wh->is;
-
-  struct TipPickupState *tps = wh->tps;
-
-  wh->wsh = NULL;
-  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-              "Withdraw operation %u completed with %u (%d)\n",
-              wh->off,
-              http_status,
-              ec);
-  GNUNET_assert (wh->off < tps->num_coins);
-  if ( (MHD_HTTP_OK != http_status) ||
-       (TALER_EC_NONE != ec) )
-  {
-    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
-                "Unexpected response code %u (%d)"
-                " to command %s when withdrawing\n",
-                http_status,
-                ec,
-                TALER_TESTING_interpreter_get_current_label (is));
-    TALER_TESTING_interpreter_fail (is);
-    return;
-  }
-  if (NULL == tps->sigs)
-    tps->sigs = GNUNET_new_array
-                  (tps->num_coins, struct TALER_DenominationSignature);
-
-  GNUNET_assert (NULL == tps->sigs[wh->off].rsa_signature);
-  tps->sigs[wh->off].rsa_signature
-    = GNUNET_CRYPTO_rsa_signature_dup (sig->rsa_signature);
-
-  for (unsigned int i = 0; i<tps->num_coins; i++)
-    if (NULL != tps->withdraws[wh->off].wsh)
-      return;
-  /* still some ops ongoing */
-
-  GNUNET_free (tps->withdraws);
-  tps->withdraws = NULL;
-  TALER_TESTING_interpreter_next (is);
-}
-
-
-/**
- * Callback for a /tip-pickup request, it mainly checks if
- * values returned from the backend are as expected, and if so
- * (and if the status was 200 OK) proceede with the withdrawal.
- *
- * @param cls closure
- * @param http_status HTTP status returned by the merchant
- *        backend, "200 OK" on success
- * @param ec taler-specific error code
- * @param reserve_pub public key of the reserve that made the
- *        @a reserve_sigs, NULL on error
- * @param num_reserve_sigs length of the @a reserve_sigs array,
- *        0 on error
- * @param reserve_sigs array of signatures authorizing withdrawals,
- *        NULL on error
- * @param json original json response
- */
-static void
-pickup_cb (void *cls,
-           unsigned int http_status,
-           enum TALER_ErrorCode ec,
-           const struct TALER_ReservePublicKeyP *reserve_pub,
-           unsigned int num_reserve_sigs,
-           const struct TALER_ReserveSignatureP *reserve_sigs,
-           const json_t *json)
-{
-  struct TipPickupState *tps = cls;
-
-  tps->tpo = NULL;
-  if (http_status != tps->http_status)
-  {
-    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
-                "Unexpected response code %u (%d) to command %s\n",
-                http_status,
-                ec,
-                TALER_TESTING_interpreter_get_current_label
-                  (tps->is));
-    TALER_TESTING_FAIL (tps->is);
-  }
-
-  if (ec != tps->expected_ec)
-    TALER_TESTING_FAIL (tps->is);
-
-  /* Safe to go ahead: http status was expected.  */
-  if ( (MHD_HTTP_OK != http_status) ||
-       (TALER_EC_NONE != ec) )
-  {
-    TALER_TESTING_interpreter_next (tps->is);
-    return;
-  }
-  if (num_reserve_sigs != tps->num_coins)
-    TALER_TESTING_FAIL (tps->is);
-
-  /* pickup successful, now withdraw! */
-  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-              "Obtained %u signatures for withdrawal"
-              " from picking up a tip\n",
-              num_reserve_sigs);
-
-  GNUNET_assert (NULL == tps->withdraws);
-  tps->withdraws = GNUNET_new_array
-                     (num_reserve_sigs, struct WithdrawHandle);
-
-  for (unsigned int i = 0; i<num_reserve_sigs; i++)
-  {
-    struct WithdrawHandle *wh = &tps->withdraws[i];
-
-    wh->off = i;
-    wh->is = tps->is;
-    wh->tps = tps;
-    GNUNET_assert
-      ( (NULL == wh->wsh) &&
-      ( (NULL == tps->sigs) ||
-        (NULL == tps->sigs[wh->off].rsa_signature) ) );
-    wh->wsh = TALER_EXCHANGE_reserve_withdraw2
-                (tps->is->exchange,
-                tps->dks[i],
-                &reserve_sigs[i],
-                reserve_pub,
-                &tps->psa[i],
-                &pickup_withdraw_cb,
-                wh);
-    if (NULL == wh->wsh)
-      TALER_TESTING_FAIL (tps->is);
-  }
-  if (0 == num_reserve_sigs)
-    TALER_TESTING_interpreter_next (tps->is);
-}
-
-
-/**
- * Run a /tip-pickup CMD.
- *
- * @param cls closure
- * @param cmd the current /tip-pickup CMD.
- * @param is interpreter state.
- */
-static void
-tip_pickup_run (void *cls,
-                const struct TALER_TESTING_Command *cmd,
-                struct TALER_TESTING_Interpreter *is)
-{
-  struct TipPickupState *tps = cls;
-  unsigned int num_planchets;
-  const struct TALER_TESTING_Command *replay_cmd;
-  const struct TALER_TESTING_Command *authorize_cmd;
-  const struct GNUNET_HashCode *tip_id;
-
-  tps->is = is;
-  tps->exchange_url = TALER_EXCHANGE_get_base_url (is->exchange);
-  if (NULL == tps->replay_reference)
-  {
-    replay_cmd = NULL;
-
-    /* Count planchets. */
-    for (num_planchets = 0;
-         NULL != tps->amounts[num_planchets];
-         num_planchets++)
-      ;
-  }
-  else
-  {
-    const unsigned int *np;
-    if (NULL ==  /* looking for "parent" tip-pickup command */
-        (replay_cmd = TALER_TESTING_interpreter_lookup_command
-                        (is, tps->replay_reference)) )
-      TALER_TESTING_FAIL (is);
-
-    if (GNUNET_OK != TALER_TESTING_get_trait_uint
-          (replay_cmd, 0, &np))
-      TALER_TESTING_FAIL (is);
-    num_planchets = *np;
-  }
-
-  if (NULL ==
-      (authorize_cmd = TALER_TESTING_interpreter_lookup_command
-                         (is, tps->authorize_reference)) )
-    TALER_TESTING_FAIL (is);
-
-  tps->num_coins = num_planchets;
-  {
-    struct TALER_PlanchetDetail planchets[num_planchets];
-
-    tps->psa = GNUNET_new_array (num_planchets,
-                                 struct TALER_PlanchetSecretsP);
-    tps->dks = GNUNET_new_array
-                 (num_planchets,
-                 const struct TALER_EXCHANGE_DenomPublicKey *);
-
-    tps->amounts_obj = GNUNET_new_array
-                         (num_planchets, struct TALER_Amount);
-
-    for (unsigned int i = 0; i<num_planchets; i++)
-    {
-      if (NULL == replay_cmd)
-      {
-        GNUNET_assert (GNUNET_OK == TALER_string_to_amount
-                         (tps->amounts[i], &tps->amounts_obj[i]));
-
-        tps->dks[i] = TALER_TESTING_find_pk
-                        (is->keys,
-                        &tps->amounts_obj[i]);
-
-        if (NULL == tps->dks[i])
-          TALER_TESTING_FAIL (is);
-
-        TALER_planchet_setup_random (&tps->psa[i]);
-      }
-      else
-      {
-        if (GNUNET_OK != TALER_TESTING_get_trait_denom_pub
-              (replay_cmd, i, &tps->dks[i]))
-          TALER_TESTING_FAIL (is);
-
-        struct TALER_PlanchetSecretsP *ps;
-
-        if (GNUNET_OK != TALER_TESTING_get_trait_planchet_secrets
-              (replay_cmd, i, &ps))
-          TALER_TESTING_FAIL (is);
-        tps->psa[i] = *ps;
-      }
-
-      if (GNUNET_OK != TALER_planchet_prepare (&tps->dks[i]->key,
-                                               &tps->psa[i],
-                                               &planchets[i]))
-        TALER_TESTING_FAIL (is);
-    }
-
-    if (GNUNET_OK != TALER_TESTING_get_trait_tip_id
-          (authorize_cmd, 0, &tip_id))
-      TALER_TESTING_FAIL (is);
-
-    tps->tpo = TALER_MERCHANT_tip_pickup (is->ctx,
-                                          tps->merchant_url,
-                                          tip_id,
-                                          num_planchets,
-                                          planchets,
-                                          &pickup_cb,
-                                          tps);
-    for (unsigned int i = 0; i<num_planchets; i++)
-    {
-      GNUNET_free (planchets[i].coin_ev);
-      planchets[i].coin_ev = NULL;
-      planchets[i].coin_ev_size = 0;
-    }
-    GNUNET_assert (NULL != tps->tpo);
-  }
-}
-
-
-/**
- * Free a /tip-pickup CMD state, and possibly cancel a
- * pending /tip-pickup request.
- *
- * @param cls closure.
- * @param cmd current CMD to be freed.
- */
-static void
-tip_pickup_cleanup (void *cls,
-                    const struct TALER_TESTING_Command *cmd)
-{
-  struct TipPickupState *tps = cls;
-
-  GNUNET_free_non_null (tps->amounts_obj);
-  GNUNET_free_non_null (tps->dks);
-  GNUNET_free_non_null (tps->psa);
-  GNUNET_free_non_null (tps->withdraws);
-  if (NULL != tps->sigs)
-  {
-    for (unsigned int i = 0; i<tps->num_coins; i++)
-      if (NULL != tps->sigs[i].rsa_signature)
-        GNUNET_CRYPTO_rsa_signature_free (tps->sigs[i].rsa_signature);
-    GNUNET_free (tps->sigs);
-  }
-
-  if (NULL != tps->tpo)
-  {
-    TALER_LOG_WARNING ("Tip-pickup operation"
-                       " did not complete\n");
-    TALER_MERCHANT_tip_pickup_cancel (tps->tpo);
-  }
-
-  GNUNET_free (tps);
-}
-
-
-/**
- * Offers information from the /tip-pickup CMD state to other
- * commands.
- *
- * @param cls closure
- * @param ret[out] result (could be anything)
- * @param trait name of the trait
- * @param index index number of the object to extract.
- * @return #GNUNET_OK on success
- */
-static int
-tip_pickup_traits (void *cls,
-                   const void **ret,
-                   const char *trait,
-                   unsigned int index)
-{
-  struct TipPickupState *tps = cls;
-  #define NUM_TRAITS (tps->num_coins * 5) + 2
-  struct TALER_TESTING_Trait traits[NUM_TRAITS];
-
-  for (unsigned int i = 0; i<tps->num_coins; i++)
-  {
-    traits[i] = TALER_TESTING_make_trait_planchet_secrets
-                  (i, &tps->psa[i]);
-
-    traits[i + tps->num_coins] =
-      TALER_TESTING_make_trait_coin_priv
-        (i, &tps->psa[i].coin_priv);
-
-    traits[i + (tps->num_coins * 2)] =
-      TALER_TESTING_make_trait_denom_pub (i, tps->dks[i]);
-
-    traits[i + (tps->num_coins * 3)] =
-      TALER_TESTING_make_trait_denom_sig (i, &tps->sigs[i]);
-
-    traits[i + (tps->num_coins * 4)] =
-      TALER_TESTING_make_trait_amount_obj
-        (i, &tps->amounts_obj[i]);
-
-  }
-  traits[NUM_TRAITS - 2] = TALER_TESTING_make_trait_url
-                             (0, tps->exchange_url);
-  traits[NUM_TRAITS - 1] = TALER_TESTING_trait_end ();
-
-  return TALER_TESTING_get_trait (traits,
-                                  ret,
-                                  trait,
-                                  index);
-}
-
-
-/**
- * Define a /tip-pickup CMD, equipped with the expected error
- * code.
- *
- * @param label the command label
- * @param merchant_url base URL of the backend which will serve
- *        the /tip-pickup request.
- * @param http_status expected HTTP response code.
- * @param authorize_reference reference to a /tip-autorize CMD
- *        that offers a tip id to pick up.
- * @param amounts array of string-defined amounts that specifies
- *        which denominations will be accepted for tipping.
- * @param exchange connection handle to the exchange that will
- *        eventually serve the withdraw operation.
- * @param ec expected Taler error code.
- */
-struct TALER_TESTING_Command
-TALER_TESTING_cmd_tip_pickup_with_ec
-  (const char *label,
-  const char *merchant_url,
-  unsigned int http_status,
-  const char *authorize_reference,
-  const char **amounts,
-  enum TALER_ErrorCode ec)
-{
-  struct TipPickupState *tps;
-
-  tps = GNUNET_new (struct TipPickupState);
-  tps->merchant_url = merchant_url;
-  tps->authorize_reference = authorize_reference;
-  tps->amounts = amounts;
-  tps->http_status = http_status;
-  tps->expected_ec = ec;
-
-  struct TALER_TESTING_Command cmd = {
-    .cls = tps,
-    .label = label,
-    .run = &tip_pickup_run,
-    .cleanup = &tip_pickup_cleanup,
-    .traits = &tip_pickup_traits
-  };
-
-  return cmd;
-}
-
-
-/**
- * Define a /tip-pickup CMD.
- *
- * @param label the command label
- * @param merchant_url base URL of the backend which will serve
- *        the /tip-pickup request.
- * @param http_status expected HTTP response code.
- * @param authorize_reference reference to a /tip-autorize CMD
- *        that offers a tip id to pick up.
- * @param amounts array of string-defined amounts that specifies
- *        which denominations will be accepted for tipping.
- */
-struct TALER_TESTING_Command
-TALER_TESTING_cmd_tip_pickup
-  (const char *label,
-  const char *merchant_url,
-  unsigned int http_status,
-  const char *authorize_reference,
-  const char **amounts)
-{
-  struct TipPickupState *tps;
-
-  tps = GNUNET_new (struct TipPickupState);
-  tps->merchant_url = merchant_url;
-  tps->authorize_reference = authorize_reference;
-  tps->amounts = amounts;
-  tps->http_status = http_status;
-
-  struct TALER_TESTING_Command cmd = {
-    .cls = tps,
-    .label = label,
-    .run = &tip_pickup_run,
-    .cleanup = &tip_pickup_cleanup,
-    .traits = &tip_pickup_traits
-  };
-
-  return cmd;
-}
-
-
-/**
- * This commands does not query the backend at all,
- * but just makes up a fake authorization id that will
- * be subsequently used by the "pick up" CMD in order
- * to test against such a case.
- *
- * @param label command label.
- *
- * @return the command.
- */
-struct TALER_TESTING_Command
-TALER_TESTING_cmd_tip_authorize_fake (const char *label)
-{
-  struct TipAuthorizeState *tas;
-
-  tas = GNUNET_new (struct TipAuthorizeState);
-
-  struct TALER_TESTING_Command cmd = {
-    .label = label,
-    .cls = tas,
-    .run = &tip_authorize_fake_run,
-    .cleanup = &tip_authorize_cleanup,
-    .traits = &tip_authorize_traits
-  };
-
-  return cmd;
-}
-
-
-/* end of testing_api_cmd_tip.c */
diff --git a/src/lib/testing_api_cmd_tip_authorize.c b/src/lib/testing_api_cmd_tip_authorize.c
@@ -0,0 +1,375 @@
+/*
+  This file is part of TALER
+  Copyright (C) 2014-2018 Taler Systems SA
+
+  TALER is free software; you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as
+  published by the Free Software Foundation; either version 3, or
+  (at your option) any later version.
+
+  TALER is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public
+  License along with TALER; see the file COPYING.  If not, see
+  <http://www.gnu.org/licenses/>
+*/
+
+/**
+ * @file lib/testing_api_cmd_tip_authorize.c
+ * @brief command to test the tipping.
+ * @author Marcello Stanisci
+ */
+
+#include "platform.h"
+#include <taler/taler_exchange_service.h>
+#include <taler/taler_testing_lib.h>
+#include "taler_merchant_service.h"
+#include "taler_merchant_testing_lib.h"
+
+
+/**
+ * State for a /tip-authorize CMD.
+ */
+struct TipAuthorizeState
+{
+
+  /**
+   * Merchant base URL.
+   */
+  const char *merchant_url;
+
+  /**
+   * Expected HTTP response code.
+   */
+  unsigned int http_status;
+
+  /**
+   * Human-readable justification for the
+   * tip authorization carried on by this CMD.
+   */
+  const char *justification;
+
+  /**
+   * Amount that should be authorized for tipping.
+   */
+  const char *amount;
+
+  /**
+   * Expected Taler error code for this CMD.
+   */
+  enum TALER_ErrorCode expected_ec;
+
+  /**
+   * Tip taler:// URI.
+   */
+  const char *tip_uri;
+
+  /**
+   * The tip id; set when the CMD succeeds.
+   */
+  struct GNUNET_HashCode tip_id;
+
+  /**
+   * Expiration date for this tip.
+   */
+  struct GNUNET_TIME_Absolute tip_expiration;
+
+  /**
+   * Handle to the on-going /tip-authorize request.
+   */
+  struct TALER_MERCHANT_TipAuthorizeOperation *tao;
+
+  /**
+   * The interpreter state.
+   */
+  struct TALER_TESTING_Interpreter *is;
+};
+
+
+/**
+ * Callback for a /tip-authorize request.  Set into the state
+ * what was returned from the backend (@a tip_id and @a
+ * tip_expiration).
+ *
+ * @param cls closure
+ * @param http_status HTTP status returned by the merchant backend
+ * @param ec taler-specific error code
+ * @param taler_tip_uri URI to let the wallet know about the tip
+ * @param tip_id unique identifier for the tip
+ */
+static void
+tip_authorize_cb (void *cls,
+                  unsigned int http_status,
+                  enum TALER_ErrorCode ec,
+                  const char *taler_tip_uri,
+                  struct GNUNET_HashCode *tip_id)
+{
+  struct TipAuthorizeState *tas = cls;
+
+  tas->tao = NULL;
+  if (tas->http_status != http_status)
+  {
+    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                "Unexpected response code %u (%d)"
+                " to command %s\n",
+                http_status,
+                ec,
+                TALER_TESTING_interpreter_get_current_label
+                  (tas->is));
+
+    TALER_TESTING_interpreter_fail (tas->is);
+    return;
+  }
+
+  if (tas->expected_ec != ec)
+  {
+    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                "Unexpected error code %d (%u) to command %s\n",
+                ec,
+                http_status,
+                TALER_TESTING_interpreter_get_current_label
+                  (tas->is));
+    TALER_TESTING_interpreter_fail (tas->is);
+    return;
+  }
+  if ( (MHD_HTTP_OK == http_status) &&
+       (TALER_EC_NONE == ec) )
+  {
+    tas->tip_uri = strdup (taler_tip_uri);
+    tas->tip_id = *tip_id;
+  }
+
+  TALER_TESTING_interpreter_next (tas->is);
+}
+
+
+/**
+ * Offers information from the /tip-authorize CMD state to other
+ * commands.
+ *
+ * @param cls closure
+ * @param ret[out] result (could be anything)
+ * @param trait name of the trait
+ * @param index index number of the object to extract.
+ * @return #GNUNET_OK on success
+ */
+static int
+tip_authorize_traits (void *cls,
+                      const void **ret,
+                      const char *trait,
+                      unsigned int index)
+{
+  struct TipAuthorizeState *tas = cls;
+  struct TALER_TESTING_Trait traits[] = {
+    TALER_TESTING_make_trait_tip_id (0, &tas->tip_id),
+    TALER_TESTING_trait_end (),
+  };
+
+  return TALER_TESTING_get_trait (traits,
+                                  ret,
+                                  trait,
+                                  index);
+}
+
+
+/**
+ * Runs the /tip-authorize CMD
+ *
+ * @param cls closure
+ * @param cmd the CMD representing _this_ command
+ * @param is interpreter state
+ */
+static void
+tip_authorize_run (void *cls,
+                   const struct TALER_TESTING_Command *cmd,
+                   struct TALER_TESTING_Interpreter *is)
+{
+  struct TipAuthorizeState *tas = cls;
+  struct TALER_Amount amount;
+
+  tas->is = is;
+  if (GNUNET_OK != TALER_string_to_amount (tas->amount,
+                                           &amount))
+    TALER_TESTING_FAIL (is);
+
+  tas->tao = TALER_MERCHANT_tip_authorize
+               (is->ctx,
+               tas->merchant_url,
+               "http://merchant.com/pickup",
+               "http://merchant.com/continue",
+               &amount,
+               tas->justification,
+               tip_authorize_cb,
+               tas);
+
+  GNUNET_assert (NULL != tas->tao);
+}
+
+
+/**
+ * Run the /tip-authorize CMD, the "fake" version of it.
+ *
+ * @param cls closure
+ * @param cmd the CMD representing _this_ command
+ * @param is interpreter state *
+ */
+static void
+tip_authorize_fake_run (void *cls,
+                        const struct TALER_TESTING_Command *cmd,
+                        struct TALER_TESTING_Interpreter *is)
+{
+  struct TipAuthorizeState *tas = cls;
+
+  /* Make up a tip id.  */
+  GNUNET_CRYPTO_random_block (GNUNET_CRYPTO_QUALITY_WEAK,
+                              &tas->tip_id,
+                              sizeof (struct GNUNET_HashCode));
+
+  TALER_TESTING_interpreter_next (is);
+}
+
+
+/**
+ * Free the state from a /tip-authorize CMD, and possibly
+ * cancel any pending operation.
+ *
+ * @param cls closure
+ * @param cmd the /tip-authorize CMD that is about to be freed.
+ */
+static void
+tip_authorize_cleanup (void *cls,
+                       const struct TALER_TESTING_Command *cmd)
+{
+  struct TipAuthorizeState *tas = cls;
+
+  if (NULL != tas->tao)
+  {
+    TALER_LOG_WARNING ("Tip-autorize operation"
+                       " did not complete\n");
+    TALER_MERCHANT_tip_authorize_cancel (tas->tao);
+  }
+  GNUNET_free (tas);
+}
+
+
+/**
+ * Create a /tip-authorize CMD, specifying the Taler error code
+ * that is expected to be returned by the backend.
+ *
+ * @param label this command label
+ * @param merchant_url the base URL of the merchant that will
+ *        serve the /tip-authorize request.
+ * @param exchange_url the base URL of the exchange that owns
+ *        the reserve from which the tip is going to be gotten.
+ * @param http_status the HTTP response code which is expected
+ *        for this operation.
+ * @param justification human-readable justification for this
+ *        tip authorization.
+ * @param amount the amount to authorize for tipping.
+ * @param ec expected Taler-defined error code.
+ */
+struct TALER_TESTING_Command
+TALER_TESTING_cmd_tip_authorize_with_ec
+  (const char *label,
+  const char *merchant_url,
+  const char *exchange_url,
+  unsigned int http_status,
+  const char *justification,
+  const char *amount,
+  enum TALER_ErrorCode ec)
+{
+  struct TipAuthorizeState *tas;
+
+  tas = GNUNET_new (struct TipAuthorizeState);
+  tas->merchant_url = merchant_url;
+  tas->justification = justification;
+  tas->amount = amount;
+  tas->http_status = http_status;
+  tas->expected_ec = ec;
+
+  struct TALER_TESTING_Command cmd = {
+    .label = label,
+    .cls = tas,
+    .run = &tip_authorize_run,
+    .cleanup = &tip_authorize_cleanup,
+    .traits = &tip_authorize_traits
+  };
+
+  return cmd;
+}
+
+
+/**
+ * Create a /tip-authorize CMD.
+ *
+ * @param label this command label
+ * @param merchant_url the base URL of the merchant that will
+ *        serve the /tip-authorize request.
+ * @param exchange_url the base URL of the exchange that owns
+ *        the reserve from which the tip is going to be gotten.
+ * @param http_status the HTTP response code which is expected
+ *        for this operation.
+ * @param justification human-readable justification for this
+ *        tip authorization.
+ * @param amount the amount to authorize for tipping.
+ */
+struct TALER_TESTING_Command
+TALER_TESTING_cmd_tip_authorize (const char *label,
+                                 const char *merchant_url,
+                                 const char *exchange_url,
+                                 unsigned int http_status,
+                                 const char *justification,
+                                 const char *amount)
+{
+  struct TipAuthorizeState *tas;
+
+  tas = GNUNET_new (struct TipAuthorizeState);
+  tas->merchant_url = merchant_url;
+  tas->justification = justification;
+  tas->amount = amount;
+  tas->http_status = http_status;
+
+  struct TALER_TESTING_Command cmd = {
+    .label = label,
+    .cls = tas,
+    .run = &tip_authorize_run,
+    .cleanup = &tip_authorize_cleanup,
+    .traits = &tip_authorize_traits
+  };
+
+  return cmd;
+}
+
+
+/**
+ * This commands does not query the backend at all,
+ * but just makes up a fake authorization id that will
+ * be subsequently used by the "pick up" CMD in order
+ * to test against such a case.
+ *
+ * @param label command label.
+ * @return the command.
+ */
+struct TALER_TESTING_Command
+TALER_TESTING_cmd_tip_authorize_fake (const char *label)
+{
+  struct TipAuthorizeState *tas;
+
+  tas = GNUNET_new (struct TipAuthorizeState);
+
+  struct TALER_TESTING_Command cmd = {
+    .label = label,
+    .cls = tas,
+    .run = &tip_authorize_fake_run,
+    .cleanup = &tip_authorize_cleanup,
+    .traits = &tip_authorize_traits
+  };
+
+  return cmd;
+}
+
+
+/* end of testing_api_cmd_tip_authorize.c */
diff --git a/src/lib/testing_api_cmd_tip_pickup.c b/src/lib/testing_api_cmd_tip_pickup.c
@@ -0,0 +1,598 @@
+/*
+  This file is part of TALER
+  Copyright (C) 2014-2018 Taler Systems SA
+
+  TALER is free software; you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as
+  published by the Free Software Foundation; either version 3, or
+  (at your option) any later version.
+
+  TALER is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public
+  License along with TALER; see the file COPYING.  If not, see
+  <http://www.gnu.org/licenses/>
+*/
+
+/**
+ * @file lib/testing_api_cmd_tip.c
+ * @brief command to test the tipping.
+ * @author Marcello Stanisci
+ */
+
+#include "platform.h"
+#include <taler/taler_exchange_service.h>
+#include <taler/taler_testing_lib.h>
+#include "taler_merchant_service.h"
+#include "taler_merchant_testing_lib.h"
+
+/**
+ * State for a /tip-pickup CMD.
+ */
+struct TipPickupState
+{
+  /**
+   * Merchant base URL.
+   */
+  const char *merchant_url;
+
+  /**
+   * Exchange base URL.
+   */
+  const char *exchange_url;
+
+  /**
+   * Expected HTTP response code.
+   */
+  unsigned int http_status;
+
+  /**
+   * Reference to a /tip/authorize CMD.  This will be used to
+   * get the tip id to make the request with.
+   */
+  const char *authorize_reference;
+
+  /**
+   * If set to non NULL, it references another pickup CMD
+   * that will provide all the data which is needed to issue
+   * the request (like planchet secrets, denomination keys..).
+   */
+  const char *replay_reference;
+
+  /**
+   * Handle to a on-going /tip/pickup request.
+   */
+  struct TALER_MERCHANT_TipPickupOperation *tpo;
+
+  /**
+   * The interpreter state.
+   */
+  struct TALER_TESTING_Interpreter *is;
+
+  /**
+   * An array of string-defined amounts that indicates
+   * which denominations are going to be used to receive
+   * tips.
+   */
+  const char **amounts;
+
+  /**
+   * The object version of the above @a amounts.
+   */
+  struct TALER_Amount *amounts_obj;
+
+  /**
+   * How many coins are involved in the tipping operation.
+   */
+  unsigned int num_coins;
+
+  /**
+   * The array of denomination keys, in the same order of @a
+   * amounts.
+   */
+  const struct TALER_EXCHANGE_DenomPublicKey **dks;
+
+  /**
+   * The array of planchet secrets, in the same order of @a
+   * amounts.
+   */
+  struct TALER_PlanchetSecretsP *psa;
+
+  /**
+   * Temporary data structure of @e num_coins entries for the
+   * withdraw operations.
+   */
+  struct WithdrawHandle *withdraws;
+
+  /**
+   * Set (by the interpreter) to an array of @a num_coins
+   * signatures created from the (successful) tip operation.
+   */
+  struct TALER_DenominationSignature *sigs;
+
+  /**
+   * Expected Taler error code (NOTE: this is NOT the HTTP
+   * response code).
+   */
+  enum TALER_ErrorCode expected_ec;
+};
+
+
+/**
+ * Internal withdraw handle used when withdrawing tips.
+ */
+struct WithdrawHandle
+{
+  /**
+   * Withdraw operation this handle represents.
+   */
+  struct TALER_EXCHANGE_ReserveWithdrawHandle *wsh;
+
+  /**
+   * Interpreter state.
+   */
+  struct TALER_TESTING_Interpreter *is;
+
+  /**
+   * Offset of this withdraw operation in the current
+   * @e is command.
+   */
+  unsigned int off;
+
+  /**
+   * Internal state of the "pickup" CMD.
+   */
+  struct TipPickupState *tps;
+};
+
+
+/**
+ * This callback handles the response of a withdraw operation
+ * from the exchange, that is the final step in getting the tip.
+ *
+ * @param cls closure, a `struct WithdrawHandle *`
+ * @param http_status HTTP response code, #MHD_HTTP_OK (200)
+ *        for successful status request, 0 if the exchange's
+ *        reply is bogus (fails to follow the protocol)
+ * @param ec taler-specific error code, #TALER_EC_NONE on success
+ * @param sig signature over the coin, NULL on error
+ * @param full_response full response from the exchange
+ *        (for logging, in case of errors)
+ */
+static void
+pickup_withdraw_cb (void *cls,
+                    unsigned int http_status,
+                    enum TALER_ErrorCode ec,
+                    const struct TALER_DenominationSignature *sig,
+                    const json_t *full_response)
+{
+  struct WithdrawHandle *wh = cls;
+  struct TALER_TESTING_Interpreter *is = wh->is;
+
+  struct TipPickupState *tps = wh->tps;
+
+  wh->wsh = NULL;
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+              "Withdraw operation %u completed with %u (%d)\n",
+              wh->off,
+              http_status,
+              ec);
+  GNUNET_assert (wh->off < tps->num_coins);
+  if ( (MHD_HTTP_OK != http_status) ||
+       (TALER_EC_NONE != ec) )
+  {
+    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                "Unexpected response code %u (%d)"
+                " to command %s when withdrawing\n",
+                http_status,
+                ec,
+                TALER_TESTING_interpreter_get_current_label (is));
+    TALER_TESTING_interpreter_fail (is);
+    return;
+  }
+  if (NULL == tps->sigs)
+    tps->sigs = GNUNET_new_array
+                  (tps->num_coins, struct TALER_DenominationSignature);
+
+  GNUNET_assert (NULL == tps->sigs[wh->off].rsa_signature);
+  tps->sigs[wh->off].rsa_signature
+    = GNUNET_CRYPTO_rsa_signature_dup (sig->rsa_signature);
+
+  for (unsigned int i = 0; i<tps->num_coins; i++)
+    if (NULL != tps->withdraws[wh->off].wsh)
+      return;
+  /* still some ops ongoing */
+
+  GNUNET_free (tps->withdraws);
+  tps->withdraws = NULL;
+  TALER_TESTING_interpreter_next (is);
+}
+
+
+/**
+ * Callback for a /tip-pickup request, it mainly checks if
+ * values returned from the backend are as expected, and if so
+ * (and if the status was 200 OK) proceede with the withdrawal.
+ *
+ * @param cls closure
+ * @param http_status HTTP status returned by the merchant
+ *        backend, "200 OK" on success
+ * @param ec taler-specific error code
+ * @param reserve_pub public key of the reserve that made the
+ *        @a reserve_sigs, NULL on error
+ * @param num_reserve_sigs length of the @a reserve_sigs array,
+ *        0 on error
+ * @param reserve_sigs array of signatures authorizing withdrawals,
+ *        NULL on error
+ * @param json original json response
+ */
+static void
+pickup_cb (void *cls,
+           unsigned int http_status,
+           enum TALER_ErrorCode ec,
+           const struct TALER_ReservePublicKeyP *reserve_pub,
+           unsigned int num_reserve_sigs,
+           const struct TALER_ReserveSignatureP *reserve_sigs,
+           const json_t *json)
+{
+  struct TipPickupState *tps = cls;
+
+  tps->tpo = NULL;
+  if (http_status != tps->http_status)
+  {
+    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                "Unexpected response code %u (%d) to command %s\n",
+                http_status,
+                ec,
+                TALER_TESTING_interpreter_get_current_label
+                  (tps->is));
+    TALER_TESTING_FAIL (tps->is);
+  }
+
+  if (ec != tps->expected_ec)
+    TALER_TESTING_FAIL (tps->is);
+
+  /* Safe to go ahead: http status was expected.  */
+  if ( (MHD_HTTP_OK != http_status) ||
+       (TALER_EC_NONE != ec) )
+  {
+    TALER_TESTING_interpreter_next (tps->is);
+    return;
+  }
+  if (num_reserve_sigs != tps->num_coins)
+    TALER_TESTING_FAIL (tps->is);
+
+  /* pickup successful, now withdraw! */
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+              "Obtained %u signatures for withdrawal"
+              " from picking up a tip\n",
+              num_reserve_sigs);
+
+  GNUNET_assert (NULL == tps->withdraws);
+  tps->withdraws = GNUNET_new_array
+                     (num_reserve_sigs, struct WithdrawHandle);
+
+  for (unsigned int i = 0; i<num_reserve_sigs; i++)
+  {
+    struct WithdrawHandle *wh = &tps->withdraws[i];
+
+    wh->off = i;
+    wh->is = tps->is;
+    wh->tps = tps;
+    GNUNET_assert
+      ( (NULL == wh->wsh) &&
+      ( (NULL == tps->sigs) ||
+        (NULL == tps->sigs[wh->off].rsa_signature) ) );
+    wh->wsh = TALER_EXCHANGE_reserve_withdraw2
+                (tps->is->exchange,
+                tps->dks[i],
+                &reserve_sigs[i],
+                reserve_pub,
+                &tps->psa[i],
+                &pickup_withdraw_cb,
+                wh);
+    if (NULL == wh->wsh)
+      TALER_TESTING_FAIL (tps->is);
+  }
+  if (0 == num_reserve_sigs)
+    TALER_TESTING_interpreter_next (tps->is);
+}
+
+
+/**
+ * Run a /tip-pickup CMD.
+ *
+ * @param cls closure
+ * @param cmd the current /tip-pickup CMD.
+ * @param is interpreter state.
+ */
+static void
+tip_pickup_run (void *cls,
+                const struct TALER_TESTING_Command *cmd,
+                struct TALER_TESTING_Interpreter *is)
+{
+  struct TipPickupState *tps = cls;
+  unsigned int num_planchets;
+  const struct TALER_TESTING_Command *replay_cmd;
+  const struct TALER_TESTING_Command *authorize_cmd;
+  const struct GNUNET_HashCode *tip_id;
+
+  tps->is = is;
+  tps->exchange_url = TALER_EXCHANGE_get_base_url (is->exchange);
+  if (NULL == tps->replay_reference)
+  {
+    replay_cmd = NULL;
+
+    /* Count planchets. */
+    for (num_planchets = 0;
+         NULL != tps->amounts[num_planchets];
+         num_planchets++)
+      ;
+  }
+  else
+  {
+    const unsigned int *np;
+    if (NULL ==  /* looking for "parent" tip-pickup command */
+        (replay_cmd = TALER_TESTING_interpreter_lookup_command
+                        (is, tps->replay_reference)) )
+      TALER_TESTING_FAIL (is);
+
+    if (GNUNET_OK != TALER_TESTING_get_trait_uint
+          (replay_cmd, 0, &np))
+      TALER_TESTING_FAIL (is);
+    num_planchets = *np;
+  }
+
+  if (NULL ==
+      (authorize_cmd = TALER_TESTING_interpreter_lookup_command
+                         (is, tps->authorize_reference)) )
+    TALER_TESTING_FAIL (is);
+
+  tps->num_coins = num_planchets;
+  {
+    struct TALER_PlanchetDetail planchets[num_planchets];
+
+    tps->psa = GNUNET_new_array (num_planchets,
+                                 struct TALER_PlanchetSecretsP);
+    tps->dks = GNUNET_new_array
+                 (num_planchets,
+                 const struct TALER_EXCHANGE_DenomPublicKey *);
+
+    tps->amounts_obj = GNUNET_new_array
+                         (num_planchets, struct TALER_Amount);
+
+    for (unsigned int i = 0; i<num_planchets; i++)
+    {
+      if (NULL == replay_cmd)
+      {
+        GNUNET_assert (GNUNET_OK == TALER_string_to_amount
+                         (tps->amounts[i], &tps->amounts_obj[i]));
+
+        tps->dks[i] = TALER_TESTING_find_pk
+                        (is->keys,
+                        &tps->amounts_obj[i]);
+
+        if (NULL == tps->dks[i])
+          TALER_TESTING_FAIL (is);
+
+        TALER_planchet_setup_random (&tps->psa[i]);
+      }
+      else
+      {
+        if (GNUNET_OK != TALER_TESTING_get_trait_denom_pub
+              (replay_cmd, i, &tps->dks[i]))
+          TALER_TESTING_FAIL (is);
+
+        struct TALER_PlanchetSecretsP *ps;
+
+        if (GNUNET_OK != TALER_TESTING_get_trait_planchet_secrets
+              (replay_cmd, i, &ps))
+          TALER_TESTING_FAIL (is);
+        tps->psa[i] = *ps;
+      }
+
+      if (GNUNET_OK != TALER_planchet_prepare (&tps->dks[i]->key,
+                                               &tps->psa[i],
+                                               &planchets[i]))
+        TALER_TESTING_FAIL (is);
+    }
+
+    if (GNUNET_OK != TALER_TESTING_get_trait_tip_id
+          (authorize_cmd, 0, &tip_id))
+      TALER_TESTING_FAIL (is);
+
+    tps->tpo = TALER_MERCHANT_tip_pickup (is->ctx,
+                                          tps->merchant_url,
+                                          tip_id,
+                                          num_planchets,
+                                          planchets,
+                                          &pickup_cb,
+                                          tps);
+    for (unsigned int i = 0; i<num_planchets; i++)
+    {
+      GNUNET_free (planchets[i].coin_ev);
+      planchets[i].coin_ev = NULL;
+      planchets[i].coin_ev_size = 0;
+    }
+    GNUNET_assert (NULL != tps->tpo);
+  }
+}
+
+
+/**
+ * Free a /tip-pickup CMD state, and possibly cancel a
+ * pending /tip-pickup request.
+ *
+ * @param cls closure.
+ * @param cmd current CMD to be freed.
+ */
+static void
+tip_pickup_cleanup (void *cls,
+                    const struct TALER_TESTING_Command *cmd)
+{
+  struct TipPickupState *tps = cls;
+
+  GNUNET_free_non_null (tps->amounts_obj);
+  GNUNET_free_non_null (tps->dks);
+  GNUNET_free_non_null (tps->psa);
+  GNUNET_free_non_null (tps->withdraws);
+  if (NULL != tps->sigs)
+  {
+    for (unsigned int i = 0; i<tps->num_coins; i++)
+      if (NULL != tps->sigs[i].rsa_signature)
+        GNUNET_CRYPTO_rsa_signature_free (tps->sigs[i].rsa_signature);
+    GNUNET_free (tps->sigs);
+  }
+
+  if (NULL != tps->tpo)
+  {
+    TALER_LOG_WARNING ("Tip-pickup operation"
+                       " did not complete\n");
+    TALER_MERCHANT_tip_pickup_cancel (tps->tpo);
+  }
+
+  GNUNET_free (tps);
+}
+
+
+/**
+ * Offers information from the /tip-pickup CMD state to other
+ * commands.
+ *
+ * @param cls closure
+ * @param ret[out] result (could be anything)
+ * @param trait name of the trait
+ * @param index index number of the object to extract.
+ * @return #GNUNET_OK on success
+ */
+static int
+tip_pickup_traits (void *cls,
+                   const void **ret,
+                   const char *trait,
+                   unsigned int index)
+{
+  struct TipPickupState *tps = cls;
+  #define NUM_TRAITS (tps->num_coins * 5) + 2
+  struct TALER_TESTING_Trait traits[NUM_TRAITS];
+
+  for (unsigned int i = 0; i<tps->num_coins; i++)
+  {
+    traits[i] = TALER_TESTING_make_trait_planchet_secrets
+                  (i, &tps->psa[i]);
+
+    traits[i + tps->num_coins] =
+      TALER_TESTING_make_trait_coin_priv
+        (i, &tps->psa[i].coin_priv);
+
+    traits[i + (tps->num_coins * 2)] =
+      TALER_TESTING_make_trait_denom_pub (i, tps->dks[i]);
+
+    traits[i + (tps->num_coins * 3)] =
+      TALER_TESTING_make_trait_denom_sig (i, &tps->sigs[i]);
+
+    traits[i + (tps->num_coins * 4)] =
+      TALER_TESTING_make_trait_amount_obj
+        (i, &tps->amounts_obj[i]);
+
+  }
+  traits[NUM_TRAITS - 2] = TALER_TESTING_make_trait_url
+                             (0, tps->exchange_url);
+  traits[NUM_TRAITS - 1] = TALER_TESTING_trait_end ();
+
+  return TALER_TESTING_get_trait (traits,
+                                  ret,
+                                  trait,
+                                  index);
+}
+
+
+/**
+ * Define a /tip-pickup CMD, equipped with the expected error
+ * code.
+ *
+ * @param label the command label
+ * @param merchant_url base URL of the backend which will serve
+ *        the /tip-pickup request.
+ * @param http_status expected HTTP response code.
+ * @param authorize_reference reference to a /tip-autorize CMD
+ *        that offers a tip id to pick up.
+ * @param amounts array of string-defined amounts that specifies
+ *        which denominations will be accepted for tipping.
+ * @param exchange connection handle to the exchange that will
+ *        eventually serve the withdraw operation.
+ * @param ec expected Taler error code.
+ */
+struct TALER_TESTING_Command
+TALER_TESTING_cmd_tip_pickup_with_ec
+  (const char *label,
+  const char *merchant_url,
+  unsigned int http_status,
+  const char *authorize_reference,
+  const char **amounts,
+  enum TALER_ErrorCode ec)
+{
+  struct TipPickupState *tps;
+
+  tps = GNUNET_new (struct TipPickupState);
+  tps->merchant_url = merchant_url;
+  tps->authorize_reference = authorize_reference;
+  tps->amounts = amounts;
+  tps->http_status = http_status;
+  tps->expected_ec = ec;
+
+  struct TALER_TESTING_Command cmd = {
+    .cls = tps,
+    .label = label,
+    .run = &tip_pickup_run,
+    .cleanup = &tip_pickup_cleanup,
+    .traits = &tip_pickup_traits
+  };
+
+  return cmd;
+}
+
+
+/**
+ * Define a /tip-pickup CMD.
+ *
+ * @param label the command label
+ * @param merchant_url base URL of the backend which will serve
+ *        the /tip-pickup request.
+ * @param http_status expected HTTP response code.
+ * @param authorize_reference reference to a /tip-autorize CMD
+ *        that offers a tip id to pick up.
+ * @param amounts array of string-defined amounts that specifies
+ *        which denominations will be accepted for tipping.
+ */
+struct TALER_TESTING_Command
+TALER_TESTING_cmd_tip_pickup
+  (const char *label,
+  const char *merchant_url,
+  unsigned int http_status,
+  const char *authorize_reference,
+  const char **amounts)
+{
+  struct TipPickupState *tps;
+
+  tps = GNUNET_new (struct TipPickupState);
+  tps->merchant_url = merchant_url;
+  tps->authorize_reference = authorize_reference;
+  tps->amounts = amounts;
+  tps->http_status = http_status;
+
+  struct TALER_TESTING_Command cmd = {
+    .cls = tps,
+    .label = label,
+    .run = &tip_pickup_run,
+    .cleanup = &tip_pickup_cleanup,
+    .traits = &tip_pickup_traits
+  };
+
+  return cmd;
+}
+
+
+/* end of testing_api_cmd_tip_pickup.c */
diff --git a/src/lib/testing_api_cmd_tip_query.c b/src/lib/testing_api_cmd_tip_query.c
@@ -0,0 +1,297 @@
+/*
+  This file is part of TALER
+  Copyright (C) 2014-2018 Taler Systems SA
+
+  TALER is free software; you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as
+  published by the Free Software Foundation; either version 3, or
+  (at your option) any later version.
+
+  TALER is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public
+  License along with TALER; see the file COPYING.  If not, see
+  <http://www.gnu.org/licenses/>
+*/
+
+/**
+ * @file lib/testing_api_cmd_tip_query.c
+ * @brief command to test the tipping.
+ * @author Marcello Stanisci
+ */
+
+#include "platform.h"
+#include <taler/taler_exchange_service.h>
+#include <taler/taler_testing_lib.h>
+#include "taler_merchant_service.h"
+#include "taler_merchant_testing_lib.h"
+
+
+/**
+ * State for a /tip-query CMD.
+ */
+struct TipQueryState
+{
+
+  /**
+   * The merchant base URL.
+   */
+  const char *merchant_url;
+
+  /**
+   * Expected HTTP response code for this CMD.
+   */
+  unsigned int http_status;
+
+  /**
+   * The handle to the current /tip-query request.
+   */
+  struct TALER_MERCHANT_TipQueryOperation *tqo;
+
+  /**
+   * The interpreter state.
+   */
+  struct TALER_TESTING_Interpreter *is;
+
+  /**
+   * Expected amount to be picked up.
+   */
+  const char *expected_amount_picked_up;
+
+  /**
+   * Expected amount to be tip-authorized.
+   */
+  const char *expected_amount_authorized;
+
+  /**
+   * Amount that is expected to be still available
+   * from the tip reserve.
+   */
+  const char *expected_amount_available;
+};
+
+
+/**
+ * Callback to process a GET /tip-query request, it mainly
+ * checks that what the backend returned matches the command's
+ * expectations.
+ *
+ * @param cls closure
+ * @param http_status HTTP status code for this request
+ * @param ec Taler-specific error code
+ * @param raw raw response body
+ * @param reserve_expiration when the tip reserve will expire
+ * @param reserve_pub tip reserve public key
+ * @param amount_authorized total amount authorized on tip reserve
+ * @param amount_available total amount still available on
+ *        tip reserve
+ * @param amount_picked_up total amount picked up from tip reserve
+ */
+static void
+tip_query_cb (void *cls,
+              unsigned int http_status,
+              enum TALER_ErrorCode ec,
+              const json_t *raw,
+              struct GNUNET_TIME_Absolute reserve_expiration,
+              struct TALER_ReservePublicKeyP *reserve_pub,
+              struct TALER_Amount *amount_authorized,
+              struct TALER_Amount *amount_available,
+              struct TALER_Amount *amount_picked_up)
+{
+  struct TipQueryState *tqs = cls;
+  struct TALER_Amount a;
+
+  tqs->tqo = NULL;
+  GNUNET_log (GNUNET_ERROR_TYPE_INFO,
+              "Tip query callback at command `%s'\n",
+              TALER_TESTING_interpreter_get_current_label
+                (tqs->is));
+
+  GNUNET_assert (NULL != reserve_pub);
+  GNUNET_assert (NULL != amount_authorized);
+  GNUNET_assert (NULL != amount_available);
+  GNUNET_assert (NULL != amount_picked_up);
+
+  if (tqs->expected_amount_available)
+  {
+    GNUNET_assert (GNUNET_OK == TALER_string_to_amount
+                     (tqs->expected_amount_available, &a));
+    {
+      char *str;
+
+      str = TALER_amount_to_string (amount_available);
+      TALER_LOG_INFO ("expected available %s, actual %s\n",
+                      TALER_amount2s (&a),
+                      str);
+      GNUNET_free (str);
+    }
+    if (0 != TALER_amount_cmp (amount_available, &a))
+      TALER_TESTING_FAIL (tqs->is);
+  }
+
+  if (tqs->expected_amount_authorized)
+  {
+    GNUNET_assert (GNUNET_OK == TALER_string_to_amount
+                     (tqs->expected_amount_authorized, &a));
+    {
+      char *str;
+
+      str = TALER_amount_to_string (amount_authorized);
+      TALER_LOG_INFO ("expected authorized %s, actual %s\n",
+                      TALER_amount2s (&a),
+                      str);
+      GNUNET_free (str);
+    }
+    if (0 != TALER_amount_cmp (amount_authorized, &a))
+      TALER_TESTING_FAIL (tqs->is);
+  }
+
+  if (tqs->expected_amount_picked_up)
+  {
+    GNUNET_assert (GNUNET_OK == TALER_string_to_amount
+                     (tqs->expected_amount_picked_up, &a));
+    {
+      char *str;
+      str = TALER_amount_to_string (amount_picked_up);
+      TALER_LOG_INFO ("expected picked_up %s, actual %s\n",
+                      TALER_amount2s (&a),
+                      str);
+      GNUNET_free (str);
+    }
+    if (0 != TALER_amount_cmp (amount_picked_up, &a))
+      TALER_TESTING_FAIL (tqs->is);
+  }
+
+  if (tqs->http_status != http_status)
+    TALER_TESTING_FAIL (tqs->is);
+
+  TALER_TESTING_interpreter_next (tqs->is);
+}
+
+
+/**
+ * Free the state from a /tip-query CMD, and possibly cancel
+ * a pending /tip-query request.
+ *
+ * @param cls closure.
+ * @param cmd the /tip-query CMD to free.
+ */
+static void
+tip_query_cleanup (void *cls,
+                   const struct TALER_TESTING_Command *cmd)
+{
+  struct TipQueryState *tqs = cls;
+
+  if (NULL != tqs->tqo)
+  {
+    TALER_LOG_WARNING ("Tip-query operation"
+                       " did not complete\n");
+    TALER_MERCHANT_tip_query_cancel (tqs->tqo);
+  }
+  GNUNET_free (tqs);
+}
+
+
+/**
+ * Run a /tip-query CMD.
+ *
+ * @param cls closure.
+ * @param cmd the current /tip-query CMD.
+ * @param is the interpreter state.
+ */
+static void
+tip_query_run (void *cls,
+               const struct TALER_TESTING_Command *cmd,
+               struct TALER_TESTING_Interpreter *is)
+{
+  struct TipQueryState *tqs = cls;
+
+  tqs->is = is;
+  tqs->tqo = TALER_MERCHANT_tip_query (is->ctx,
+                                       tqs->merchant_url,
+                                       &tip_query_cb,
+                                       tqs);
+  GNUNET_assert (NULL != tqs->tqo);
+}
+
+
+/**
+ * Define a /tip-query CMD equipped with a expected amount.
+ *
+ * @param label the command label
+ * @param merchant_url base URL of the merchant which will
+ *        server the /tip-query request.
+ * @param http_status expected HTTP response code for the
+ *        /tip-query request.
+ * @param expected_amount_picked_up expected amount already
+ *        picked up.
+ * @param expected_amount_authorized expected amount that was
+ *        authorized in the first place.
+ * @param expected_amount_available expected amount which is
+ *        still available from the tip reserve
+ * @return the command
+ */
+struct TALER_TESTING_Command
+TALER_TESTING_cmd_tip_query_with_amounts
+  (const char *label,
+  const char *merchant_url,
+  unsigned int http_status,
+  const char *expected_amount_picked_up,
+  const char *expected_amount_authorized,
+  const char *expected_amount_available)
+{
+  struct TipQueryState *tqs;
+
+  tqs = GNUNET_new (struct TipQueryState);
+  tqs->merchant_url = merchant_url;
+  tqs->http_status = http_status;
+  tqs->expected_amount_picked_up = expected_amount_picked_up;
+  tqs->expected_amount_authorized = expected_amount_authorized;
+  tqs->expected_amount_available = expected_amount_available;
+
+  struct TALER_TESTING_Command cmd = {
+    .cls = tqs,
+    .label = label,
+    .run = &tip_query_run,
+    .cleanup = &tip_query_cleanup
+  };
+
+  return cmd;
+}
+
+
+/**
+ * Define a /tip-query CMD.
+ *
+ * @param label the command label
+ * @param merchant_url base URL of the merchant which will
+ *        server the /tip-query request.
+ * @param http_status expected HTTP response code for the
+ *        /tip-query request.
+ */
+struct TALER_TESTING_Command
+TALER_TESTING_cmd_tip_query (const char *label,
+                             const char *merchant_url,
+                             unsigned int http_status)
+{
+  struct TipQueryState *tqs;
+
+  tqs = GNUNET_new (struct TipQueryState);
+  tqs->merchant_url = merchant_url;
+  tqs->http_status = http_status;
+
+  struct TALER_TESTING_Command cmd = {
+    .cls = tqs,
+    .label = label,
+    .run = &tip_query_run,
+    .cleanup = &tip_query_cleanup
+  };
+
+  return cmd;
+}
+
+
+/* end of testing_api_cmd_tip_query.c */