1 files changed, 121 insertions, 0 deletions
diff --git a/packages/taler-wallet-core/src/operations/errors.ts b/packages/taler-wallet-core/src/operations/errors.ts
new file mode 100644
index 000000000..198d3f8c5
--- /dev/null
+++ b/packages/taler-wallet-core/src/operations/errors.ts
@@ -0,0 +1,121 @@
+/*
+ This file is part of GNU Taler
+ (C) 2019-2020 Taler Systems SA
+
+ GNU 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.
+
+ GNU 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
+ GNU Taler; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>
+ */
+
+/**
+ * Classes and helpers for error handling specific to wallet operations.
+ *
+ * @author Florian Dold <dold@taler.net>
+ */
+
+/**
+ * Imports.
+ */
+import { OperationErrorDetails } from "../types/walletTypes";
+import { TalerErrorCode } from "../TalerErrorCode";
+
+/**
+ * This exception is there to let the caller know that an error happened,
+ * but the error has already been reported by writing it to the database.
+ */
+export class OperationFailedAndReportedError extends Error {
+  constructor(public operationError: OperationErrorDetails) {
+    super(operationError.message);
+
+    // Set the prototype explicitly.
+    Object.setPrototypeOf(this, OperationFailedAndReportedError.prototype);
+  }
+}
+
+/**
+ * This exception is thrown when an error occured and the caller is
+ * responsible for recording the failure in the database.
+ */
+export class OperationFailedError extends Error {
+  static fromCode(
+    ec: TalerErrorCode,
+    message: string,
+    details: Record<string, unknown>,
+  ): OperationFailedError {
+    return new OperationFailedError(makeErrorDetails(ec, message, details));
+  }
+
+  constructor(public operationError: OperationErrorDetails) {
+    super(operationError.message);
+
+    // Set the prototype explicitly.
+    Object.setPrototypeOf(this, OperationFailedError.prototype);
+  }
+}
+
+export function makeErrorDetails(
+  ec: TalerErrorCode,
+  message: string,
+  details: Record<string, unknown>,
+): OperationErrorDetails {
+  return {
+    talerErrorCode: ec,
+    talerErrorHint: `Error: ${TalerErrorCode[ec]}`,
+    details: details,
+    message,
+  };
+}
+
+/**
+ * Run an operation and call the onOpError callback
+ * when there was an exception or operation error that must be reported.
+ * The cause will be re-thrown to the caller.
+ */
+export async function guardOperationException<T>(
+  op: () => Promise<T>,
+  onOpError: (e: OperationErrorDetails) => Promise<void>,
+): Promise<T> {
+  try {
+    return await op();
+  } catch (e) {
+    if (e instanceof OperationFailedAndReportedError) {
+      throw e;
+    }
+    if (e instanceof OperationFailedError) {
+      await onOpError(e.operationError);
+      throw new OperationFailedAndReportedError(e.operationError);
+    }
+    if (e instanceof Error) {
+      const opErr = makeErrorDetails(
+        TalerErrorCode.WALLET_UNEXPECTED_EXCEPTION,
+        `unexpected exception (message: ${e.message})`,
+        {},
+      );
+      await onOpError(opErr);
+      throw new OperationFailedAndReportedError(opErr);
+    }
+    // Something was thrown that is not even an exception!
+    // Try to stringify it.
+    let excString: string;
+    try {
+      excString = e.toString();
+    } catch (e) {
+      // Something went horribly wrong.
+      excString = "can't stringify exception";
+    }
+    const opErr = makeErrorDetails(
+      TalerErrorCode.WALLET_UNEXPECTED_EXCEPTION,
+      `unexpected exception (not an exception, ${excString})`,
+      {},
+    );
+    await onOpError(opErr);
+    throw new OperationFailedAndReportedError(opErr);
+  }
+}