Improve config error fmt

2 files changed, 40 insertions, 39 deletions

diff --git a/bank/src/main/kotlin/tech/libeufin/bank/Config.kt b/bank/src/main/kotlin/tech/libeufin/bank/Config.kt
index 5d881461..9926672e 100644
--- a/bank/src/main/kotlin/tech/libeufin/bank/Config.kt
+++ b/bank/src/main/kotlin/tech/libeufin/bank/Config.kt
@@ -86,7 +86,7 @@ fun TalerConfig.loadServerConfig(): ServerConfig {
     return when (val method = requireString("libeufin-bank", "serve")) {
         "tcp" -> ServerConfig.Tcp(requireNumber("libeufin-bank", "port"))
         "unix" -> ServerConfig.Unix(requireString("libeufin-bank", "unixpath"), requireNumber("libeufin-bank", "unixpath_mode"))
-        else -> throw Exception(" Unknown server method '$method' expected 'tcp' or 'unix' got '$method'")
+        else -> throw TalerConfigError.invalid("server method", "libeufin-bank", "serve", "expected 'tcp' or 'unix' got '$method'")
     }
 }
 
@@ -106,10 +106,10 @@ fun TalerConfig.loadBankConfig(): BankConfig  {
             }
         }
     }
-    val method = when (val raw = lookupString("libeufin-bank", "wire_type")) {
+    val method = when (val type = lookupString("libeufin-bank", "wire_type")) {
         "iban" -> WireMethod.IBAN
         "x-taler-bank" -> WireMethod.X_TALER_BANK
-        else -> throw TalerConfigError("expected a payment target type for section libeufin-bank, option wire_type, but $raw is unknown")
+        else -> throw TalerConfigError.invalid("payment target type", "libeufin-bank", "wire_type", "expected 'iban' or 'x-taler-bank' got '$type'")
     }
     val payto = when (method) {
         WireMethod.IBAN -> BankPaytoCtx(bic = lookupString("libeufin-bank", "iban_payto_bic"))
@@ -141,7 +141,7 @@ fun String.notEmptyOrNull(): String? = if (isEmpty()) null else this
 fun TalerConfig.currencySpecificationFor(currency: String): CurrencySpecification
     = sections.find {
         it.startsWith("CURRENCY-") && requireBoolean(it, "enabled") && requireString(it, "code") == currency
-    }?.let { loadCurrencySpecification(it) } ?: throw TalerConfigError("missing currency specification for $currency")
+    }?.let { loadCurrencySpecification(it) } ?: throw TalerConfigError.generic("missing currency specification for $currency")
 
 private fun TalerConfig.loadCurrencySpecification(section: String): CurrencySpecification {
     return CurrencySpecification(
@@ -154,39 +154,30 @@ private fun TalerConfig.loadCurrencySpecification(section: String): CurrencySpec
 }
 
 private fun TalerConfig.amount(section: String, option: String, currency: String): TalerAmount? {
-    val amountStr = lookupString(section, option) ?: return null
+    val raw = lookupString(section, option) ?: return null
     val amount = try {
-        TalerAmount(amountStr)
+        TalerAmount(raw)
     } catch (e: Exception) {
-        throw TalerConfigError("amount", section, option, "but amount is malformed")
+        throw TalerConfigError.invalid("amount", section, option, "amount '$raw' is malformed")
     }
 
     if (amount.currency != currency) {
-        throw TalerConfigError("amount", section, option, "but currency is wrong : got ${amount.currency} expected $currency")
+        throw TalerConfigError.invalid("amount", section, option, "expected currency $currency got ${amount.currency}")
     }
     return amount
 }
 
 private fun TalerConfig.requireAmount(section: String, option: String, currency: String): TalerAmount =
-    amount(section, option, currency) ?: throw TalerConfigError("amount", section, option, "but config value is empty")
+    amount(section, option, currency) ?: throw TalerConfigError.missing("amount", section, option)
 
 private fun TalerConfig.decimalNumber(section: String, option: String): DecimalNumber? {
-    val numberStr = lookupString(section, option) ?: return null
+    val raw = lookupString(section, option) ?: return null
     try {
-        return DecimalNumber(numberStr)
+        return DecimalNumber(raw)
     } catch (e: Exception) {
-        throw TalerConfigError("decimal number", section, option, "but number is malformed")
+        throw TalerConfigError.invalid("decimal number", section, option, "number '$raw' is malformed")
     }
 }
 
 private fun TalerConfig.requireDecimalNumber(section: String, option: String): DecimalNumber
-    = decimalNumber(section, option) ?: throw TalerConfigError("decimal number", section, option, "but config value is empty")
-
-private fun TalerConfig.RoundingMode(section: String, option: String): RoundingMode? {
-    val str = lookupString(section, option) ?: return null;
-    try {
-        return RoundingMode.valueOf(str)
-    } catch (e: Exception) {
-        throw TalerConfigError("rouding mode", section, option, "but $str is unknown")
-    }
-}
\ No newline at end of file
+    = decimalNumber(section, option) ?: throw TalerConfigError.missing("decimal number", section, option)
\ No newline at end of file
diff --git a/common/src/main/kotlin/TalerConfig.kt b/common/src/main/kotlin/TalerConfig.kt
index a22564f5..cf6dd5d3 100644
--- a/common/src/main/kotlin/TalerConfig.kt
+++ b/common/src/main/kotlin/TalerConfig.kt
@@ -36,9 +36,17 @@ private val reSection = Regex("^\\s*\\[\\s*([^]]*)\\s*]\\s*$")
 private val reParam = Regex("^\\s*([^=]+?)\\s*=\\s*(.*?)\\s*$")
 private val reDirective = Regex("^\\s*@([a-zA-Z-_]+)@\\s*(.*?)\\s*$")
 
-class TalerConfigError(m: String) : Exception(m) {
-    constructor(type: String, section: String, option: String, err: String): this("expected $type in configuration section $section option $option $err")
-    constructor(type: String, section: String, option: String): this("expected $type in configuration section $section option $option")
+class TalerConfigError private constructor (m: String) : Exception(m) {
+    companion object {
+        fun missing(type: String, option: String, section: String): TalerConfigError =
+            TalerConfigError("Missing $type option '$option' in section '$section'")
+
+        fun invalid(type: String, option: String, section: String, err: String): TalerConfigError =
+            TalerConfigError("Expected $type option '$option' in section '$section': $err")
+
+        fun generic(msg: String): TalerConfigError =
+            TalerConfigError(msg)
+    }
 }
 
 /**
@@ -161,7 +169,7 @@ class TalerConfig internal constructor(
             val directiveMatch = reDirective.matchEntire(line)
             if (directiveMatch != null) {
                 if (source == null) {
-                    throw TalerConfigError("Directives are only supported when loading from file")
+                    throw TalerConfigError.generic("Directives are only supported when loading from file")
                 }
                 val directiveName = directiveMatch.groups[1]!!.value.lowercase()
                 val directiveArg = directiveMatch.groups[2]!!.value
@@ -178,7 +186,7 @@ class TalerConfig internal constructor(
                         val arg = directiveArg.trim()
                         val sp = arg.split(" ")
                         if (sp.size != 2) {
-                            throw TalerConfigError("invalid configuration, @inline-secret@ directive requires exactly two arguments")
+                            throw TalerConfigError.generic("invalid configuration, @inline-secret@ directive requires exactly two arguments")
                         }
                         val sectionName = sp[0]
                         val secretFilename = source.resolveSibling(sp[1])
@@ -186,7 +194,7 @@ class TalerConfig internal constructor(
                     }
 
                     else -> {
-                        throw TalerConfigError("unsupported directive '$directiveName'")
+                        throw TalerConfigError.generic("unsupported directive '$directiveName'")
                     }
                 }
                 continue
@@ -198,7 +206,7 @@ class TalerConfig internal constructor(
                 continue
             }
             if (currentSection == null) {
-                throw TalerConfigError("section expected")
+                throw TalerConfigError.generic("section expected")
             }
 
             val paramMatch = reParam.matchEntire(line)
@@ -213,7 +221,7 @@ class TalerConfig internal constructor(
                 section.entries[optName] = optVal
                 continue
             }
-            throw TalerConfigError("expected section header, option assignment or directive in line $lineNum file ${source ?: "<input>"}")
+            throw TalerConfigError.generic("expected section header, option assignment or directive in line $lineNum file ${source ?: "<input>"}")
         }
     }
 
@@ -281,7 +289,7 @@ class TalerConfig internal constructor(
      */
     fun pathsub(x: String, recursionDepth: Int = 0): Path {
         if (recursionDepth > 128) {
-            throw TalerConfigError("recursion limit in path substitution exceeded")
+            throw TalerConfigError.generic("recursion limit in path substitution exceeded")
         }
         val result = StringBuilder()
         var l = 0
@@ -339,10 +347,10 @@ class TalerConfig internal constructor(
                         l = p
                         continue
                     } else {
-                        throw TalerConfigError("malformed variable expression can't resolve variable '$varName'")
+                        throw TalerConfigError.generic("malformed variable expression can't resolve variable '$varName'")
                     }
                 }
-                throw TalerConfigError("malformed variable expression (unbalanced)")
+                throw TalerConfigError.generic("malformed variable expression (unbalanced)")
             } else {
                 // $var
                 var varEnd = l + 1
@@ -426,22 +434,24 @@ class TalerConfig internal constructor(
     }
 
     fun requireString(section: String, option: String): String  =
-        lookupString(section, option) ?: throw TalerConfigError("string", section, option)
+        lookupString(section, option) ?: throw TalerConfigError.missing("string", section, option)
 
-    fun requireNumber(section: String, option: String): Int = 
-        lookupString(section, option)?.toInt() ?: throw TalerConfigError("number", section, option)
+    fun requireNumber(section: String, option: String): Int {
+        val raw = lookupString(section, option) ?: throw TalerConfigError.missing("number", section, option)
+        return raw.toIntOrNull() ?: throw TalerConfigError.invalid("number", section, option, "'$raw' not a valid number")
+    }
 
     fun lookupBoolean(section: String, option: String): Boolean? {
         val entry = lookupString(section, option) ?: return null
         return when (val v = entry.lowercase()) {
             "yes" -> true
             "no" -> false
-            else -> throw TalerConfigError("yes/no", section, option, "but got '$v'")
+            else -> throw TalerConfigError.invalid("yes/no", section, option, "got '$v'")
         }
     }
 
     fun requireBoolean(section: String, option: String): Boolean =
-        lookupBoolean(section, option) ?: throw TalerConfigError("boolean", section, option)
+        lookupBoolean(section, option) ?: throw TalerConfigError.missing("boolean", section, option)
 
     fun lookupPath(section: String, option: String): Path? {
         val entry = lookupString(section, option) ?: return null
@@ -449,5 +459,5 @@ class TalerConfig internal constructor(
     }
 
     fun requirePath(section: String, option: String): Path =
-        lookupPath(section, option) ?: throw TalerConfigError("path", section, option)
+        lookupPath(section, option) ?: throw TalerConfigError.missing("path", section, option)
 }