uri-malformed-hides-cause.diff (5,049 bytes)   

diff --git a/packages/taler-util/src/errors.ts b/packages/taler-util/src/errors.ts
index a27970173..36f8069c6 100644
--- a/packages/taler-util/src/errors.ts
+++ b/packages/taler-util/src/errors.ts
@@ -101,8 +101,21 @@ export interface DetailsMap {
     /**
      * The taler:// action that the request expected, if the URI parsed
      * but denotes something else.
+     *
+     * Set ONLY in that case.  Setting it for every parse failure says the
+     * URI denotes some other action when it may well denote the right one
+     * and be malformed for an unrelated reason, which is actively
+     * misleading: a well-formed-looking `taler://pay-push/...` reported
+     * `expectedAction: "pay-push"`, i.e. "this is not a pay-push URI"
+     * about a pay-push URI.
      */
     expectedAction?: string;
+    /**
+     * The name of the `TalerUriParseError` the parser actually returned,
+     * e.g. `"INVALID_TARGET_PATH"`.  Without it every failure is
+     * indistinguishable at the API boundary.
+     */
+    parseError?: string;
   };
   [TalerErrorCode.WALLET_UNEXPECTED_REQUEST_ERROR]: {
     requestUrl: string;
diff --git a/packages/taler-wallet-core/src/pay-peer-pull-debit.ts b/packages/taler-wallet-core/src/pay-peer-pull-debit.ts
index 4095cfe56..d3592074c 100644
--- a/packages/taler-wallet-core/src/pay-peer-pull-debit.ts
+++ b/packages/taler-wallet-core/src/pay-peer-pull-debit.ts
@@ -47,6 +47,7 @@ import {
   TalerPayPullUri,
   TalerPreciseTimestamp,
   TalerUriAction,
+  TalerUriParseError,
   TalerUris,
   Transaction,
   TransactionAction,
@@ -1879,16 +1880,34 @@ async function internalPreparePeerPullDebit(
 
   let uri: TalerPayPullUri | undefined;
   if (req.talerUri) {
-    uri = Result.orUndefined(
-      TalerUris.parseRestricted(req.talerUri, TalerUriAction.PayPull),
+    const parsedUriRes = TalerUris.parseRestricted(
+      req.talerUri,
+      TalerUriAction.PayPull,
     );
-    if (!uri) {
+    if (Result.isError(parsedUriRes)) {
+      // Report WHY it failed.  `Result.orUndefined` threw the parse error
+      // away, and the message below was emitted for every cause, so a
+      // malformed-but-correctly-typed URI was reported as having the wrong
+      // action -- see the note on `expectedAction` in errors.ts.
+      const wrongAction =
+        parsedUriRes.error === TalerUriParseError.UNEXPECTED_ACTION;
       throw TalerError.fromDetail(
         TalerErrorCode.WALLET_TALER_URI_MALFORMED,
-        { talerUri: req.talerUri, expectedAction: TalerUriAction.PayPull },
-        "expected a taler://pay-pull URI",
+        {
+          talerUri: req.talerUri,
+          ...(wrongAction
+            ? { expectedAction: TalerUriAction.PayPull }
+            : {}),
+          parseError: TalerUriParseError[parsedUriRes.error],
+        },
+        wrongAction
+          ? "expected a taler://pay-pull URI"
+          : `malformed taler://pay-pull URI: ${
+              TalerUriParseError[parsedUriRes.error]
+            }`,
       );
     }
+    uri = parsedUriRes.value;
   }
 
   let parsedTxId: string | undefined;
diff --git a/packages/taler-wallet-core/src/pay-peer-push-credit.ts b/packages/taler-wallet-core/src/pay-peer-push-credit.ts
index 40aba243a..d7c72063a 100644
--- a/packages/taler-wallet-core/src/pay-peer-push-credit.ts
+++ b/packages/taler-wallet-core/src/pay-peer-push-credit.ts
@@ -36,6 +36,7 @@ import {
   TalerPayPushUri,
   TalerPreciseTimestamp,
   TalerUriAction,
+  TalerUriParseError,
   TalerUris,
   Transaction,
   TransactionAction,
@@ -563,16 +564,34 @@ async function internalPreparePeerPushCredit(
 
   let uri: TalerPayPushUri | undefined;
   if (req.talerUri) {
-    uri = Result.orUndefined(
-      TalerUris.parseRestricted(req.talerUri, TalerUriAction.PayPush),
+    const parsedUriRes = TalerUris.parseRestricted(
+      req.talerUri,
+      TalerUriAction.PayPush,
     );
-    if (!uri) {
+    if (Result.isError(parsedUriRes)) {
+      // Report WHY it failed.  `Result.orUndefined` threw the parse error
+      // away, and the message below was emitted for every cause, so a
+      // malformed-but-correctly-typed URI was reported as having the wrong
+      // action -- see the note on `expectedAction` in errors.ts.
+      const wrongAction =
+        parsedUriRes.error === TalerUriParseError.UNEXPECTED_ACTION;
       throw TalerError.fromDetail(
         TalerErrorCode.WALLET_TALER_URI_MALFORMED,
-        { talerUri: req.talerUri, expectedAction: TalerUriAction.PayPush },
-        "expected a taler://pay-push URI",
+        {
+          talerUri: req.talerUri,
+          ...(wrongAction
+            ? { expectedAction: TalerUriAction.PayPush }
+            : {}),
+          parseError: TalerUriParseError[parsedUriRes.error],
+        },
+        wrongAction
+          ? "expected a taler://pay-push URI"
+          : `malformed taler://pay-push URI: ${
+              TalerUriParseError[parsedUriRes.error]
+            }`,
       );
     }
+    uri = parsedUriRes.value;
   }
 
   let parsedTxId: string | undefined;