improve error message when error response doesn't even contain JSON

1 files changed, 15 insertions, 0 deletions

diff --git a/packages/taler-util/src/http-common.ts b/packages/taler-util/src/http-common.ts
index da2fbb9da..e934c07f7 100644
--- a/packages/taler-util/src/http-common.ts
+++ b/packages/taler-util/src/http-common.ts
@@ -141,9 +141,24 @@ type ResponseOrError<T> =
   | { isError: false; response: T }
   | { isError: true; talerErrorResponse: TalerErrorResponse };
 
+/**
+ * Read Taler error details from an HTTP response.
+ */
 export async function readTalerErrorResponse(
   httpResponse: HttpResponse,
 ): Promise<TalerErrorDetail> {
+  const contentType = httpResponse.headers.get("content-type");
+  if (contentType !== "application/json") {
+    throw TalerError.fromDetail(
+      TalerErrorCode.WALLET_RECEIVED_MALFORMED_RESPONSE,
+      {
+        requestUrl: httpResponse.requestUrl,
+        requestMethod: httpResponse.requestMethod,
+        httpStatusCode: httpResponse.status,
+      },
+      "Error response did not even contain JSON. The request URL might be wrong or the service might be unavailable.",
+    );
+  }
   let errJson;
   try {
     errJson = await httpResponse.json();