fix: JSON stringify Axios error response data (#5585) (#5588)

Author: ZhongpinWang

.changeset/clever-grapes-dance.md

@@ -0,0 +1,5 @@
+---
+'@sap-cloud-sdk/util': patch
+---
+
+[Fixed Issue] Stringify Axios response data object in the error stack of `ErrorWithCause` class.

.github/actions/check-public-api/index.js

@@ -1,4 +1,5 @@
 import { ErrorWithCause } from './error-with-cause';
+import type { AxiosError } from 'axios';
 
 describe('ErrorWithCause', () => {
   it('creates an error', () => {
@@ -32,4 +33,32 @@ describe('ErrorWithCause', () => {
       }"
     `);
   });
+
+  it('adds Axios error to stack', () => {
+    const axiosError: AxiosError = {
+      message: 'Request failed with status code 400',
+      name: 'AxiosError',
+      stack: 'AxiosError: Request failed with status code 400',
+      code: 'ERR_BAD_REQUEST',
+      status: 400,
+      response: {
+        data: {
+          my_error: {
+            my_code: 'Four Hundred',
+            my_message: 'This is a bad request'
+          }
+        }
+      } as any,
+      isAxiosError: true,
+      toJSON: () => ({})
+    };
+    const err = new ErrorWithCause('message', axiosError);
+    expect(err.stack).toContain('ErrorWithCause: message');
+    expect(err.stack).toContain('at ');
+    expect(err.stack).toContain('Caused by:');
+    expect(err.stack).toContain(
+      'HTTP Response: Request failed with status code 400'
+    );
+    expect(err.stack).toContain('Four Hundred');
+  });
 });

packages/util/src/error-with-cause.spec.ts

@@ -1,6 +1,12 @@
 import { unixEOL } from './string-formatter';
+import { createLogger } from './logger';
 import type { AxiosError } from 'axios';
 
+const logger = createLogger({
+  package: 'util',
+  messageContext: 'error-with-cause'
+});
+
 /**
  * Represents an error that was caused by another error.
  */
@@ -29,7 +35,15 @@ export class ErrorWithCause extends Error {
   private addStack(cause: Error) {
     // Axios removed the stack property in version 0.27 which gave no useful information anyway. This adds the http cause.
     if (this.isAxiosError(cause)) {
-      const response = cause.response?.data ? ` - ${cause.response?.data}` : '';
+      let response = '';
+      if (cause.response?.data) {
+        try {
+          response = `${unixEOL}${JSON.stringify(cause.response?.data, null, 2)}`;
+        } catch (error) {
+          logger.warn(`Failed to stringify response data: ${error.message}`);
+          response = `${unixEOL}${cause.response?.data}`;
+        }
+      }
       this.stack = `${this.stack}${unixEOL}Caused by:${unixEOL}HTTP Response: ${cause.message}${response}`;
     } else if (this.stack && cause?.stack) {
       // Stack is a non-standard property according to https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error#Custom_Error_Types