surface Docker Hub OIDC error responses

Signed-off-by: CrazyMax <1951866+crazy-max@users.noreply.github.com>

Author: crazy-max

__tests__/dockerhub.test.ts

@@ -126,8 +126,14 @@ describe('getOIDCToken', () => {
     expect(core.info).toHaveBeenCalledWith('Docker Hub OIDC token request rate limited, retrying in 0ms (attempt 1/5)');
   });
 
-  test('throws Docker Hub API errors', async () => {
-    postSpy.mockResolvedValue(httpResponse(400, JSON.stringify({description: 'bad connection'})));
-    await expect(dockerhub.getOIDCToken('docker.io', 'dbowie')).rejects.toThrow('Docker Hub API: bad status code 400: bad connection');
+  test('throws Docker Hub OIDC error responses', async () => {
+    postSpy.mockResolvedValue(httpResponse(400, JSON.stringify({error: 'invalid_request', error_description: 'bad connection', error_uri: 'https://docs.docker.com'})));
+    await expect(dockerhub.getOIDCToken('docker.io', 'dbowie')).rejects.toThrow('Docker Hub API: bad status code 400: {"error":"invalid_request","error_description":"bad connection","error_uri":"https://docs.docker.com"}');
+  });
+
+  test('throws rate limited Docker Hub OIDC error response after retries', async () => {
+    postSpy.mockResolvedValue(httpResponse(429, JSON.stringify({error: 'rate_limited', error_description: 'slow down'}), {'retry-after': '0'}));
+    await expect(dockerhub.getOIDCToken('docker.io', 'dbowie')).rejects.toThrow('Docker Hub API: bad status code 429: {"error":"rate_limited","error_description":"slow down"}');
+    expect(postSpy).toHaveBeenCalledTimes(6);
   });
 });

src/dockerhub.ts

@@ -108,24 +108,19 @@ const handleResponse = async (resp: httpm.HttpClientResponse): Promise<string> =
 };
 
 const parseError = (statusCode: number, body: string): Error => {
-  if (statusCode === 401) {
-    throw new Error(`Docker Hub API: operation not permitted`);
-  }
   if (body) {
-    const errResp = parseErrorBody(body);
-    for (const k of ['description', 'message', 'detail', 'error']) {
-      if (errResp[k]) {
-        throw new Error(`Docker Hub API: bad status code ${statusCode}: ${errResp[k]}`);
-      }
+    let errResp: unknown;
+    try {
+      errResp = JSON.parse(body);
+    } catch {
+      errResp = undefined;
+    }
+    if (errResp !== undefined) {
+      throw new Error(`Docker Hub API: bad status code ${statusCode}: ${JSON.stringify(errResp)}`);
     }
   }
-  throw new Error(`Docker Hub API: bad status code ${statusCode}`);
-};
-
-const parseErrorBody = (body: string): Record<string, string> => {
-  try {
-    return <Record<string, string>>JSON.parse(body);
-  } catch {
-    return {};
+  if (statusCode === 401) {
+    throw new Error(`Docker Hub API: operation not permitted`);
   }
+  throw new Error(`Docker Hub API: bad status code ${statusCode}`);
 };