Provide more detailed on-chain error messages for failed API calls (#…

…1509)

* Use lodash compact instead of .filter(Boolean)

* Clarify message for error in building HTTP request

.changeset/short-zoos-exercise.md

@@ -0,0 +1,5 @@
+---
+'@api3/airnode-node': minor
+---
+
+Provide more detailed on-chain error messages for failed API calls

packages/airnode-node/src/api/index.test.ts

@@ -1,5 +1,6 @@
 import * as adapter from '@api3/airnode-adapter';
 import { ethers } from 'ethers';
+import { AxiosError } from 'axios';
 import * as fixtures from '../../test/fixtures';
 import { getExpectedTemplateIdV0 } from '../evm/templates';
 import { ApiCallErrorResponse, RequestErrorMessage } from '../types';
@@ -208,20 +209,41 @@ describe('callApi', () => {
 
   it('returns an error if the API call fails to execute', async () => {
     const spy = jest.spyOn(adapter, 'buildAndExecuteRequest') as any;
-    spy.mockRejectedValueOnce(new Error('Network is down'));
+    const nonAxiosError = new Error('A non-axios error');
+    spy.mockRejectedValueOnce(nonAxiosError);
 
     const parameters = { _type: 'int256', _path: 'unknown', from: 'ETH' };
     const aggregatedApiCall = fixtures.buildAggregatedRegularApiCall({ parameters });
     const [logs, res] = await callApi({ type: 'regular', config: fixtures.buildConfig(), aggregatedApiCall });
-    expect(logs).toEqual([
-      { level: 'ERROR', message: 'Failed to call Endpoint:convertToUSD', error: new Error('Network is down') },
-    ]);
+    expect(logs).toEqual([{ level: 'ERROR', message: 'Failed to call Endpoint:convertToUSD', error: nonAxiosError }]);
     expect(res).toEqual({
       errorMessage: `${RequestErrorMessage.ApiCallFailed}`,
       success: false,
     });
   });
 
+  test.each([
+    { e: new AxiosError('Error!', 'CODE', {}, {}, undefined), msg: 'with no response' },
+    { e: new AxiosError('Error!', 'CODE', {}, undefined, undefined), msg: 'in building the HTTP request' },
+    {
+      e: new AxiosError('Error!', 'CODE', {}, {}, { status: 404, data: {}, statusText: '', headers: {}, config: {} }),
+      msg: 'with status code 404',
+    },
+  ])(`returns an error containing "$msg" for the respective axios API call failure`, async ({ e, msg }) => {
+    const spy = jest.spyOn(adapter, 'buildAndExecuteRequest') as any;
+    const axiosError = e;
+    spy.mockRejectedValueOnce(axiosError);
+
+    const parameters = { _type: 'int256', _path: 'unknown', from: 'ETH' };
+    const aggregatedApiCall = fixtures.buildAggregatedRegularApiCall({ parameters });
+    const [logs, res] = await callApi({ type: 'regular', config: fixtures.buildConfig(), aggregatedApiCall });
+    expect(logs).toEqual([{ level: 'ERROR', message: 'Failed to call Endpoint:convertToUSD', error: axiosError }]);
+    expect(res).toEqual({
+      errorMessage: `${RequestErrorMessage.ApiCallFailed} ${msg}`,
+      success: false,
+    });
+  });
+
   it('returns an error if the value cannot be found with the _path', async () => {
     const spy = jest.spyOn(adapter, 'buildAndExecuteRequest') as any;
     spy.mockResolvedValueOnce({ data: { price: 1000 } });

packages/airnode-node/src/api/index.ts

@@ -1,8 +1,10 @@
 import * as adapter from '@api3/airnode-adapter';
 import { RESERVED_PARAMETERS } from '@api3/ois';
-import { ethers } from 'ethers';
 import { logger, removeKeys, removeKey } from '@api3/airnode-utilities';
 import { go, goSync } from '@api3/promise-utils';
+import axios, { AxiosError } from 'axios';
+import { ethers } from 'ethers';
+import compact from 'lodash/compact';
 import { postProcessApiSpecifications, preProcessApiSpecifications } from './processing';
 import { getAirnodeWalletFromPrivateKey, deriveSponsorWalletFromMnemonic } from '../evm';
 import { getReservedParameters } from '../adapters/http/parameters';
@@ -184,6 +186,16 @@ export function isPerformApiCallFailure(
   return !!(value as ApiCallErrorResponse).errorMessage;
 }
 
+export function errorMsgFromAxiosError(e: AxiosError): string {
+  if (e.response) {
+    return `with status code ${e.response.status}`;
+  } else if (e.request) {
+    return 'with no response';
+  } else {
+    return 'in building the HTTP request';
+  }
+}
+
 export async function performApiCall(
   payload: ApiCallPayload
 ): Promise<LogsData<ApiCallErrorResponse | PerformApiCallSuccess>> {
@@ -198,7 +210,10 @@ export async function performApiCall(
   if (!goRes.success) {
     const { aggregatedApiCall } = payload;
     const log = logger.pend('ERROR', `Failed to call Endpoint:${aggregatedApiCall.endpointName}`, goRes.error);
-    return [[log], { success: false, errorMessage: `${RequestErrorMessage.ApiCallFailed}` }];
+    // eslint-disable-next-line import/no-named-as-default-member
+    const axiosErrorMsg = axios.isAxiosError(goRes.error) ? errorMsgFromAxiosError(goRes.error) : '';
+    const errorMessage = compact([RequestErrorMessage.ApiCallFailed, axiosErrorMsg]).join(' ');
+    return [[log], { success: false, errorMessage: errorMessage }];
   }
 
   return [[], { ...goRes.data }];

packages/airnode-node/test/e2e/request-status.feature.ts

@@ -42,6 +42,6 @@ it('sets the correct status code for both successful and failed requests', async
   const failedRequest = logs.find(
     (log) => log.args.requestId === invalidRequest!.args.requestId && log.name === 'FailedRequest'
   );
-  // The error message will not contain the API error message
-  expect(failedRequest!.args.errorMessage).toEqual(`${RequestErrorMessage.ApiCallFailed}`);
+  // The error message will contain the status code, but not the API error message
+  expect(failedRequest!.args.errorMessage).toEqual(`${RequestErrorMessage.ApiCallFailed} with status code 404`);
 });