feat: Improve support for HTTP-client request cancellation (#6278)

Author: davidkna-sap

.changeset/lemon-sides-hear.md

@@ -0,0 +1,5 @@
+---
+'@sap-cloud-sdk/http-client': minor
+---
+
+[Improvement] Add `signal` property to `CustomRequestConfig` and `HttpRequestConfigBase` type definition to document `AbortSignal` support for cancelling HTTP requests.

packages/eslint-config/flat-config.js

@@ -142,6 +142,14 @@ const flatConfig = [
       '@typescript-eslint/prefer-for-of': 'error',
       '@typescript-eslint/prefer-function-type': 'error',
       '@typescript-eslint/unified-signatures': 'error',
+      '@typescript-eslint/no-unused-vars': [
+        'error',
+        {
+          argsIgnorePattern: '^_',
+          varsIgnorePattern: '^_',
+          destructuredArrayIgnorePattern: '^_'
+        }
+      ]
       'import/named': 'error',
       'import/default': 'error',
       'import/namespace': 'error',

packages/eslint-config/index.js

@@ -147,6 +147,14 @@ module.exports = {
     '@typescript-eslint/prefer-for-of': 'error',
     '@typescript-eslint/prefer-function-type': 'error',
     '@typescript-eslint/unified-signatures': 'error',
+    '@typescript-eslint/no-unused-vars': [
+      'error',
+      {
+        argsIgnorePattern: '^_',
+        varsIgnorePattern: '^_',
+        destructuredArrayIgnorePattern: '^_'
+      }
+    ],
     'import/named': 'error',
     'import/default': 'error',
     'import/namespace': 'error',

packages/http-client/src/http-client-types.ts

@@ -155,6 +155,10 @@ export interface HttpRequestConfigBase {
    * Encoder for the query parameters key and values. Per default parameters and keys are percent encoded.
    */
   parameterEncoder?: ParameterEncoder;
+  /**
+   * An `AbortSignal` to cancel the request.
+   */
+  signal?: AbortSignal;
 }
 
 /**
@@ -207,6 +211,7 @@ export type CustomRequestConfig = Pick<
   | 'httpAgent'
   | 'httpsAgent'
   | 'parameterEncoder'
+  | 'signal'
 > &
   Record<string, any>;
 

packages/http-client/src/http-client.spec.ts

@@ -244,6 +244,79 @@ describe('generic http client', () => {
       );
     });
 
+    it('considers abort signal to cancel the request', async () => {
+      const signal = AbortSignal.timeout(10);
+
+      const _scope = nock('https://example.com')
+        .get('/abort')
+        .delay(1000)
+        .reply(200, 'Should not get this');
+
+      const requestPromise = executeHttpRequest(
+        { url: 'https://example.com' },
+        {
+          method: 'get',
+          url: '/abort',
+          signal
+        }
+      );
+
+      await expect(requestPromise).rejects.toMatchObject({
+        code: 'ERR_CANCELED'
+      });
+      // I have confirmed this get's cancelled, but this is not reflected in nock.
+      // expect(scope.isDone()).toBe(false);
+    });
+
+    it('cancels CSRF token fetch when signal is aborted', async () => {
+      const _csrfScope = nock('https://example.com')
+        .head('/api/entity')
+        .delay(10000)
+        .reply(200, {}, { 'x-csrf-token': 'test-token' });
+
+      const postScope = nock('https://example.com')
+        .post('/api/entity')
+        .reply(200, 'Should not get this');
+
+      await expect(
+        executeHttpRequest(
+          { url: 'https://example.com' },
+          {
+            method: 'post',
+            url: '/api/entity',
+            signal: AbortSignal.timeout(50)
+          }
+        )
+      ).rejects.toMatchObject({
+        code: 'ERR_CANCELED'
+      });
+      // I have confirmed this get's cancelled, but this is not reflected in nock.
+      // expect(csrfScope.isDone()).toBe(false);
+      expect(postScope.isDone()).toBe(false);
+    });
+
+    it('rejects immediately when signal is already aborted', async () => {
+      const signal = AbortSignal.abort();
+
+      const scope = nock('https://example.com')
+        .get('/should-not-reach')
+        .reply(200, 'Should never reach this');
+
+      await expect(
+        executeHttpRequest(
+          { url: 'https://example.com' },
+          {
+            method: 'get',
+            url: '/should-not-reach',
+            signal
+          }
+        )
+      ).rejects.toMatchObject({
+        code: 'ERR_CANCELED'
+      });
+      expect(scope.isDone()).toBe(false);
+    });
+
     it('attaches one middleware', async () => {
       nock('https://example.com').get(/.*/).reply(200, 'Initial value.');
       const myMiddleware = buildMiddleware('Middleware One.');