test_runner: pass abort signal to test

doc/api/test.md

@@ -337,6 +337,7 @@ changes:
   * `only` {boolean} If truthy, and the test context is configured to run
     `only` tests, then this test will be run. Otherwise, the test is skipped.
     **Default:** `false`.
+  * `signal` {AbortSignal} Allows aborting an in-progress test
   * `skip` {boolean|string} If truthy, the test is skipped. If a string is
     provided, that string is displayed in the test results as the reason for
     skipping the test. **Default:** `false`.
@@ -385,8 +386,9 @@ test('top level test', async (t) => {
   does not have a name.
 * `options` {Object} Configuration options for the suite.
   supports the same options as `test([name][, options][, fn])`
-* `fn` {Function} The function under suite.
-  a synchronous function declaring all subtests and subsuites.
+* `fn` {Function|AsyncFunction} The function under suite
+  declaring all subtests and subsuites.
+  The first argument to this function is a [`SuiteContext`][] object.
   **Default:** A no-op function.
 * Returns: `undefined`.
 
@@ -483,6 +485,20 @@ test('top level test', (t) => {
 });
 ```
 
+### `context.signal`
+
+<!-- YAML
+added: REPLACEME
+-->
+
+* <AbortSignal> Can be used to abort test subtasks when the test has been aborted.
+
+```js
+test('top level test', async (t) => {
+  await fetch('some/uri', { signal: t.signal });
+});
+```
+
 ### `context.skip([message])`
 
 <!-- YAML
@@ -573,9 +589,28 @@ test('top level test', async (t) => {
 });
 ```
 
+## Class: `SuiteContext`
+
+<!-- YAML
+added: REPLACEME
+-->
+
+An instance of `SuiteContext` is passed to each suite function in order to
+interact with the test runner. However, the `SuiteContext` constructor is not
+exposed as part of the API.
+
+### `context.signal`
+
+<!-- YAML
+added: REPLACEME
+-->
+
+* <AbortSignal> Can be used to abort test subtasks when the test has been aborted.
+
 [TAP]: https://testanything.org/
 [`--test-only`]: cli.md#--test-only
 [`--test`]: cli.md#--test
+[`SuiteContext`]: #class-suitecontext
 [`TestContext`]: #class-testcontext
 [`test()`]: #testname-options-fn
 [describe options]: #describename-options-fn

lib/internal/main/test_runner.js

@@ -3,20 +3,18 @@ const {
   ArrayFrom,
   ArrayPrototypeFilter,
   ArrayPrototypeIncludes,
+  ArrayPrototypeJoin,
   ArrayPrototypePush,
   ArrayPrototypeSlice,
   ArrayPrototypeSort,
-  Promise,
-  PromiseAll,
-  SafeArrayIterator,
+  SafePromiseAll,
   SafeSet,
 } = primordials;
 const {
   prepareMainThreadExecution,
 } = require('internal/bootstrap/pre_execution');
 const { spawn } = require('child_process');
 const { readdirSync, statSync } = require('fs');
-const { finished } = require('internal/streams/end-of-stream');
 const console = require('internal/console/global');
 const {
   codes: {
@@ -30,6 +28,7 @@ const {
   doesPathMatchFilter,
 } = require('internal/test_runner/utils');
 const { basename, join, resolve } = require('path');
+const { once } = require('events');
 const kFilterArgs = ['--test'];
 
 prepareMainThreadExecution(false);
@@ -102,53 +101,39 @@ function filterExecArgv(arg) {
 }
 
 function runTestFile(path) {
-  return test(path, () => {
-    return new Promise((resolve, reject) => {
-      const args = ArrayPrototypeFilter(process.execArgv, filterExecArgv);
-      ArrayPrototypePush(args, path);
-
-      const child = spawn(process.execPath, args);
-      // TODO(cjihrig): Implement a TAP parser to read the child's stdout
-      // instead of just displaying it all if the child fails.
-      let stdout = '';
-      let stderr = '';
-      let err;
-
-      child.on('error', (error) => {
-        err = error;
-      });
-
-      child.stdout.setEncoding('utf8');
-      child.stderr.setEncoding('utf8');
-
-      child.stdout.on('data', (chunk) => {
-        stdout += chunk;
-      });
-
-      child.stderr.on('data', (chunk) => {
-        stderr += chunk;
-      });
-
-      child.once('exit', async (code, signal) => {
-        if (code !== 0 || signal !== null) {
-          if (!err) {
-            await PromiseAll(new SafeArrayIterator([finished(child.stderr), finished(child.stdout)]));
-            err = new ERR_TEST_FAILURE('test failed', kSubtestsFailed);
-            err.exitCode = code;
-            err.signal = signal;
-            err.stdout = stdout;
-            err.stderr = stderr;
-            // The stack will not be useful since the failures came from tests
-            // in a child process.
-            err.stack = undefined;
-          }
-
-          return reject(err);
-        }
-
-        resolve();
-      });
+  return test(path, async (t) => {
+    const args = ArrayPrototypeFilter(process.execArgv, filterExecArgv);
+    ArrayPrototypePush(args, path);
+
+    const child = spawn(process.execPath, args, { signal: t.signal, encoding: 'utf8' });
+    // TODO(cjihrig): Implement a TAP parser to read the child's stdout
+    // instead of just displaying it all if the child fails.
+    let err;
+
+    child.on('error', (error) => {
+      err = error;
     });
+
+    const { 0: { code, signal }, 1: stdout, 2: stderr } = await SafePromiseAll([
+      once(child, 'exit', { signal: t.signal }),
+      child.stdout.toArray({ signal: t.signal }),
+      child.stderr.toArray({ signal: t.signal }),
+    ]);
+
+    if (code !== 0 || signal !== null) {
+      if (!err) {
+        err = new ERR_TEST_FAILURE('test failed', kSubtestsFailed);
+        err.exitCode = code;
+        err.signal = signal;
+        err.stdout = ArrayPrototypeJoin(stdout, '');
+        err.stderr = ArrayPrototypeJoin(stderr, '');
+        // The stack will not be useful since the failures came from tests
+        // in a child process.
+        err.stack = undefined;
+      }
+
+      throw err;
+    }
   });
 }