Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

Always use workers when using the watch mode #6647

Merged
merged 1 commit into from
Jul 6, 2018
Merged

Always use workers when using the watch mode #6647

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
4 changes: 4 additions & 0 deletions CHANGELOG.md
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,5 +1,9 @@
## master

### Fixes

- `[jest-runner]` Force parallel runs for watch mode, to avoid TTY freeze ([#6647](https://github.com/facebook/jest/pull/6647))

## 23.3.0

### Features
Expand Down
26 changes: 18 additions & 8 deletions packages/jest-cli/src/test_scheduler.js
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -30,7 +30,7 @@ import TestRunner from 'jest-runner';
import TestWatcher from './test_watcher';
import VerboseReporter from './reporters/verbose_reporter';

const SLOW_TEST_TIME = 3000;
const SLOW_TEST_TIME = 1000;

// The default jest-runner is required because it is the default test runner
// and required implicitly through the `runner` ProjectConfig option.
Expand Down Expand Up @@ -85,15 +85,25 @@ export default class TestScheduler {
getEstimatedTime(timings, this._globalConfig.maxWorkers) / 1000,
);

// Run in band if we only have one test or one worker available.
// If we are confident from previous runs that the tests will finish quickly
// we also run in band to reduce the overhead of spawning workers.
const runInBand =
// Run in band if we only have one test or one worker available, unless we
// are using the watch mode, in which case the TTY has to be responsive and
// we cannot schedule anything in the main thread. Same logic applies to
// watchAll.
//
// If we are confident from previous runs that the tests will finish
// quickly we also run in band to reduce the overhead of spawning workers.
const areFastTests = timings.every(timing => timing < SLOW_TEST_TIME);

const runInBandWatch = tests.length <= 1 && areFastTests;
const runInBandNonWatch =
this._globalConfig.maxWorkers <= 1 ||
tests.length <= 1 ||
(tests.length <= 20 &&
timings.length > 0 &&
timings.every(timing => timing < SLOW_TEST_TIME));
(tests.length <= 20 && timings.length > 0 && areFastTests);

const runInBand =
this._globalConfig.watch || this._globalConfig.watchAll
? runInBandWatch
: runInBandNonWatch;

const onResult = async (test: Test, testResult: TestResult) => {
if (watcher.isInterrupted()) {
Expand Down