🚀 Feature [watch mode]: begin running tests immediately instead of waiting for watcher ready event #5372
Description
Feature Request Checklist
- I have read and agree to Mocha's Code of Conduct and Contributing Guidelines
- I have searched for related issues and issues with the
faqlabel, but none matched my issue. - I want to provide a PR to resolve this
Overview
In my large project with thousands of files, mocha watch mode takes many seconds longer to start the first test run than non-watch mode, unnecessarily wasting time. I wish it would start running the tests immediately instead of waiting for the watcher to be ready.
Suggested Solution
To run immediately but still be able to rerun on a file change, we just need to turn off ignoreInitial and distinguish between initial 'add' events and paths added after test startup. We can compare the mtime of the path to the test startup time to decide if the change should trigger a rerun.
I am ready to make a PR for this, the change to createWatcher looks like:
const watcher = chokidar.watch('.');
const rerunner = createRerunner(mocha, watcher, {
beforeRun
});
const startTime = new Date();
let ready = false;
watcher.on('ready', () => {
ready = true;
});
watcher.on('all', async function handleEvent(event, filePath, stat) {
if (exiting) return;
if (event === 'unlink' || (stat ? stat.mtime > startTime : ready)) {
if (event === 'add') {
tracker.regenerate();
}
if (tracker.has(filePath)) {
rerunner.scheduleRun();
}
return;
}
if (!ready && !stat) {
fs.stat(filePath, (err, stat) => {
if (stat) handleEvent(event, filePath, stat);
});
}
});
(async () => {
if (!globalFixtureContext) {
debug('triggering global setup');
try {
globalFixtureContext = await mocha.runGlobalSetup();
} catch (err) {
console.error(err);
}
}
rerunner.run();
})();Alternatives
Right now I'm pnpm patching mocha in my projects that have this issue.
Additional Info
No response