react/scripts/jest/TestFlags.js

98 lines
2.8 KiB
JavaScript

'use strict';
// These flags can be in a @gate pragma to declare that a test depends on
// certain conditions. They're like GKs.
//
// Examples:
// // @gate enableBlocksAPI
// test('uses an unstable API', () => {/*...*/})
//
// // @gate __DEV__
// test('only passes in development', () => {/*...*/})
//
// Most flags are defined in ReactFeatureFlags. If it's defined there, you don't
// have to do anything extra here.
//
// There are also flags based on the environment, like __DEV__. Feel free to
// add new flags and aliases below.
//
// You can also combine flags using multiple gates:
//
// // @gate enableBlocksAPI
// // @gate __DEV__
// test('both conditions must pass', () => {/*...*/})
//
// Or using logical operators
// // @gate enableBlocksAPI && __DEV__
// test('both conditions must pass', () => {/*...*/})
//
// Negation also works:
// // @gate !deprecateLegacyContext
// test('uses a deprecated feature', () => {/*...*/})
// These flags are based on the environment and don't change for the entire
// test run.
const environmentFlags = {
__DEV__,
build: __DEV__ ? 'development' : 'production',
// TODO: Should "experimental" also imply "modern"? Maybe we should
// always compare to the channel?
experimental: __EXPERIMENTAL__,
// Similarly, should stable imply "classic"?
stable: !__EXPERIMENTAL__,
// Use this for tests that are known to be broken.
FIXME: false,
};
function getTestFlags() {
// These are required on demand because some of our tests mutate them. We try
// not to but there are exceptions.
const featureFlags = require('shared/ReactFeatureFlags');
// TODO: This is a heuristic to detect the release channel by checking a flag
// that is known to only be enabled in www. What we should do instead is set
// the release channel explicitly in the each test config file.
const www = featureFlags.enableSuspenseCallback === true;
const releaseChannel = www
? __EXPERIMENTAL__
? 'modern'
: 'classic'
: __EXPERIMENTAL__
? 'experimental'
: 'stable';
// Return a proxy so we can throw if you attempt to access a flag that
// doesn't exist.
return new Proxy(
{
// Feature flag aliases
old: featureFlags.enableNewReconciler === false,
new: featureFlags.enableNewReconciler === true,
channel: releaseChannel,
modern: releaseChannel === 'modern',
classic: releaseChannel === 'classic',
www,
...featureFlags,
...environmentFlags,
},
{
get(flags, flagName) {
const flagValue = flags[flagName];
if (flagValue === undefined && typeof flagName === 'string') {
throw Error(
`Feature flag "${flagName}" does not exist. See TestFlags.js ` +
'for more details.'
);
}
return flagValue;
},
}
);
}
exports.getTestFlags = getTestFlags;