nodejs/test/parallel/test-promises-warning-on-un...

57 lines
1.9 KiB
JavaScript

// Flags: --no-warnings
'use strict';
// Test that warnings are emitted when a Promise experiences an uncaught
// rejection, and then again if the rejection is handled later on.
const common = require('../common');
const assert = require('assert');
common.disableCrashOnUnhandledRejection();
let b = 0;
process.on('warning', common.mustCall((warning) => {
switch (b++) {
case 0:
// String rejection error displayed
assert.strictEqual(warning.message, 'This was rejected');
break;
case 1:
// Warning about rejection not being handled (will be next tick)
assert.strictEqual(warning.name, 'UnhandledPromiseRejectionWarning');
assert(
/Unhandled promise rejection/.test(warning.message),
'Expected warning message to contain "Unhandled promise rejection" ' +
`but did not. Had "${warning.message}" instead.`
);
break;
case 2:
// One time deprecation warning, first unhandled rejection
assert.strictEqual(warning.name, 'DeprecationWarning');
break;
case 3:
// Number rejection error displayed. Note it's been stringified
assert.strictEqual(warning.message, '42');
break;
case 4:
// Unhandled rejection warning (won't be handled next tick)
assert.strictEqual(warning.name, 'UnhandledPromiseRejectionWarning');
assert(
/Unhandled promise rejection/.test(warning.message),
'Expected warning message to contain "Unhandled promise rejection" ' +
`but did not. Had "${warning.message}" instead.`
);
break;
case 5:
// Rejection handled asynchronously.
assert.strictEqual(warning.name, 'PromiseRejectionHandledWarning');
assert(/Promise rejection was handled asynchronously/
.test(warning.message));
}
}, 6));
const p = Promise.reject('This was rejected'); // Reject with a string
setImmediate(common.mustCall(() => p.catch(() => { })));
Promise.reject(42); // Reject with a number