promise.finally.spec.js

'use strict';

var assert = require('assert');
var adapter = require('./promise-adapter');
var P = global['__zone_symbol__Promise'];

var someRejectionReason = {message: 'some rejection reason'};
var anotherReason = {message: 'another rejection reason'};
process.on('unhandledRejection', function(reason, promise) {
  console.log('unhandledRejection', reason);
});

describe('mocha promise sanity check', () => {
	it('passes with a resolved promise', () => {
		return P.resolve(3);
	});

	it('passes with a rejected then resolved promise', () => {
		return P.reject(someRejectionReason).catch(x => 'this should be resolved');
	});

    var ifPromiseIt = P === Promise ? it : it.skip;
	ifPromiseIt('is the native Promise', () => {
		assert.equal(P, Promise);
	});
});

describe('onFinally', () => {
	describe('no callback', () => {
		specify('from resolved', (done) => {
			adapter.resolved(3)
				.then((x) => {
					assert.strictEqual(x, 3);
					return x;
				})
				.finally()
				.then(function onFulfilled(x) {
					assert.strictEqual(x, 3);
					done();
				}, function onRejected() {
					done(new Error('should not be called'));
				});
		});

		specify('from rejected', (done) => {
			adapter.rejected(someRejectionReason)
				.catch((e) => {
					assert.strictEqual(e, someRejectionReason);
					throw e;
				})
				.finally()
				.then(function onFulfilled() {
					done(new Error('should not be called'));
				}, function onRejected(reason) {
					assert.strictEqual(reason, someRejectionReason);
					done();
				});
		});
	});

	describe('throws an exception', () => {
		specify('from resolved', (done) => {
			adapter.resolved(3)
				.then((x) => {
					assert.strictEqual(x, 3);
					return x;
				})
				.finally(function onFinally() {
					assert(arguments.length === 0);
					throw someRejectionReason;
				}).then(function onFulfilled() {
					done(new Error('should not be called'));
				}, function onRejected(reason) {
					assert.strictEqual(reason, someRejectionReason);
					done();
				});
		});

		specify('from rejected', (done) => {
			adapter.rejected(anotherReason).finally(function onFinally() {
				assert(arguments.length === 0);
				throw someRejectionReason;
			}).then(function onFulfilled() {
				done(new Error('should not be called'));
			}, function onRejected(reason) {
				assert.strictEqual(reason, someRejectionReason);
				done();
			});
		});
	});

	describe('returns a non-promise', () => {
		specify('from resolved', (done) => {
			adapter.resolved(3)
				.then((x) => {
					assert.strictEqual(x, 3);
					return x;
				})
				.finally(function onFinally() {
					assert(arguments.length === 0);
					return 4;
				}).then(function onFulfilled(x) {
					assert.strictEqual(x, 3);
					done();
				}, function onRejected() {
					done(new Error('should not be called'));
				});
		});

		specify('from rejected', (done) => {
			adapter.rejected(anotherReason)
				.catch((e) => {
					assert.strictEqual(e, anotherReason);
					throw e;
				})
				.finally(function onFinally() {
					assert(arguments.length === 0);
					throw someRejectionReason;
				}).then(function onFulfilled() {
					done(new Error('should not be called'));
				}, function onRejected(e) {
					assert.strictEqual(e, someRejectionReason);
					done();
				});
		});
	});

	describe('returns a pending-forever promise', () => {
		specify('from resolved', (done) => {
			var timeout;
			adapter.resolved(3)
				.then((x) => {
					assert.strictEqual(x, 3);
					return x;
				})
				.finally(function onFinally() {
					assert(arguments.length === 0);
					timeout = setTimeout(done, 0.1e3);
					return new P(() => {}); // forever pending
				}).then(function onFulfilled(x) {
					clearTimeout(timeout);
					done(new Error('should not be called'));
				}, function onRejected() {
					clearTimeout(timeout);
					done(new Error('should not be called'));
				});
		});

		specify('from rejected', (done) => {
			var timeout;
			adapter.rejected(someRejectionReason)
				.catch((e) => {
					assert.strictEqual(e, someRejectionReason);
					throw e;
				})
				.finally(function onFinally() {
					assert(arguments.length === 0);
					timeout = setTimeout(done, 0.1e3);
					return new P(() => {}); // forever pending
				}).then(function onFulfilled(x) {
					clearTimeout(timeout);
					done(new Error('should not be called'));
				}, function onRejected() {
					clearTimeout(timeout);
					done(new Error('should not be called'));
				});
		});
	});

	describe('returns an immediately-fulfilled promise', () => {
		specify('from resolved', (done) => {
			adapter.resolved(3)
				.then((x) => {
					assert.strictEqual(x, 3);
					return x;
				})
				.finally(function onFinally() {
					assert(arguments.length === 0);
					return adapter.resolved(4);
				}).then(function onFulfilled(x) {
					assert.strictEqual(x, 3);
					done();
				}, function onRejected() {
					done(new Error('should not be called'));
				});
		});

		specify('from rejected', (done) => {
			adapter.rejected(someRejectionReason)
				.catch((e) => {
					assert.strictEqual(e, someRejectionReason);
					throw e;
				})
				.finally(function onFinally() {
					assert(arguments.length === 0);
					return adapter.resolved(4);
				}).then(function onFulfilled() {
					done(new Error('should not be called'));
				}, function onRejected(e) {
					assert.strictEqual(e, someRejectionReason);
					done();
				});
		});
	});

	describe('returns an immediately-rejected promise', () => {
		specify('from resolved ', (done) => {
			adapter.resolved(3)
				.then((x) => {
					assert.strictEqual(x, 3);
					return x;
				})
				.finally(function onFinally() {
					assert(arguments.length === 0);
					return adapter.rejected(4);
				}).then(function onFulfilled(x) {
					done(new Error('should not be called'));
				}, function onRejected(e) {
					assert.strictEqual(e, 4);
					done();
				});
		});

		specify('from rejected', (done) => {
			const newReason = {};
			adapter.rejected(someRejectionReason)
				.catch((e) => {
					assert.strictEqual(e, someRejectionReason);
					throw e;
				})
				.finally(function onFinally() {
					assert(arguments.length === 0);
					return adapter.rejected(newReason);
				}).then(function onFulfilled(x) {
					done(new Error('should not be called'));
				}, function onRejected(e) {
					assert.strictEqual(e, newReason);
					done();
				});
		});
	});

	describe('returns a fulfilled-after-a-second promise', () => {
		specify('from resolved', (done) => {
			var timeout;
			adapter.resolved(3)
				.then((x) => {
					assert.strictEqual(x, 3);
					return x;
				})
				.finally(function onFinally() {
					assert(arguments.length === 0);
					timeout = setTimeout(done, 1.5e3);
					return new P((resolve) => {
						setTimeout(() => resolve(4), 1e3);
					});
				}).then(function onFulfilled(x) {
					clearTimeout(timeout);
					assert.strictEqual(x, 3);
					done();
				}, function onRejected() {
					clearTimeout(timeout);
					done(new Error('should not be called'));
				});
		});

		specify('from rejected', (done) => {
			var timeout;
			adapter.rejected(3)
				.catch((e) => {
					assert.strictEqual(e, 3);
					throw e;
				})
				.finally(function onFinally() {
					assert(arguments.length === 0);
					timeout = setTimeout(done, 1.5e3);
					return new P((resolve) => {
						setTimeout(() => resolve(4), 1e3);
					});
				}).then(function onFulfilled() {
					clearTimeout(timeout);
					done(new Error('should not be called'));
				}, function onRejected(e) {
					clearTimeout(timeout);
					assert.strictEqual(e, 3);
					done();
				});
		});
	});

	describe('returns a rejected-after-a-second promise', () => {
		specify('from resolved', (done) => {
			var timeout;
			adapter.resolved(3)
				.then((x) => {
					assert.strictEqual(x, 3);
					return x;
				})
				.finally(function onFinally() {
					assert(arguments.length === 0);
					timeout = setTimeout(done, 1.5e3);
					return new P((resolve, reject) => {
						setTimeout(() => reject(4), 1e3);
					});
				}).then(function onFulfilled() {
					clearTimeout(timeout);
					done(new Error('should not be called'));
				}, function onRejected(e) {
					clearTimeout(timeout);
					assert.strictEqual(e, 4);
					done();
				});
		});

		specify('from rejected', (done) => {
			var timeout;
			adapter.rejected(someRejectionReason)
				.catch((e) => {
					assert.strictEqual(e, someRejectionReason);
					throw e;
				})
				.finally(function onFinally() {
					assert(arguments.length === 0);
					timeout = setTimeout(done, 1.5e3);
					return new P((resolve, reject) => {
						setTimeout(() => reject(anotherReason), 1e3);
					});
				}).then(function onFulfilled() {
					clearTimeout(timeout);
					done(new Error('should not be called'));
				}, function onRejected(e) {
					clearTimeout(timeout);
					assert.strictEqual(e, anotherReason);
					done();
				});
		});
	});

	specify('has the correct property descriptor', () => {
		var descriptor = Object.getOwnPropertyDescriptor(Promise.prototype, 'finally');

		assert.strictEqual(descriptor.writable, true);
		assert.strictEqual(descriptor.configurable, true);
	});
});