| 1 | /**
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| 2 | * Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved.
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| 3 | *
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| 4 | * This source code is licensed under the MIT license found in the
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| 5 | * LICENSE file in the root directory of this source tree.
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| 6 | */
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| 7 | import type { AggregatedResult, Test } from '@jest/test-result';
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| 8 | import type { Context } from 'jest-runtime';
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| 9 | declare type Cache = {
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| 10 | [key: string]: [0 | 1, number];
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| 11 | };
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| 12 | /**
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| 13 | * The TestSequencer will ultimately decide which tests should run first.
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| 14 | * It is responsible for storing and reading from a local cache
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| 15 | * map that stores context information for a given test, such as how long it
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| 16 | * took to run during the last run and if it has failed or not.
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| 17 | * Such information is used on:
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| 18 | * TestSequencer.sort(tests: Array<Test>)
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| 19 | * to sort the order of the provided tests.
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| 20 | *
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| 21 | * After the results are collected,
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| 22 | * TestSequencer.cacheResults(tests: Array<Test>, results: AggregatedResult)
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| 23 | * is called to store/update this information on the cache map.
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| 24 | */
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| 25 | export default class TestSequencer {
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| 26 | private _cache;
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| 27 | _getCachePath(context: Context): string;
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| 28 | _getCache(test: Test): Cache;
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| 29 | /**
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| 30 | * Sorting tests is very important because it has a great impact on the
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| 31 | * user-perceived responsiveness and speed of the test run.
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| 32 | *
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| 33 | * If such information is on cache, tests are sorted based on:
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| 34 | * -> Has it failed during the last run ?
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| 35 | * Since it's important to provide the most expected feedback as quickly
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| 36 | * as possible.
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| 37 | * -> How long it took to run ?
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| 38 | * Because running long tests first is an effort to minimize worker idle
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| 39 | * time at the end of a long test run.
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| 40 | * And if that information is not available they are sorted based on file size
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| 41 | * since big test files usually take longer to complete.
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| 42 | *
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| 43 | * Note that a possible improvement would be to analyse other information
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| 44 | * from the file other than its size.
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| 45 | *
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| 46 | */
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| 47 | sort(tests: Array<Test>): Array<Test>;
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| 48 | allFailedTests(tests: Array<Test>): Array<Test>;
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| 49 | cacheResults(tests: Array<Test>, results: AggregatedResult): void;
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| 50 | }
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| 51 | export {};
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