获取按持续时间排序的笑话测试

Question

我正在努力提高我们的笑话测试的性能，其中包含 4,000 多个测试。为了查看单独的测试持续时间，我使用了该--verbose标志。

有没有一种简单的方法可以发现运行时间最长的测试，或者我是否必须滚动浏览整个输出？

Answer 1

您可以编写一个测试报告器并将其添加到jest 的报告器配置中。

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./reporters/slow-test.js：

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class JestSlowTestReporter {\n  constructor(globalConfig, options) {\n    this._globalConfig = globalConfig;\n    this._options = options;\n    this._slowTests = [];\n  }\n\n  onRunComplete() {\n    console.log();\n    this._slowTests.sort((a, b) => b.duration - a.duration);\n    var rootPathRegex = new RegExp(`^${process.cwd()}`);\n    var slowestTests = this._slowTests.slice(0, this._options.numTests || 10);\n    var slowTestTime = this._slowTestTime(slowestTests);\n    var allTestTime = this._allTestTime();\n    var percentTime = (slowTestTime / allTestTime) * 100;\n\n    console.log(\n      `Top ${slowestTests.length} slowest examples (${slowTestTime / 1000} seconds,` +\n        ` ${percentTime.toFixed(1)}% of total time):`\n    );\n\n    for (var i = 0; i < slowestTests.length; i++) {\n      var duration = slowestTests[i].duration;\n      var fullName = slowestTests[i].fullName;\n      var filePath = slowestTests[i].filePath.replace(rootPathRegex, \'.\');\n\n      console.log(`  ${fullName}`);\n      console.log(`    ${duration / 1000} seconds ${filePath}`);\n    }\n    console.log();\n  }\n\n  onTestResult(test, testResult) {\n    for (var i = 0; i < testResult.testResults.length; i++) {\n      this._slowTests.push({\n        duration: testResult.testResults[i].duration,\n        fullName: testResult.testResults[i].fullName,\n        filePath: testResult.testFilePath,\n      });\n    }\n  }\n\n  _slowTestTime(slowestTests) {\n    var slowTestTime = 0;\n    for (var i = 0; i < slowestTests.length; i++) {\n      slowTestTime += slowestTests[i].duration;\n    }\n    return slowTestTime;\n  }\n\n  _allTestTime() {\n    var allTestTime = 0;\n    for (var i = 0; i < this._slowTests.length; i++) {\n      allTestTime += this._slowTests[i].duration;\n    }\n    return allTestTime;\n  }\n}\n\nmodule.exports = JestSlowTestReporter;\n

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jest.config.js：

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module.exports = {\n  preset: \'ts-jest/presets/js-with-ts\',\n  reporters: [\'default\', [\'<rootDir>/reporters/slow-test\', { numTests: 3 }]],\n};\n

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numTests: 3argument 意味着找到前 3 个最慢的测试用例。

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index.test.js：

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describe(\'find top slowest test\', () => {\n  test(\'should 1\', (done) => {\n    setTimeout(() => {\n      expect(1 + 1).toBe(2);\n      done();\n    }, 1000);\n  });\n  test(\'should 2\', (done) => {\n    setTimeout(() => {\n      expect(1 + 1).toBe(2);\n      done();\n    }, 1200);\n  });\n  test(\'should 3\', (done) => {\n    setTimeout(() => {\n      expect(1 + 1).toBe(2);\n      done();\n    }, 100);\n  });\n});\n

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测试结果：

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 PASS  examples/find-top-slowest-test/index.test.js\n  find top slowest test\n    \xe2\x9c\x93 should 1 (1007 ms)\n    \xe2\x9c\x93 should 2 (1201 ms)\n    \xe2\x9c\x93 should 3 (103 ms)\n\nTest Suites: 1 passed, 1 total\nTests:       3 passed, 3 total\nSnapshots:   0 total\nTime:        3.588 s, estimated 4 s\nRan all test suites matching /\\/Users\\/dulin\\/workspace\\/github.com\\/mrdulin\\/jest-v26-codelab\\/examples\\/find-top-slowest-test\\/index.test.js/i.\n\nTop 3 slowest examples (2.311 seconds, 100.0% of total time):\n  find top slowest test should 2\n    1.201 seconds ./examples/find-top-slowest-test/index.test.js\n  find top slowest test should 1\n    1.007 seconds ./examples/find-top-slowest-test/index.test.js\n  find top slowest test should 3\n    0.103 seconds ./examples/find-top-slowest-test/index.test.js\n

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