&引用；“描述未定义”；将Jest与Node.JS服务器应用程序一起使用时

我有一个相对简单的Node.js应用程序，我试图在其中使用Jest进行单元测试（因为我在其他客户机项目上使用它，并且希望在这里使用它的一致性）。为了弄清问题的症结所在，我尝试创建一个精简的项目，尽可能少地重现问题

My package.json在这里：

{
  "name": "jest-sample",
  "version": "0.2.0",
  "private": true,
  "description": "NodeJS backend to the Service Manager UI",
  "author": "Me",
  "license": "SEE LICENSE IN LICENSE",
  "deprecated": false,
  "main": "src/js/app.js",
  "type": "module",
  "engines": {
    "node": "^8.15.1"
  },
  "scripts": {
    "test": "npx jest"
  },
  "devDependencies": {
    "jest": "26.0.1",
    "supertest": "4.0.2"
  },
  "jest": {
    "testEnvironment": "node"
  }
}

我在项目中没有eslint或其他任何东西

➜  jest-sample ls -a
.                 ..                __tests__         node_modules      package-lock.json package.json

测试也很简单：

describe('Sample Test', function() {
    it('should be', function() {
        expect(true).toBe(true);
    })
});

然而，当我开玩笑时，我得到：

➜  jest-sample npx jest
 FAIL  __tests__/sample.spec.js
  ● Test suite failed to run

    ReferenceError: describe is not defined

    > 1 | describe('Sample Test', function() {
        | ^
      2 |     it('should be', function() {
      3 |         expect(true).toBe(true);
      4 |     })

      at Object.<anonymous> (__tests__/sample.spec.js:1:1)

Test Suites: 1 failed, 1 total
Tests:       0 total
Snapshots:   0 total
Time:        2.562 s
Ran all test suites.

➜  jest示例npx jest
失败_测试_/sample.spec.js
● 测试套件无法运行
ReferenceError:未定义描述
>1 |描述（'样本测试'，功能（）{
| ^
2 |它（'should be'，function（）{
3 |期望（正确）。托比（正确）；
4 |     })
在对象上。（\uu tests_uuu/sample.spec.js:1:1）
测试套件：1个失败，共1个
测试：共0项
快照：共0个
时间：2.562秒
运行所有测试套件。

更新： jest调试的输出如下：

➜  jest-sample npx jest --debug
{
  "configs": [
    {
      "automock": false,
      "cache": true,
      "cacheDirectory": "/private/var/folders/4m/6tytrddj3g90b8rmbrccw3lm0000gn/T/jest_dx",
      "clearMocks": false,
      "coveragePathIgnorePatterns": [
        "/node_modules/"
      ],
      "cwd": "/Users/rbair/Projects/gitlab/iot/infrastructure/service-manager/jest-sample",
      "detectLeaks": false,
      "detectOpenHandles": false,
      "errorOnDeprecated": false,
      "extraGlobals": [],
      "forceCoverageMatch": [],
      "globals": {},
      "haste": {
        "computeSha1": false,
        "throwOnModuleCollision": false
      },
      "moduleDirectories": [
        "node_modules"
      ],
      "moduleFileExtensions": [
        "js",
        "json",
        "jsx",
        "ts",
        "tsx",
        "node"
      ],
      "moduleNameMapper": [],
      "modulePathIgnorePatterns": [],
      "name": "d652708218018aa212b40c53d7999ccc",
      "prettierPath": "prettier",
      "resetMocks": false,
      "resetModules": false,
      "restoreMocks": false,
      "rootDir": "/Users/rbair/Projects/gitlab/iot/infrastructure/service-manager/jest-sample",
      "roots": [
        "/Users/rbair/Projects/gitlab/iot/infrastructure/service-manager/jest-sample"
      ],
      "runner": "jest-runner",
      "setupFiles": [],
      "setupFilesAfterEnv": [],
      "skipFilter": false,
      "snapshotSerializers": [],
      "testEnvironment": "/Users/rbair/Projects/gitlab/iot/infrastructure/service-manager/jest-sample/node_modules/jest-environment-node/build/index.js",
      "testEnvironmentOptions": {},
      "testLocationInResults": false,
      "testMatch": [
        "**/__tests__/**/*.[jt]s?(x)",
        "**/?(*.)+(spec|test).[tj]s?(x)"
      ],
      "testPathIgnorePatterns": [
        "/node_modules/"
      ],
      "testRegex": [],
      "testRunner": "/Users/rbair/Projects/gitlab/iot/infrastructure/service-manager/jest-sample/node_modules/jest-jasmine2/build/index.js",
      "testURL": "http://localhost",
      "timers": "real",
      "transform": [
        [
          "^.+\\.[jt]sx?$",
          "/Users/rbair/Projects/gitlab/iot/infrastructure/service-manager/jest-sample/node_modules/babel-jest/build/index.js",
          {}
        ]
      ],
      "transformIgnorePatterns": [
        "/node_modules/"
      ],
      "watchPathIgnorePatterns": []
    }
  ],
  "globalConfig": {
    "bail": 0,
    "changedFilesWithAncestor": false,
    "collectCoverage": false,
    "collectCoverageFrom": [],
    "coverageDirectory": "/Users/rbair/Projects/gitlab/iot/infrastructure/service-manager/jest-sample/coverage",
    "coverageProvider": "babel",
    "coverageReporters": [
      "json",
      "text",
      "lcov",
      "clover"
    ],
    "detectLeaks": false,
    "detectOpenHandles": false,
    "errorOnDeprecated": false,
    "expand": false,
    "findRelatedTests": false,
    "forceExit": false,
    "json": false,
    "lastCommit": false,
    "listTests": false,
    "logHeapUsage": false,
    "maxConcurrency": 5,
    "maxWorkers": 3,
    "noStackTrace": false,
    "nonFlagArgs": [],
    "notify": false,
    "notifyMode": "failure-change",
    "onlyChanged": false,
    "onlyFailures": false,
    "passWithNoTests": false,
    "projects": [],
    "rootDir": "/Users/rbair/Projects/gitlab/iot/infrastructure/service-manager/jest-sample",
    "runTestsByPath": false,
    "skipFilter": false,
    "testFailureExitCode": 1,
    "testPathPattern": "",
    "testSequencer": "/Users/rbair/Projects/gitlab/iot/infrastructure/service-manager/jest-sample/node_modules/@jest/test-sequencer/build/index.js",
    "updateSnapshot": "new",
    "useStderr": false,
    "watch": false,
    "watchAll": false,
    "watchman": true
  },
  "version": "26.0.1"
}
 FAIL  __tests__/sample.spec.js
  ● Test suite failed to run

    ReferenceError: describe is not defined

    > 1 | describe('Sample Test', function() {
        | ^
      2 |     it('should be', function() {
      3 |         expect(true).toBe(true);
      4 |     })

      at Object.<anonymous> (__tests__/sample.spec.js:1:1)

Test Suites: 1 failed, 1 total
Tests:       0 total
Snapshots:   0 total
Time:        0.523 s
Ran all test suites.

➜  jest示例npx jest—调试
{
“配置”：[
{
“自动模拟”：错误，
“缓存”：正确，
“缓存目录”：“/private/var/folders/4m/6tytrddj3g90b8RMBCW3lm0000gn/T/jest_dx”，
“clearMocks”：错误，
“coveragePathIgnorePatterns”：[
“/node_modules/”
],
“cwd”：“/Users/rbair/Projects/gitlab/iot/infrastructure/service manager/jest sample”，
“detectLeaks”：错误，
“detectOpenHandles”：错误，
“errorOnDeprecated”：错误，
“全球外”：[]，
“强制覆盖匹配”：[]，
“全球”：{}，
“匆忙”：{
“computeSha1”：false，
“throwOnModuleCollision”：错误
},
“模块目录”：[
“节点_模块”
],
“moduleFileExtensions”：[
“js”，
“json”，
“jsx”，
“ts”，
“tsx”，
“节点”
],
“moduleNameMapper”：[]，
“modulePathIgnorePatterns”：[]，
“名称”：“d652708218018aa212b40c53d7999ccc”，
“prettierPath”：“prettier”，
“重置模拟”：错误，
“重置模块”：错误，
“restoreMocks”：假，
“rootDir”：“/Users/rbair/Projects/gitlab/iot/infrastructure/service manager/jest sample”，
“根”：[
“/Users/rbair/Projects/gitlab/iot/infrastructure/service manager/jest sample”
],
“跑步者”：“开玩笑的跑步者”，
“设置文件”：[]，
“SetupFileAfterEnv”：[]，
“skipFilter”：错误，
“快照序列化程序”：[]，
“测试环境”：“/Users/rbair/Projects/gitlab/iot/infrastructure/service manager/jest sample/node_modules/jest environment node/build/index.js”，
“测试环境选项”：{}，
“testLocationInResults”：错误，
“测试匹配”：[
“***/\\\\\/***.[jt]s？（x）”，
“***/？（*）+（规范测试）。[tj]s？（x）”
],
“testPathIgnorePatterns”：[
“/node_modules/”
],
“testRegex”：[]，
“testRunner”：“/Users/rbair/Projects/gitlab/iot/infrastructure/service manager/jest sample/node_modules/jest-jasmine2/build/index.js”，
“testURL”：”http://localhost",
“计时器”：“真实的”，
“转变”：[
[
“^.+\.[jt]sx？$”，
“/Users/rbair/Projects/gitlab/iot/infrastructure/service manager/jest sample/node_modules/babel jest/build/index.js”，
{}
]
],
“transformIgnorePatterns”：[
“/node_modules/”
],
“watchPathIgnorePatterns”：[]
}
],
“全球配置”：{
“保释”：0，
“ChangedFileWithAsentor”：false，
“保险范围”：虚假，
“CollectionCoverage from”：[]，
“coverage目录”：“/Users/rbair/Projects/gitlab/iot/infrastructure/service manager/jest sample/coverage”，
“Coverage Provider”：“babel”，
“搬运工”：[
“json”，
“文本”，
“lcov”，
“三叶草”
],
“detectLeaks”：错误，
“detectOpenHandles”：错误，
“errorOnDeprecated”：错误，
“扩展”：错误，
“findRelatedTests”：错误，
“强制退出”：错误，
“json”：false，
“lastCommit”：false，
“列表测试”：错误，
“logHeapUsage”：错误，
“maxConcurrency”：5，
“maxWorkers”：3，
“noStackTrace”：false，
“非标签”：[]，
“通知”：错误，
“notifyMode”：“故障更改”，
“仅更改”：错误，
“唯一的失败”：错误，
“passWithNoTests”：false，
“项目”：[…]，
“rootDir”：“/Users/rbair/Projects/gitlab/iot/infrastructure/service manager/jest sample”，
“runTestsByPath”：false，
“skipFilter”：错误，
“testFailureExitCode”：1，
“testPathPattern”：“”，
“testSequencer”：“/Users/rbair/Projects/gitlab/iot/infrastructure/service manager/jest sample/node_modules/@jest/test sequencer/build/index.js”，
“更新快照”：“新建”，
“useStderr”：false，
“手表”：假的，
“watchAll”：错误，
“守望者”：真的吗
},
“版本”：“26.0.1”
}
失败_测试_/sample.spec.js
● 测试套件无法运行
ReferenceError:未定义描述
>1 |描述（'样本测试'，功能（）{
| ^
2 |它（'should be'，function（）{
3 |期望（正确）。托比（正确）；
4 |     })
at对象。（uuu测试uu/sample.spec.js:1:1）
测试套件：1个失败，共1个
测试：共0项
快照：共0个
时间：0.523秒
运行所有测试套件。

正如@jornsharpe发现的，我的根本问题是我使用的节点版本（10.13.0）更新到12.18.0版后，问题就消失了。

你为什么要使用

npx jest

？这也是你的

软件包中的问题。json

，请给出一个答案。我想使用

npm install

安装的jest，而不需要全局安装。我对jest来说是新手，对npm来说也是新手，所以也许有更好的方法而不是npx？如果这个示例对您有效，那么我的环境中肯定有其他原因导致了问题。有什么想法会导致这个问题吗？

“test”：“jest”

已经使用了

jest