typescript 找不到名称“描述”。您是否需要为测试运行程序安装类型定义？

Cannot find name 'describe'. Do you need to install type definitions for a test runner?

提问by Ronin

When using TypeScript in conjunction with Jest, my specs would fail with error messages like:

将 TypeScript 与 Jest 结合使用时，我的规范会失败并显示如下错误消息：

test/unit/some.spec.ts:1:1 - error TS2582: Cannot find name 'describe'. Do you need to install type definitions for a test runner? Try `npm i @types/jest` or `npm i @types/mocha`.
test/unit/some.spec.ts:2:3 - error TS2582: Cannot find name 'it'. Do you need to install type definitions for a test runner? Try `npm i @types/jest` or `npm i @types/mocha`.
test/unit/some.spec.ts:3:7 - error TS2304: Cannot find name 'expect'.
test/unit/some.spec.ts:7:1 - error TS2582: Cannot find name 'test'. Do you need to install type definitions for a test runner? Try `npm i @types/jest` or `npm i @types/mocha`.

The types are already installed.

类型已经安装。

I use:

我用：

    "@types/jest": "^23.3.12",
    "jest": "^23.6.0",
    "ts-jest": "^23.10.5",
    "typescript": "^3.1.6"

I run tests using jest --forceExit --coverage --verbose

我运行测试使用 jest --forceExit --coverage --verbose

采纳答案by Ronin

After fiddling with the tsconfig.jsonfor a while I finally figured, that commenting the "types": [],will work.

在摆弄了tsconfig.json一段时间后，我终于想通了，评论"types": [],将起作用。

failing config (before)

失败的配置（之前）

// tsconfig.json
{
  "compilerOptions": {
    "types": []
  }
}

working config

工作配置

// tsconfig.json
{
  "compilerOptions": {
    // "types": []
  }
}

回答by Melvin Sy

I'm using VSCode as my IDE and in my Angular project, I had to comment-out/remove types in tsconfig.json and add jest in types at tsconfig.spec.json.

我使用 VSCode 作为我的 IDE，在我的 Angular 项目中，我不得不注释掉/删除 tsconfig.json 中的类型，并在 tsconfig.spec.json 中的类型中添加 jest。

tsconfig.json

配置文件

{
  "compilerOptions": {
    // "types": []
  }
}

tsconfig.spec.json

tsconfig.spec.json

{
  "compilerOptions": {
    "types": ["jest", "node"]
  }
}

回答by Victor Jatobá

You need to include in tsconfig.json your test path.

您需要在 tsconfig.json 中包含您的测试路径。

Example: suppose you named your path to tests/and put it in root project directory, you need to specify in "include" param from tsconfig to look out for testes files:

示例：假设您将路径命名为tests/并将其放在根项目目录中，您需要在 tsconfig 中的“include”参数中指定以查找 testes 文件：

1. Go to: tsconfig.json
2. Add:

1. 去： tsconfig.json
2. 添加：

"include": [
    "tests/*.<file_test_extension>",
],

• <file_test_extension>:ts | js | etc.

• <file_test_extension>:ts | js | 等等。

Hope to help

希望有所帮助

回答by Daniel Manfred

You have to import jest in your test file:

您必须在测试文件中导入 jest：

import 'jest';

Another way to solve is adding in your tsconfig.json file:

另一种解决方法是在您的 tsconfig.json 文件中添加：

   "compilerOptions": {
     "types": [ "node", "jest" ],
     "moduleResolution": "node"
   }

回答by Polor Beer

You can have a separate tsconfig.jsonin the test folder __tests__:

您可以tsconfig.json在测试文件夹中有一个单独的__tests__：

{
    "extends": "../tsconfig.json",
    "compilerOptions": {
        "baseUrl": "./",
        "outDir": "../build",
        "noEmit": true,
        "rootDir": "../",
    },
    "exclude": ["node_modules"],
}

which extends the one in the root folder:

它扩展了根文件夹中的那个：

{
  "compilerOptions": {
    "target": "es6",
    "module": "commonjs",
    "moduleResolution": "node",
    "outDir": "./lib",
    "rootDir": "./src",
    "strict": true,
    "noImplicitAny": true,
    "esModuleInterop": true,
  },
  "exclude": ["node_modules", "**/*.test.ts", "__tests__"]
}

This way you tests files still get excluded from the public build, but still get to share all the common options.

通过这种方式，您的测试文件仍然会被排除在公共构建之外，但仍然可以共享所有常见选项。

回答by Greg Woz

Simple checklist to solve this (for TypeScript and Jest).

解决此问题的简单清单（针对 TypeScript 和 Jest）。

1. Make sure you have @types/jestand @types/nodeinstalled.
2. Make sure you have linked these types in tsconfig.jsonso that: types: ["jest", "node"]
3. Make sure you don't have your tests or the tests directory excludedfrom tsconfig.jsonconfiguration in excludedproperty.

1. 确保您已安装@types/jest并@types/node安装。
2. 确保您已链接这些类型，tsconfig.json以便：types: ["jest", "node"]
3. 确保您没有从属性中的tsconfig.json配置中排除测试或测试目录excluded。

If you transpile to JS then you will need a separate tsconfig.jsonin your tests that includes your test files along with the necessary compiler options and files to build the appropriate context.

如果您转译为 JS，那么您将需要tsconfig.json在您的测试中单独包含您的测试文件以及必要的编译器选项和文件以构建适当的上下文。

回答by Fyodor

In my case, the problem was in one particular file. I hadn't found the issue itself but it was cured by adding import {} from 'jest'to file's imports.

就我而言，问题出在一个特定文件中。我还没有发现问题本身，但它通过添加import {} from 'jest'到文件的导入来解决。

No other way from jest issue tracker or SO or wherenot did help. Just some crazy bug fixed by some crazy workaround ?♂?

从玩笑问题跟踪器或 SO 或 wherenot 没有其他帮助。只是通过一些疯狂的解决方法修复了一些疯狂的错误？♂？

Yes, and I added the latest jest, ts-jestand @types/jestto package.json of course

是的，我当然添加了最新的jest,ts-jest和@types/jestpackage.json

回答by Ritesh

I am using mocha, chaiand chai-httpfor testing node express js project. I was not using typesin compilerOptionsearlier, but adding below setting in tsconfig.jsonmade it work for me:

我正在使用mocha,chai并chai-http用于测试 node express js 项目。我没有用types在compilerOptions前面，但加入低于设定tsconfig.json使得它对我来说有效：

{
  "compilerOptions": {
    // ...rest of my settings
    "types": ["mocha", "chai", "chai-http"]
  }
}

I hope it'll help someone..!!

我希望它会帮助某人.. !!