删除@type/jest后如何使用jest.mock (^jest@24)

Question

最近，我将@angular-builders/jest从7更新到8。在迁移指南中，它规定我应该删除@types/jest，因为它现在带有Jest v24。(我也是更新了我的tsconfig)

到目前一切尚好。

但现在我的测试失败了

error TS2304: Cannot find name 'jest'.

jest.mock('src/app/omitted');

error TS2304: Cannot find name 'jest'.

jest.clearAllMocks();

VS代码与jest全局变量无关。根据迁移指南，当我从tsconfig中删除typeRoots时，哪种方式是有意义的。

在tsconfig.json (根目录，由IDE使用)中： 删除typeRoots数组 同样，由于Jest类型被打包在jest包中，而不是位于节点_模块/@类型下，所以不希望类型根被限制在特定的文件夹中。

但是是什么原因呢？迁移指南说我应该删除@types/jest，但是如何使它再次与jest.mock和jest.clearAllMocks保持良好关系呢？

我试过：

import { mock } from 'jest'; // mock isn't found
import * as jest from 'jest'; // jest.mock isn't found

请指点。

以下是我的心声(和简单-app示例一样)

相关开发包

{
    "@angular-builders/jest": "^8.0.3",
    "jest": "^24.8.0",
    "jest-preset-angular": "^7.1.1",
    "ts-jest": "^24.0.2",
}

tsconfig.json

{
  "compileOnSave": false,
  "compilerOptions": {
    "baseUrl": "./",
    "outDir": "./dist/out-tsc",
    "sourceMap": true,
    "declaration": false,
    "module": "esnext",
    "moduleResolution": "node",
    "emitDecoratorMetadata": true,
    "experimentalDecorators": true,
    "importHelpers": true,
    "target": "es2015",
    "lib": ["es2018", "dom"],
    "strict": true                // note strict mode
  }
}

tsconfig.spec.json

{
  "extends": "./tsconfig.json",
  "compilerOptions": {
    "outDir": "./out-tsc/spec",
    "allowJs": true
  },
  "files": ["src/polyfills.ts"],
  "include": ["src/**/*.spec.ts", "src/**/*.d.ts"]
}

angular.json

{
  "$schema": "./node_modules/@angular/cli/lib/config/schema.json",
  "version": 1,
  "newProjectRoot": "projects",
  "projects": {
    "my-project": {
      //...
      "architect": {
        //...
        "test": {
          "builder": "@angular-builders/jest:run",
          "options": {}
        }
      }
    }
  }
}

Answer 1

@types/jest显然是仍需。对迁移指南进行了调整，以反映这一点。

这些吐露现在看起来是这样的：

package.json

"@angular-builders/jest": "^8.0.3",
"@types/jest": "^24.0.15",
"jest": "^24.8.0",
"jest-preset-angular": "^7.1.1",
"ts-jest": "^24.0.2",

tsconfig.json

{
  "compileOnSave": false,
  "compilerOptions": {
    "baseUrl": "./",
    "outDir": "./dist/out-tsc",
    "sourceMap": true,
    "declaration": false,
    "module": "esnext",
    "moduleResolution": "node",
    "emitDecoratorMetadata": true,
    "experimentalDecorators": true,
    "importHelpers": true,
    "target": "es2015",
    "lib": ["es2018", "dom"],
    "types": ["jest"],
    "strict": true                     // note strict mode, this isn't default
  }
}

tsconfig.spec.json

{
  "extends": "./tsconfig.json",
  "compilerOptions": {
    "outDir": "./out-tsc/spec"
  },
  "files": ["src/polyfills.ts"],
  "include": ["src/**/*.spec.ts", "src/**/*.d.ts"]
}