未找到转换选项中的模块 <rootDir>/node_modules/jest-preset-angular/preprocessor.js
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【中文标题】未找到转换选项中的模块 <rootDir>/node_modules/jest-preset-angular/preprocessor.js【英文标题】：Module <rootDir>/node_modules/jest-preset-angular/preprocessor.js in the transform option was not found 【发布时间】：2019-10-16 17:19:40 【问题描述】：当我的 Angular 7 应用程序从 karma-jasmine 切换到 jest 时，我收到以下错误：
Validation Error:
Module <rootDir>/node_modules/jest-preset-angular/preprocessor.js in the transform option was not found.
<rootDir> is: C:\newAdminJestTest\jest-angular-example
Configuration Documentation:
https://jestjs.io/docs/configuration.html
我一直在关注这个开关指南：https://blog.skarby.info/jest-with-angular/
如果我从 package.json 中的 jest 对象中删除 transform 属性，测试用例似乎运行良好。但是，使用 transform 属性运行时出现上述错误。
这是我的 package.json ：
"name": "jest-angular-example",
"version": "0.0.0",
"scripts":
"ng": "ng",
"start": "ng serve",
"build": "ng build",
"test": "jest",
"test:watch": "jest --watch",
"test:ci": "jest -ci --runInBand",
"lint": "ng lint",
"e2e": "ng e2e"
,
"private": true,
"dependencies":
"@angular/animations": "~7.2.0",
"@angular/common": "~7.2.0",
"@angular/compiler": "~7.2.0",
"@angular/core": "~7.2.0",
"@angular/forms": "~7.2.0",
"@angular/platform-browser": "~7.2.0",
"@angular/platform-browser-dynamic": "~7.2.0",
"@angular/router": "~7.2.0",
"@types/jest": "^24.0.13",
"core-js": "^2.5.4",
"rxjs": "~6.3.3",
"tslib": "^1.9.0",
"zone.js": "~0.8.26"
,
"devDependencies":
"@angular-builders/jest": "^8.0.1",
"@angular-devkit/build-angular": "~0.13.0",
"@angular/cli": "~7.3.7",
"@angular/compiler-cli": "~7.2.0",
"@angular/language-service": "~7.2.0",
"@types/jsdom": "^12.2.3",
"@types/node": "~8.9.4",
"babel-preset-env": "^1.7.0",
"codelyzer": "~4.5.0",
"jest": "^24.8.0",
"jest-createspyobj": "^1.2.2",
"jest-preset-angular": "^7.1.1",
"protractor": "~5.4.0",
"ts-node": "~7.0.0",
"tslint": "~5.11.0",
"typescript": "~3.2.2"
,
"jest":
"preset": "jest-preset-angular",
"setupFilesAfterEnv": [
"<rootDir>/src/setupJest.ts"
],
"transform":
"^.+\\.(ts|html)$": "<rootDir>/node_modules/jest-preset-angular/preprocessor.js",
"^.+\\.js$": "babel-jest"
这是我的 setupJest.ts：
import 'jest-preset-angular';
import './jestGlobalMocks.ts';
这是 jestGlobalMocks.ts ：
global['CSS'] = null;
const mock = () =>
let storage = ;
return
getItem: key => key in storage ? storage[key] : null,
setItem: (key, value) => storage[key] = value || '',
removeItem: key => delete storage[key],
clear: () => storage = ,
;
;
Object.defineProperty(window, 'localStorage', value: mock());
Object.defineProperty(window, 'sessionStorage', value: mock());
Object.defineProperty(document, 'doctype',
value: '<!DOCTYPE html>'
);
Object.defineProperty(window, 'getComputedStyle',
value: () =>
return
display: 'none',
appearance: ['-webkit-appearance']
;
);
/**
* ISSUE: https://github.com/angular/material2/issues/7101
* Workaround for JSDOM missing transform property
*/
Object.defineProperty(document.body.style, 'transform',
value: () =>
return
enumerable: true,
configurable: true,
;
,
);
我的 tsconfig.spec.json ：
"extends": "../tsconfig.json",
"compilerOptions":
"outDir": "../out-tsc/spec",
"module": "commonjs",
"types": [
"node",
"jest",
"jsdom"
]
,
"files": [
"polyfills.ts"
],
"include": [
"**/*.spec.ts",
"**/*.d.ts"
]
我希望看到以下结果：
PS C:\newAdminJestTest\jest-example-master> npm run test
> jest-example@0.0.0 test C:\newAdminJestTest\jest-example-master
> jest
PASS src/app/store/todolist.effects.spec.ts (16.555s)
PASS src/app/app.component.spec.ts (16.836s)
PASS src/app/store/todolist.reducer.spec.ts
PASS src/app/item-list/item/item.component.spec.ts (18.045s)
PASS src/app/store/todolist.actions.spec.ts
PASS src/app/item-list/item-list.component.spec.ts
PASS src/app/pie-chart/pie-chart.component.spec.ts
PASS src/app/checkbox/checkbox.component.spec.ts
PASS src/app/local-storage.service.spec.ts
PASS src/app/window.service.spec.ts
Test Suites: 10 passed, 10 total
Tests: 68 passed, 68 total
Snapshots: 1 passed, 1 total
Time: 28.776s
Ran all test suites.
如果我从package.json 中的jest 对象中删除transform 属性，我会得到。
我该如何解决这个问题？
【问题讨论】：
【参考方案1】：我通过更新我的 jest.config.json 文件并更改转换属性解决了这个问题，如下所示：
// before
...
"transform":
"^.+\\.(ts|js|html)$": "<rootDir>/node_modules/jest-preset-angular/preprocessor.js"
...
//after
...
"transform":
"^.+\\.(ts|js|html)$": "ts-jest"
...
【讨论】：
【参考方案2】：尝试删除 node_modules 和 package-lock.json 然后运行 npm install 或 yarn
【讨论】：
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