Jest 无法解析路径映射并抛出未找到模块错误

Question

我有 tsconfig.json 文件，我在其中映射了所有路径，例如

{
  "compilerOptions": {
    "lib": ["es2015", "dom"],
    "target": "es2015",
    "baseUrl": ".",
    "types": ["reflect-metadata", "jest", "node", "@types/jest"],
    "typeRoots": ["./types", "./node_modules/@types"],
    "esModuleInterop": true,
    "experimentalDecorators": true,
    "emitDecoratorMetadata": true,
    "paths": {
      "@utils/*": ["./utils/*"],
      "@helpers/*": ["./ui/helpers/*"],
      "@domElements/*": ["./core/dom/*"],
      "@networking/*": ["./networking/*"],
      "@components/*": ["./ui/components/*"],
      "@decorators/*": ["./core/decorators/*"],
      "@eventFunctions/*": ["./ui/event functions/*"]
    }
  }
}

我有一个名为 form.ts 的文件，其中有以下代码。

import { component } from '@decorators/component';
import { event } from '@decorators/events';
import { DOMElements } from '@domElements/domElements';
import { submitForm } from '@eventFunctions/formSubmit';

@component
export class FormComponent {
  @event('submit', submitForm)
  getForm(): HTMLDivElement {
    return DOMElements.getForm();
  }
}

编译 typescript 时一切正常，但是当我为此 class 运行测试时，例如->

import { FormComponent } from '../../ui/components/form';

describe('Form class test', () => {
  test('It should have a method called getForm', () => {
    expect(new FormComponent().getForm).toBeInstanceOf(Function);
  });
});

它失败并出现错误找不到模块 '@decorators/component' from 'ui/components/form.ts' at Resolver._throwModNotFoundError (node_modules/jest-resolve/build/resolver.js:491:11) 在 Object。 (ui/components/form.ts:1:1)

我知道这是因为 tsconfig.json 中的路径映射，它只适用于代码的编译，看起来 jest 无法解析我的 form.ts 文件中的这些路径映射，顺便说一句，它是原始 typescript 代码，没有库或框架，那么有什么办法可以解决这个问题吗？ 不丢弃所有这些路径映射并恢复为长导入？

Answer 1

我使用TS-Jest插件添加此支持，然后路径在您的 tsconfig.json 文件中。

const tsconfig = require('./tsconfig.json');
const moduleNameMapper = require('tsconfig-paths-jest')(tsconfig); // This adds the support

module.exports = {
    moduleNameMapper,
    preset: 'ts-jest',
    testEnvironment: 'node',

    rootDir: './',
...
};

然后在您的 tsconfig.json 中定义的路径将在测试中起作用。

{
    "compilerOptions": {
        "module": "commonjs",
        ...
        "paths": {
            "@LIBRARY/*": [
                "./src/library/*"
            ],
            "@TEST_LIBRARY/*": [
                "./test/library/*"
            ],
            "@APP/*": [
                "./src/*"
            ]
        }

    }