如何在Jest测试中使用webpack的html-loader导入? [英] How can I use my webpack's html-loader imports in Jest tests?

问题描述

我刚开始使用Jest测试框架，虽然直接的单元测试可以正常工作，但在测试其模块中的任何组件(通过babel + webpack的ES模块)中需要HTML文件的组件时，我遇到了很多问题.

I am just getting started with the Jest test framework and while straight up unit tests work fine, I am having massive issues testing any component that in its module (ES module via babel+webpack) requires a HTML file.

这里是一个例子:

import './errorHandler.scss';
import template from './errorHandler.tmpl';

class ErrorHandler {
    ...

我正在加载在Jest的package.json配置中设置的特定于组件的SCSS文件，以返回一个空对象，但是当Jest尝试运行import template from './errorHandler.tmpl';行时，它会中断说:

I am loading the component specific SCSS file which I have set in Jest's package.json config to return an empty object but when Jest tries to run the import template from './errorHandler.tmpl'; line it breaks saying:

/Users/jannis/Sites/my-app/src/scripts/errorHandler/errorHandler.tmpl.html:1
({"Object.<anonymous>":function(module,exports,require,__dirname,__filename,global,jest){<div class="overlay--top">
                                                                                         ^
    SyntaxError: Unexpected token <

        at transformAndBuildScript (node_modules/jest-runtime/build/transform.js:284:10)

package.json中的我的Jest配置如下:

My Jest config from package.json is as follows:

"jest": {
    "setupTestFrameworkScriptFile": "<rootDir>/test/setupFile.js",
    "moduleDirectories": ["node_modules"],
    "moduleFileExtensions": ["js", "json", "html", "scss"],
    "moduleNameMapper": {
        "^.+\\.scss$": "<rootDir>/test/styleMock.js"
    }
}

webpack html-loader似乎无法与Jest一起正常使用，但是我找不到任何解决方法.

It seems that the webpack html-loader is not working correctly with Jest but I can't find any solution on how to fix this.

有人知道我可以如何在测试中使用这些html-loader import作品吗?他们加载了我的lodash模板标记，我宁愿在我的.js文件中有时不包含大量HTML块，因此我可以省略import template from x部分.

Does anyone know how I can make these html-loader imports work in my tests? They load my lodash template markup and i'd rather not have these at times massive HTML chunks in my .js file so i can omit the import template from x part.

PS:这不是一个React项目，只是普通的webpack，babel，es6.

PS: This is not a react project, just plain webpack, babel, es6.

推荐答案

我最近遇到了这个特定问题，并创建了自己的

I encountered this specific problem recently and creating your own transform preprocesser will solve it. This was my set up:

package.json

"jest": {
    "moduleFileExtensions": [
      "js",
      "html"
    ],
    "transform": {
      "^.+\\.js$": "babel-jest",
      "^.+\\.html$": "<rootDir>/test/utils/htmlLoader.js"
    }
 }

注意:通常默认情况下会包含babel-jest，但是如果您指定自定义转换预处理器，则您似乎必须手动将其包括在内.

NOTE: babel-jest is normally included by default, but if you specify a custom transform preprocessor, you seem to have to include it manually.

test/utils/htmlLoader.js:

const htmlLoader = require('html-loader');

module.exports = {
    process(src, filename, config, options) {
        return htmlLoader(src);
    }
}

这篇关于如何在Jest测试中使用webpack的html-loader导入?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！