Javascript Svelte 3:单元测试时无法导入模块
我正试着用笑话测试一个苗条的组件。此组件在浏览器中工作正常,但导入模块时单元测试失败 例如,在运行Jest时,Javascript Svelte 3:单元测试时无法导入模块,javascript,unit-testing,jestjs,svelte,svelte-3,Javascript,Unit Testing,Jestjs,Svelte,Svelte 3,我正试着用笑话测试一个苗条的组件。此组件在浏览器中工作正常,但导入模块时单元测试失败 例如,在运行Jest时,从“uuid”导入uuid编译为const{default:uuid}=require(“uuid”),调用uuid.v4()会导致TypeError:无法读取未定义的属性“v4”。当我使用import*作为来自“uuid”的uuid或const uuid=require('uuid')时,Jest单元测试通过,但在浏览器中不起作用 我如何处理这个问题?任何信息都会大有帮助。多谢各位 p
从“uuid”导入uuid
编译为const{default:uuid}=require(“uuid”)代码>,调用uuid.v4()
会导致TypeError:无法读取未定义的属性“v4”
。当我使用import*作为来自“uuid”的uuid
或const uuid=require('uuid')
时,Jest单元测试通过,但在浏览器中不起作用
我如何处理这个问题?任何信息都会大有帮助。多谢各位
package.json:
{
"name": "svelte-app",
"version": "1.0.0",
"scripts": {
"build": "rollup -c",
"dev": "rollup -c -w",
"start": "firebase serve --only hosting"
},
"devDependencies": {
"@rollup/plugin-json": "^4.0.0",
"@testing-library/jest-dom": "^5.1.1",
"@testing-library/svelte": "^1.11.0",
"bulma": "^0.8.0",
"eslint": "^6.7.0",
"eslint-config-standard": "^14.1.0",
"eslint-plugin-import": "^2.18.2",
"eslint-plugin-jest": "^23.0.4",
"eslint-plugin-node": "^10.0.0",
"eslint-plugin-promise": "^4.2.1",
"eslint-plugin-standard": "^4.0.1",
"eslint-plugin-svelte3": "^2.7.3",
"jest-transform-svelte": "^2.1.1",
"node-sass": "^4.13.1",
"rollup": "^1.12.0",
"rollup-jest": "0.0.2",
"rollup-plugin-commonjs": "^10.0.0",
"rollup-plugin-livereload": "^1.0.0",
"rollup-plugin-node-builtins": "^2.1.2",
"rollup-plugin-node-globals": "^1.4.0",
"rollup-plugin-node-resolve": "^5.2.0",
"rollup-plugin-svelte": "^5.0.3",
"rollup-plugin-terser": "^5.1.2",
"sirv-cli": "^0.4.5",
"svelma": "^0.3.2",
"svelte": "^3.18.2",
"svelte-preprocess": "^3.4.0"
},
"dependencies": {
"firebase": "^7.8.2"
},
"private": true
}
rollup.config.js
import json from '@rollup/plugin-json'
import commonjs from 'rollup-plugin-commonjs'
import builtins from 'rollup-plugin-node-builtins'
import globals from 'rollup-plugin-node-globals'
import livereload from 'rollup-plugin-livereload'
import resolve from 'rollup-plugin-node-resolve'
import svelte from 'rollup-plugin-svelte'
import { terser } from 'rollup-plugin-terser'
import preprocess from 'svelte-preprocess'
const production = !process.env.ROLLUP_WATCH
export default {
input: 'src/main.js',
output: {
sourcemap: true,
format: 'iife',
name: 'app',
file: 'public/build/bundle.js',
},
plugins: [
// https://github.com/rollup/plugins/tree/master/packages/json
json(),
svelte({
// enable run-time checks when not in production
dev: !production,
// we'll extract any component CSS out into
// a separate file — better for performance
css: css => {
css.write('public/build/bundle.css')
},
preprocess: preprocess(),
}),
// If you have external dependencies installed from
// npm, you'll most likely need these plugins. In
// some cases you'll need additional configuration —
// consult the documentation for details:
// https://github.com/rollup/rollup-plugin-commonjs
resolve({
browser: true,
dedupe: importee => importee === 'svelte' || importee.startsWith('svelte/'),
}),
commonjs(),
globals(),
builtins(),
// In dev mode, call `npm run start` once
// the bundle has been generated
!production && serve(),
// Watch the `public` directory and refresh the
// browser on changes when not in production
!production && livereload('public'),
// If we're building for production (npm run build
// instead of npm run dev), minify
production && terser(),
],
watch: {
clearScreen: false,
},
}
function serve () {
let started = false
return {
writeBundle () {
if (!started) {
started = true
require('child_process').spawn('npm', ['run', 'start'], {
stdio: ['ignore', 'inherit', 'inherit'],
shell: true,
})
}
},
}
}
const sveltePreprocess = require('svelte-preprocess')
module.exports = {
displayName: { name: 'web', color: 'magentaBright' },
moduleFileExtensions: [
'js',
'json',
'svelte',
],
preset: 'rollup-jest',
transform: {
'\\.js$': 'rollup-jest',
'\\.svelte$': ['jest-transform-svelte', { preprocess: sveltePreprocess(), debug: true }],
},
setupFilesAfterEnv: ['@testing-library/jest-dom/extend-expect'],
}
module.exports = {
preset: 'jest-puppeteer', //ignore the preset part, I used for puppeteer
transform: {
'^.+\\.js?$': require.resolve('babel-jest'),
"^.+\\.ts?$": "ts-jest" // this part is only required if you have typescript project
}
};
const svelteJestPreprocessor = require('./svelteJestPreprocessor')
const sveltePreprocess = require('svelte-preprocess')
module.exports = {
moduleFileExtensions: [
'js',
'json',
'svelte',
],
preset: 'rollup-jest',
transform: {
'\\.js$': 'rollup-jest',
'\\.svelte$': ['jest-transform-svelte', {
preprocess: [
svelteJestPreprocessor(),
sveltePreprocess(),
],
}],
},
setupFilesAfterEnv: ['@testing-library/jest-dom/extend-expect'],
}
jest.config.js
import json from '@rollup/plugin-json'
import commonjs from 'rollup-plugin-commonjs'
import builtins from 'rollup-plugin-node-builtins'
import globals from 'rollup-plugin-node-globals'
import livereload from 'rollup-plugin-livereload'
import resolve from 'rollup-plugin-node-resolve'
import svelte from 'rollup-plugin-svelte'
import { terser } from 'rollup-plugin-terser'
import preprocess from 'svelte-preprocess'
const production = !process.env.ROLLUP_WATCH
export default {
input: 'src/main.js',
output: {
sourcemap: true,
format: 'iife',
name: 'app',
file: 'public/build/bundle.js',
},
plugins: [
// https://github.com/rollup/plugins/tree/master/packages/json
json(),
svelte({
// enable run-time checks when not in production
dev: !production,
// we'll extract any component CSS out into
// a separate file — better for performance
css: css => {
css.write('public/build/bundle.css')
},
preprocess: preprocess(),
}),
// If you have external dependencies installed from
// npm, you'll most likely need these plugins. In
// some cases you'll need additional configuration —
// consult the documentation for details:
// https://github.com/rollup/rollup-plugin-commonjs
resolve({
browser: true,
dedupe: importee => importee === 'svelte' || importee.startsWith('svelte/'),
}),
commonjs(),
globals(),
builtins(),
// In dev mode, call `npm run start` once
// the bundle has been generated
!production && serve(),
// Watch the `public` directory and refresh the
// browser on changes when not in production
!production && livereload('public'),
// If we're building for production (npm run build
// instead of npm run dev), minify
production && terser(),
],
watch: {
clearScreen: false,
},
}
function serve () {
let started = false
return {
writeBundle () {
if (!started) {
started = true
require('child_process').spawn('npm', ['run', 'start'], {
stdio: ['ignore', 'inherit', 'inherit'],
shell: true,
})
}
},
}
}
const sveltePreprocess = require('svelte-preprocess')
module.exports = {
displayName: { name: 'web', color: 'magentaBright' },
moduleFileExtensions: [
'js',
'json',
'svelte',
],
preset: 'rollup-jest',
transform: {
'\\.js$': 'rollup-jest',
'\\.svelte$': ['jest-transform-svelte', { preprocess: sveltePreprocess(), debug: true }],
},
setupFilesAfterEnv: ['@testing-library/jest-dom/extend-expect'],
}
module.exports = {
preset: 'jest-puppeteer', //ignore the preset part, I used for puppeteer
transform: {
'^.+\\.js?$': require.resolve('babel-jest'),
"^.+\\.ts?$": "ts-jest" // this part is only required if you have typescript project
}
};
const svelteJestPreprocessor = require('./svelteJestPreprocessor')
const sveltePreprocess = require('svelte-preprocess')
module.exports = {
moduleFileExtensions: [
'js',
'json',
'svelte',
],
preset: 'rollup-jest',
transform: {
'\\.js$': 'rollup-jest',
'\\.svelte$': ['jest-transform-svelte', {
preprocess: [
svelteJestPreprocessor(),
sveltePreprocess(),
],
}],
},
setupFilesAfterEnv: ['@testing-library/jest-dom/extend-expect'],
}
我一直面临着同样的问题,通过在测试文件中模拟模块并给它一个默认键,我找到了解决办法
jest.mock('uuid', () => ({
default: {
v4: jest.fn(),
},
}))
另一种似乎有效的方法是在组件文件中分解导入
import { v4 as uuidv4 } from 'uuid'
这对我很有效。
问题似乎是jest在运行时构建代码时无法解析uuid。
这很明显,因为默认情况下,会忽略节点模块包
我遇到了类似的问题并解决了它。该方法是通过配置通知JEST,它还必须包括节点\单元模块包。在我的项目中,我使用了汇总插件babel。
这是babel插件配置
...
...
babel({
extensions: [ '.js', '.mjs', '.html', '.svelte' ],
runtimeHelpers: true,
exclude: [ 'node_modules/@babel/**', 'node_modules/core-js/**' ],
presets: [
[
'@babel/preset-env',
{
targets: '> 0.25%, not dead',
useBuiltIns: 'usage',
corejs: 3
}
]
]
})
我还添加了babel jest,用于转换jest.config.js
import json from '@rollup/plugin-json'
import commonjs from 'rollup-plugin-commonjs'
import builtins from 'rollup-plugin-node-builtins'
import globals from 'rollup-plugin-node-globals'
import livereload from 'rollup-plugin-livereload'
import resolve from 'rollup-plugin-node-resolve'
import svelte from 'rollup-plugin-svelte'
import { terser } from 'rollup-plugin-terser'
import preprocess from 'svelte-preprocess'
const production = !process.env.ROLLUP_WATCH
export default {
input: 'src/main.js',
output: {
sourcemap: true,
format: 'iife',
name: 'app',
file: 'public/build/bundle.js',
},
plugins: [
// https://github.com/rollup/plugins/tree/master/packages/json
json(),
svelte({
// enable run-time checks when not in production
dev: !production,
// we'll extract any component CSS out into
// a separate file — better for performance
css: css => {
css.write('public/build/bundle.css')
},
preprocess: preprocess(),
}),
// If you have external dependencies installed from
// npm, you'll most likely need these plugins. In
// some cases you'll need additional configuration —
// consult the documentation for details:
// https://github.com/rollup/rollup-plugin-commonjs
resolve({
browser: true,
dedupe: importee => importee === 'svelte' || importee.startsWith('svelte/'),
}),
commonjs(),
globals(),
builtins(),
// In dev mode, call `npm run start` once
// the bundle has been generated
!production && serve(),
// Watch the `public` directory and refresh the
// browser on changes when not in production
!production && livereload('public'),
// If we're building for production (npm run build
// instead of npm run dev), minify
production && terser(),
],
watch: {
clearScreen: false,
},
}
function serve () {
let started = false
return {
writeBundle () {
if (!started) {
started = true
require('child_process').spawn('npm', ['run', 'start'], {
stdio: ['ignore', 'inherit', 'inherit'],
shell: true,
})
}
},
}
}
const sveltePreprocess = require('svelte-preprocess')
module.exports = {
displayName: { name: 'web', color: 'magentaBright' },
moduleFileExtensions: [
'js',
'json',
'svelte',
],
preset: 'rollup-jest',
transform: {
'\\.js$': 'rollup-jest',
'\\.svelte$': ['jest-transform-svelte', { preprocess: sveltePreprocess(), debug: true }],
},
setupFilesAfterEnv: ['@testing-library/jest-dom/extend-expect'],
}
module.exports = {
preset: 'jest-puppeteer', //ignore the preset part, I used for puppeteer
transform: {
'^.+\\.js?$': require.resolve('babel-jest'),
"^.+\\.ts?$": "ts-jest" // this part is only required if you have typescript project
}
};
const svelteJestPreprocessor = require('./svelteJestPreprocessor')
const sveltePreprocess = require('svelte-preprocess')
module.exports = {
moduleFileExtensions: [
'js',
'json',
'svelte',
],
preset: 'rollup-jest',
transform: {
'\\.js$': 'rollup-jest',
'\\.svelte$': ['jest-transform-svelte', {
preprocess: [
svelteJestPreprocessor(),
sveltePreprocess(),
],
}],
},
setupFilesAfterEnv: ['@testing-library/jest-dom/extend-expect'],
}
在使用之前,不要忘记安装babel jest、rollup插件babel等软件包。自我回答:
最后,我编写了一个小预处理器,将从'foo'导入foo
->导入*替换为'foo'中的foo
SvelteTestPreprocessor.js
const svelteJestPreprocessor = () => ({
// replace `import foo from 'foo'` -> `import * as foo from 'foo'`
script: ({ content }) => ({
// process each line of code
code: content.split('\n').map(line =>
// pass: no import, import with {}, import svelte component
(!line.match(/\s*import/)) || (line.match(/{/)) || (line.match(/\.svelte/)) ? line
: line.replace(/import/, 'import * as'),
).join('\n'),
}),
})
module.exports = svelteJestPreprocessor
jest.config.js
import json from '@rollup/plugin-json'
import commonjs from 'rollup-plugin-commonjs'
import builtins from 'rollup-plugin-node-builtins'
import globals from 'rollup-plugin-node-globals'
import livereload from 'rollup-plugin-livereload'
import resolve from 'rollup-plugin-node-resolve'
import svelte from 'rollup-plugin-svelte'
import { terser } from 'rollup-plugin-terser'
import preprocess from 'svelte-preprocess'
const production = !process.env.ROLLUP_WATCH
export default {
input: 'src/main.js',
output: {
sourcemap: true,
format: 'iife',
name: 'app',
file: 'public/build/bundle.js',
},
plugins: [
// https://github.com/rollup/plugins/tree/master/packages/json
json(),
svelte({
// enable run-time checks when not in production
dev: !production,
// we'll extract any component CSS out into
// a separate file — better for performance
css: css => {
css.write('public/build/bundle.css')
},
preprocess: preprocess(),
}),
// If you have external dependencies installed from
// npm, you'll most likely need these plugins. In
// some cases you'll need additional configuration —
// consult the documentation for details:
// https://github.com/rollup/rollup-plugin-commonjs
resolve({
browser: true,
dedupe: importee => importee === 'svelte' || importee.startsWith('svelte/'),
}),
commonjs(),
globals(),
builtins(),
// In dev mode, call `npm run start` once
// the bundle has been generated
!production && serve(),
// Watch the `public` directory and refresh the
// browser on changes when not in production
!production && livereload('public'),
// If we're building for production (npm run build
// instead of npm run dev), minify
production && terser(),
],
watch: {
clearScreen: false,
},
}
function serve () {
let started = false
return {
writeBundle () {
if (!started) {
started = true
require('child_process').spawn('npm', ['run', 'start'], {
stdio: ['ignore', 'inherit', 'inherit'],
shell: true,
})
}
},
}
}
const sveltePreprocess = require('svelte-preprocess')
module.exports = {
displayName: { name: 'web', color: 'magentaBright' },
moduleFileExtensions: [
'js',
'json',
'svelte',
],
preset: 'rollup-jest',
transform: {
'\\.js$': 'rollup-jest',
'\\.svelte$': ['jest-transform-svelte', { preprocess: sveltePreprocess(), debug: true }],
},
setupFilesAfterEnv: ['@testing-library/jest-dom/extend-expect'],
}
module.exports = {
preset: 'jest-puppeteer', //ignore the preset part, I used for puppeteer
transform: {
'^.+\\.js?$': require.resolve('babel-jest'),
"^.+\\.ts?$": "ts-jest" // this part is only required if you have typescript project
}
};
const svelteJestPreprocessor = require('./svelteJestPreprocessor')
const sveltePreprocess = require('svelte-preprocess')
module.exports = {
moduleFileExtensions: [
'js',
'json',
'svelte',
],
preset: 'rollup-jest',
transform: {
'\\.js$': 'rollup-jest',
'\\.svelte$': ['jest-transform-svelte', {
preprocess: [
svelteJestPreprocessor(),
sveltePreprocess(),
],
}],
},
setupFilesAfterEnv: ['@testing-library/jest-dom/extend-expect'],
}
这是一个不需要的解决方法,但它目前仍然有效。我也遇到了同样的问题。我还没有找到解决问题的办法,你的解决办法对我来说不管用,但我真的很高兴你花时间解决这个问题。非常感谢。我真的很感激你花时间给我一个详细的解释。我现在不想添加更多的编译器,但是你的方法对于已经在使用Babel的人来说真的很有用。也许我将来不得不接受你的方式。谢谢大家!@astanet如果你觉得这个答案有帮助,接受并投票表决,这样面对类似问题的人就会受益。