vue cli4 cannot be configured according to karma, but cli3 can succeed

[changhe-fu]

Version

4.1.2

Reproduction link

https://github.com/heyi-let/vue-cli4_unit_karma

Environment info

System:
OS: macOS Mojave 10.14.5
CPU: (8) x64 Intel(R) Core(TM) i5-8259U CPU @ 2.30GHz
Binaries:
Node: 11.14.0 - ~/.nvm/versions/node/v11.14.0/bin/node
Yarn: Not Found
npm: 6.7.0 - ~/.nvm/versions/node/v11.14.0/bin/npm
Browsers:
Chrome: 81.0.4044.138
Firefox: 71.0
Safari: 12.1.1
npmPackages:
@vue/babel-helper-vue-jsx-merge-props: 1.0.0
@vue/babel-plugin-transform-vue-jsx: 1.1.2
@vue/babel-preset-app: 4.4.1
@vue/babel-preset-jsx: 1.1.2
@vue/babel-sugar-functional-vue: 1.1.2
@vue/babel-sugar-inject-h: 1.1.2
@vue/babel-sugar-v-model: 1.1.2
@vue/babel-sugar-v-on: 1.1.2
@vue/cli-overlay: 4.4.1
@vue/cli-plugin-babel: ^4.4.0 => 4.4.1
@vue/cli-plugin-e2e-cypress: ^4.4.0 => 4.4.1
@vue/cli-plugin-eslint: ^4.4.0 => 4.4.1
@vue/cli-plugin-router: ^4.4.0 => 4.4.1
@vue/cli-plugin-unit-mocha: ^4.4.0 => 4.4.1
@vue/cli-plugin-vuex: ^4.4.0 => 4.4.1
@vue/cli-service: ^4.4.0 => 4.4.1
@vue/cli-shared-utils: 4.4.1
@vue/component-compiler-utils: 3.1.2
@vue/eslint-config-standard: ^5.1.2 => 5.1.2
@vue/preload-webpack-plugin: 1.1.1
@vue/test-utils: ^1.0.3 => 1.0.3
@vue/web-component-wrapper: 1.2.0
eslint-plugin-vue: ^6.2.2 => 6.2.2
vue: ^2.6.11 => 2.6.11
vue-eslint-parser: 7.1.0
vue-hot-reload-api: 2.3.4
vue-loader: 15.9.2
vue-router: ^3.2.0 => 3.2.0
vue-style-loader: 4.1.2
vue-template-compiler: ^2.6.11 => 2.6.11
vue-template-es2015-compiler: 1.9.1
vuex: ^3.4.0 => 3.4.0
npmGlobalPackages:
@vue/cli: 4.1.2

Steps to reproduce

git clone https://github.com/heyi-let/vue-cli4_unit_karma

The test:unit can be executed successfully in the cli-service4 branch.

git checkout cli-service3

npm install

npm run test:unit

But will fail in the cli-service4 branch

git checkout cli-service4

npm install

npm run test:unit

They have different @vue/cli-service versions，everything else is the same.

What is expected?

Can successfully run when using cli4

What is actually happening?

failed

[haoqunjiang]

Thanks for submitting this issue. Due to our limited time, we have to ask you to include a reproduction link to a minimal full reproduction of your problem (for example in a GitHub repository) so we can find what is causing the issue. Thank you for your understanding.

[changhe-fu]

already added

[haoqunjiang]

Please add a NODE_ENV=test prefix to the test command.

---

The reason: dfe3987

Karma can't handle split chunks.

• In @vue/cli-service v3, unless you explicitly set NODE_ENV to production, splitChunks won't be turned on.
• In @vue/cli-service v4, unless you explicitly set NODE_ENV to test, splitChunks will be turned on by default.

---

It is a good practice to always set NODE_ENV to test during unit testing because many of the packages in Node.js ecosystem follows this convention.

Actually, with NODE_ENV=test, you can skip BABEL_ENV=test because it will default to NODE_ENV.

[changhe-fu]

config worked for me.
thank you very much !