 [](https://badge.fury.io/js/webpack-deep-scope-plugin)
npm install deep-scope-analyser
A webpack plugin for deep scope analysis.
It's a project of GSoC 2018 webpack organization.
It's a plugin to improve tree-shaking. It can make webpack eliminate the unused imports related to the unused exports. It solves the issue 6254 for webpack.
Student: @Vincent Mentor: @Tobias
Demo: https://vincentdchan.github.io/webpack-deep-scope-demo/
Install the plugin:
``bash`
$ yarn add webpack-deep-scope-plugin
- Node.js 8 \+
- webpack 4.14.0 \+
Enable the plugin in webpack.config.js:
`javascript
const WebpackDeepScopeAnalysisPlugin = require('webpack-deep-scope-plugin').default;
module.exports = {
...,
plugins: [
...,
new WebpackDeepScopeAnalysisPlugin(),
],
}
`
Notice: the plugin only works for import and export syntax module. If your code are transpiled to module.export and require syntax, the analyzer can't work correctly.
The plugin will analyze the scope and determine if the variables should be imported automatically.
As you know, it's difficult for ECMAScript to analyze the side effects. Hence, PURE annotation is introduced, which is from Uglify:
> A function call is marked as "pure" if a comment annotation /\@\_\_PURE\_\_\/ or /\#\_\_PURE\_\_\/ immediately precedes the call. For example: /\@\_\_PURE\_\_\/foo();
- Upgrade tslint for security issue
- Fix: #12 : Add README to npm
- rename package webpack-deep-scope-analysis to deep-scope-analyser, which is published as a new npm package. It's aimed to be a standalone analyser.
- Fix #7: import * from 'xxx' syntax
- Fix #5
- Improve performance and code quality
- Introduce VirtualScope to simulate module variable
- Fix #4
- Publish
Use lerna to build and test:`sh`
$ lerna run build
$ lerna run tslint
$ lerna run test
Now the src/` includes a Typescript version of escope,
because the plugin needs some internal changes of the escope manager. So I didn't import the
escope directly.
When the plugin is nearly finished, I will make some PRs to the original escope repo.