Hi! I'm really excited that you are interested in contributing to Vue.js. Before submitting your contribution, please make sure to take a moment and read through the following guidelines:
- The `master` branch is just a snapshot of the latest stable release. All development should be done in dedicated branches. **Do not submit PRs against the `master` branch.**
- If you are resolving a special issue, add `(fix #xxxx[,#xxxx])` (#xxxx is the issue id) in your PR title for a better release log, e.g. `update entities encoding/decoding (fix #3899)`.
You will need [Node.js](http://nodejs.org) **version 6+** and [Java Runtime Environment](http://www.oracle.com/technetwork/java/javase/downloads/index.html) (for running Selenium server during e2e tests).
Commit messages should follow the [commit message convention](./COMMIT_CONVENTION.md) so that changelogs can be automatically generated. Commit messages will be automatically validated upon commit. If you are not familiar with the commit message convention, you can use `npm run commit` instead of `git commit`, which provides an interactive CLI for generating proper commit messages.
The default test script will do the following: lint with ESLint -> type check with Flow -> unit tests with coverage -> e2e tests. **Please make sure to have this pass successfully before submitting a PR.** Although the same tests will be run against your PR on the CI server, it is better to have it working locally.
- **`scripts`**: contains build-related scripts and configuration files. Usually, you don't need to touch them. However, it would be helpful to familiarize yourself with the following files:
-`scripts/config.js`: contains the build configurations for all files found in `dist/`. Check this file if you want to find out the entry source file for a dist file.
- **`dist`**: contains built files for distribution. Note this directory is only updated when a release happens; they do not reflect the latest changes in development branches.
- **`flow`**: contains type declarations for [Flow](https://flowtype.org/). These declarations are loaded **globally** and you will see them used in type annotations in normal source code.
- **`packages`**: contains `vue-server-renderer` and `vue-template-compiler`, which are distributed as separate NPM packages. They are automatically generated from the source code and always have the same version with the main `vue` package.
- **`test`**: contains all tests. The unit tests are written with [Jasmine](http://jasmine.github.io/2.3/introduction.html) and run with [Karma](http://karma-runner.github.io/0.13/index.html). The e2e tests are written for and run with [Nightwatch.js](http://nightwatchjs.org/).
The compiler consists of a parser (converts template strings to element ASTs), an optimizer (detects static trees for vdom render optimization), and a code generator (generate render function code from element ASTs). Note that codegen directly generates code strings from the element AST - it's done this way for smaller code size because the compiler is shipped to the browser in the standalone build.
The Vue 2.0 core is platform-agnostic. That is, code inside `core` is able to be run in any JavaScript environment, be it the browser, Node.js, or an embedded JavaScript runtime in native applications.
Each platform module contains three parts: `compiler`, `runtime` and `server`, corresponding to the three directories above. Each part contains platform-specific modules/utilities which are imported and injected to the core counterparts in platform-specific entry files. For example, the code implementing the logic behind `v-bind:class` is in `platforms/web/runtime/modules/class.js` - which is imported in `entries/web-runtime.js` and used to create the browser-specific vdom patching function.
Funds donated via Patreon go directly to support Evan You's full-time work on Vue.js. Funds donated via OpenCollective are managed with transparent expenses and will be used for compensating work and expenses for core team members or sponsoring community events. Your name/logo will receive proper recognition and exposure by donating on either platform.
