# Developer Guide
Contributing is welcome.
# 🐛 Bug reporting
If you think you’ve found a bug in ESLint, please create a new issue (opens new window) or a pull request on GitHub.
Please include as much detail as possible to help us properly address your issue. If we need to triage issues and constantly ask people for more detail, that’s time taken away from actually fixing issues. Help us be as efficient as possible by including a lot of detail in your issues.
# ✨ Proposing a new rule or a rule change
In order to add a new rule or a rule change, you should:
- Create issue on GitHub with description of proposed rule
- Generate a new rule using the
npm run new -- [rule-name]command
- Write test scenarios & implement logic
- Describe the rule in the generated
- Make sure all tests are passing
npm run lintand fix any errors
npm run updatein order to update readme and recommended configuration
- Create PR and link created issue in description
We're more than happy to see potential contributions, so don't hesitate. If you have any suggestions, ideas or problems feel free to add new issue (opens new window), but first please make sure your question does not repeat previous ones.
# 🔥 Working with rules
Before you start writing new rule, please read the official ESLint guide (opens new window).
Next, in order to get an idea how does the AST of the code that you want to check looks like, use the astexplorer.net (opens new window). The astexplorer.net (opens new window) is a great tool to inspect ASTs, also Vue templates are supported.
After opening astexplorer.net (opens new window), select
Vue as the syntax and
vue-eslint-parser as the parser.
vue-eslint-parser, that generates enhanced AST with nodes that represent specific parts of the template syntax, as well as what's inside the
To know more about certain nodes in produced ASTs, go here:
vue-eslint-parser provides few useful parser services, to help traverse the produced AST and access tokens of the template:
Check out an example rule (opens new window) to get a better understanding of how these work.
Please be aware that regarding what kind of code examples you'll write in tests, you'll have to accordingly setup the parser in
RuleTester (you can do it on per test case basis though). See an example here (opens new window)
If you'll stuck, remember there are plenty of rules you can learn from already, and if you can't find the right solution - don't hesitate to reach out in issues. We're happy to help!
# ✅ JSDoc type checking with TypeScript
We have type checking enabled via TypeScript and JSDoc.
The command to perform type checking is:
npm run tsc
This is just to help you write the rules, not to do strict type checking. If you find it difficult to resolve type checking warnings, feel free to suppress warnings using the
// @ts-nocheck and
// @ts-ignore comment.