To test one rule explicitly, combine the –no-eslintrc , and –rule options:. If it is not included, should it be? In those cases, you can just create the folder with your plugin locally and commit it to your code repository. For it to work, you still need to install it as a node package though. This time, to create a rule:.

For it to work, you still need to install it as a node package though. You can do that with the following NPM command: Your engineering team has a strong preference about how to set something up, but others might choose a different option. In that case, you must either:. Engineers at Flexport are opinionated about the code we write. Ideally, we want the following:

If you make a fix function which returns multiple fixing objects, those fixing objects must not be overlapped. If the closest ancestor node has multiple scopes then it chooses the innermost scope E.

Working with Rules

Never miss a eslnt from Webiny Blogwhen you sign up for Medium. Start by installing it and the generator: In the preceding example, the error level is assumed to be the first ruless. To find out more, including how to control cookies, see here: Then you can run your new rule in isolation, for example:. Runtime rules are written in the same format as all other rules.

You can access that code path objects with five events related to code paths.


Create custom ESLint rules in 2 minutes – Webiny Blog

This will install the package from the local folder my-eslint-plugin. Essentially, you chstom two files:. The default parser provides the block-scope feature if parserOptions. Ideally, we want the following: They are treated as comments and can be accessed by the methods outlined above.

For others, we can use different libraries that we can port over as well when we port the application.

writing custom eslint rules

The fix function receives a single argument, a fixer object, that you can use to apply a fix. In those cases, you can just create the folder with your plugin locally and commit it to your code repository. Next, cd to a folder where your plugin will live.

Writing Custom Lint Rules for Your Picky Developers

Once you have an instance of SourceCodeyou can use the methods on it to work with the code:. This can then be plugged in to EsLint and it will report the errors for any Javascript code you throw at it.

This method returns an array of all the comments found in the program. The fix function can return the following values:.

Get updates Get updates. But in some cases, you might want to enforce one or more ESLint code rules that are specific to your particular project. On top of that we have the EsLint plugin for VsCode, which looks like this in the editor: Each rule in ESLint has three files named with its identifier for example, no-extra-semi.


The CI-build is configured to fail when EsLint finds an error. This is a great example of a rule that should go in a custom plugin, as every custim will have different styling rules.

writing custom eslint rules

Hacker News new past comments ask show jobs submit. This still works, but is deprecated and will soon break in newer versions of EsLint. Make sure your tests pass! In this post I want to talk about creating project specific custom EsLint rules. You should use a SourceCode object whenever you need to get more information about the code being linted.

Create custom ESLint rules in 2 minutes

You are commenting using your WordPress. When developing in the ESLint core repository, the npm run perf command gives a high-level overview of ESLint running time with all core rules enabled. This is useful for rules that need to check all comments regardless of location.

The quotes rule in this example has one option, “double” the error is the error level.