ryanzim / eslint-config-problems

An eslint config that catches problems in your code, without checking style. For use with prettier.

eslint-config-problems

eslint-config-problems is an ESLint config that doesn't regulate your code style. It only catches actual problems with your code.

It's designed for use with Prettier, the opinionated code formatter; but you could also use this as a solid base config to add stylistic rules on top of.

Contents

• Rules
  • I disagree with rule X; you missed rule Y
• Installation & Usage
  • Just ESLint
  • With eslint-plugin-prettier
• License

Rules

Rules were chosen based on the following criteria:

• No stylistic rules; nothing that Prettier can fix
• Prevent guaranteed runtime errors (i.e. no undefined variables)
• Disallow "evil" things like eval
• Disallow archaic language features like with
• Disallow obvious bad practices like new Number(13)
• Force usage of ES2015+ features supported by Node.js v10+
• Point out places the code could be made shorter. For example:

  if (someCondition) return someValue;
  else {
    // Do something else
  }

  The else block is unneeded, since the if block contains a return statement. eslint-config-problems will point this out to you (or auto-fix with the --fix option).

eslint-config-problems also sets ecmaVersion: 2020 in the parserOptions, so that ESLint can parse modern code (including BigInt) with no additional setup.

I disagree with rule X; you missed rule Y

If you disagree; feel free to open an issue. I'm open to changing rules if you have a good reason.

If I missed a rule that prevents an actual problem or is otherwise in keeping with the general guidelines above, please open an issue as well; I just might add it.

Installation & Usage

eslint-config-problems doesn't set any environments by default, other than the es6 environment. So you'll have to manually set your environment in your ESLint config. Here's a list of environments.

If you're using ES Modules, you will need to set sourceType: module in the parserOptions, like this:

parserOptions:
  sourceType: module

Just ESLint

npm install -D eslint eslint-config-problems

In your eslintrc.yaml:

extends: 'problems'
env:
  # Set your environments here; for example:
  node: true

With eslint-plugin-prettier

npm install -D eslint prettier eslint-config-problems eslint-plugin-prettier

In your eslintrc.yaml:

extends: 'problems'
env:
  # Set your environments here; for example:
  node: true
plugins:
  - prettier
rules:
  - prettier/prettier: error

License

ISC

eslint-config-problems's Issues

Missing node8 subconfig

I installed the new 3.0 version and try to run eslint. It says that it cannot find module eslint-config-problems/node8 when using the node10 subconfig.

The node10.js file references the removed node8 subconfig:

eslint-config-problems/node10.js

Line 3 in 39ecc6a

extends: 'problems/node8',

How should I solve this?

Add checkForEach

https://eslint.org/docs/latest/rules/array-callback-return#checkforeach

Dependency Dashboard

This issue lists Renovate updates and detected dependencies. Read the Dependency Dashboard docs to learn more.

Open

These updates have all been created already. Click a checkbox below to force a retry/rebase of any.

• Update dependency eslint to ~8.57.0
• Update dependency eslint to v9

Detected dependencies

npm

package.json

• doctoc ^2.0.0
• eslint ~8.38.0
• lodash.defaultsdeep ^4.6.0
• prettier ^3.0.0
• eslint ^8.27.0

---

• Check this box to trigger a request for Renovate to run again on this repository

Rule: strict

Hi,

I see that the rule strict is enabled by your config. I find that strange, as writing "use strict" in all my source files when writing a module in 2019 is unnecessary, especially that Module code is always strict mode code.

10.2.1 Strict Mode Code
[...]

• Module code is always strict mode code.

[...]

Shouldn't this rule be opt-in when writing code for the browser instead of opt-out for node.js? I mean, most of the time we use some kind of bundler for browser code which puts the "use strict" there anyway.

Merge renovate bot's updated eslint dependency

Hi!
Please merge the dependency update so that your config would support eslint v6.
Thanks. :)

`async`/`await` support?

I love the idea behind this config, but it's complaining about async / await in my Node 8 code.

Enable logical-assignment-operators?

Should we enable https://eslint.org/docs/latest/rules/logical-assignment-operators on Node 16+?

Logically, if we enable it, we should perhaps also enable https://eslint.org/docs/latest/rules/operator-assignment.

However, this whole thing might be too stylistic for eslint-config-problems.