eslint-plugin-rxjs-x

This ESLint plugin is intended to prevent issues with RxJS.

Most of these rules require TypeScript typed linting and are indicated as such below.

Installation Guide (Flat Configuration)

See typescript-eslint's Getting Started for a full ESLint setup guide.

1. Install eslint-plugin-rxjs-x using your preferred package manager.

2. Enable typed linting.

   • See Linting with Type Information for more information.

3. Import this plugin into your config. Add the rxjsX.configs.recommended shared config to your configuration like so:

   // @ts-check
   import { defineConfig } from 'eslint/config';
   import tseslint from 'typescript-eslint';
   + import rxjsX from 'eslint-plugin-rxjs-x';
   
   export default defineConfig({
       extends: [
           tseslint.configs.recommended,
   +       rxjsX.configs.recommended,
       ],
       languageOptions: {
           parserOptions: {
               projectService: true,
           },
       },
   });

Additionally, consider if the rxjsX.configs.strict shared config is right for your project.

Legacy Migration Guide from eslint-plugin-rxjs

[!TIP] A complete description of all changes from eslint-plugin-rxjs are documented in the CHANGELOG file.

This project started as a fork of eslint-plugin-rxjs but is still compatible with the eslintrc configuration format.

[!WARNING] eslintrc compatibility will be removed in v1. Users are highly encouraged to upgrade to ESLint's flat configuration format. See: [https://eslint.org/docs/latest/use/configure/migration-guide]

1. Install eslint-plugin-rxjs-x using your preferred package manager.

2. If you previously used the plugin:rxjs/recommended shared config, replace it with plugin:rxjs-x/recommended-legacy:

   "extends": [
       "plugin:@typescript-eslint/recommended",
   -   "plugin:rxjs/recommended",
   +   "plugin:rxjs-x/recommended-legacy",
   ],

3. If you previously did not use a shared config, then replace the rxjs plugin to your plugins block:

   "plugins": [
       "@typescript-eslint",
   -   "rxjs",
   +   "rxjs-x",
   ],

   • Note: this is unnecessary if you are using the recommended-legacy shared config.

4. In your rules blocks, replace the namespace rxjs with rxjs-x for all rules:

   "rules": {
   -   "rxjs/no-subject-value": "error",
   +   "rxjs-x/no-subject-value": "error",
   },

   • Note: if your project has inline comments (e.g. eslint-disable-next-line) referencing rxjs rules, you must update the namespace there too.

5. If you previously used rxjs/no-ignored-observable, consider replacing it with rxjs-x/no-floating-observables. no-ignored-observable will be removed in v1.

   -   'rxjs/no-ignored-observable': 'error',
   +   'rxjs-x/no-floating-observables': 'error',

Configs

| | Name | | :- | :------------ | | ✅ | recommended | | 🔒 | strict |

Rules

The package includes the following rules.

💼 Configurations enabled in.
✅ Set in the recommended configuration.
🔒 Set in the strict configuration.
🔧 Automatically fixable by the --fix CLI option.
💡 Manually fixable by editor suggestions.
💭 Requires type information.
❌ Deprecated.

| Name                            | Description | 💼 | 🔧 | 💡 | 💭 | ❌ | | :------------------------------------------------------------------------------- | :-------------------------------------------------------------------------------------------------------- | :--- | :- | :- | :- | :- | | ban-observables | Disallow banned observable creators. | | | | | | | ban-operators | Disallow banned operators. | | | | 💭 | | | finnish | Enforce Finnish notation. | | | | 💭 | | | just | Require the use of just instead of of. | | 🔧 | | | | | macro | Require the use of the RxJS Tools Babel macro. | | 🔧 | | | ❌ | | no-async-subscribe | Disallow passing async functions to subscribe. | ✅ 🔒 | | | 💭 | | | no-compat | Disallow the rxjs-compat package. | | | | | ❌ | | no-connectable | Disallow operators that return connectable observables. | | | | 💭 | | | no-create | Disallow the static Observable.create and Subject.create functions. | ✅ 🔒 | | | 💭 | | | no-cyclic-action | Disallow cyclic actions in effects and epics. | | | | 💭 | | | no-explicit-generics | Disallow unnecessary explicit generic type arguments. | | | | 💭 | | | no-exposed-subjects | Disallow public and protected subjects. | 🔒 | | | 💭 | | | no-finnish | Disallow Finnish notation. | | | | 💭 | | | no-floating-observables | Require Observables to be handled appropriately. | 🔒 | | | 💭 | | | no-ignored-default-value | Disallow using firstValueFrom, lastValueFrom, first, and last without specifying a default value. | 🔒 | | | 💭 | | | no-ignored-error | Disallow calling subscribe without specifying an error handler. | 🔒 | | | 💭 | | | no-ignored-notifier | Disallow observables not composed from the repeatWhen or retryWhen notifier. | ✅ 🔒 | | | 💭 | | | no-ignored-observable | Disallow ignoring of observables returned by functions. | | | | | ❌ | | no-ignored-replay-buffer | Disallow using ReplaySubject, publishReplay or shareReplay without specifying the buffer size. | ✅ 🔒 | | | | | | no-ignored-subscribe | Disallow calling subscribe without specifying arguments. | | | | 💭 | | | no-ignored-subscription | Disallow ignoring the subscription returned by subscribe. | | | | 💭 | | | no-ignored-takewhile-value | Disallow ignoring the value within takeWhile. | ✅ 🔒 | | | | | | no-implicit-any-catch | Disallow implicit any error parameters in catchError, subscribe, and tap. | ✅ 🔒 | 🔧 | 💡 | 💭 | | | no-index | Disallow importing index modules. | ✅ 🔒 | | | | | | no-internal | Disallow importing internal modules. | ✅ 🔒 | 🔧 | 💡 | | | | no-misused-observables | Disallow Observables in places not designed to handle them. | 🔒 | | | 💭 | | | no-nested-subscribe | Disallow calling subscribe within a subscribe callback. | ✅ 🔒 | | | 💭 | | | no-redundant-notify | Disallow sending redundant notifications from completed or errored observables. | ✅ 🔒 | | | 💭 | | | no-sharereplay | Disallow unsafe shareReplay usage. | ✅ 🔒 | | | | | | no-sharereplay-before-takeuntil | Disallow using shareReplay({ refCount: false }) before takeUntil. | 🔒 | | | | | | no-subclass | Disallow subclassing RxJS classes. | 🔒 | | | 💭 | | | no-subject-unsubscribe | Disallow calling the unsubscribe method of subjects. | ✅ 🔒 | | | 💭 | | | no-subject-value | Disallow accessing the value property of a BehaviorSubject instance. | | | | 💭 | | | no-subscribe-handlers | Disallow passing handlers to subscribe. | | | | 💭 | | | no-subscribe-in-pipe | Disallow calling of subscribe within any RxJS operator inside a pipe. | ✅ 🔒 | | | 💭 | | | no-tap | Disallow the tap operator. | | | | | ❌ | | no-topromise | Disallow use of the toPromise method. | ✅ 🔒 | | 💡 | 💭 | | | no-unbound-methods | Disallow passing unbound methods. | ✅ 🔒 | | | 💭 | | | no-unnecessary-collection | Disallow unnecessary usage of collection arguments with single values. | 🔒 | | | | | | no-unsafe-catch | Disallow unsafe catchError usage in effects and epics. | | | | 💭 | | | no-unsafe-first | Disallow unsafe first/take usage in effects and epics. | | | | 💭 | | | no-unsafe-subject-next | Disallow unsafe optional next calls. | ✅ 🔒 | | | 💭 | | | no-unsafe-switchmap | Disallow unsafe switchMap usage in effects and epics. | | | | 💭 | | | no-unsafe-takeuntil | Disallow applying operators after takeUntil. | ✅ 🔒 | | | 💭 | | | prefer-observer | Disallow passing separate handlers to subscribe and tap. | ✅ 🔒 | 🔧 | 💡 | 💭 | | | prefer-root-operators | Disallow importing operators from rxjs/operators. | ✅ 🔒 | 🔧 | 💡 | | | | suffix-subjects | Enforce the use of a suffix in subject identifiers. | | | | 💭 | | | throw-error | Enforce passing only Error values to throwError or Subject.error. | ✅ 🔒 | | 💡 | 💭 | |