eslint-plugin-rxjs


This package contains a bunch of ESLint rules for RxJS. Essentially, it's a re-implementation of the rules that are in the rxjs-tslint-rules package. (The Angular-specific rules in rxjs-tslint-rules have been re-implemented in eslint-plugin-rxjs-angular.)

Some of the rules are rather opinionated and are not included in the recommended configuration. Developers can decide for themselves whether they want to enable opinionated rules.

Almost all of these rules require the TypeScript parser for ESLint.

Install

Install the ESLint TypeScript parser using npm:

``
npm install @typescript-eslint/parser --save-dev
`

Install the package using npm:

`
npm install eslint-plugin-rxjs --save-dev
`

Configure the parser and the parserOptions for ESLint. Here, I use a .eslintrc.js file for the configuration:

`js
const { join } = require("path");
module.exports = {
parser: "@typescript-eslint/parser",
parserOptions: {
ecmaVersion: 2019,
project: join(__dirname, "./tsconfig.json"),
sourceType: "module"
},
plugins: ["rxjs"],
extends: [],
rules: {
"rxjs/no-async-subscribe": "error",
"rxjs/no-ignored-observable": "error",
"rxjs/no-ignored-subscription": "error",
"rxjs/no-nested-subscribe": "error",
"rxjs/no-unbound-methods": "error",
"rxjs/throw-error": "error"
}
};
`

Or, using the recommended configuration:

`js
const { join } = require("path");
module.exports = {
parser: "@typescript-eslint/parser",
parserOptions: {
ecmaVersion: 2019,
project: join(__dirname, "./tsconfig.json"),
sourceType: "module"
},
extends: ["plugin:rxjs/recommended"],
};
`

Rules

The package includes the following rules.

Rules marked with ✅ are recommended and rules marked with 🔧 have fixers.

| Rule | Description | | |
| --- | --- | --- | --- |
| ban-observables | Forbids the use of banned observables. | | |
| ban-operators | Forbids the use of banned operators. | | |
| finnish | Enforces the use of Finnish notation. | | |
| just | Enforces the use of a just alias for of. | | 🔧 |
| no-async-subscribe | Forbids passing async functions to subscribe. | ✅ | |
| no-compat | Forbids importation from locations that depend upon rxjs-compat. | | |
| no-connectable | Forbids operators that return connectable observables. | | |
| no-create | Forbids the calling of Observable.create. | ✅ | |
| no-cyclic-action | Forbids effects and epics that re-emit filtered actions. | | |
| no-explicit-generics | Forbids explicit generic type arguments. | | |
| no-exposed-subjects | Forbids exposed (i.e. non-private) subjects. | | |
| no-finnish | Forbids the use of Finnish notation. | | |
| no-ignored-error | Forbids the calling of subscribe without specifying an error handler. | | |
| no-ignored-notifier | Forbids observables not composed from the repeatWhen or retryWhen notifier. | ✅ | |
| no-ignored-observable | Forbids the ignoring of observables returned by functions. | | |
| no-ignored-replay-buffer | Forbids using ReplaySubject, publishReplay or shareReplay without specifying the buffer size. | ✅ | |
| no-ignored-subscribe | Forbids the calling of subscribe without specifying arguments. | | |
| no-ignored-subscription | Forbids ignoring the subscription returned by subscribe. | | |
| no-ignored-takewhile-value | Forbids ignoring the value within takeWhile. | ✅ | |
| no-implicit-any-catch | Like the no-implicit-any-catch rule in @typescript-eslint/eslint-plugin, but for the catchError operator instead of catch clauses. | ✅ | 🔧 |
| no-index | Forbids the importation from index modules - for the reason, see this issue. | ✅ | |
| no-internal | Forbids the importation of internals. | ✅ | 🔧 |
| no-nested-subscribe | Forbids the calling of subscribe within a subscribe callback. | ✅ | |
| no-redundant-notify | Forbids redundant notifications from completed or errored observables. | ✅ | |
| no-sharereplay | Forbids using the shareReplay operator. | ✅ | |
| no-subclass | Forbids subclassing RxJS classes. | | |
| no-subject-unsubscribe | Forbids calling the unsubscribe method of a subject instance. | ✅ | |
| no-subject-value | Forbids accessing the value property of a BehaviorSubject instance. | | |
| no-subscribe-handlers | Forbids the passing of handlers to subscribe. | | |
| no-topromise | Forbids the use of the toPromise method. | | |
| no-unbound-methods | Forbids the passing of unbound methods. | ✅ | |
| no-unsafe-catch | Forbids unsafe catchError usage in effects and epics. | | |
| no-unsafe-first | Forbids unsafe first/take usage in effects and epics. | | |
| no-unsafe-subject-next | Forbids unsafe optional next calls. | ✅ | |
| no-unsafe-switchmap | Forbids unsafe switchMap usage in effects and epics. | | |
| no-unsafe-takeuntil | Forbids the application of operators after takeUntil. | ✅ | |
| prefer-observer | Forbids the passing separate handlers to subscribe and tap. | | 🔧 |
| suffix-subjects | Enforces the use of a suffix in subject identifiers. | | |
| throw-error | Enforces the passing of Error` values to error notifications. | | |