Registry / testing / eslint-plugin-neverthrow

eslint-plugin-neverthrow

library1.1.4jsnpmunverified

ESLint plugin enforcing that neverthrow Result types are handled. Current stable version is 1.1.4, released November 2021. It provides a single rule `must-use-result` that flags unhandled `Result` values from the neverthrow library. The plugin is TypeScript‑first, requires `@typescript-eslint/parser`, and relies on type information to detect unhandled results. Unlike manual lint rules, it integrates with ESLint's type‑aware analysis. No updates since 2021; the plugin is stable and low‑maintenance.

testing devops

npm install eslint-plugin-neverthrow

github ↗package ↗

INSTALL

IMPORT

SIG · ESLINT-PLUGIN-NEVE

eslint-plugin-neverthrow

testingjavascriptv1.1.4

Install

—

Import

—

Disk

—

Pass rate

0/ 6

Env Coverage0 / 6

glibc

18–22

musl

18–22

Install & Compatibility

Where this runs

tested against v? · npm install

Install × environment matrix

Each cell = how many times install + import succeeded across repeated harness runs. Partial = flaky.
glibc = Debian/Ubuntu slim · musl = Alpine Linux

musl

node 18–226 runs

build_error

glibc

node 18–226 runs

build_error

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

eslint-plugin-neverthrow (plugin)

✓ plugins: ['neverthrow']

✗ plugins: ['eslint-plugin-neverthrow']

ESLint automatically adds the 'eslint-plugin-' prefix. So the plugin name in config is just 'neverthrow'.

must-use-result rule

✓ rules: { 'neverthrow/must-use-result': 'error' }

✗ rules: { 'must-use-result': 'error' }

Rules are always prefixed with the plugin name, e.g., 'neverthrow/rule-name'.

recommended config

✓ extends: ['plugin:neverthrow/recommended']

✗ extends: ['neverthrow/recommended']

Full format is 'plugin:pluginName/configName'. Otherwise ESLint will look for an npm package 'eslint-config-neverthrow'.

Shows ESLint configuration to enforce handling neverthrow Result types and an example that triggers the rule.

// .eslintrc.js module.exports = { plugins: ['neverthrow'], rules: { 'neverthrow/must-use-result': 'error', }, parser: '@typescript-eslint/parser', parserOptions: { ecmaVersion: 2021, sourceType: 'module', project: ['./tsconfig.json'], tsconfigRootDir: __dirname, }, }; // Example.ts import { ok, err, Result } from 'neverthrow'; function compute(): Result<number, string> { return ok(42); } const result = compute(); // ❌ flagged: result not handled type: 'typescript'

Debug

Known issues

gotchaThe plugin requires type information from TypeScript. Without setting 'parserOptions.project' pointing to a valid tsconfig.json, the rule will silently not work (no errors reported).

fix

Add 'parser: '@typescript-eslint/parser'' and 'parserOptions.project' pointing to your tsconfig.json.

affects: all

gotchaThe rule only works on synchronous code. Async/await with neverthrow Result is not detected (see issue #3).

fix

For async functions, manually handle the result or use a helper like .unwrapOr() within the async context.

affects: >=1.0.0 <=1.1.4

deprecatedAs of v1.1.2, the plugin switched from using '@typescript-eslint/experimental-utils' to internal utilities to fix incompatibility with ESLint >=8. Ensure your ESLint version is >=5.16.

fix

Update to v1.1.2 or later if using ESLint 8. If on an older version, still upgrade to avoid shared type issues.

affects: >=1.1.2

gotchaThe plugin is not the official neverthrow plugin. It's community-maintained and has only one rule. For comprehensive handling, consider combining with other lint rules.

fix

Verify the plugin meets your needs; consider supplementing with manual checks or other plugins.

affects: all

Errors

Common errors & fixes

Error: Cannot find module '@typescript-eslint/parser'

Missing required peer dependency @typescript-eslint/parser.

fix

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

Error: Failed to load plugin 'neverthrow': Cannot find module 'eslint-plugin-neverthrow'

Plugin not installed or ESLint cannot resolve it.

fix

npm install --save-dev eslint-plugin-neverthrow

Definition for rule 'neverthrow/must-use-result' was not found

Plugin not loaded in the config's 'plugins' array or misspelled rule name.

fix

Ensure plugins: ['neverthrow'] is present in config and rule is 'neverthrow/must-use-result' (lowercase).

Upgrade

Version history

1.1.4latest on npm

Audit

Dependencies

eslintrequiredpeer dependency: required as runtime

@typescript-eslint/parserrequiredpeer dependency: used to parse TypeScript and provide type information

Agent activity

4 hits · last 30 days

node

Resources

githubhttps://github.com/mdbetancourt/eslint-plugin-nevethrow ↗

packagehttps://www.npmjs.com/package/eslint-plugin-neverthrow ↗