ESLint Plugin String to Lingui

0.25.0 verified Sat Apr 25 auth: no javascript

An ESLint plugin (v0.25.0, actively maintained) that enforces proper usage of the Lingui internationalization library. It includes rules to detect untranslated strings, enforce `t` calls inside functions for dynamic language switching, prevent incorrect i18n macro usage, and validate message consistency against a reference JSON file. Key differentiators include support for JSX text, template literals, and customizable ignore patterns, making it suitable for large codebases migrating to Lingui v3+.

Common errors

error Configuration for rule "string-to-lingui/check-en-messages" is invalid: value.forEach is not a function ↓

cause The 'check-en-messages' rule expects an object, not an array.

fix

Replace the array with an object: ["warn", { "sourcePath": "..." }]

error Cannot read property 'some' of undefined ↓

cause The 'missing-lingui-transformation' rule is missing its options object when using sub-options like 'ignore'.

fix

Ensure the rule configuration includes an object: ["error", { "ignore": ["rgba"] }]

Warnings

gotcha The rule 'no-single-varibles-to-translate' has a typo in its name ('varibles' instead of 'variables'). This is intentional for backward compatibility, but may cause confusion. ↓

fix Use the exact rule name 'string-to-lingui/no-single-varibles-to-translate' in your configuration.

deprecated The rule 'i18n-number-call-in-function' is deprecated and likely replaced by 't-call-in-function' or a more general rule. ↓

fix Use 'string-to-lingui/t-call-in-function' instead.

gotcha The 'forbid-i18n-calls' rule may not cover all i18n methods (e.g., 'i18n.date'). Custom rules may be needed. ↓

fix Add additional rules for any i18n methods you want to forbid.

Install

npm install eslint-plugin-string-to-lingui

yarn add eslint-plugin-string-to-lingui

pnpm add eslint-plugin-string-to-lingui

Imports

plugin
wrong
```
plugins: ['eslint-plugin-string-to-lingui']
```
correct
```
plugins: ['string-to-lingui']
```
ESLint automatically strips the 'eslint-plugin-' prefix when referencing in .eslintrc

Quickstart

Configure all 8 ESLint rules to enforce Lingui best practices: detect untranslated strings, ensure t calls in functions, validate macros, and check messages against a reference file.

// .eslintrc.json
{
  "plugins": ["string-to-lingui"],
  "rules": {
    "string-to-lingui/missing-lingui-transformation": "error",
    "string-to-lingui/t-call-in-function": "warn",
    "string-to-lingui/macro-inside-t-and-i18": "error",
    "string-to-lingui/t-should-be-before-macro": "warn",
    "string-to-lingui/no-single-variables-to-translate": "warn",
    "string-to-lingui/check-en-messages": ["warn", {
      "sourcePath": "path/to/en/messages.json",
      "similarityThreshold": 0.9,
      "maxSuggestions": 3
    }],
    "string-to-lingui/text-restrictions": ["error", {
      "rules": [{
        "patterns": ["''", "’", "“"],
        "message": "Use straight quotes and apostrophes."
      }]
    }],
    "string-to-lingui/forbid-i18n-calls": ["error", {
      "rules": [
        { "handlerName": "_", "message": "Use t`` from '@lingui/macro' instead" },
        { "handlerName": "number", "message": "Use formatCurrency or formatNumber instead" }
      ]
    }]
  }
}