Add ESLint rule to enforce Lingui msg usage

Adds a custom ESLint rule 'lingui-msg-rule' that ensures the Lingui _() function is called with msg`` template literals or plural/select macros, preventing accidental misuse like _('string') which bypasses i18n. https://claude.ai/code/session_01JMXXPUgAHiSBGmfGwUojKy
2026-01-28 22:33:28 +00:00
parent 31553f0d40
commit 6817b990a8
4 changed files with 214 additions and 0 deletions
@@ -0,0 +1,139 @@
+const {RuleTester} = require('eslint')
+const tseslint = require('typescript-eslint')
+const linguiMsgRule = require('../lingui-msg-rule')
+
+const ruleTester = new RuleTester({
+  languageOptions: {
+    parser: tseslint.parser,
+    parserOptions: {
+      ecmaFeatures: {
+        jsx: true,
+      },
+      ecmaVersion: 'latest',
+      sourceType: 'module',
+    },
+  },
+})
+
+describe('lingui-msg-rule', () => {
+  const tests = {
+    valid: [
+      // msg template literal
+      {
+        code: `
+const {_} = useLingui()
+const x = _(msg\`Hello\`)
+        `,
+      },
+      // msg template literal with interpolation
+      {
+        code: `
+const {_} = useLingui()
+const name = 'World'
+const x = _(msg\`Hello \${name}\`)
+        `,
+      },
+      // plural macro
+      {
+        code: `
+const {_} = useLingui()
+const count = 5
+const x = _(plural(count, {one: '# item', other: '# items'}))
+        `,
+      },
+      // select macro
+      {
+        code: `
+const {_} = useLingui()
+const gender = 'female'
+const x = _(select(gender, {male: 'He', female: 'She', other: 'They'}))
+        `,
+      },
+      // selectOrdinal macro
+      {
+        code: `
+const {_} = useLingui()
+const position = 1
+const x = _(selectOrdinal(position, {one: '#st', two: '#nd', few: '#rd', other: '#th'}))
+        `,
+      },
+      // Different function named _ (not from useLingui context, but rule doesn't track that)
+      // This is fine - the rule just checks the pattern
+      {
+        code: `
+const _ = (x) => x
+const x = _(someValue)
+        `,
+      },
+    ],
+    invalid: [
+      // Plain string literal (single quotes)
+      {
+        code: `
+const {_} = useLingui()
+const x = _('Bad')
+        `,
+        errors: [{messageId: 'missingMsg'}],
+      },
+      // Plain string literal (double quotes)
+      {
+        code: `
+const {_} = useLingui()
+const x = _("Bad")
+        `,
+        errors: [{messageId: 'missingMsg'}],
+      },
+      // Template literal without msg tag
+      {
+        code: `
+const {_} = useLingui()
+const x = _(\`Bad\`)
+        `,
+        errors: [{messageId: 'missingMsg'}],
+      },
+      // Variable/identifier
+      {
+        code: `
+const {_} = useLingui()
+const message = 'Hello'
+const x = _(message)
+        `,
+        errors: [{messageId: 'missingMsg'}],
+      },
+      // Arbitrary function call
+      {
+        code: `
+const {_} = useLingui()
+const x = _(getMessage())
+        `,
+        errors: [{messageId: 'missingMsg'}],
+      },
+      // Empty call
+      {
+        code: `
+const {_} = useLingui()
+const x = _()
+        `,
+        errors: [{messageId: 'missingMsg'}],
+      },
+      // Tagged template with wrong tag
+      {
+        code: `
+const {_} = useLingui()
+const x = _(html\`Hello\`)
+        `,
+        errors: [{messageId: 'missingMsg'}],
+      },
+      // Number literal
+      {
+        code: `
+const {_} = useLingui()
+const x = _(123)
+        `,
+        errors: [{messageId: 'missingMsg'}],
+      },
+    ],
+  }
+
+  ruleTester.run('lingui-msg-rule', linguiMsgRule, tests)
+})