no-unused-keys: allow configuring of callExpression

Closes #643

Author: alxndrsn

docs/rules/no-unused-keys.md

@@ -164,7 +164,8 @@ i18n.t('hi')
       "src": "./src",
       "extensions": [".js", ".vue"],
       "ignores": [],
-      "enableFix": false
+      "enableFix": false,
+      "callExpression": "^(\\$t|t|\\$tc|tc)$"
     }
   ]
 }
@@ -174,6 +175,7 @@ i18n.t('hi')
 - `extensions`: an array to allow specified lintable target file extension. If you don't set any options, it set to `.js` and `.vue` as default.
 - `ignores`: An array of key names and patterns to exclude from the check. If you want to specify a pattern, specify a string such as `/pattern/`.
 - `enableFix`: if `true`, enable automatically remove unused keys on `eslint --fix`. If you don't set any options, it set to `false` as default. (This is an experimental feature.)
+- `callExpression`: A regular expression used to identify translation function calls.
 
 ## :couple: Related Rules
 

lib/rules/no-unused-keys.ts

@@ -81,6 +81,9 @@ function create(context: RuleContext): RuleListener {
   const options = (context.options && context.options[0]) || {}
   const enableFix = options.enableFix
   const ignores = ((options.ignores || []) as string[]).map(toRegExp)
+  const callExpression =
+    (options.callExpression && new RegExp(options.callExpression)) ||
+    /^(\$t|t|\$tc|tc)$/
 
   function createVerifyContext<N extends JSONAST.JSONNode | YAMLAST.YAMLNode>(
     usedKeys: UsedKeys,
@@ -512,7 +515,8 @@ function create(context: RuleContext): RuleListener {
         const localeMessages = getLocaleMessages(context)
         const usedLocaleMessageKeys = collectKeysFromAST(
           sourceCode.ast as VAST.ESLintProgram,
-          sourceCode.visitorKeys
+          sourceCode.visitorKeys,
+          callExpression
         )
         const targetLocaleMessage = localeMessages.findBlockLocaleMessage(
           ctx.parserServices.customBlock
@@ -601,6 +605,9 @@ export = createRule({
           },
           enableFix: {
             type: 'boolean'
+          },
+          callExpression: {
+            type: 'string'
           }
         },
         additionalProperties: false

lib/utils/collect-keys.ts

@@ -20,7 +20,10 @@ const debug = debugBuilder('eslint-plugin-vue-i18n:collect-keys')
  *
  * @param {CallExpression} node
  */
-function getKeyFromCallExpression(node: VAST.ESLintCallExpression) {
+function getKeyFromCallExpression(
+  node: VAST.ESLintCallExpression,
+  callExpression?: RegExp
+) {
   const funcName =
     (node.callee.type === 'MemberExpression' &&
       node.callee.property.type === 'Identifier' &&
@@ -29,7 +32,7 @@ function getKeyFromCallExpression(node: VAST.ESLintCallExpression) {
     ''
 
   if (
-    !/^(\$t|t|\$tc|tc)$/.test(funcName) ||
+    !(callExpression ?? /^(\$t|t|\$tc|tc)$/).test(funcName) ||
     !node.arguments ||
     !node.arguments.length
   ) {
@@ -121,7 +124,8 @@ function collectKeyResourcesFromFiles(fileNames: string[], cwd: string) {
  */
 export function collectKeysFromAST(
   node: VAST.ESLintProgram,
-  visitorKeys?: VisitorKeys
+  visitorKeys?: VisitorKeys,
+  callExpression?: RegExp
 ): string[] {
   debug('collectKeysFromAST')
 
@@ -168,7 +172,7 @@ export function collectKeysFromAST(
       }
     } else if (node.type === 'CallExpression') {
       debug('CallExpression handling ...')
-      const key = getKeyFromCallExpression(node)
+      const key = getKeyFromCallExpression(node, callExpression)
       if (key) {
         results.add(String(key))
       }

tests/lib/rules/no-unused-keys.ts

@@ -289,6 +289,27 @@ new RuleTester({
         }
       }
       </script>`
+    },
+    {
+      filename: 'test.vue',
+      code: `
+    <i18n locale="en">
+    {
+      "foo": "foo",
+      "bar": {
+        "nest": "nest",
+      },
+    }
+    </i18n>
+    <script>
+    export default {
+      created () {
+        this.customFn1('foo')
+        this.customFn2('bar.nest')
+      }
+    }
+    </script>`,
+      options: [{ callExpression: 'customFn\\d' }]
     }
   ],
   invalid: [