refactor(prefer-use-template-ref): optimize performance and type safety (#2982)

Author: 9romise

.changeset/nine-zebras-rule.md

@@ -0,0 +1,5 @@
+---
+"eslint-plugin-vue": patch
+---
+
+Improved performance and type safety in `vue/prefer-use-template-ref`

lib/rules/prefer-use-template-ref.js

@@ -8,40 +8,29 @@ const utils = require('../utils')
 
 /**
  * @typedef ScriptRef
- * @type {{node: Expression, ref: string}}
+ * @type {[string, CallExpression]}
  */
 
-/**
- * @param declarator {VariableDeclarator}
- * @returns {ScriptRef}
- * */
-function convertDeclaratorToScriptRef(declarator) {
-  return {
-    // @ts-ignore
-    node: declarator.init,
-    // @ts-ignore
-    ref: declarator.id.name
-  }
-}
-
 /**
  * @param body {(Statement | ModuleDeclaration)[]}
  * @returns {ScriptRef[]}
  * */
 function getScriptRefsFromSetupFunction(body) {
-  /** @type {VariableDeclaration[]} */
-  const variableDeclarations = body.filter(
-    (child) => child.type === 'VariableDeclaration'
-  )
-  const variableDeclarators = variableDeclarations.map(
-    (declaration) => declaration.declarations[0]
-  )
-  const refDeclarators = variableDeclarators.filter((declarator) =>
-    // @ts-ignore
-    ['ref', 'shallowRef'].includes(declarator.init?.callee?.name)
-  )
+  return body.flatMap((child) => {
+    if (child.type === 'VariableDeclaration') {
+      const declarator = child.declarations[0]
+
+      if (
+        declarator.init?.type === 'CallExpression' &&
+        declarator.init.callee?.type === 'Identifier' &&
+        declarator.id.type === 'Identifier' &&
+        ['ref', 'shallowRef'].includes(declarator.init.callee.name)
+      )
+        return [[declarator.id.name, declarator.init]]
+    }
 
-  return refDeclarators.map(convertDeclaratorToScriptRef)
+    return []
+  })
 }
 
 /** @type {import("eslint").Rule.RuleModule} */
@@ -94,21 +83,20 @@ module.exports = {
       }),
       {
         'Program:exit'() {
+          const scriptRefsMap = new Map(scriptRefs)
+
           for (const templateRef of templateRefs) {
-            const scriptRef = scriptRefs.find(
-              (scriptRef) => scriptRef.ref === templateRef
-            )
+            const scriptRef = scriptRefsMap.get(templateRef)
 
             if (!scriptRef) {
               continue
             }
 
             context.report({
-              node: scriptRef.node,
+              node: scriptRef,
               messageId: 'preferUseTemplateRef',
               data: {
-                // @ts-ignore
-                name: scriptRef.node?.callee?.name
+                name: /** @type {Identifier} */ (scriptRef.callee).name
               }
             })
           }