use :exit.

Author: aladdin-add

lib/rules/no-unused-vars.js

@@ -6,76 +6,54 @@
 
 const utils = require('../utils')
 
-/**
- * Collect used variables recursively.
- *
- * @param {Node} node - The node to collect.
- * @param {Object} used(optional) - The object to restore result.
- * @returns {Object} used variables.
- */
-function collectUsed (node, used) {
-  used = used || {}
-
-  if (node.type === 'VExpressionContainer') {
-    node.references.forEach(ref => {
-      used[ref.id.name] = true
-    })
-  }
-
-  if (node.type === 'VAttribute') {
-    collectUsed(node.value, used)
-  }
-
-  if (node.type === 'VElement') {
-    node.children.forEach(child => collectUsed(child, used))
-    node.startTag.attributes.forEach(attr => collectUsed(attr, used))
-  }
-
-  return used
-}
-
 /**
  * Creates AST event handlers for require-v-for-key.
  *
  * @param {RuleContext} context - The rule context.
  * @returns {Object} AST event handlers.
  */
 function create (context) {
-  utils.registerTemplateBodyVisitor(context, {
-    "VAttribute[directive=true][key.name='for']": function (node) {
-      const vars = node.value.expression.left
-      const used = collectUsed(node.parent.parent)
+  const stack = []
+  let unused = []
 
-      // report unused.
-      vars.filter(v => !used[v.name]).forEach(v => {
-        context.report({
-          node,
-          loc: v.loc,
-          message: `'{{name}}' is defined but never used.`,
-          data: {
-            name: v.name
-          }
+  return utils.defineTemplateBodyVisitor(context, {
+    'VElement:exit' () {
+      unused
+        .forEach((node) => {
+          context.report({
+            node,
+            loc: node.loc,
+            message: `'{{name}}' is defined but never used.`,
+            data: {
+              name: node.name
+            }
+          })
         })
-      })
+      unused = stack.pop()
     },
-
-    "VAttribute[directive=false][key.name='scope']": function (node) {
-      const used = collectUsed(node.parent.parent)
-
-      if (!used[node.value.value]) {
-        context.report({
-          node,
-          loc: node.value.loc,
-          message: `'{{name}}' is defined but never used.`,
-          data: {
-            name: node.value.value
+    VElement (node) {
+      stack.push(unused)
+      unused = []
+      if (node.variables) {
+        for (const variable of node.variables) {
+          unused.push(variable.id)
+        }
+      }
+    },
+    VExpressionContainer (node) {
+      if (node.references) {
+        for (const reference of node.references) {
+          if (reference.mode !== 'w') {
+            const name = reference.id.name
+            unused = unused.filter((el) => el.name !== name)
+            stack.forEach((list, i) => {
+              stack[i] = list.filter((el) => el.name !== name)
+            })
           }
-        })
+        }
       }
     }
   })
-
-  return {}
 }
 
 // ------------------------------------------------------------------------------