Add no-deprecated-router-link-tag-prop rule

docs/rules/README.md

@@ -301,6 +301,7 @@ For example:
 | [vue/no-bare-strings-in-template](./no-bare-strings-in-template.md) | disallow the use of bare strings in `<template>` |  |
 | [vue/no-boolean-default](./no-boolean-default.md) | disallow boolean defaults | :wrench: |
 | [vue/no-computed-properties-in-data](./no-computed-properties-in-data.md) | disallow accessing computed properties in `data`. |  |
+| [vue/no-deprecated-router-link-tag-prop](./no-deprecated-router-link-tag-prop.md) | disallow using deprecated `tag` property on `RouterLink` (in Vue.js 3.0.0+) |  |
 | [vue/no-deprecated-v-is](./no-deprecated-v-is.md) | disallow deprecated `v-is` directive (in Vue.js 3.1.0+) | :wrench: |
 | [vue/no-duplicate-attr-inheritance](./no-duplicate-attr-inheritance.md) | enforce `inheritAttrs` to be set to `false` when using `v-bind="$attrs"` |  |
 | [vue/no-empty-component-block](./no-empty-component-block.md) | disallow the `<template>` `<script>` `<style>` block to be empty |  |

docs/rules/no-deprecated-router-link-tag-prop.md

@@ -0,0 +1,72 @@
+---
+pageClass: rule-details
+sidebarDepth: 0
+title: vue/no-deprecated-router-link-tag-prop
+description: disallow using deprecated `tag` property on `RouterLink` (in Vue.js 3.0.0+)
+---
+# vue/no-deprecated-router-link-tag-prop
+
+> disallow using deprecated `tag` property on `RouterLink` (in Vue.js 3.0.0+)
+
+- :exclamation: <badge text="This rule has not been released yet." vertical="middle" type="error"> ***This rule has not been released yet.*** </badge>
+
+## :book: Rule Details
+
+This rule reports deprecated the `tag` attribute on `RouterLink` elements (removed in Vue.js v3.0.0+).
+
+<eslint-code-block :rules="{'vue/no-deprecated-router-link-tag-prop': ['error']}">
+
+```vue
+<template>
+  <!-- ✓ GOOD -->
+  <RouterLink to="/">Home</RouterLink>
+
+  <RouterLink to="/">
+    <div>Home</div>
+  </RouterLink>
+
+  <NuxtLink tag="div" to="/">Home</NuxtLink>
+
+  <!-- ✗ BAD -->
+  <RouterLink tag="div" to="/">Home</RouterLink>
+  <RouterLink :tag="someVariable" to="/">Home</RouterLink>
+</template>
+```
+
+</eslint-code-block>
+
+## :wrench: Options
+
+```json
+{
+  "vue/no-deprecated-router-link-tag-prop": ["error", {
+    "components": ['RouterLink', 'NuxtLink']
+  }]
+}
+```
+
+### `{ "components": ['RouterLink', 'NuxtLink'] }`
+
+<eslint-code-block :rules="{'vue/no-deprecated-router-link-tag-prop': ['error', {'components': ['RouterLink', 'NuxtLink']}]}">
+
+```vue
+<template>
+  <!-- ✗ BAD -->
+  <NuxtLink tag="div" to="/">Home</NuxtLink>
+  <NuxtLink :tag="someVariable" to="/">Home</NuxtLink>
+
+  <RouterLink tag="div" to="/">Home</RouterLink>
+  <RouterLink :tag="someVariable" to="/">Home</RouterLink>
+</template>
+```
+
+</eslint-code-block>
+
+## :books: Further Reading
+
+- [Vue RFCs - 0021-router-link-scoped-slot](https://github.com/vuejs/rfcs/blob/master/active-rfcs/0021-router-link-scoped-slot.md)
+
+## :mag: Implementation
+
+- [Rule source](https://github.com/vuejs/eslint-plugin-vue/blob/master/lib/rules/no-deprecated-router-link-tag-prop.js)
+- [Test source](https://github.com/vuejs/eslint-plugin-vue/blob/master/tests/lib/rules/no-deprecated-router-link-tag-prop.js)

lib/index.js

@@ -70,6 +70,7 @@ module.exports = {
     'no-deprecated-html-element-is': require('./rules/no-deprecated-html-element-is'),
     'no-deprecated-inline-template': require('./rules/no-deprecated-inline-template'),
     'no-deprecated-props-default-this': require('./rules/no-deprecated-props-default-this'),
+    'no-deprecated-router-link-tag-prop': require('./rules/no-deprecated-router-link-tag-prop'),
     'no-deprecated-scope-attribute': require('./rules/no-deprecated-scope-attribute'),
     'no-deprecated-slot-attribute': require('./rules/no-deprecated-slot-attribute'),
     'no-deprecated-slot-scope-attribute': require('./rules/no-deprecated-slot-scope-attribute'),

lib/rules/no-deprecated-router-link-tag-prop.js

@@ -0,0 +1,84 @@
+/**
+ * @author Marton Csordas
+ * See LICENSE file in root directory for full license.
+ */
+'use strict'
+
+// ------------------------------------------------------------------------------
+// Requirements
+// ------------------------------------------------------------------------------
+
+const utils = require('../utils')
+
+// ------------------------------------------------------------------------------
+// Rule Definition
+// ------------------------------------------------------------------------------
+
+module.exports = {
+  meta: {
+    type: 'problem',
+    docs: {
+      description:
+        'disallow using deprecated `tag` property on `RouterLink` (in Vue.js 3.0.0+)',
+      categories: undefined,
+      url: 'https://eslint.vuejs.org/rules/no-deprecated-router-link-tag-prop'
+    },
+    fixable: null,
+    schema: [
+      {
+        type: 'object',
+        properties: {
+          components: {
+            type: 'array',
+            items: {
+              type: 'string'
+            },
+            uniqueItems: true,
+            minItems: 1
+          }
+        }
+      }
+    ],
+    messages: {
+      deprecated: "'tag' property on '{{element}}' component is deprecated. Use scoped slots instead."
+    }
+  },
+  /** @param {RuleContext} context */
+  create(context) {
+    let components = ['RouterLink']
+    if (context.options[0] && context.options[0].components) {
+      components = context.options[0].components
+    }
+
+    return utils.defineTemplateBodyVisitor(context, {
+      "VElement"(node) {
+        if (!components.includes(node.rawName)) return
+
+        const attributes = node.startTag.attributes
+        attributes.forEach(attr => {
+          /** @type VIdentifier | null */
+          let tagAttr = null;
+
+          if (attr.key.type === 'VIdentifier') {
+            tagAttr = attr.key;
+          } else if (attr.directive && attr.key.type === 'VDirectiveKey') {
+            const arg = attr.key.argument
+            if (arg && arg.type === 'VIdentifier') {
+              tagAttr = arg
+            }
+          }
+
+          if (tagAttr && tagAttr.name === 'tag') {
+            context.report({
+              node: tagAttr,
+              messageId: 'deprecated',
+              data: {
+                element: node.rawName
+              }
+            })
+          }
+        })
+      }
+    })
+  }
+}

tests/lib/rules/no-deprecated-router-link-tag-prop.js

@@ -0,0 +1,153 @@
+/**
+ * @author Marton Csordas
+ * See LICENSE file in root directory for full license.
+ */
+'use strict'
+
+const RuleTester = require('eslint').RuleTester
+const rule = require('../../../lib/rules/no-deprecated-router-link-tag-prop')
+
+const tester = new RuleTester({
+  parser: require.resolve('vue-eslint-parser'),
+  parserOptions: {
+    ecmaVersion: 2020,
+    sourceType: 'module'
+  }
+})
+
+tester.run('no-deprecated-router-link-tag-prop', rule, {
+  valid: [
+    {
+      filename: 'test.vue',
+      code: `
+      <template>
+        <RouterLink to="/">Home</RouterLink>
+      </template>
+      `
+    },
+    {
+      filename: 'test.vue',
+      code: `
+      <template>
+        <RouterLink to="/">
+          <div>Home</div>
+        </RouterLink>
+      </template>
+      `
+    },
+    {
+      filename: 'test.vue',
+      code: `
+      <template>
+        <NuxtLink to="/">Home</NuxtLink>
+      </template>
+      `
+    },
+    {
+      filename: 'test.vue',
+      code: `
+      <template>
+        <NuxtLink to="/">
+          <div>Home</div>
+        </NuxtLink>
+      </template>
+      `
+    },
+  ],
+  invalid: [
+    {
+      filename: 'test.vue',
+      code: `
+      <template>
+        <RouterLink tag="div" to="/">Home</RouterLink>
+      </template>
+      `,
+      errors: [
+        {
+          message: "'tag' property on 'RouterLink' component is deprecated. Use scoped slots instead.",
+          line: 3,
+          column: 21
+        },
+      ]
+    },
+    {
+      filename: 'test.vue',
+      code: `
+      <template>
+        <RouterLink tag="div" to="/">Home</RouterLink>
+      </template>
+      `,
+      options: [{ components: ['RouterLink'] }],
+      errors: [
+        {
+          message: "'tag' property on 'RouterLink' component is deprecated. Use scoped slots instead.",
+          line: 3,
+          column: 21
+        },
+      ]
+    },
+    {
+      filename: 'test.vue',
+      code: `
+      <template>
+        <RouterLink :tag="someVariable" to="/">Home</RouterLink>
+      </template>
+      `,
+      errors: [
+        {
+          message: "'tag' property on 'RouterLink' component is deprecated. Use scoped slots instead.",
+          line: 3,
+          column: 22
+        },
+      ]
+    },
+    {
+      filename: 'test.vue',
+      code: `
+      <template>
+        <RouterLink :tag="someVariable" to="/">Home</RouterLink>
+      </template>
+      `,
+      options: [{ components: ['RouterLink'] }],
+      errors: [
+        {
+          message: "'tag' property on 'RouterLink' component is deprecated. Use scoped slots instead.",
+          line: 3,
+          column: 22
+        },
+      ]
+    },
+    {
+      filename: 'test.vue',
+      code: `
+      <template>
+        <NuxtLink tag="div" to="/">Home</NuxtLink>
+      </template>
+      `,
+      options: [{ components: ['NuxtLink'] }],
+      errors: [
+        {
+          message: "'tag' property on 'NuxtLink' component is deprecated. Use scoped slots instead.",
+          line: 3,
+          column: 19
+        },
+      ]
+    },
+    {
+      filename: 'test.vue',
+      code: `
+      <template>
+        <NuxtLink :tag="someVariable" to="/">Home</NuxtLink>
+      </template>
+      `,
+      options: [{ components: ['NuxtLink'] }],
+      errors: [
+        {
+          message: "'tag' property on 'NuxtLink' component is deprecated. Use scoped slots instead.",
+          line: 3,
+          column: 20
+        },
+      ]
+    },
+  ]
+})