From 1be76b56a2b5a34532b350f448e5af3bab6a574e Mon Sep 17 00:00:00 2001
From: yosuke ota <otameshiyo23@gmail.com>
Date: Sun, 13 Jan 2019 17:33:37 +0900
Subject: [PATCH] =?UTF-8?q?=E2=AD=90=EF=B8=8FNew:=20Add=20`vue/comma-dangl?=
 =?UTF-8?q?e`=20rule?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 docs/rules/README.md            |   1 +
 docs/rules/comma-dangle.md      |  23 +++++++
 lib/configs/no-layout-rules.js  |   1 +
 lib/index.js                    |   1 +
 lib/rules/comma-dangle.js       |   9 +++
 tests/lib/rules/comma-dangle.js | 108 ++++++++++++++++++++++++++++++++
 6 files changed, 143 insertions(+)
 create mode 100644 docs/rules/comma-dangle.md
 create mode 100644 lib/rules/comma-dangle.js
 create mode 100644 tests/lib/rules/comma-dangle.js

diff --git a/docs/rules/README.md b/docs/rules/README.md
index b37c250a0..97fbede97 100644
--- a/docs/rules/README.md
+++ b/docs/rules/README.md
@@ -140,6 +140,7 @@ For example:
 | Rule ID | Description |    |
 |:--------|:------------|:---|
 | [vue/array-bracket-spacing](./array-bracket-spacing.md) | enforce consistent spacing inside array brackets | :wrench: |
+| [vue/comma-dangle](./comma-dangle.md) | require or disallow trailing commas | :wrench: |
 | [vue/component-name-in-template-casing](./component-name-in-template-casing.md) | enforce specific casing for the component naming style in template | :wrench: |
 | [vue/eqeqeq](./eqeqeq.md) | require the use of `===` and `!==` | :wrench: |
 | [vue/key-spacing](./key-spacing.md) | enforce consistent spacing between keys and values in object literal properties | :wrench: |
diff --git a/docs/rules/comma-dangle.md b/docs/rules/comma-dangle.md
new file mode 100644
index 000000000..0ccdf1518
--- /dev/null
+++ b/docs/rules/comma-dangle.md
@@ -0,0 +1,23 @@
+---
+pageClass: rule-details
+sidebarDepth: 0
+title: vue/comma-dangle
+description: require or disallow trailing commas
+---
+# vue/comma-dangle
+> require or disallow trailing commas
+
+- :wrench: The `--fix` option on the [command line](https://eslint.org/docs/user-guide/command-line-interface#fixing-problems) can automatically fix some of the problems reported by this rule.
+
+This rule is the same rule as core [comma-dangle] rule but it applies to the expressions in `<template>`.
+
+## :books: Further reading
+
+- [comma-dangle]
+
+[comma-dangle]: https://eslint.org/docs/rules/comma-dangle
+
+## :mag: Implementation
+
+- [Rule source](https://github.com/vuejs/eslint-plugin-vue/blob/master/lib/rules/comma-dangle.js)
+- [Test source](https://github.com/vuejs/eslint-plugin-vue/blob/master/tests/lib/rules/comma-dangle.js)
diff --git a/lib/configs/no-layout-rules.js b/lib/configs/no-layout-rules.js
index 560bde3cf..2e8622159 100644
--- a/lib/configs/no-layout-rules.js
+++ b/lib/configs/no-layout-rules.js
@@ -6,6 +6,7 @@
 module.exports = {
   rules: {
     'vue/array-bracket-spacing': 'off',
+    'vue/comma-dangle': 'off',
     'vue/html-closing-bracket-newline': 'off',
     'vue/html-closing-bracket-spacing': 'off',
     'vue/html-indent': 'off',
diff --git a/lib/index.js b/lib/index.js
index bb5b86031..770071823 100644
--- a/lib/index.js
+++ b/lib/index.js
@@ -10,6 +10,7 @@ module.exports = {
     'array-bracket-spacing': require('./rules/array-bracket-spacing'),
     'attribute-hyphenation': require('./rules/attribute-hyphenation'),
     'attributes-order': require('./rules/attributes-order'),
+    'comma-dangle': require('./rules/comma-dangle'),
     'comment-directive': require('./rules/comment-directive'),
     'component-name-in-template-casing': require('./rules/component-name-in-template-casing'),
     'eqeqeq': require('./rules/eqeqeq'),
diff --git a/lib/rules/comma-dangle.js b/lib/rules/comma-dangle.js
new file mode 100644
index 000000000..cfd0a4185
--- /dev/null
+++ b/lib/rules/comma-dangle.js
@@ -0,0 +1,9 @@
+/**
+ * @author Yosuke Ota
+ */
+'use strict'
+
+const { wrapCoreRule } = require('../utils')
+
+// eslint-disable-next-line
+module.exports = wrapCoreRule(require('eslint/lib/rules/comma-dangle'))
diff --git a/tests/lib/rules/comma-dangle.js b/tests/lib/rules/comma-dangle.js
new file mode 100644
index 000000000..aca710198
--- /dev/null
+++ b/tests/lib/rules/comma-dangle.js
@@ -0,0 +1,108 @@
+/**
+ * @author Yosuke Ota
+ */
+'use strict'
+
+const RuleTester = require('eslint').RuleTester
+const rule = require('../../../lib/rules/comma-dangle')
+
+const tester = new RuleTester({
+  parser: 'vue-eslint-parser',
+  parserOptions: { ecmaVersion: 2018 }
+})
+
+tester.run('comma-dangle', rule, {
+  valid: [
+    `<template>
+      <button @click="() => fn([a, b])" ></button>
+    </template>`,
+    {
+      code: `
+        <template>
+          <CustomButton @click="($event) => fn()" />
+        </template>`,
+      options: [{
+        'functions': 'never'
+      }]
+    },
+    {
+      code: `
+        <template>
+          <button @click="() => fn([a, b, ])" ></button>
+        </template>`,
+      options: [{
+        'arrays': 'ignore'
+      }]
+    }
+  ],
+  invalid: [
+    {
+      code: `
+        <template>
+          <button @click="() => fn([a, b,])" ></button>
+        </template>`,
+      output: `
+        <template>
+          <button @click="() => fn([a, b])" ></button>
+        </template>`,
+      errors: [
+        {
+          message: 'Unexpected trailing comma.',
+          line: 3
+        }
+      ]
+    },
+    {
+      code: `
+        <template>
+          <CustomButton @click="($event, ) => fn()" />
+        </template>`,
+      options: [{
+        'functions': 'never'
+      }],
+      output: `
+        <template>
+          <CustomButton @click="($event ) => fn()" />
+        </template>`,
+      errors: [
+        {
+          message: 'Unexpected trailing comma.',
+          line: 3
+        }
+      ]
+    },
+    {
+      code: `
+        <template>
+          <button @click="() => {
+            fn([a, b, ])
+            fn([
+              a,
+              b
+            ])
+          }"></button>
+        </template>`,
+      options: ['always-multiline'],
+      output: `
+        <template>
+          <button @click="() => {
+            fn([a, b ])
+            fn([
+              a,
+              b,
+            ])
+          }"></button>
+        </template>`,
+      errors: [
+        {
+          message: 'Unexpected trailing comma.',
+          line: 4
+        },
+        {
+          message: 'Missing trailing comma.',
+          line: 7
+        }
+      ]
+    }
+  ]
+})