From ec2dc7914404a23e5bde2ed2bed7c3055afa2c6c Mon Sep 17 00:00:00 2001
From: Flo Edelmann <florian-edelmann@online.de>
Date: Thu, 21 Jan 2021 13:32:08 +0100
Subject: [PATCH] Add `vue/next-tick-style` rule (#1400)

* Add rule docs

* Add rule tests

* Initial implementation: detect nextTick calls

* Finish rule implementation

* Add fixer for promise style

* Add new rule to rule collections

* Improve short description

* Use `output: null` instead of copying the unchanged code

* Update documentation with update tool

* Simplify rule fix code

* Drop unused `recommended` property

* Fix require path

* Update docs

* Fix docs

* Prevent false positives for `foo.then(nextTick)`

* Update rule type

* Add `foo.then(nextTick, catchHandler)` test case
---
 docs/rules/README.md               |   1 +
 docs/rules/next-tick-style.md      | 103 ++++++++++
 lib/index.js                       |   1 +
 lib/rules/next-tick-style.js       | 146 ++++++++++++++
 tests/lib/rules/next-tick-style.js | 304 +++++++++++++++++++++++++++++
 5 files changed, 555 insertions(+)
 create mode 100644 docs/rules/next-tick-style.md
 create mode 100644 lib/rules/next-tick-style.js
 create mode 100644 tests/lib/rules/next-tick-style.js

diff --git a/docs/rules/README.md b/docs/rules/README.md
index c96f44a00..92674e1f5 100644
--- a/docs/rules/README.md
+++ b/docs/rules/README.md
@@ -294,6 +294,7 @@ For example:
 | [vue/html-comment-indent](./html-comment-indent.md) | enforce consistent indentation in HTML comments | :wrench: |
 | [vue/match-component-file-name](./match-component-file-name.md) | require component name property to match its file name |  |
 | [vue/new-line-between-multi-line-property](./new-line-between-multi-line-property.md) | enforce new lines between multi-line properties in Vue components | :wrench: |
+| [vue/next-tick-style](./next-tick-style.md) | enforce Promise or callback style in `nextTick` | :wrench: |
 | [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-duplicate-attr-inheritance](./no-duplicate-attr-inheritance.md) | enforce `inheritAttrs` to be set to `false` when using `v-bind="$attrs"` |  |
diff --git a/docs/rules/next-tick-style.md b/docs/rules/next-tick-style.md
new file mode 100644
index 000000000..52188fd06
--- /dev/null
+++ b/docs/rules/next-tick-style.md
@@ -0,0 +1,103 @@
+---
+pageClass: rule-details
+sidebarDepth: 0
+title: vue/next-tick-style
+description: enforce Promise or callback style in `nextTick`
+---
+# vue/next-tick-style
+
+> enforce Promise or callback style in `nextTick`
+
+- :exclamation: <badge text="This rule has not been released yet." vertical="middle" type="error"> ***This rule has not been released yet.*** </badge>
+- :wrench: The `--fix` option on the [command line](https://eslint.org/docs/user-guide/command-line-interface#fixing-problems) can automatically fix some of the problems reported by this rule.
+
+## :book: Rule Details
+
+This rule enforces whether the callback version or Promise version (which was introduced in Vue v2.1.0) should be used in `Vue.nextTick` and `this.$nextTick`.
+
+<eslint-code-block fix :rules="{'vue/next-tick-style': ['error']}">
+
+```vue
+<script>
+import { nextTick as nt } from 'vue';
+
+export default {
+  async mounted() {
+    /* ✓ GOOD */
+    nt().then(() => callback());
+    await nt(); callback();
+    Vue.nextTick().then(() => callback());
+    await Vue.nextTick(); callback();
+    this.$nextTick().then(() => callback());
+    await this.$nextTick(); callback();
+
+    /* ✗ BAD */
+    nt(() => callback());
+    nt(callback);
+    Vue.nextTick(() => callback());
+    Vue.nextTick(callback);
+    this.$nextTick(() => callback());
+    this.$nextTick(callback);
+  }
+}
+</script>
+```
+
+</eslint-code-block>
+
+## :wrench: Options
+Default is set to `promise`.
+
+```json
+{
+  "vue/next-tick-style": ["error", "promise" | "callback"]
+}
+```
+
+- `"promise"` (default) ... requires using the promise version.
+- `"callback"` ... requires using the callback version. Use this if you use a Vue version below v2.1.0.
+
+### `"callback"`
+
+<eslint-code-block fix :rules="{'vue/next-tick-style': ['error', 'callback']}">
+
+```vue
+<script>
+import { nextTick as nt } from 'vue';
+
+export default {
+  async mounted() {
+    /* ✓ GOOD */
+    nt(() => callback());
+    nt(callback);
+    Vue.nextTick(() => callback());
+    Vue.nextTick(callback);
+    this.$nextTick(() => callback());
+    this.$nextTick(callback);
+
+    /* ✗ BAD */
+    nt().then(() => callback());
+    await nt(); callback();
+    Vue.nextTick().then(() => callback());
+    await Vue.nextTick(); callback();
+    this.$nextTick().then(() => callback());
+    await this.$nextTick(); callback();
+  }
+}
+</script>
+```
+
+</eslint-code-block>
+
+## :books: Further Reading
+
+- [`Vue.nextTick` API in Vue 2](https://vuejs.org/v2/api/#Vue-nextTick)
+- [`vm.$nextTick` API in Vue 2](https://vuejs.org/v2/api/#vm-nextTick)
+- [Global API Treeshaking](https://v3.vuejs.org/guide/migration/global-api-treeshaking.html)
+- [Global `nextTick` API in Vue 3](https://v3.vuejs.org/api/global-api.html#nexttick)
+- [Instance `$nextTick` API in Vue 3](https://v3.vuejs.org/api/instance-methods.html#nexttick)
+
+## :mag: Implementation
+
+- [Rule source](https://github.com/vuejs/eslint-plugin-vue/blob/master/lib/rules/next-tick-style.js)
+- [Test source](https://github.com/vuejs/eslint-plugin-vue/blob/master/tests/lib/rules/next-tick-style.js)
diff --git a/lib/index.js b/lib/index.js
index 699d2f405..ec311919d 100644
--- a/lib/index.js
+++ b/lib/index.js
@@ -48,6 +48,7 @@ module.exports = {
     'mustache-interpolation-spacing': require('./rules/mustache-interpolation-spacing'),
     'name-property-casing': require('./rules/name-property-casing'),
     'new-line-between-multi-line-property': require('./rules/new-line-between-multi-line-property'),
+    'next-tick-style': require('./rules/next-tick-style'),
     'no-arrow-functions-in-watch': require('./rules/no-arrow-functions-in-watch'),
     'no-async-in-computed-properties': require('./rules/no-async-in-computed-properties'),
     'no-bare-strings-in-template': require('./rules/no-bare-strings-in-template'),
diff --git a/lib/rules/next-tick-style.js b/lib/rules/next-tick-style.js
new file mode 100644
index 000000000..d015bb5b7
--- /dev/null
+++ b/lib/rules/next-tick-style.js
@@ -0,0 +1,146 @@
+/**
+ * @fileoverview enforce Promise or callback style in `nextTick`
+ * @author Flo Edelmann
+ * @copyright 2020 Flo Edelmann. All rights reserved.
+ * See LICENSE file in root directory for full license.
+ */
+'use strict'
+
+// ------------------------------------------------------------------------------
+// Requirements
+// ------------------------------------------------------------------------------
+
+const utils = require('../utils')
+const { findVariable } = require('eslint-utils')
+
+// ------------------------------------------------------------------------------
+// Helpers
+// ------------------------------------------------------------------------------
+
+/**
+ * @param {Identifier} identifier
+ * @param {RuleContext} context
+ * @returns {CallExpression|undefined}
+ */
+function getVueNextTickCallExpression(identifier, context) {
+  // Instance API: this.$nextTick()
+  if (
+    identifier.name === '$nextTick' &&
+    identifier.parent.type === 'MemberExpression' &&
+    utils.isThis(identifier.parent.object, context) &&
+    identifier.parent.parent.type === 'CallExpression' &&
+    identifier.parent.parent.callee === identifier.parent
+  ) {
+    return identifier.parent.parent
+  }
+
+  // Vue 2 Global API: Vue.nextTick()
+  if (
+    identifier.name === 'nextTick' &&
+    identifier.parent.type === 'MemberExpression' &&
+    identifier.parent.object.type === 'Identifier' &&
+    identifier.parent.object.name === 'Vue' &&
+    identifier.parent.parent.type === 'CallExpression' &&
+    identifier.parent.parent.callee === identifier.parent
+  ) {
+    return identifier.parent.parent
+  }
+
+  // Vue 3 Global API: import { nextTick as nt } from 'vue'; nt()
+  if (
+    identifier.parent.type === 'CallExpression' &&
+    identifier.parent.callee === identifier
+  ) {
+    const variable = findVariable(context.getScope(), identifier)
+
+    if (variable != null && variable.defs.length === 1) {
+      const def = variable.defs[0]
+      if (
+        def.type === 'ImportBinding' &&
+        def.node.type === 'ImportSpecifier' &&
+        def.node.imported.type === 'Identifier' &&
+        def.node.imported.name === 'nextTick' &&
+        def.node.parent.type === 'ImportDeclaration' &&
+        def.node.parent.source.value === 'vue'
+      ) {
+        return identifier.parent
+      }
+    }
+  }
+
+  return undefined
+}
+
+/**
+ * @param {CallExpression} callExpression
+ * @returns {boolean}
+ */
+function isAwaitedPromise(callExpression) {
+  return (
+    callExpression.parent.type === 'AwaitExpression' ||
+    (callExpression.parent.type === 'MemberExpression' &&
+      callExpression.parent.property.type === 'Identifier' &&
+      callExpression.parent.property.name === 'then')
+  )
+}
+
+// ------------------------------------------------------------------------------
+// Rule Definition
+// ------------------------------------------------------------------------------
+
+module.exports = {
+  meta: {
+    type: 'suggestion',
+    docs: {
+      description: 'enforce Promise or callback style in `nextTick`',
+      categories: undefined,
+      url: 'https://eslint.vuejs.org/rules/next-tick-style.html'
+    },
+    fixable: 'code',
+    schema: [{ enum: ['promise', 'callback'] }]
+  },
+  /** @param {RuleContext} context */
+  create(context) {
+    const preferredStyle =
+      /** @type {string|undefined} */ (context.options[0]) || 'promise'
+
+    return utils.defineVueVisitor(context, {
+      /** @param {Identifier} node */
+      Identifier(node) {
+        const callExpression = getVueNextTickCallExpression(node, context)
+        if (!callExpression) {
+          return
+        }
+
+        if (preferredStyle === 'callback') {
+          if (
+            callExpression.arguments.length !== 1 ||
+            isAwaitedPromise(callExpression)
+          ) {
+            context.report({
+              node,
+              message:
+                'Pass a callback function to `nextTick` instead of using the returned Promise.'
+            })
+          }
+
+          return
+        }
+
+        if (
+          callExpression.arguments.length !== 0 ||
+          !isAwaitedPromise(callExpression)
+        ) {
+          context.report({
+            node,
+            message:
+              'Use the Promise returned by `nextTick` instead of passing a callback function.',
+            fix(fixer) {
+              return fixer.insertTextAfter(node, '().then')
+            }
+          })
+        }
+      }
+    })
+  }
+}
diff --git a/tests/lib/rules/next-tick-style.js b/tests/lib/rules/next-tick-style.js
new file mode 100644
index 000000000..9f2d0ae5b
--- /dev/null
+++ b/tests/lib/rules/next-tick-style.js
@@ -0,0 +1,304 @@
+/**
+ * @fileoverview enforce Promise or callback style in `nextTick`
+ * @author Flo Edelmann
+ * @copyright 2020 Flo Edelmann. All rights reserved.
+ * See LICENSE file in root directory for full license.
+ */
+'use strict'
+
+// ------------------------------------------------------------------------------
+// Requirements
+// ------------------------------------------------------------------------------
+
+const RuleTester = require('eslint').RuleTester
+const rule = require('../../../lib/rules/next-tick-style')
+
+// ------------------------------------------------------------------------------
+// Tests
+// ------------------------------------------------------------------------------
+
+const tester = new RuleTester({
+  parser: require.resolve('vue-eslint-parser'),
+  parserOptions: {
+    ecmaVersion: 2017,
+    sourceType: 'module'
+  }
+})
+
+tester.run('next-tick-style', rule, {
+  valid: [
+    {
+      filename: 'test.vue',
+      code: ''
+    },
+    {
+      filename: 'test.vue',
+      code: `<script>import { nextTick as nt } from 'vue';
+      export default {
+        async mounted() {
+          this.$nextTick().then(() => callback());
+          Vue.nextTick().then(() => callback());
+          nt().then(() => callback());
+
+          await this.$nextTick(); callback();
+          await Vue.nextTick(); callback();
+          await nt(); callback();
+        }
+      }</script>`
+    },
+    {
+      filename: 'test.vue',
+      options: ['promise'],
+      code: `<script>import { nextTick as nt } from 'vue';
+      export default {
+        async mounted() {
+          this.$nextTick().then(() => callback());
+          Vue.nextTick().then(() => callback());
+          nt().then(() => callback());
+
+          await this.$nextTick(); callback();
+          await Vue.nextTick(); callback();
+          await nt(); callback();
+        }
+      }</script>`
+    },
+    {
+      filename: 'test.vue',
+      options: ['callback'],
+      code: `<script>import { nextTick as nt } from 'vue';
+      export default {
+        mounted() {
+          this.$nextTick(() => callback());
+          Vue.nextTick(() => callback());
+          nt(() => callback());
+
+          this.$nextTick(callback);
+          Vue.nextTick(callback);
+          nt(callback);
+        }
+      }</script>`
+    },
+
+    // https://github.com/vuejs/eslint-plugin-vue/pull/1400#discussion_r550937977
+    {
+      filename: 'test.vue',
+      options: ['promise'],
+      code: `<script>import { nextTick as nt } from 'vue';
+      export default {
+        mounted() {
+          foo.then(this.$nextTick);
+          foo.then(Vue.nextTick);
+          foo.then(nt);
+
+          foo.then(nt, catchHandler);
+          foo.then(Vue.nextTick, catchHandler);
+          foo.then(this.$nextTick, catchHandler);
+        }
+      }</script>`
+    },
+    {
+      filename: 'test.vue',
+      options: ['callback'],
+      code: `<script>import { nextTick as nt } from 'vue';
+      export default {
+        mounted() {
+          foo.then(this.$nextTick);
+          foo.then(Vue.nextTick);
+          foo.then(nt);
+
+          foo.then(nt, catchHandler);
+          foo.then(Vue.nextTick, catchHandler);
+          foo.then(this.$nextTick, catchHandler);
+        }
+      }</script>`
+    }
+  ],
+  invalid: [
+    {
+      filename: 'test.vue',
+      code: `<script>import { nextTick as nt } from 'vue';
+      export default {
+        mounted() {
+          this.$nextTick(() => callback());
+          Vue.nextTick(() => callback());
+          nt(() => callback());
+
+          this.$nextTick(callback);
+          Vue.nextTick(callback);
+          nt(callback);
+        }
+      }</script>`,
+      output: `<script>import { nextTick as nt } from 'vue';
+      export default {
+        mounted() {
+          this.$nextTick().then(() => callback());
+          Vue.nextTick().then(() => callback());
+          nt().then(() => callback());
+
+          this.$nextTick().then(callback);
+          Vue.nextTick().then(callback);
+          nt().then(callback);
+        }
+      }</script>`,
+      errors: [
+        {
+          message:
+            'Use the Promise returned by `nextTick` instead of passing a callback function.',
+          line: 4,
+          column: 16
+        },
+        {
+          message:
+            'Use the Promise returned by `nextTick` instead of passing a callback function.',
+          line: 5,
+          column: 15
+        },
+        {
+          message:
+            'Use the Promise returned by `nextTick` instead of passing a callback function.',
+          line: 6,
+          column: 11
+        },
+        {
+          message:
+            'Use the Promise returned by `nextTick` instead of passing a callback function.',
+          line: 8,
+          column: 16
+        },
+        {
+          message:
+            'Use the Promise returned by `nextTick` instead of passing a callback function.',
+          line: 9,
+          column: 15
+        },
+        {
+          message:
+            'Use the Promise returned by `nextTick` instead of passing a callback function.',
+          line: 10,
+          column: 11
+        }
+      ]
+    },
+    {
+      filename: 'test.vue',
+      options: ['promise'],
+      code: `<script>import { nextTick as nt } from 'vue';
+      export default {
+        mounted() {
+          this.$nextTick(() => callback());
+          Vue.nextTick(() => callback());
+          nt(() => callback());
+
+          this.$nextTick(callback);
+          Vue.nextTick(callback);
+          nt(callback);
+        }
+      }</script>`,
+      output: `<script>import { nextTick as nt } from 'vue';
+      export default {
+        mounted() {
+          this.$nextTick().then(() => callback());
+          Vue.nextTick().then(() => callback());
+          nt().then(() => callback());
+
+          this.$nextTick().then(callback);
+          Vue.nextTick().then(callback);
+          nt().then(callback);
+        }
+      }</script>`,
+      errors: [
+        {
+          message:
+            'Use the Promise returned by `nextTick` instead of passing a callback function.',
+          line: 4,
+          column: 16
+        },
+        {
+          message:
+            'Use the Promise returned by `nextTick` instead of passing a callback function.',
+          line: 5,
+          column: 15
+        },
+        {
+          message:
+            'Use the Promise returned by `nextTick` instead of passing a callback function.',
+          line: 6,
+          column: 11
+        },
+        {
+          message:
+            'Use the Promise returned by `nextTick` instead of passing a callback function.',
+          line: 8,
+          column: 16
+        },
+        {
+          message:
+            'Use the Promise returned by `nextTick` instead of passing a callback function.',
+          line: 9,
+          column: 15
+        },
+        {
+          message:
+            'Use the Promise returned by `nextTick` instead of passing a callback function.',
+          line: 10,
+          column: 11
+        }
+      ]
+    },
+    {
+      filename: 'test.vue',
+      options: ['callback'],
+      code: `<script>import { nextTick as nt } from 'vue';
+      export default {
+        async mounted() {
+          this.$nextTick().then(() => callback());
+          Vue.nextTick().then(() => callback());
+          nt().then(() => callback());
+
+          await this.$nextTick(); callback();
+          await Vue.nextTick(); callback();
+          await nt(); callback();
+        }
+      }</script>`,
+      output: null,
+      errors: [
+        {
+          message:
+            'Pass a callback function to `nextTick` instead of using the returned Promise.',
+          line: 4,
+          column: 16
+        },
+        {
+          message:
+            'Pass a callback function to `nextTick` instead of using the returned Promise.',
+          line: 5,
+          column: 15
+        },
+        {
+          message:
+            'Pass a callback function to `nextTick` instead of using the returned Promise.',
+          line: 6,
+          column: 11
+        },
+        {
+          message:
+            'Pass a callback function to `nextTick` instead of using the returned Promise.',
+          line: 8,
+          column: 22
+        },
+        {
+          message:
+            'Pass a callback function to `nextTick` instead of using the returned Promise.',
+          line: 9,
+          column: 21
+        },
+        {
+          message:
+            'Pass a callback function to `nextTick` instead of using the returned Promise.',
+          line: 10,
+          column: 17
+        }
+      ]
+    }
+  ]
+})