⭐️New: Add rule no-boolean-default

README.md

@@ -148,6 +148,7 @@ Enforce all the rules in this category, as well as all higher priority rules, wi
 |    | Rule ID | Description |
 |:---|:--------|:------------|
 |  | [vue/no-async-in-computed-properties](./docs/rules/no-async-in-computed-properties.md) | disallow asynchronous actions in computed properties |
+|  | [vue/no-boolean-default](./docs/rules/no-boolean-default.md) | Prevents boolean defaults from being set |
 |  | [vue/no-dupe-keys](./docs/rules/no-dupe-keys.md) | disallow duplication of field names |
 |  | [vue/no-duplicate-attributes](./docs/rules/no-duplicate-attributes.md) | disallow duplication of attributes |
 |  | [vue/no-parsing-error](./docs/rules/no-parsing-error.md) | disallow parsing errors in `<template>` |

docs/rules/no-boolean-default.md

@@ -0,0 +1,38 @@
+# Prevents boolean defaults from being set (vue/no-boolean-default)
+
+- :gear: This rule is included in all of `"plugin:vue/essential"`, `"plugin:vue/strongly-recommended"` and `"plugin:vue/recommended"`.
+
+Please describe the origin of the rule here.
+
+
+## Rule Details
+
+This rule aims to...
+
+Examples of **incorrect** code for this rule:
+
+```js
+
+// fill me in
+
+```
+
+Examples of **correct** code for this rule:
+
+```js
+
+// fill me in
+
+```
+
+### Options
+
+If there are any options, describe them here. Otherwise, delete this section.
+
+## When Not To Use It
+
+Give a short description of when it would be appropriate to turn off this rule.
+
+## Further Reading
+
+If there are other links that describe the issue this rule addresses, please include them here in a bulleted list.

lib/configs/essential.js

@@ -7,6 +7,7 @@ module.exports = {
   extends: require.resolve('./base'),
   rules: {
     'vue/no-async-in-computed-properties': 'error',
+    'vue/no-boolean-default': 'error',
     'vue/no-dupe-keys': 'error',
     'vue/no-duplicate-attributes': 'error',
     'vue/no-parsing-error': 'error',

lib/index.js

@@ -23,6 +23,7 @@ module.exports = {
     'mustache-interpolation-spacing': require('./rules/mustache-interpolation-spacing'),
     'name-property-casing': require('./rules/name-property-casing'),
     'no-async-in-computed-properties': require('./rules/no-async-in-computed-properties'),
+    'no-boolean-default': require('./rules/no-boolean-default'),
     'no-confusing-v-for-v-if': require('./rules/no-confusing-v-for-v-if'),
     'no-dupe-keys': require('./rules/no-dupe-keys'),
     'no-duplicate-attributes': require('./rules/no-duplicate-attributes'),

lib/rules/no-boolean-default.js

@@ -0,0 +1,108 @@
+/**
+ * @fileoverview Prevents boolean defaults from being set
+ * @author Hiroki Osame
+ */
+'use strict'
+
+const utils = require('../utils')
+
+// ------------------------------------------------------------------------------
+// Rule Definition
+// ------------------------------------------------------------------------------
+
+module.exports = {
+  meta: {
+    docs: {
+      description: 'disallow boolean defaults',
+      category: 'essential',
+      recommended: false,
+      url: 'https://github.com/vuejs/eslint-plugin-vue/blob/v5.0.0-beta.3/docs/rules/no-boolean-default.md'
+    },
+    fixable: 'code',
+    schema: [
+      {
+        enum: ['default-false', 'no-default', 'constructor']
+      }
+    ]
+  },
+
+  create (context) {
+    function getPropsDef (vueComp) {
+      return vueComp.properties.find(p =>
+        p.type === 'Property' &&
+            p.key.type === 'Identifier' &&
+            p.key.name === 'props' &&
+            p.value.type === 'ObjectExpression'
+      )
+    }
+
+    function getBooleanProps (propsDef) {
+      return propsDef.value.properties
+        .filter(p => {
+          return (p.value.type === 'ObjectExpression') && p.value.properties.find(p => (
+            p.key.type === 'Identifier' &&
+                p.key.name === 'type' &&
+                p.value.type === 'Identifier' &&
+                p.value.name === 'Boolean'
+          ))
+        })
+    }
+
+    function getDefaultNode (propDef) {
+      return propDef.value.properties.find(p => (p.key.type === 'Identifier' && p.key.name === 'default'))
+    }
+
+    return utils.executeOnVueComponent(context, (obj) => {
+      const propsDef = getPropsDef(obj)
+
+      if (!propsDef) { return }
+
+      const booleanProps = getBooleanProps(propsDef)
+
+      if (!booleanProps.length) { return }
+
+      const booleanType = context.options[0] || 'constructor'
+
+      booleanProps.forEach((propDef) => {
+        const defaultNode = getDefaultNode(propDef)
+
+        switch (booleanType) {
+          case 'no-default':
+            if (defaultNode) {
+              context.report({
+                node: defaultNode,
+                message: 'Boolean prop should not set a default (Vue defaults it to false).'
+              })
+            }
+            break
+
+          case 'default-false':
+            if (defaultNode.value.value !== false) {
+              context.report({
+                node: defaultNode,
+                message: 'Boolean prop should be defaulted to false.'
+              })
+            }
+            break
+
+          default:
+            const nonConstProperties = propDef.value.properties.filter(p => p.key.name !== 'type')
+
+            let fix
+            if (
+              nonConstProperties.length === 0 ||
+              (nonConstProperties.length === 1 && (nonConstProperties[0].key.name === 'default' && nonConstProperties[0].value.value === false))
+            ) {
+              fix = fixer => fixer.replaceText(propDef.value, 'Boolean')
+            }
+
+            context.report({
+              node: propDef,
+              message: 'Boolean prop should use a constructor.',
+              fix
+            })
+        }
+      })
+    })
+  }
+}

tests/lib/rules/no-boolean-default.js

@@ -0,0 +1,113 @@
+/**
+ * @fileoverview Prevents boolean defaults from being set
+ * @author Hiroki Osame
+ */
+'use strict'
+
+// ------------------------------------------------------------------------------
+// Requirements
+// ------------------------------------------------------------------------------
+
+var rule = require('../../../lib/rules/no-boolean-default')
+
+var RuleTester = require('eslint').RuleTester
+
+// ------------------------------------------------------------------------------
+// Tests
+// ------------------------------------------------------------------------------
+
+var ruleTester = new RuleTester({
+  parserOptions: {
+    ecmaVersion: 2015,
+    sourceType: 'module'
+  }
+})
+ruleTester.run('no-boolean-default', rule, {
+
+  valid: [
+    {
+      filename: 'test.vue',
+      code: `
+        export default {
+          props: {
+            enabled: Boolean
+          }
+        }
+      `
+    }
+  ],
+
+  invalid: [
+    {
+      filename: 'test.vue',
+      code: `
+        export default {
+          props: {
+            enabled: {
+              type: Boolean,
+              default: true,
+            }
+          }
+        }
+      `,
+      options: ['default-false'],
+      errors: [{
+        message: 'Boolean prop should be defaulted to false.',
+        line: 6
+      }]
+    },
+    {
+      filename: 'test.vue',
+      code: `
+        export default {
+          props: {
+            enabled: {
+              type: Boolean,
+              default: null,
+            }
+          }
+        }
+      `,
+      options: ['default-false'],
+      errors: [{
+        message: 'Boolean prop should be defaulted to false.',
+        line: 6
+      }]
+    },
+    {
+      filename: 'test.vue',
+      code: `
+        export default {
+          props: {
+            enabled: {
+              type: Boolean,
+              default: false,
+            }
+          }
+        }
+      `,
+      options: ['no-default'],
+      errors: [{
+        message: 'Boolean prop should not set a default (Vue defaults it to false).',
+        line: 6
+      }]
+    },
+    {
+      filename: 'test.vue',
+      code: `
+        export default {
+          props: {
+            enabled: {
+              type: Boolean,
+            }
+          }
+        }
+      `,
+      options: ['constructor'],
+      errors: [{
+        message: 'Boolean prop should use a constructor.',
+        line: 4
+      }]
+    }
+  ]
+})