Ignore Boolean props in require-default-prop rule (#529)

* Ignore Boolean props in require-default-prop rule

* Support edgecase with array of types

Author: michalsnik

docs/rules/require-default-prop.md

@@ -2,7 +2,7 @@
 
 - :gear: This rule is included in `"plugin:vue/strongly-recommended"` and `"plugin:vue/recommended"`.
 
-This rule requires default value to be set for each props that are not marked as `required`.
+This rule requires default value to be set for each props that are not marked as `required` (except `Boolean` props).
 
 ## Rule Details
 
@@ -12,10 +12,11 @@ Examples of **incorrect** code for this rule:
 props: {
   a: Number,
   b: [Number, String],
-  c: {
+  c: [Boolean, Number],
+  d: {
     type: Number
   },
-  d: {
+  e: {
     type: Number,
     required: false
   }
@@ -38,6 +39,9 @@ props: {
     type: Number,
     default: 0,
     required: false
+  },
+  d: {
+    type: Boolean, // Boolean is the only type that doesn't require default
   }
 }
 ```

lib/rules/require-default-prop.js

@@ -61,7 +61,7 @@ module.exports = {
     /**
      * Finds all props that don't have a default value set
      * @param {Property} propsNode - Vue component's "props" node
-     * @return {boolean}
+     * @return {Array} Array of props without "default" value
      */
     function findPropsWithoutDefaultValue (propsNode) {
       return propsNode.value.properties
@@ -75,6 +75,50 @@ module.exports = {
         })
     }
 
+    /**
+     * Detects whether given value node is a Boolean type
+     * @param {Node} value
+     * @return {Boolean}
+     */
+    function isValueNodeOfBooleanType (value) {
+      return (
+        value.type === 'Identifier' &&
+        value.name === 'Boolean'
+      ) || (
+        value.type === 'ArrayExpression' &&
+        value.elements.length === 1 &&
+        value.elements[0].type === 'Identifier' &&
+        value.elements[0].name === 'Boolean'
+      )
+    }
+
+    /**
+     * Detects whether given prop node is a Boolean
+     * @param {Node} prop
+     * @return {Boolean}
+     */
+    function isBooleanProp (prop) {
+      const value = prop.value
+
+      return isValueNodeOfBooleanType(value) || (
+        value.type === 'ObjectExpression' &&
+        value.properties.find(p =>
+          p.key.type === 'Identifier' &&
+          p.key.name === 'type' &&
+          isValueNodeOfBooleanType(p.value)
+        )
+      )
+    }
+
+    /**
+     * Excludes purely Boolean props from the Array
+     * @param {Array} props - Array with props
+     * @return {Array}
+     */
+    function excludeBooleanProps (props) {
+      return props.filter(prop => !isBooleanProp(prop))
+    }
+
     // ----------------------------------------------------------------------
     // Public
     // ----------------------------------------------------------------------
@@ -91,8 +135,9 @@ module.exports = {
       if (!propsNode) return
 
       const propsWithoutDefault = findPropsWithoutDefaultValue(propsNode)
+      const propsToReport = excludeBooleanProps(propsWithoutDefault)
 
-      propsWithoutDefault.forEach(prop => {
+      propsToReport.forEach(prop => {
         context.report({
           node: prop,
           message: `Prop '{{propName}}' requires default value to be set.`,

tests/lib/rules/require-default-prop.js

@@ -19,7 +19,7 @@ const parserOptions = {
 // Tests
 // ------------------------------------------------------------------------------
 
-const ruleTester = new RuleTester()
+const ruleTester = new RuleTester({ parserOptions })
 ruleTester.run('require-default-prop', rule, {
 
   valid: [
@@ -46,12 +46,27 @@ ruleTester.run('require-default-prop', rule, {
               required: false,
               'default': 'lorem'
             },
+            e: {
+              type: Boolean
+            },
+            f: {
+              type: Boolean,
+              required: false
+            },
+            g: {
+              type: Boolean,
+              default: true
+            },
+            h: {
+              type: [Boolean]
+            },
+            i: Boolean,
+            j: [Boolean],
             // eslint-disable-next-line require-default-prop
-            e: Number
+            k: Number
           }
         }
-      `,
-      parserOptions
+      `
     },
     {
       filename: 'test.vue',
@@ -70,8 +85,7 @@ ruleTester.run('require-default-prop', rule, {
             }
           }
         }
-      `,
-      parserOptions
+      `
     },
     {
       filename: 'test.vue',
@@ -98,8 +112,7 @@ ruleTester.run('require-default-prop', rule, {
             }
           }
         }
-      `,
-      parserOptions
+      `
     }
   ],
 
@@ -117,11 +130,14 @@ ruleTester.run('require-default-prop', rule, {
             d: {
               type: Number,
               required: false
+            },
+            e: [Boolean, String],
+            f: {
+              type: [Boolean, String],
             }
           }
         }
       `,
-      parserOptions,
       errors: [{
         message: `Prop 'a' requires default value to be set.`,
         line: 4
@@ -134,6 +150,12 @@ ruleTester.run('require-default-prop', rule, {
       }, {
         message: `Prop 'd' requires default value to be set.`,
         line: 9
+      }, {
+        message: `Prop 'e' requires default value to be set.`,
+        line: 13
+      }, {
+        message: `Prop 'f' requires default value to be set.`,
+        line: 14
       }]
     }
   ]