Add no-mutating-props rule.

Author: armano2

Diff for: lib/rules/no-mutating-props.js

@@ -0,0 +1,139 @@
+/**
+ * @fileoverview Check if component props are not mutated
+ * @author 2018 Armano
+ */
+'use strict'
+
+const utils = require('../utils')
+
+// ------------------------------------------------------------------------------
+// Rule Definition
+// ------------------------------------------------------------------------------
+
+module.exports = {
+  meta: {
+    docs: {
+      description: 'disallow mutation of props',
+      category: undefined,
+      url: 'https://github.com/vuejs/eslint-plugin-vue/blob/v5.0.0-beta.3/docs/rules/no-mutating-props.md'
+    },
+    fixable: null, // or "code" or "whitespace"
+    schema: [
+      // fill in your schema
+    ]
+  },
+
+  create (context) {
+    let mutatedNodes = []
+    let props = []
+
+    function checkForMutations () {
+      for (const prop of props) {
+        const propName = utils.getStaticPropertyName(prop.key)
+
+        for (const node of mutatedNodes) {
+          if (propName === node.name) {
+            context.report({
+              node: node.node,
+              message: 'Unexpected mutation of "{{key}}" prop.',
+              data: { key: node.name }
+            })
+          }
+        }
+      }
+      mutatedNodes = []
+    }
+
+    function checkTemplateProperty (node) {
+      if (node.type === 'MemberExpression') {
+        const expression = utils.parseMemberExpression(node)
+        mutatedNodes.push({
+          name: expression[0] === 'this' ? expression[1] : expression[0],
+          node
+        })
+      } else if (node.type === 'Identifier') {
+        mutatedNodes.push({
+          name: node.name,
+          node
+        })
+      }
+    }
+
+    return Object.assign({},
+      {
+        // this.xxx <=|+=|-=>
+        'AssignmentExpression' (node) {
+          if (node.left.type !== 'MemberExpression') return
+          const expression = utils.parseMemberExpression(node.left)
+          if (expression[0] === 'this') {
+            mutatedNodes.push({
+              name: expression[1],
+              node
+            })
+          }
+        },
+        // this.xxx <++|-->
+        'UpdateExpression > MemberExpression' (node) {
+          const expression = utils.parseMemberExpression(node)
+          if (expression[0] === 'this') {
+            mutatedNodes.push({
+              name: expression[1],
+              node
+            })
+          }
+        },
+        // this.xxx.func()
+        'CallExpression' (node) {
+          const expression = utils.parseMemberOrCallExpression(node)
+          const code = expression.join('.').replace(/\.\[/g, '[')
+          const MUTATION_REGEX = /(this.)((?!(concat|slice|map|filter)\().)[^\)]*((push|pop|shift|unshift|reverse|splice|sort|copyWithin|fill)\()/g
+
+          if (MUTATION_REGEX.test(code)) {
+            if (expression[0] === 'this') {
+              mutatedNodes.push({
+                name: expression[1],
+                node
+              })
+            }
+          }
+        }
+      },
+      utils.executeOnVue(context, (obj) => {
+        props = utils.getComponentProps(obj)
+          .filter(cp => cp.key)
+        checkForMutations()
+      }),
+
+      utils.defineTemplateBodyVisitor(context, {
+        'VExpressionContainer AssignmentExpression' (node) {
+          checkTemplateProperty(node.left)
+        },
+        // this.xxx <++|-->
+        'VExpressionContainer UpdateExpression' (node) {
+          checkTemplateProperty(node.argument)
+        },
+        // this.xxx.func()
+        'VExpressionContainer CallExpression' (node) {
+          const expression = utils.parseMemberOrCallExpression(node)
+          const code = expression.join('.').replace(/\.\[/g, '[')
+          const MUTATION_REGEX = /(this.)?((?!(concat|slice|map|filter)\().)[^\)]*((push|pop|shift|unshift|reverse|splice|sort|copyWithin|fill)\()/g
+
+          if (MUTATION_REGEX.test(code)) {
+            mutatedNodes.push({
+              name: expression[0] === 'this' ? expression[1] : expression[0],
+              node
+            })
+          }
+        },
+
+        "VAttribute[directive=true][key.name='model'] VExpressionContainer" (node) {
+          checkTemplateProperty(node.expression)
+        },
+
+        "VElement[name='template']:exit" () {
+          checkForMutations()
+        }
+      })
+    )
+  }
+}

Diff for: lib/rules/no-side-effects-in-computed-properties.js

@@ -42,6 +42,9 @@ module.exports = {
         // this.xxx.func()
         'CallExpression' (node) {
           const code = utils.parseMemberOrCallExpression(node)
+            .join('.')
+            .replace(/\.\[/g, '[')
+
           const MUTATION_REGEX = /(this.)((?!(concat|slice|map|filter)\().)[^\)]*((push|pop|shift|unshift|reverse|splice|sort|copyWithin|fill)\()/g
 
           if (MUTATION_REGEX.test(code)) {
@@ -52,8 +55,8 @@ module.exports = {
       utils.executeOnVue(context, (obj) => {
         const computedProperties = utils.getComputedProperties(obj)
 
-        computedProperties.forEach(cp => {
-          forbiddenNodes.forEach(node => {
+        for (const cp of computedProperties) {
+          for (const node of forbiddenNodes) {
             if (
               cp.value &&
               node.loc.start.line >= cp.value.loc.start.line &&
@@ -65,8 +68,8 @@ module.exports = {
                 data: { key: cp.key }
               })
             }
-          })
-        })
+          }
+        }
       })
     )
   }

Diff for: lib/utils/index.js

@@ -365,9 +365,46 @@ module.exports = {
     return null
   },
 
+  /**
+   * Get all props by looking at all component's properties
+   * @param {ObjectExpression} componentObject Object with component definition
+   * @return {Array} Array of component props in format: [{key?: String, value?: ASTNode, node: ASTNod}]
+   */
+  getComponentProps (componentObject) {
+    const propsNode = componentObject.properties
+      .find(p =>
+        p.type === 'Property' &&
+        p.key.type === 'Identifier' &&
+        p.key.name === 'props' &&
+        (p.value.type === 'ObjectExpression' || p.value.type === 'ArrayExpression')
+      )
+
+    if (!propsNode) {
+      return []
+    }
+
+    let props
+
+    if (propsNode.value.type === 'ObjectExpression') {
+      props = propsNode.value.properties
+        .filter(cp => cp.type === 'Property')
+        .map(cp => {
+          return { key: cp.key, value: this.unwrapTypes(cp.value), node: cp }
+        })
+    } else {
+      props = propsNode.value.elements
+        .map(cp => {
+          const key = cp.type === 'Literal' && typeof cp.value === 'string' ? cp : null
+          return { key, value: null, node: cp }
+        })
+    }
+
+    return props
+  },
+
   /**
    * Get all computed properties by looking at all component's properties
-   * @param {ObjectExpression} Object with component definition
+   * @param {ObjectExpression} componentObject Object with component definition
    * @return {Array} Array of computed properties in format: [{key: String, value: ASTNode}]
    */
   getComputedProperties (componentObject) {
@@ -710,7 +747,7 @@ module.exports = {
       parsedCallee.push('this')
     }
 
-    return parsedCallee.reverse().join('.').replace(/\.\[/g, '[')
+    return parsedCallee.reverse()
   },
 
   /**