New: no-aggregating-enable rule

Author: mysticatea

docs/rules/no-aggregating-enable.md

@@ -0,0 +1,52 @@
+# disallows `eslint-enable` comments for multiple `eslint-disable` comments (no-aggregating-enable)
+
+`eslint-enable` directive-comments can enable rules which are disabled by different `eslint-disable` directive-comments.
+It can enable a rule unintentionally.
+
+```js
+/*eslint-disable no-undef */
+f()
+/*eslint-disable no-var */
+var a
+/*eslint-enable */ "※ Enables both no-undef and no-var."
+```
+
+This rule warns `eslint-enable` directive-comments which enable rules for multiple `eslint-disable` directive-comments.
+
+## Rule Details
+
+:-1: Examples of **incorrect** code for this rule:
+
+```js
+/*eslint no-aggregating-enable: "error"*/
+
+/*eslint-disable no-undef */
+f()
+/*eslint-disable no-var */
+var a
+/*eslint-enable */ "ERROR: This `eslint-enable` comment affects 2 `eslint-disable` comments. An `eslint-enable` comment should be for an `eslint-disable` comment."
+```
+
+```js
+/*eslint no-aggregating-enable: "error"*/
+
+/*eslint-disable no-undef */
+f()
+/*eslint-disable no-var */
+var a
+/*eslint-enable no-undef, no-var */ "ERROR: This `eslint-enable` comment affects 2 `eslint-disable` comments. An `eslint-enable` comment should be for an `eslint-disable` comment."
+```
+
+:+1: Examples of **correct** code for this rule:
+
+```js
+/*eslint no-aggregating-enable: "error"*/
+
+/*eslint-disable no-undef */
+f()
+/*eslint-disable no-var */
+var a
+/*eslint-enable no-var */
+
+/*eslint-enable no-undef */
+```

lib/disabled-area.js

@@ -15,7 +15,7 @@ const utils = require("./utils")
 // Helpers
 //------------------------------------------------------------------------------
 
-const COMMENT_DIRECTIVE = /^\s*(eslint-(?:en|dis)able(?:(?:-next)?-line)?)\s*(?:(\S[\s\S]+\S)\s*)?$/
+const COMMENT_DIRECTIVE = /^\s*(eslint-(?:en|dis)able(?:(?:-next)?-line)?)\s*(?:(\S|\S[\s\S]*\S)\s*)?$/
 const DELIMITER = /[\s,]+/g
 const pool = new WeakMap()
 
@@ -49,6 +49,7 @@ module.exports = class DisabledArea {
         this.areas = []
         this.duplicateDisableDirectives = []
         this.unusedEnableDirectives = []
+        this.numberOfRelatedDisableDirectives = new Map()
     }
 
     /**
@@ -105,6 +106,8 @@ module.exports = class DisabledArea {
      * @private
      */
     _enable(comment, location, ruleIds, kind) {
+        const relatedDisableDirectives = new Set()
+
         if (ruleIds) {
             for (const ruleId of ruleIds) {
                 let used = false
@@ -113,6 +116,7 @@ module.exports = class DisabledArea {
                     const area = this.areas[i]
 
                     if (area.end === null && area.kind === kind && area.ruleId === ruleId) {
+                        relatedDisableDirectives.add(area.comment)
                         area.end = location
                         used = true
                     }
@@ -130,6 +134,7 @@ module.exports = class DisabledArea {
                 const area = this.areas[i]
 
                 if (area.end === null && area.kind === kind) {
+                    relatedDisableDirectives.add(area.comment)
                     area.end = location
                     used = true
                 }
@@ -139,6 +144,8 @@ module.exports = class DisabledArea {
                 this.unusedEnableDirectives.push({ comment, ruleId: null })
             }
         }
+
+        this.numberOfRelatedDisableDirectives.set(comment, relatedDisableDirectives.size)
     }
 
     /**

lib/rules/no-aggregating-enable.js

@@ -0,0 +1,58 @@
+/**
+ * @author Toru Nagashima
+ * @copyright 2016 Toru Nagashima. All rights reserved.
+ * See LICENSE file in root directory for full license.
+ */
+"use strict"
+
+//------------------------------------------------------------------------------
+// Requirements
+//------------------------------------------------------------------------------
+
+const DisabledArea = require("../disabled-area")
+const utils = require("../utils")
+
+//------------------------------------------------------------------------------
+// Rule Definition
+//------------------------------------------------------------------------------
+
+/**
+ * Creates AST event handlers for no-aggregating-enable.
+ * 
+ * @param {RuleContext} context - The rule context.
+ * @returns {object} AST event handlers.
+ */
+function create(context) {
+    const sourceCode = context.getSourceCode()
+    const disabledArea = DisabledArea.get(sourceCode)
+
+    return {
+        Program() {
+            for (const entry of disabledArea.numberOfRelatedDisableDirectives) {
+                const comment = entry[0]
+                const count = entry[1]
+
+                if (count >= 2) {
+                    context.report({
+                        loc: utils.toForceLocation(comment.loc),
+                        message: "This `eslint-enable` comment affects {{count}} `eslint-disable` comments. An `eslint-enable` comment should be for an `eslint-disable` comment.",
+                        data: { count },
+                    })
+                }
+            }
+        },
+    }
+}
+
+module.exports = {
+    create,
+    meta: {
+        docs: {
+            description: "disallows `eslint-enable` comments for multiple `eslint-disable` comments",
+            category: "Best Practices",
+            recommended: false,
+        },
+        fixable: false,
+        schema: [],
+    },
+}

tests/lib/rules/no-aggregating-enable.js

@@ -0,0 +1,72 @@
+/**
+ * @author Toru Nagashima
+ * @copyright 2016 Toru Nagashima. 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/no-aggregating-enable")
+
+//------------------------------------------------------------------------------
+// Tests
+//------------------------------------------------------------------------------
+
+const tester = new RuleTester()
+
+tester.run("no-aggregating-enable", rule, {
+    valid: [
+        `
+            /*eslint-disable a*/
+            /*eslint-enable a*/
+        `,
+        `
+            /*eslint-disable a*/
+            /*eslint-enable b*/
+        `,
+        `
+            /*eslint-disable a, b*/
+            /*eslint-enable*/
+        `,
+        `
+            /*eslint-disable a, b*/
+            /*eslint-enable a, b*/
+        `,
+        `
+            /*eslint-disable a, b*/
+            /*eslint-enable a*/
+            /*eslint-enable b*/
+        `,
+    ],
+    invalid: [
+        {
+            code: `
+                /*eslint-disable a*/
+                /*eslint-disable b*/
+                /*eslint-enable*/
+            `,
+            errors: ["This `eslint-enable` comment affects 2 `eslint-disable` comments. An `eslint-enable` comment should be for an `eslint-disable` comment."],
+        },
+        {
+            code: `
+                /*eslint-disable a*/
+                /*eslint-disable b*/
+                /*eslint-disable c*/
+                /*eslint-enable*/
+            `,
+            errors: ["This `eslint-enable` comment affects 3 `eslint-disable` comments. An `eslint-enable` comment should be for an `eslint-disable` comment."],
+        },
+        {
+            code: `
+                /*eslint-disable a*/
+                /*eslint-disable b*/
+                /*eslint-enable a, b*/
+            `,
+            errors: ["This `eslint-enable` comment affects 2 `eslint-disable` comments. An `eslint-enable` comment should be for an `eslint-disable` comment."],
+        },
+    ],
+})