Update: add enforceInMethodNames to no-underscore-dangle (fixes eslin…

…t#7065) When enforceInMethodNames is true, the rule checks for dangling underscores in method names too. This includes methods of classes and method properties of objects. The rule is false by default.
gabro · Jul 11, 2017 · 521500b · 521500b
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diff --git a/docs/rules/no-underscore-dangle.md b/docs/rules/no-underscore-dangle.md
@@ -42,6 +42,7 @@ This rule has an object option:
 * `"allow"` allows specified identifiers to have dangling underscores
 * `"allowAfterThis": false` (default) disallows dangling underscores in members of the `this` object
 * `"allowAfterSuper": false` (default) disallows dangling underscores in members of the `super` object
+* `"enforceInMethodNames": false (default) allows dangling underscores in method names`
 
 ### allow
 
@@ -76,6 +77,30 @@ var a = super.foo_;
 super._bar();
 ```
 
+### enforceInMethodNames
+
+Examples of incorrect code for this rule with the `{ "enforceInMethodNames": true }` option:
+
+```js
+/*eslint no-underscore-dangle: ["error", { "enforceInMethodNames": true }]*/
+
+class Foo {
+  _bar() {}
+}
+
+class Foo {
+  bar_() {}
+}
+
+const o = {
+  _bar() {}
+};
+
+const o = {
+  bar_() = {}
+};
+```
+
 ## When Not To Use It
 
 If you want to allow dangling underscores in identifiers, then you can safely turn this rule off.
diff --git a/lib/rules/no-underscore-dangle.js b/lib/rules/no-underscore-dangle.js
@@ -32,6 +32,9 @@ module.exports = {
                     },
                     allowAfterSuper: {
                         type: "boolean"
+                    },
+                    enforceInMethodNames: {
+                        type: "boolean"
                     }
                 },
                 additionalProperties: false
@@ -45,6 +48,7 @@ module.exports = {
         const ALLOWED_VARIABLES = options.allow ? options.allow : [];
         const allowAfterThis = typeof options.allowAfterThis !== "undefined" ? options.allowAfterThis : false;
         const allowAfterSuper = typeof options.allowAfterSuper !== "undefined" ? options.allowAfterSuper : false;
+        const enforceInMethodNames = typeof options.enforceInMethodNames !== "undefined" ? options.enforceInMethodNames : false;
 
         //-------------------------------------------------------------------------
         // Helpers
@@ -162,14 +166,37 @@ module.exports = {
             }
         }
 
+        /**
+         * Check if method declaration or method property has a underscore at the end
+         * @param {ASTNode} node node to evaluate
+         * @returns {void}
+         * @private
+         */
+        function checkForTrailingUnderscoreInMethod(node) {
+            const identifier = node.key.name;
+            const isMethod = node.type === "MethodDefinition" || node.type === "Property" && node.method;
+
+            if (typeof identifier !== "undefined" && enforceInMethodNames && isMethod && hasTrailingUnderscore(identifier)) {
+                context.report({
+                    node,
+                    message: "Unexpected dangling '_' in '{{identifier}}'.",
+                    data: {
+                        identifier
+                    }
+                });
+            }
+        }
+
         //--------------------------------------------------------------------------
         // Public API
         //--------------------------------------------------------------------------
 
         return {
             FunctionDeclaration: checkForTrailingUnderscoreInFunctionDeclaration,
             VariableDeclarator: checkForTrailingUnderscoreInVariableExpression,
-            MemberExpression: checkForTrailingUnderscoreInMemberExpression
+            MemberExpression: checkForTrailingUnderscoreInMemberExpression,
+            MethodDefinition: checkForTrailingUnderscoreInMethod,
+            Property: checkForTrailingUnderscoreInMethod
         };
 
     }

diff --git a/tests/lib/rules/no-underscore-dangle.js b/tests/lib/rules/no-underscore-dangle.js
@@ -32,7 +32,12 @@ ruleTester.run("no-underscore-dangle", rule, {
         { code: "foo._bar;", options: [{ allow: ["_bar"] }] },
         { code: "function _foo() {}", options: [{ allow: ["_foo"] }] },
         { code: "this._bar;", options: [{ allowAfterThis: true }] },
-        { code: "class foo { constructor() { super._bar; } }", parserOptions: { ecmaVersion: 6 }, options: [{ allowAfterSuper: true }] }
+        { code: "class foo { constructor() { super._bar; } }", parserOptions: { ecmaVersion: 6 }, options: [{ allowAfterSuper: true }] },
+        { code: "class foo { _onClick() { } }", parserOptions: { ecmaVersion: 6 } },
+        { code: "class foo { onClick_() { } }", parserOptions: { ecmaVersion: 6 } },
+        { code: "const o = { _onClick() { } }", parserOptions: { ecmaVersion: 6 } },
+        { code: "const o = { onClick_() { } }", parserOptions: { ecmaVersion: 6 } },
+        { code: "const o = { _foo: 'bar' }", parserOptions: { ecmaVersion: 6 } }
     ],
     invalid: [
         { code: "var _foo = 1", errors: [{ message: "Unexpected dangling '_' in '_foo'.", type: "VariableDeclarator" }] },
@@ -43,6 +48,10 @@ ruleTester.run("no-underscore-dangle", rule, {
         { code: "foo._bar;", errors: [{ message: "Unexpected dangling '_' in '_bar'.", type: "MemberExpression" }] },
         { code: "this._prop;", errors: [{ message: "Unexpected dangling '_' in '_prop'.", type: "MemberExpression" }] },
         { code: "class foo { constructor() { super._prop; } }", parserOptions: { ecmaVersion: 6 }, errors: [{ message: "Unexpected dangling '_' in '_prop'.", type: "MemberExpression" }] },
-        { code: "class foo { constructor() { this._prop; } }", options: [{ allowAfterSuper: true }], parserOptions: { ecmaVersion: 6 }, errors: [{ message: "Unexpected dangling '_' in '_prop'.", type: "MemberExpression" }] }
+        { code: "class foo { constructor() { this._prop; } }", options: [{ allowAfterSuper: true }], parserOptions: { ecmaVersion: 6 }, errors: [{ message: "Unexpected dangling '_' in '_prop'.", type: "MemberExpression" }] },
+        { code: "class foo { _onClick() { } }", options: [{ enforceInMethodNames: true }], parserOptions: { ecmaVersion: 6 }, errors: [{ message: "Unexpected dangling '_' in '_onClick'.", type: "MethodDefinition" }] },
+        { code: "class foo { onClick_() { } }", options: [{ enforceInMethodNames: true }], parserOptions: { ecmaVersion: 6 }, errors: [{ message: "Unexpected dangling '_' in 'onClick_'.", type: "MethodDefinition" }] },
+        { code: "const o = { _onClick() { } }", options: [{ enforceInMethodNames: true }], parserOptions: { ecmaVersion: 6 }, errors: [{ message: "Unexpected dangling '_' in '_onClick'.", type: "Property" }] },
+        { code: "const o = { onClick_() { } }", options: [{ enforceInMethodNames: true }], parserOptions: { ecmaVersion: 6 }, errors: [{ message: "Unexpected dangling '_' in 'onClick_'.", type: "Property" }] }
     ]
 });