Update: camelcase rule fix for import declarations (fixes #6755) (#6784)

Calmecase rule now doesn't report an error if camelcased identifier
is imported with a camecased alias. Otherwhise it reports an error
as expected.

docs/rules/camelcase.md

@@ -4,7 +4,7 @@ When it comes to naming variables, style guides generally fall into one of two c
 
 ## Rule Details
 
-This rule looks for any underscores (`_`) located within the source code. It ignores leading and trailing underscores and only checks those in the middle of a variable name. If ESLint decides that the variable is a constant (all uppercase), then no warning will be thrown. Otherwise, a warning will be thrown. This rule only flags definitions and assignments but not function calls.
+This rule looks for any underscores (`_`) located within the source code. It ignores leading and trailing underscores and only checks those in the middle of a variable name. If ESLint decides that the variable is a constant (all uppercase), then no warning will be thrown. Otherwise, a warning will be thrown. This rule only flags definitions and assignments but not function calls. In case of ES6 `import` statements, this rule only targets the name of the variable that will be imported into the local module scope.
 
 ## Options
 
@@ -20,6 +20,8 @@ Examples of **incorrect** code for this rule with the default `{ "properties": "
 ```js
 /*eslint camelcase: "error"*/
 
+import { no_camelcased } from "external-module"
+
 var my_favorite_color = "#112C85";
 
 function do_something() {
@@ -40,6 +42,8 @@ Examples of **correct** code for this rule with the default `{ "properties": "al
 ```js
 /*eslint camelcase: "error"*/
 
+import { no_camelcased as camelCased } from "external-module";
+
 var myFavoriteColor   = "#112C85";
 var _myFavoriteColor  = "#112C85";
 var myFavoriteColor_  = "#112C85";

lib/rules/camelcase.js

@@ -122,6 +122,14 @@ module.exports = {
                         report(node);
                     }
 
+                // Check if it's an import specifier
+                } else if (["ImportSpecifier", "ImportNamespaceSpecifier", "ImportDefaultSpecifier"].indexOf(node.parent.type) >= 0) {
+
+                    // Report only if the local imported identifier is underscored
+                    if (node.parent.local && node.parent.local.name === node.name && isUnderscored(name)) {
+                        report(node);
+                    }
+
                 // Report anything that is underscored that isn't a CallExpression
                 } else if (isUnderscored(name) && effectiveParent.type !== "CallExpression") {
                     report(node);

tests/lib/rules/camelcase.js

@@ -65,6 +65,18 @@ ruleTester.run("camelcase", rule, {
             code: "var { category_id: category } = query;",
             parserOptions: { ecmaVersion: 6 },
             options: [{properties: "never"}]
+        },
+        {
+            code: "import { camelCased } from \"external module\";",
+            parserOptions: { ecmaVersion: 6, sourceType: "module" }
+        },
+        {
+            code: "import { no_camelcased as camelCased } from \"external-module\";",
+            parserOptions: { ecmaVersion: 6, sourceType: "module" }
+        },
+        {
+            code: "import { no_camelcased as camelCased, anoterCamelCased } from \"external-module\";",
+            parserOptions: { ecmaVersion: 6, sourceType: "module" }
         }
     ],
     invalid: [
@@ -207,6 +219,96 @@ ruleTester.run("camelcase", rule, {
                     type: "Identifier"
                 }
             ]
+        },
+        {
+            code: "import no_camelcased from \"external-module\";",
+            parserOptions: { ecmaVersion: 6, sourceType: "module" },
+            errors: [
+                {
+                    message: "Identifier 'no_camelcased' is not in camel case.",
+                    type: "Identifier"
+                }
+            ]
+        },
+        {
+            code: "import * as no_camelcased from \"external-module\";",
+            parserOptions: { ecmaVersion: 6, sourceType: "module" },
+            errors: [
+                {
+                    message: "Identifier 'no_camelcased' is not in camel case.",
+                    type: "Identifier"
+                }
+            ]
+        },
+        {
+            code: "import { no_camelcased } from \"external-module\";",
+            parserOptions: { ecmaVersion: 6, sourceType: "module" },
+            errors: [
+                {
+                    message: "Identifier 'no_camelcased' is not in camel case.",
+                    type: "Identifier"
+                }
+            ]
+        },
+        {
+            code: "import { no_camelcased as no_camel_cased } from \"external module\";",
+            parserOptions: { ecmaVersion: 6, sourceType: "module" },
+            errors: [
+                {
+                    message: "Identifier 'no_camel_cased' is not in camel case.",
+                    type: "Identifier"
+                }
+            ]
+        },
+        {
+            code: "import { camelCased as no_camel_cased } from \"external module\";",
+            parserOptions: { ecmaVersion: 6, sourceType: "module" },
+            errors: [
+                {
+                    message: "Identifier 'no_camel_cased' is not in camel case.",
+                    type: "Identifier"
+                }
+            ]
+        },
+        {
+            code: "import { camelCased, no_camelcased } from \"external-module\";",
+            parserOptions: { ecmaVersion: 6, sourceType: "module" },
+            errors: [
+                {
+                    message: "Identifier 'no_camelcased' is not in camel case.",
+                    type: "Identifier"
+                }
+            ]
+        },
+        {
+            code: "import { no_camelcased as camelCased, another_no_camelcased } from \"external-module\";",
+            parserOptions: { ecmaVersion: 6, sourceType: "module" },
+            errors: [
+                {
+                    message: "Identifier 'another_no_camelcased' is not in camel case.",
+                    type: "Identifier"
+                }
+            ]
+        },
+        {
+            code: "import camelCased, { no_camelcased } from \"external-module\";",
+            parserOptions: { ecmaVersion: 6, sourceType: "module" },
+            errors: [
+                {
+                    message: "Identifier 'no_camelcased' is not in camel case.",
+                    type: "Identifier"
+                }
+            ]
+        },
+        {
+            code: "import no_camelcased, { another_no_camelcased as camelCased } from \"external-module\";",
+            parserOptions: { ecmaVersion: 6, sourceType: "module" },
+            errors: [
+                {
+                    message: "Identifier 'no_camelcased' is not in camel case.",
+                    type: "Identifier"
+                }
+            ]
         }
     ]
 });