Merge pull request #2680 from eslint/issue2678

Fix: Check unused vars in exported functions (fixes #2678)

Author: nzakas

lib/rules/no-unused-vars.js

@@ -44,12 +44,14 @@ module.exports = function(context) {
 
         if (definition) {
 
-            definition = definition.node;
-            if (definition.type === "VariableDeclarator") {
-                definition = definition.parent;
+            var node = definition.node;
+            if (node.type === "VariableDeclarator") {
+                node = node.parent;
+            } else if (definition.type === "Parameter" && node.type === "FunctionDeclaration") {
+                return false;
             }
 
-            return definition.parent.type.indexOf("Export") === 0;
+            return node.parent.type.indexOf("Export") === 0;
         } else {
             return false;
         }

tests/lib/rules/no-unused-vars.js

@@ -136,6 +136,8 @@ eslintTester.addRuleTest("lib/rules/no-unused-vars", {
         { code: "(function z(foo) { var bar = 33; })();", options: [{"vars": "all", "args": "all"}], errors: [{ message: "foo is defined but never used" }, { message: "bar is defined but never used" }]},
         { code: "(function z(foo) { z(); })();", options: [{}], errors: [{ message: "foo is defined but never used" }]},
         { code: "function f() { var a = 1; return function(){ f(a = 2); }; }", options: [{}], errors: [{ message: "f is defined but never used" }, {message: "a is defined but never used"}]},
-        { code: "import x from \"y\";", ecmaFeatures: { modules: true }, errors: [{ message: "x is defined but never used" }]}
+        { code: "import x from \"y\";", ecmaFeatures: { modules: true }, errors: [{ message: "x is defined but never used" }]},
+        { code: "export function fn2({ x, y }) {\n console.log(x); \n};", ecmaFeatures: { modules: true, destructuring: true }, errors: [{ message: "y is defined but never used" }]},
+        { code: "export function fn2( x, y ) {\n console.log(x); \n};", ecmaFeatures: { modules: true }, errors: [{ message: "y is defined but never used" }]}
     ]
 });