unit tests for let keyword (#477)

test/fixtures/letkeyword.js

@@ -0,0 +1,17 @@
+/*global define: true */
+define( [], function() {
+    "use strict";
+
+    /**
+     * My example module.
+     * @exports exampleModule
+     */
+    let myModule = {
+        /**
+         * My example method.
+         */
+        exampleMethod: function() {}
+    };
+
+    return myModule;
+} );

test/specs/documentation/letkeyword.js

@@ -0,0 +1,28 @@
+/*global describe: true, expect: true, it: true, jasmine: true */
+describe('let keyword', function() {
+    var docSet;
+    var exampleModule;
+    var exampleMethod;
+
+    function getDocSet() {
+        docSet = jasmine.getDocSetFromFile('test/fixtures/letkeyword.js');
+        exampleModule = docSet.getByLongname('module:exampleModule');
+        exampleMethod = docSet.getByLongname('module:exampleModule.exampleMethod');
+    }
+
+    it('should be able to compile JS files that contain the "let" keyword', function() {
+        expect(getDocSet).not.toThrow();
+    });
+
+    it('should correctly recognize a module defined with the "let" keyword', function() {
+        expect(exampleModule).toBeDefined();
+        expect( Array.isArray(exampleModule) ).toBe(true);
+        expect(exampleModule.length).toBe(1);
+    });
+
+    it('should correctly recognize members of a module defined with the "let" keyword', function() {
+        expect(exampleMethod).toBeDefined();
+        expect( Array.isArray(exampleMethod) ).toBe(true);
+        expect(exampleMethod.length).toBe(1);
+    });
+});