support the this tag correctly for Closure Compiler (#605)

lib/jsdoc/tag/dictionary/definitions.js

@@ -204,6 +204,21 @@ function firstWordOf(string) {
     }
 }
 
+function combineTypes(tag) {
+    var combined;
+
+    if (tag.value && tag.value.type) {
+        if (tag.value.type.names.length === 1) {
+            combined = tag.value.type.names[0];
+        }
+        else {
+            combined = '(' + tag.value.type.names.join('|') + ')';
+        }
+    }
+
+    return combined;
+}
+
 // Tags that JSDoc uses internally, and that must always be defined.
 var internalTags = {
     // Special separator tag indicating that multiple doclets should be generated for the same
@@ -978,7 +993,12 @@ exports.closureTags = {
     template: {
         onTagged: ignore
     },
-    'this': cloneTagDef(baseTags.this),
+    'this': {
+        canHaveType: true,
+        onTagged: function(doclet, tag) {
+            doclet.this = combineTypes(tag);
+        }
+    },
     throws: cloneTagDef(baseTags.throws),
     type: cloneTagDef(baseTags.type, {
         mustNotHaveDescription: false

test/fixtures/thistag2.js

@@ -0,0 +1,15 @@
+/** @constructor */
+function Foo(name) {
+    setName.apply(this, name);
+}
+
+/** @this {Foo} */
+function setName(name) {
+    /** document me */
+    this.name = name;
+}
+
+/** @this {(Foo|Bar)} */
+function getName(name) {
+    return this.name;
+}

test/specs/tags/thistag.js

@@ -1,18 +1,60 @@
 'use strict';
 
 describe('@this tag', function() {
+    afterEach(function() {
+        jasmine.restoreTagDictionary();
+    });
+
+    describe('JSDoc tags', function() {
+        beforeEach(function() {
+            jasmine.replaceTagDictionary('jsdoc');
+        });
+
+        it('should add a `this` property set to the @this tag\'s value', function() {
             var docSet = jasmine.getDocSetFromFile('test/fixtures/thistag.js');
             var setName = docSet.getByLongname('setName')[0];
-    var fooName = docSet.getByLongname('Foo#name')[0];
 
-    it('When a symbol has a @this tag, the doclet has a this property that is set to that value.', function() {
             expect(setName.this).toBe('Foo');
         });
 
-    it('When a this symbol is documented inside a function with a @this tag, the symbol is documented as a member of that tags value.', function() {
+        it('should change the memberof for symbols like `this.foo`', function() {
+            var docSet = jasmine.getDocSetFromFile('test/fixtures/thistag.js');
+            var fooName = docSet.getByLongname('Foo#name')[0];
+
             expect(typeof fooName).toBe('object');
             expect(fooName.name).toBe('name');
             expect(fooName.memberof).toBe('Foo');
             expect(fooName.scope).toBe('instance');
         });
+    });
+
+    describe('Closure Compiler tags', function() {
+        beforeEach(function() {
+            jasmine.replaceTagDictionary('closure');
+        });
+
+        it('should add a `this` property set to the @this tag\'s type expression', function() {
+            var docSet = jasmine.getDocSetFromFile('test/fixtures/thistag2.js');
+            var setName = docSet.getByLongname('setName')[0];
+
+            expect(setName.this).toBe('Foo');
+        });
+
+        it('should change the memberof for symbols like `this.foo`', function() {
+            var docSet = jasmine.getDocSetFromFile('test/fixtures/thistag2.js');
+            var fooName = docSet.getByLongname('Foo#name')[0];
+
+            expect(typeof fooName).toBe('object');
+            expect(fooName.name).toBe('name');
+            expect(fooName.memberof).toBe('Foo');
+            expect(fooName.scope).toBe('instance');
+        });
+
+        it('should work with type unions', function() {
+            var docSet = jasmine.getDocSetFromFile('test/fixtures/thistag2.js');
+            var getName = docSet.getByLongname('getName')[0];
+
+            expect(getName.this).toBe('(Foo|Bar)');
+        });
+    });
 });