support goog.require syntax.

Closes #113

src/main/java/com/google/javascript/clutz/DeclarationGenerator.java

@@ -250,6 +250,17 @@ public int compare(TypedVar o1, TypedVar o2) {
       treeWalker.walkDefaultInterface((FunctionType) symbol.getType());
       emitNamespaceEnd();
     }
+    emitGoogRequireSupport(namespace, isDefault ? symbol.getName() : namespace);
+  }
+
+  private void emitGoogRequireSupport(String namespace, String closureNamespace) {
+    // goog namespace doesn't need to be goog.required.
+    if (namespace.equals("goog")) return;
+    emitNamespaceBegin("goog");
+    String qualifiedClosureNamespace = INTERNAL_NAMESPACE + "." + closureNamespace;
+    emit("function require(name: '" + closureNamespace + "'): typeof " + qualifiedClosureNamespace + ";");
+    emitBreak();
+    emitNamespaceEnd();
   }
 
 

src/resources/base.js

@@ -0,0 +1,4 @@
+/** @provideGoog */
+/** @const */ var goog = goog || {};
+goog.provide = function (arg) {};
+goog.require = function (arg) {};

src/resources/closure.lib.d.ts

@@ -5,3 +5,7 @@ declare namespace ಠ_ಠ.clutz_internal {
   type GlobalError = Error;
   var GlobalError: ErrorConstructor;
 }
+
+// Closures' goog namespace is accessible as global symbol without need for
+// explicit goog.require, during the closure compiler pass.
+declare var goog: typeof ಠ_ಠ.clutz_internal.goog;

src/test/java/com/google/javascript/clutz/ProgramSubject.java

@@ -47,17 +47,24 @@ public ProgramSubject(FailureStrategy failureStrategy, ProgramSubject.Program su
   public void generatesDeclarations(Boolean withExterns, String expected) {
     Options opts = new Options(!withExterns);
 
+
+
     List<SourceFile> sourceFiles = new ArrayList<>();
+    sourceFiles.add(SourceFile.fromFile("src/resources/base.js", UTF_8));
+
     for (File nonroot : getSubject().nonroots) {
       sourceFiles.add(SourceFile.fromFile(nonroot, UTF_8));
     }
 
     List<String> roots = new ArrayList<>();
+    roots.add("src/resources/base.js");
+
     for (File root : getSubject().roots) {
       sourceFiles.add(SourceFile.fromFile(root, UTF_8));
       roots.add(root.getPath());
     }
 
+
     String actual = new DeclarationGenerator(opts)
         .generateDeclarations(sourceFiles, NO_EXTERNS, new Depgraph(roots));
     actual = DeclarationGenerator.GOLDEN_FILE_COMMENTS_REGEXP.matcher(actual).replaceAll("");

src/test/java/com/google/javascript/clutz/goog_require.d.ts

@@ -0,0 +1,28 @@
+declare namespace ಠ_ಠ.clutz_internal.foo {
+  class SimpleClass {
+  }
+}
+declare namespace ಠ_ಠ.clutz_internal.goog {
+  function require(name: 'foo.SimpleClass'): typeof ಠ_ಠ.clutz_internal.foo.SimpleClass;
+}
+declare module 'goog:foo.SimpleClass' {
+  import alias = ಠ_ಠ.clutz_internal.foo.SimpleClass;
+  export default alias;
+}
+declare namespace ಠ_ಠ.clutz_internal.foo.simpleNamespace {
+  var a : number ;
+}
+declare namespace ಠ_ಠ.clutz_internal.goog {
+  function require(name: 'foo.simpleNamespace'): typeof ಠ_ಠ.clutz_internal.foo.simpleNamespace;
+}
+declare module 'goog:foo.simpleNamespace' {
+  import alias = ಠ_ಠ.clutz_internal.foo.simpleNamespace;
+  export = alias;
+}
+declare namespace ಠ_ಠ.clutz_internal.goog {
+  function require (name : string ) : void ;
+}
+declare module 'goog:goog.require' {
+  import alias = ಠ_ಠ.clutz_internal.goog.require;
+  export default alias;
+}

src/test/java/com/google/javascript/clutz/goog_require.js

@@ -0,0 +1,12 @@
+goog.provide('foo.SimpleClass');
+goog.provide('foo.simpleNamespace');
+
+/**
+ * @constructor
+ */
+foo.SimpleClass = function() {};
+
+/**
+ * @const {number}
+ */
+foo.simpleNamespace.a = 0;

src/test/java/com/google/javascript/clutz/goog_require_usage.ts

@@ -0,0 +1,10 @@
+const SimpleClass = goog.require('foo.SimpleClass');
+const {a} = goog.require('foo.simpleNamespace');
+
+// Asserting that types carry through.
+var b: number = a;
+// TODO(rado): this should be c: SimpleClass, but without ES6 module
+// imports we cannot bring the type symbol in.
+// Note that does not mean that the type won't flow through the assignment
+// but simply it does not have accessible symbol in the client code.
+var c = new SimpleClass();