feature(tsc-wrapped): add option for closure compiler JSDoc annotations

tools/@angular/tsc-wrapped/src/options.ts

@@ -9,31 +9,43 @@
 import * as ts from 'typescript';
 
 interface Options extends ts.CompilerOptions {
-  // Absolute path to a directory where generated file structure is written
-  genDir: string;
+  // Absolute path to a directory where generated file structure is written.
+  // If unspecified, generated files will be written alongside sources.
+  genDir?: string;
 
   // Path to the directory containing the tsconfig.json file.
-  basePath: string;
+  basePath?: string;
 
   // Don't produce .metadata.json files (they don't work for bundled emit with --out)
-  skipMetadataEmit: boolean;
+  skipMetadataEmit?: boolean;
 
   // Produce an error if the metadata written for a class would produce an error if used.
-  strictMetadataEmit: boolean;
+  strictMetadataEmit?: boolean;
 
   // Don't produce .ngfactory.ts or .css.shim.ts files
-  skipTemplateCodegen: boolean;
+  skipTemplateCodegen?: boolean;
 
   // Whether to generate code for library code.
   // If true, produce .ngfactory.ts and .css.shim.ts files for .d.ts inputs.
   // Default is true.
   generateCodeForLibraries?: boolean;
 
+  // Insert JSDoc type annotations needed by Closure Compiler
+  annotateForClosureCompiler?: boolean;
+
   // Modify how angular annotations are emitted to improve tree-shaking.
-  annotationsAs?: string; /* 'decorator'|'static field' */
+  // Default is static fields.
+  // decorators: Leave the Decorators in-place. This makes compilation faster.
+  //             TypeScript will emit calls to the __decorate helper.
+  //             `--emitDecoratorMetadata` can be used for runtime reflection.
+  //             However, the resulting code will not properly tree-shake.
+  // static fields: Replace decorators with a static field in the class.
+  //                Allows advanced tree-shakers like Closure Compiler to remove
+  //                unused classes.
+  annotationsAs?: 'decorators'|'static fields';
 
   // Print extra information while running the compiler
-  trace: boolean;
+  trace?: boolean;
 
   // Whether to embed debug information in the compiled templates
   debug?: boolean;