function types: optional and vararg arguments.

package.json

@@ -35,6 +35,7 @@
     "@types/source-map": "^0.5.1",
     "@types/source-map-support": "^0.2.27",
     "chai": "^3.5.0",
+    "chai-diff": "^1.0.1",
     "clang-format": "^1.0.55",
     "diff": "^3.2.0",
     "glob": "^7.0.0",

src/type-translator.ts

@@ -589,6 +589,7 @@ export class TypeTranslator {
 
   /** Converts a ts.Signature (function signature) to a Closure function type. */
   private signatureToClosure(sig: ts.Signature): string {
+    // TODO(martinprobst): Consider harmonizing some overlap with emitFunctionType in tsickle.ts.
     const params = this.convertParams(sig);
     let typeStr = `function(${params.join(', ')})`;
 
@@ -601,10 +602,27 @@ export class TypeTranslator {
   }
 
   private convertParams(sig: ts.Signature): string[] {
-    return sig.parameters.map(param => {
-      const paramType = this.typeChecker.getTypeOfSymbolAtLocation(param, this.node);
-      return this.translate(paramType);
-    });
+    const paramTypes: string[] = [];
+    // The Signature itself does not include information on optional and var arg parameters.
+    // Use its declaration to recover that information.
+    const decl = sig.declaration;
+    for (let i = 0; i < sig.parameters.length; i++) {
+      const param = sig.parameters[i];
+
+      const paramDecl = decl.parameters[i];
+      const optional = !!paramDecl.questionToken;
+      const varArgs = !!paramDecl.dotDotDotToken;
+      let paramType = this.typeChecker.getTypeOfSymbolAtLocation(param, this.node);
+      if (varArgs) {
+        const typeRef = paramType as ts.TypeReference;
+        paramType = typeRef.typeArguments![0];
+      }
+      let typeStr = this.translate(paramType);
+      if (varArgs) typeStr = '...' + typeStr;
+      if (optional) typeStr = typeStr + '=';
+      paramTypes.push(typeStr);
+    }
+    return paramTypes;
   }
 
   warn(msg: string) {

test/BUILD

@@ -61,6 +61,7 @@ ts_library(
     name = "golden_test_lib",
     srcs = [
         "golden_tsickle_test.ts",
+        "chai-diff.d.ts",
     ],
     tsconfig = "//:tsconfig.json",
     deps = [

test/chai-diff.d.ts

@@ -0,0 +1,24 @@
+/**
+ * @license
+ * Copyright Google Inc. All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.io/license
+ */
+
+/**
+ * @fileoverview Minimal type declarations for the chai-diff library.
+ * @see https://www.npmjs.com/package/chai-diff
+ */
+
+declare namespace Chai {
+  interface Assertion {
+    differentFrom(val: string, opts?: {}): void;
+  }
+}
+
+declare module 'chai-diff' {
+  // tslint:disable-next-line:no-any This is the type defined by chai.use.
+  function chaiDiff(chai: any, utils: any): void;
+  export = chaiDiff;
+}

test/golden_tsickle_test.ts

@@ -6,7 +6,9 @@
  * found in the LICENSE file at https://angular.io/license
  */
 
-import {expect} from 'chai';
+import {expect, use as chaiUse} from 'chai';
+// tslint:disable-next-line:no-require-imports chai-diff needs a CommonJS import.
+import chaiDiff = require('chai-diff');
 import * as fs from 'fs';
 import * as path from 'path';
 import * as ts from 'typescript';
@@ -16,6 +18,8 @@ import {normalizeLineEndings} from '../src/util';
 
 import * as testSupport from './test_support';
 
+chaiUse(chaiDiff);
+
 // Set TEST_FILTER=foo to only run tests from the foo package.
 // Set TEST_FILTER=foo/bar to also filter for the '/bar' file.
 const TEST_FILTER = (() => {
@@ -92,7 +96,7 @@ function compareAgainstGolden(
       }
     }
   } else {
-    expect(output).to.equal(golden, `${goldenPath}`);
+    expect(output).not.differentFrom(golden!, {});
   }
 }
 

test_files/type/type.js

@@ -23,6 +23,8 @@ let /** @type {{optional: (undefined|string|boolean)}} */ typeOptionalUnion = {}
 let /** @type {function(): void} */ typeFunc = function () { };
 let /** @type {function(number, ?): string} */ typeFunc2 = function (a, b) { return ''; };
 let /** @type {function(number, function(number): string): string} */ typeFunc3 = function (x, cb) { return ''; };
+let /** @type {function(number, (undefined|!Object)=): string} */ typeFuncOptionalArg;
+let /** @type {function(number, ...number): void} */ typeFuncVarArgs;
 /**
  * @param {function(number): number} callback
  * @return {void}

test_files/type/type.ts

@@ -27,8 +27,9 @@ let typeOptionalUnion: {optional?: string|boolean} = {};
 
 let typeFunc: () => void = function() {};
 let typeFunc2: (a: number, b: any) => string = function(a, b) { return ''; };
-let typeFunc3: (x: number, callback: (x: number) => string) => string = function(x, cb) { return ''; }
-// TODO: let typeFunc4: (a: number, ...args: number[]) => void;
+let typeFunc3: (x: number, callback: (x: number) => string) => string = function(x, cb) { return ''; };
+let typeFuncOptionalArg: (a: number, b?: {}) => string;
+let typeFuncVarArgs: (a: number, ...args: number[]) => void;
 
 function typeCallback(callback: (val: number) => number) { }
 typeCallback(val => val + 1);

yarn.lock

@@ -173,6 +173,12 @@ camelcase@^2.0.1:
   version "2.1.1"
   resolved "https://registry.yarnpkg.com/camelcase/-/camelcase-2.1.1.tgz#7c1d16d679a1bbe59ca02cacecfb011e201f5a1f"
 
+chai-diff@^1.0.1:
+  version "1.0.1"
+  resolved "https://registry.yarnpkg.com/chai-diff/-/chai-diff-1.0.1.tgz#6c66894700d80cd90350ab4e4403625d4f53a1c1"
+  dependencies:
+    diff "^2.2.1"
+
 chai@^3.5.0:
   version "3.5.0"
   resolved "https://registry.yarnpkg.com/chai/-/chai-3.5.0.tgz#4d02637b067fe958bdbfdd3a40ec56fef7373247"
@@ -306,7 +312,7 @@ diff@3.2.0:
   version "3.2.0"
   resolved "https://registry.yarnpkg.com/diff/-/diff-3.2.0.tgz#c9ce393a4b7cbd0b058a725c93df299027868ff9"
 
-diff@^2.0.2:
+diff@^2.0.2, diff@^2.2.1:
   version "2.2.3"
   resolved "https://registry.yarnpkg.com/diff/-/diff-2.2.3.tgz#60eafd0d28ee906e4e8ff0a52c1229521033bf99"