Add TODOs for ES2015 improvements

Author: dlarocque

packages/firestore/test/unit/specs/spec_rpc_error.ts

@@ -33,7 +33,8 @@ export class RpcError extends Error {
       this.code = mapRpcCodeFromCode(code);
     }
 
-    // TODO(mikelehen): Error is a function not a class in ES5 so extending it
+    // TODO(dlarocque): Improve this since we no longer target ES5.
+    // Error is a function not a class in ES5 so extending it
     // doesn't really work without hackery.  Just manually set .message for now.
     this.message = message;
   }

packages/installations/src/testing/compare-headers.ts

@@ -18,6 +18,7 @@
 import { AssertionError, expect } from 'chai';
 
 // Trick TS since it's set to target ES5.
+// TODO(dlarocque): Improve this since we no longer target ES5.
 declare class HeadersWithEntries extends Headers {
   entries?(): Iterable<[string, string]>;
 }

packages/messaging/rollup.config.js

@@ -78,7 +78,7 @@ const cjsBuilds = [
   // builds (contingent on updating the `idb` dependency). When we add
   // ESM Node builds, test with Nuxt and other SSR frameworks to see if
   // this can then be removed.
-  // TODO (dlarocque): ask Christina about this
+  // TODO(dlarocque): ask Christina about this
   {
     input: 'src/index.sw.ts',
     output: { file: pkg['sw-main'], format: 'cjs', sourcemap: true },

packages/messaging/src/testing/compare-headers.ts

@@ -20,6 +20,7 @@ import './setup';
 import { expect } from 'chai';
 
 // Trick TS since it's set to target ES5.
+// TODO(dlarocque): Improve this since we no longer target ES5.
 declare class HeadersWithEntries extends Headers {
   entries?(): Iterable<[string, string]>;
 }

packages/remote-config/rollup.config.js

@@ -26,9 +26,6 @@ import pkg from './package.json';
 const deps = Object.keys(
   Object.assign({}, pkg.peerDependencies, pkg.dependencies)
 );
-/**
- * ES5 Builds
- */
 
 const buildPlugins = [
   typescriptPlugin({

packages/util/src/crypt.ts

@@ -104,6 +104,7 @@ interface Base64 {
 // We define it as an object literal instead of a class because a class compiled down to es5 can't
 // be treeshaked. https://github.com/rollup/rollup/issues/1691
 // Static lookup maps, lazily populated by init_()
+// TODO(dlarocque): Define this as a class, since we no longer target ES5.
 export const base64: Base64 = {
   /**
    * Maps bytes to characters.

packages/util/src/errors.ts

@@ -86,6 +86,8 @@ export class FirebaseError extends Error {
 
     // Fix For ES5
     // https://github.com/Microsoft/TypeScript-wiki/blob/master/Breaking-Changes.md#extending-built-ins-like-error-array-and-map-may-no-longer-work
+    // TODO(dlarocque): Replace this with `new.target`: https://www.typescriptlang.org/docs/handbook/release-notes/typescript-2-2.html#support-for-newtarget
+    //                   which we can now use since we no longer target ES5.
     Object.setPrototypeOf(this, FirebaseError.prototype);
 
     // Maintains proper stack trace for where our error was thrown.

packages/vertexai/src/errors.ts

@@ -56,6 +56,8 @@ export class VertexAIError extends FirebaseError {
 
     // Allows instanceof VertexAIError in ES5/ES6
     // https://github.com/Microsoft/TypeScript-wiki/blob/master/Breaking-Changes.md#extending-built-ins-like-error-array-and-map-may-no-longer-work
+    // TODO(dlarocque): Replace this with `new.target`: https://www.typescriptlang.org/docs/handbook/release-notes/typescript-2-2.html#support-for-newtarget
+    //                   which we can now use since we no longer target ES5.
     Object.setPrototypeOf(this, VertexAIError.prototype);
 
     // Since Error is an interface, we don't inherit toString and so we define it ourselves.