Refactor rollup config, add unit test

Also, make multiple rootDirs work in rollup resolution

internal/collect_es6_sources.bzl

@@ -37,17 +37,16 @@ def collect_es6_sources(ctx):
 
   rerooted_files = []
   for file in non_rerooted_files.to_list():
-    if file.short_path.startswith(".."):
-      rerooted_path = "/".join(file.short_path.split("/")[1:])
-    else:
-      rerooted_path = "/".join([ctx.workspace_name, file.short_path])
+    path = file.short_path
+    if (path.startswith("../")):
+      path = "external/" + path[3:]
 
     rerooted_file = ctx.actions.declare_file(
       "%s.es6/%s" % (
         ctx.label.name,
         # the .closure.js filename is an artifact of the rules_typescript layout
         # TODO(mrmeku): pin to end of string, eg. don't match foo.closure.jso.js
-        rerooted_path.replace(".closure.js", ".js")))
+        path.replace(".closure.js", ".js")))
     # Cheap way to create an action that copies a file
     # TODO(alexeagle): discuss with Bazel team how we can do something like
     # runfiles to create a re-rooted tree. This has performance implications.

internal/e2e/rollup/BUILD.bazel

@@ -5,6 +5,7 @@ filegroup(
     srcs = glob([
         "node_modules/**/*",
     ]),
+    visibility = ["//internal:__subpackages__"],
 )
 
 load("//:defs.bzl", "rollup_bundle")

internal/e2e/rollup/foo.js

@@ -3,26 +3,6 @@ import {fum} from 'fumlib';
 
 console.log(`Hello, ${name} in ${fum}`);
 
-/** This class should be tree-shaken away */
-var ReflectiveInjector = /** @class */ (function () {
-  function ReflectiveInjector() {
-  }
-  return ReflectiveInjector;
-}());
-
-/** This class should be tree-shaken away */
-var ReflectiveInjector_ = /** @class */ (function () {
-  function ReflectiveInjector_(_providers, _parent) {}
-  ReflectiveInjector_.prototype.resolveAndInstantiate =
-  function (provider) {
-    return ReflectiveInjector;
-  };
-  Object.defineProperty(ReflectiveInjector_, "displayName", "foo");
-  return ReflectiveInjector_;
-}());
-
-ngDevMode && console.log("Should have been tree-shaken");
-
 // Test for sequences = false
 class A {
   a() { return document.a; }

internal/e2e/rollup/package.json

@@ -1,5 +1,7 @@
 {
   "devDependencies": {
-    "jasmine": "~2.8.0"
+    "jasmine": "~2.8.0",
+    "rollup": "0.52.3",
+    "rollup-plugin-node-resolve": "3.0.0"
   }
 }

internal/e2e/rollup/rollup.spec.js

@@ -3,7 +3,7 @@ const fs = require('fs');
 function read(relativePath) {
   // TODO(#32) Can shorten the path if https://github.com/bazelbuild/rules_nodejs/issues/32 is resolved
   const path = `build_bazel_rules_nodejs/internal/e2e/rollup/${relativePath}`;
-  return fs.readFileSync(require.resolve(path), { encoding: 'utf-8' });
+  return fs.readFileSync(require.resolve(path), { encoding: 'utf-8' }).replace(/\r\n/g, '\n');
 }
 describe('bundling', () => {
   it('should work', () => {
@@ -12,4 +12,4 @@ describe('bundling', () => {
   it('should produce a debug bundle', () => {
     expect(read('bundle.min_debug.js')).toEqual(read('bundle-min-debug_golden.js'));
   });
-});
+});