feat(@angular-devkit/build-optimizer): add rollup plugin

alexeagle · hansl · commit 562b85cdf5b1 · 2018-06-05T17:55:15.000-07:00
Also add a bazel build file so angular/angular can have a source
dependency on it.
diff --git a/packages/angular_devkit/build_optimizer/BUILD b/packages/angular_devkit/build_optimizer/BUILD
@@ -0,0 +1,32 @@
+# 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
+
+licenses(["notice"])  # MIT
+
+load("@build_bazel_rules_typescript//:defs.bzl", "ts_library")
+
+package(default_visibility = ["//visibility:public"])
+
+ts_library(
+    name = "lib",
+    srcs = glob(
+        ["**/*.ts"],
+        # Currently, this library is used only with the rollup plugin.
+        # To make it simpler for downstream repositories to compile this, we
+        # neither provide compile-time deps as an `npm_install` rule, nor do we
+        # expect the downstream repository to install @types/webpack[-*]
+        # So we exclude files that depend on webpack typings.
+        exclude = [
+            "src/build-optimizer/webpack-loader.ts",
+            "src/purify/**",
+            "src/index.ts",
+            "**/*_spec.ts",
+        ],
+    ),
+    # Note, intentionally no node_modules attribute - so it will use the
+    # compile-time deps in the downstream repository's //:node_modules.
+    # This creates the assumption that every consumer does have that target.
+    tsconfig = "//:tsconfig.json",
+)
diff --git a/packages/angular_devkit/build_optimizer/src/build-optimizer/rollup-plugin.ts b/packages/angular_devkit/build_optimizer/src/build-optimizer/rollup-plugin.ts
@@ -0,0 +1,49 @@
+/**
+ * @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 This adapts the buildOptimizer to run over each file as it is
+ * processed by Rollup. We must do this since buildOptimizer expects to see the
+ * ESModules in the input sources, and therefore cannot run on the rollup output
+ */
+
+import * as path from 'path';
+import { RawSourceMap } from 'source-map';
+import { buildOptimizer } from './build-optimizer';
+
+const DEBUG = false;
+
+export interface Options {
+  sideEffectFreeModules?: string[];
+}
+
+export default function optimizer(options: Options) {
+  return {
+    name: 'build-optimizer',
+    transform: (content: string, id: string): {code: string, map: RawSourceMap}|null => {
+      const isSideEffectFree = options.sideEffectFreeModules &&
+        options.sideEffectFreeModules.some(m => id.indexOf(m) >= 0);
+      const { content: code, sourceMap: map } = buildOptimizer({
+        content, inputFilePath: id, emitSourceMap: true, isSideEffectFree,
+      });
+      if (!code) {
+        if (DEBUG) {
+          console.error('no transforms produced by buildOptimizer for '
+             + path.relative(process.cwd(), id));
+        }
+
+        return null;
+      }
+      if (!map) {
+        throw new Error('no sourcemap produced by buildOptimizer');
+      }
+
+      return { code, map };
+    },
+  };
+}
