feat(broccoli): add incremental dartfmt plugin

Closes #2211

tools/broccoli/angular_builder.d.ts

@@ -0,0 +1,5 @@
+interface AngularBuilderOptions {
+  outputPath: string;
+  dartSDK?: any;
+  logs?: any;
+}

tools/broccoli/angular_builder.ts

@@ -7,7 +7,6 @@ var path = require('path');
 var printSlowTrees = require('broccoli-slow-trees');
 var Q = require('q');
 
-
 /**
  * BroccoliBuilder facade for all of our build pipelines.
  */
@@ -16,9 +15,9 @@ export class AngularBuilder {
   private browserDevBuilder: BroccoliBuilder;
   private browserProdBuilder: BroccoliBuilder;
   private dartBuilder: BroccoliBuilder;
+  private outputPath: string;
 
-
-  constructor(private outputPath: string) {}
+  constructor(public options: AngularBuilderOptions) { this.outputPath = options.outputPath; }
 
 
   public rebuildBrowserDevTree(): Promise<BuildResult> {
@@ -75,7 +74,12 @@ export class AngularBuilder {
 
 
   private makeDartBuilder(): BroccoliBuilder {
-    let tree = makeDartTree(path.join(this.outputPath, 'dart'));
+    let options = {
+      outputPath: path.join(this.outputPath, 'dart'),
+      dartSDK: this.options.dartSDK,
+      logs: this.options.logs
+    };
+    let tree = makeDartTree(options);
     return new broccoli.Builder(tree);
   }
 

tools/broccoli/broccoli-dartfmt.ts

@@ -0,0 +1,47 @@
+/// <reference path="../typings/node/node.d.ts" />
+/// <reference path="../typings/fs-extra/fs-extra.d.ts" />
+import fse = require('fs-extra');
+import path = require('path');
+import {wrapDiffingPlugin, DiffingBroccoliPlugin, DiffResult} from './diffing-broccoli-plugin';
+var spawn = require('child_process').spawn;
+
+function processToPromise(process) {
+  return new Promise(function(resolve, reject) {
+    process.on('close', function(code) {
+      if (code) {
+        reject(code);
+      } else {
+        resolve();
+      }
+    });
+  });
+}
+
+class DartFormatter implements DiffingBroccoliPlugin {
+  private DARTFMT: string;
+  private verbose: boolean;
+
+  constructor(public inputPath: string, public cachePath: string, options) {
+    if (!options.dartSDK) throw new Error("Missing Dart SDK");
+    this.DARTFMT = options.dartSDK.DARTFMT;
+    this.verbose = options.logs.dartfmt;
+  }
+
+  rebuild(treeDiff: DiffResult): Promise<any> {
+    let args = ['-w'];
+    treeDiff.changedPaths.forEach((changedFile) => {
+      let sourcePath = path.join(this.inputPath, changedFile);
+      let destPath = path.join(this.cachePath, changedFile);
+      if (/\.dart$/.test(changedFile)) args.push(destPath);
+      fse.copySync(sourcePath, destPath);
+    });
+    treeDiff.removedPaths.forEach((removedFile) => {
+      let destPath = path.join(this.cachePath, removedFile);
+      fse.removeSync(destPath);
+    });
+    return processToPromise(spawn(
+        this.DARTFMT, args, {stdio: this.verbose ? 'inherit' : ['ignore', 'ignore', 'inherit']}));
+  }
+}
+
+export default wrapDiffingPlugin(DartFormatter);

tools/broccoli/trees/dart_tree.ts

@@ -1,4 +1,5 @@
 /// <reference path="../../typings/node/node.d.ts" />
+/// <reference path="../angular_builder.d.ts" />
 'use strict';
 
 import {MultiCopy} from './../multi_copy';
@@ -11,6 +12,7 @@ var renderLodashTemplate = require('broccoli-lodash');
 var replace = require('broccoli-replace');
 var stew = require('broccoli-stew');
 import ts2dart from '../broccoli-ts2dart';
+import dartfmt from '../broccoli-dartfmt';
 
 /**
  * A funnel starting at modules, including the given filters, and moving into the root.
@@ -138,11 +140,12 @@ function getDocsTree() {
   return mergeTrees([licenses, mdTree, docs]);
 }
 
-module.exports = function makeDartTree(destinationPath) {
-  var sourceTree = mergeTrees([getSourceTree(), getHtmlSourcesTree()]);
+module.exports = function makeDartTree(options: AngularBuilderOptions) {
+  var dartSources = dartfmt(getSourceTree(), {dartSDK: options.dartSDK, logs: options.logs});
+  var sourceTree = mergeTrees([dartSources, getHtmlSourcesTree()]);
   sourceTree = fixDartFolderLayout(sourceTree);
 
   var dartTree = mergeTrees([sourceTree, getTemplatedPubspecsTree(), getDocsTree()]);
 
-  return destCopy(dartTree, destinationPath);
+  return destCopy(dartTree, options.outputPath);
 };