build(broccoli): allow rebuild() to return DiffResult

Plugins may opt to return a DiffResult themselves, and avoid the need to calculate a diff Closes angular#2514

Author: caitp

tools/broccoli/diffing-broccoli-plugin.ts

@@ -28,7 +28,7 @@ export function wrapDiffingPlugin(pluginClass): DiffingPluginWrapperFactory {
 
 
 export interface DiffingBroccoliPlugin {
- rebuild(diff: (DiffResult | DiffResult[])): (Promise<any>| void);
+ rebuild(diff: (DiffResult | DiffResult[])): (Promise<DiffResult | void>| DiffResult | void);
  cleanup ? () : void;
 }
 
@@ -52,6 +52,8 @@ class DiffingPluginWrapper implements BroccoliTree {
  cachePath = null;
  outputPath = null;
 
+ private diffResult: DiffResult = null;
+
  constructor(private pluginClass, private wrappedPluginArguments) {
  if (Array.isArray(wrappedPluginArguments[0])) {
  this.inputTrees = this.stabilizeTrees(wrappedPluginArguments[0]);
@@ -62,33 +64,59 @@ class DiffingPluginWrapper implements BroccoliTree {
  this.description = this.pluginClass.name;
  }
 
- private calculateDiff(firstRun: boolean): (DiffResult | DiffResult[]) {
- // TODO(caitp): optionally log trees based on environment variable or
- // command line option. It may be worth logging for trees where elapsed
- // time exceeds some threshold, like 10ms.
- if (this.treeDiffer) {
- return this.treeDiffer.diffTree();
- } else if (this.treeDiffers) {
- return this.treeDiffers.map((treeDiffer) => treeDiffer.diffTree());
+ private getDiffResult(): (DiffResult | DiffResult[]) {
+ let returnOrCalculateDiffResult = (tree, index) => {
+ // returnOrCalculateDiffResult will do one of two things:
+ //
+ // If `this.diffResult` is null, calculate a DiffResult using TreeDiffer
+ // for the input tree.
+ //
+ // Otherwise, `this.diffResult` was produced from the output of the
+ // inputTree's rebuild() method, and can be used without being checked.
+ // Set `this.diffResult` to null and return the previously stored value.
+ if (!tree.diffResult) {
+ let differ = index === false ? this.treeDiffer : this.treeDiffers[index];
+ return differ.diffTree();
+ }
+ let diffResult = tree.diffResult;
+ tree.diffResult = null;
+ return diffResult;
+ };
+
+ if (this.inputTrees) {
+ return this.inputTrees.map(returnOrCalculateDiffResult);
+ } else if (this.inputTree) {
+ return returnOrCalculateDiffResult(this.inputTree, false);
  } else {
  throw new Error("Missing TreeDiffer");
  }
  }
 
+ private maybeStoreDiffResult(value: (DiffResult | void)) {
+ this.diffResult = value ? <DiffResult>(value) : null;
+ }
 
  rebuild() {
  try {
  let firstRun = !this.initialized;
  this.init();
 
- let diffResult = this.calculateDiff(firstRun);
+ let diffResult = this.getDiffResult();
 
- var rebuildPromise = this.wrappedPlugin.rebuild(diffResult);
+ let result = this.wrappedPlugin.rebuild(diffResult);
 
- if (rebuildPromise) {
- return (<Promise<any>>rebuildPromise).then(this.relinkOutputAndCachePaths.bind(this));
+ if (result) {
+ let resultPromise = <Promise<DiffResult | void>>(result);
+ if (resultPromise.then) {
+ // rebuild() -> Promise<>
+ return resultPromise.then((result: (DiffResult | void)) => {
+ this.maybeStoreDiffResult(result);
+ this.relinkOutputAndCachePaths();
+ });
+ }
  }
 
+ this.maybeStoreDiffResult(<(DiffResult | void)>(result));
  this.relinkOutputAndCachePaths();
  } catch (e) {
  e.message = `[${this.description}]: ${e.message}`;

tools/broccoli/tree-differ.ts

@@ -121,25 +121,28 @@ export class TreeDiffer {
 }
 
 
-export interface DiffResult {
- addedPaths: string[];
- changedPaths: string[];
- removedPaths: string[];
- log(verbose: boolean): void;
- toString(): string;
-}
+export class DiffResult {
+ public addedPaths: string[] = [];
+ public changedPaths: string[] = [];
+ public removedPaths: string[] = [];
+
+ constructor(public label: string = '') {}
 
+ log(verbose: boolean): void {}
 
-class DirtyCheckingDiffResult {
+ toString(): string {
+ // TODO(@caitp): more meaningful logging
+ return '';
+ }
+}
+
+class DirtyCheckingDiffResult extends DiffResult {
  public filesChecked: number = 0;
  public directoriesChecked: number = 0;
- public addedPaths: string[] = [];
- public changedPaths: string[] = [];
- public removedPaths: string[] = [];
  public startTime: number = Date.now();
  public endTime: number = null;
 
- constructor(public label: string, public directoryName: string) {}
+ constructor(label: string, public directoryName: string) { super(label); }
 
  toString() {
  return `${pad(this.label, 30)}, ${pad(this.endTime - this.startTime, 5)}ms, ` +