feat(@angular-devkit/schematics): add lifecycle hooks to workflow

hansl · hansl · commit f04f50714bb9 · 2018-06-05T17:55:17.000-07:00
This will allow us to show logs at each new phases, for example, instead of only at the end. Reference: angular#10155
diff --git a/packages/angular_devkit/schematics/src/workflow/interface.ts b/packages/angular_devkit/schematics/src/workflow/interface.ts
@@ -21,6 +21,12 @@ export interface WorkflowExecutionContext extends RequiredWorkflowExecutionConte
   allowPrivate?: boolean;
 }
 
+export interface LifeCycleEvent {
+  kind: 'start' | 'end'  // Start and end of the full workflow execution.
+    | 'workflow-start' | 'workflow-end'  // Start and end of a workflow execution. Can be more.
+    | 'post-tasks-start' | 'post-tasks-end';  // Start and end of the post tasks execution.
+}
+
 export interface Workflow {
   readonly context: Readonly<WorkflowExecutionContext>;
 
diff --git a/packages/angular_devkit/schematics/tools/workflow/node-workflow.ts b/packages/angular_devkit/schematics/tools/workflow/node-workflow.ts
@@ -17,6 +17,7 @@ import {
   workflow,
 } from '@angular-devkit/schematics';  // tslint:disable-line:no-implicit-dependencies
 import { EMPTY, Observable, Subject, concat, of, throwError } from 'rxjs';
+import { reduce, tap } from 'rxjs/internal/operators';
 import { concatMap, ignoreElements, map } from 'rxjs/operators';
 import { NodeModulesEngineHost, validateOptionsWithSchema } from '..';
 import { DryRunEvent } from '../../src/sink/dryrun';
@@ -28,6 +29,7 @@ export class NodeWorkflow implements workflow.Workflow {
   protected _registry: schema.CoreSchemaRegistry;
 
   protected _reporter: Subject<DryRunEvent> = new Subject();
+  protected _lifeCycle: Subject<workflow.LifeCycleEvent> = new Subject();
 
   protected _context: workflow.WorkflowExecutionContext[];
 
@@ -85,12 +87,19 @@ export class NodeWorkflow implements workflow.Workflow {
   get reporter(): Observable<DryRunEvent> {
     return this._reporter.asObservable();
   }
+  get lifeCycle(): Observable<workflow.LifeCycleEvent> {
+    return this._lifeCycle.asObservable();
+  }
 
   execute(
     options: Partial<workflow.WorkflowExecutionContext> & workflow.RequiredWorkflowExecutionContext,
   ): Observable<void> {
     const parentContext = this._context[this._context.length - 1];
 
+    if (!parentContext) {
+      this._lifeCycle.next({ kind: 'start' });
+    }
+
     /** Create the collection and the schematic. */
     const collection = this._engine.createCollection(options.collection);
     // Only allow private schematics if called from the same collection.
@@ -110,6 +119,8 @@ export class NodeWorkflow implements workflow.Workflow {
       error = error || (event.kind == 'error');
     });
 
+    this._lifeCycle.next({ kind: 'workflow-start' });
+
     const context = {
       ...options,
       debug: options.debug || false,
@@ -145,15 +156,28 @@ export class NodeWorkflow implements workflow.Workflow {
       ),
       concat(new Observable<void>(obs => {
         if (!this._options.dryRun) {
-          this._engine.executePostTasks().subscribe(obs);
+          this._lifeCycle.next({ kind: 'post-tasks-start' });
+          this._engine.executePostTasks()
+            .pipe(
+              reduce(() => {}),
+              tap(() => this._lifeCycle.next({ kind: 'post-tasks-end' })),
+            )
+            .subscribe(obs);
         } else {
           obs.complete();
         }
       })),
       concat(new Observable(obs => {
+        this._lifeCycle.next({ kind: 'workflow-end' });
         this._context.pop();
+
+        if (this._context.length == 0) {
+          this._lifeCycle.next({ kind: 'end' });
+        }
+
         obs.complete();
       })),
-    ).pipe(ignoreElements());
+      reduce(() => {}),
+    );
   }
 }
diff --git a/packages/angular_devkit/schematics_cli/bin/schematics.ts b/packages/angular_devkit/schematics_cli/bin/schematics.ts
@@ -138,6 +138,7 @@ let nothingDone = true;
 // Logging queue that receives all the messages to show the users. This only get shown when no
 // errors happened.
 const loggingQueue: string[] = [];
+let error = false;
 
 /**
  * Logs out dry run events.
@@ -154,6 +155,8 @@ workflow.reporter.subscribe((event: DryRunEvent) => {
 
   switch (event.kind) {
     case 'error':
+      error = true;
+
       const desc = event.description == 'alreadyExist' ? 'already exists' : 'does not exist.';
       logger.warn(`ERROR! ${event.path} ${desc}.`);
       break;
@@ -177,6 +180,21 @@ workflow.reporter.subscribe((event: DryRunEvent) => {
 });
 
 
+/**
+ * Listen to lifecycle events of the workflow to flush the logs between each phases.
+ */
+workflow.lifeCycle.subscribe(event => {
+  if (event.kind == 'workflow-end' || event.kind == 'post-tasks-start') {
+    if (!error) {
+      // Flush the log queue and clean the error state.
+      loggingQueue.forEach(log => logger.info(log));
+    }
+
+    error = false;
+  }
+});
+
+
 /**
  * Remove every options from argv that we support in schematics itself.
  */
@@ -235,9 +253,6 @@ workflow.execute({
     process.exit(1);
   },
   complete() {
-    // Output the logging queue, no error happened.
-    loggingQueue.forEach(log => logger.info(log));
-
     if (nothingDone) {
       logger.info('Nothing to be done.');
     }
