feat(tools): do not invoke tasks if not required

In dev executes tasks only when a specific file type has changed.
Fix #1432.

tools/tasks/assets_task.ts

@@ -0,0 +1,10 @@
+import { Task } from './task';
+
+export abstract class AssetsTask extends Task {
+  shallRun(files: String[]) {
+    return files.reduce((a, f) => {
+      return a || (!f.endsWith('.css') && !f.endsWith('.sass') &&
+       !f.endsWith('.scss') && !f.endsWith('.ts'));
+    }, false);
+  }
+}

tools/tasks/css_task.ts

@@ -0,0 +1,10 @@
+import { Task } from './task';
+
+export abstract class CssTask extends Task {
+
+  shallRun(files: String[]) {
+    return files.some(f =>
+      f.endsWith('.css') || f.endsWith('.sass') || f.endsWith('.scss'));
+  }
+
+}

tools/tasks/seed/build.assets.dev.ts

@@ -1,20 +1,25 @@
 import * as gulp from 'gulp';
 import { join } from 'path';
 
+import { AssetsTask } from '../assets_task';
 import Config from '../../config';
 
 /**
  * Executes the build process, copying the assets located in `src/client` over to the appropriate
  * `dist/dev` directory.
  */
-export = () => {
-  let paths: string[] = [
-    join(Config.APP_SRC, '**'),
-    '!' + join(Config.APP_SRC, '**', '*.ts'),
-    '!' + join(Config.APP_SRC, '**', '*.scss'),
-    '!' + join(Config.APP_SRC, '**', '*.sass')
-  ].concat(Config.TEMP_FILES.map((p) => { return '!' + p; }));
+export =
+  class BuildAssetsTask extends AssetsTask {
+    run() {
+      let paths: string[] = [
+	join(Config.APP_SRC, '**'),
+	'!' + join(Config.APP_SRC, '**', '*.ts'),
+	'!' + join(Config.APP_SRC, '**', '*.scss'),
+	'!' + join(Config.APP_SRC, '**', '*.sass')
+	    ].concat(Config.TEMP_FILES.map((p) => { return '!' + p; }));
+
+      return gulp.src(paths)
+	.pipe(gulp.dest(Config.APP_DEST));
+    }
+  };
 
-  return gulp.src(paths)
-    .pipe(gulp.dest(Config.APP_DEST));
-};

tools/tasks/seed/build.bundle.rxjs.ts

@@ -4,7 +4,7 @@
 
 const Builder = require('systemjs-builder');
 
-export = (done:any) => {
+export = (done: any) => {
   const options = {
     normalize: true,
     runtime: false,

tools/tasks/seed/build.html_css.ts

@@ -7,6 +7,7 @@ import * as util from 'gulp-util';
 import { join } from 'path';
 
 import Config from '../../config';
+import { CssTask } from '../css_task';
 
 const plugins = <any>gulpLoadPlugins();
 const cleanCss = require('gulp-clean-css');
@@ -147,4 +148,14 @@ function processExternalCss() {
 /**
  * Executes the build process, processing the HTML and CSS files.
  */
-export = () => merge(processComponentStylesheets(), prepareTemplates(), processExternalStylesheets());
+export =
+  class BuildHtmlCss extends CssTask {
+
+    shallRun(files: String[]) {
+      return super.shallRun(files) || files.some(f => f.endsWith('.html'));
+    }
+
+    run() {
+      return merge(processComponentStylesheets(), prepareTemplates(), processExternalStylesheets());
+    }
+  };

tools/tasks/seed/build.js.dev.ts

@@ -1,3 +1,4 @@
+
 import * as gulp from 'gulp';
 import * as gulpLoadPlugins from 'gulp-load-plugins';
 import * as merge from 'merge-stream';
@@ -6,6 +7,7 @@ import { join/*, sep, relative*/ } from 'path';
 
 import Config from '../../config';
 import { makeTsProject, templateLocals } from '../../utils';
+import { TypeScriptTask } from '../typescript_task';
 
 const plugins = <any>gulpLoadPlugins();
 
@@ -17,60 +19,64 @@ let typedBuildCounter = Config.TYPED_COMPILE_INTERVAL; // Always start with the
  * Executes the build process, transpiling the TypeScript files (except the spec and e2e-spec files) for the development
  * environment.
  */
-export = () => {
-  let tsProject: any;
-  let typings = gulp.src([
-    Config.TOOLS_DIR + '/manual_typings/**/*.d.ts'
-  ]);
-  let src = [
-    join(Config.APP_SRC, '**/*.ts'),
-    '!' + join(Config.APP_SRC, '**/*.spec.ts'),
-    '!' + join(Config.APP_SRC, '**/*.e2e-spec.ts'),
-    '!' + join(Config.APP_SRC, `**/${Config.NG_FACTORY_FILE}.ts`)
-  ];
+export =
+  class BuildJsDev extends TypeScriptTask {
+    run() {
+      let tsProject: any;
+      let typings = gulp.src([
+        Config.TOOLS_DIR + '/manual_typings/**/*.d.ts'
+      ]);
+      let src = [
+        join(Config.APP_SRC, '**/*.ts'),
+        '!' + join(Config.APP_SRC, '**/*.spec.ts'),
+        '!' + join(Config.APP_SRC, '**/*.e2e-spec.ts'),
+        '!' + join(Config.APP_SRC, `**/${Config.NG_FACTORY_FILE}.ts`)
+      ];
 
-  let projectFiles = gulp.src(src);
-  let result: any;
-  let isFullCompile = true;
+      let projectFiles = gulp.src(src);
+      let result: any;
+      let isFullCompile = true;
 
-  // Only do a typed build every X builds, otherwise do a typeless build to speed things up
-  if (typedBuildCounter < Config.TYPED_COMPILE_INTERVAL) {
-    isFullCompile = false;
-    tsProject = makeTsProject({isolatedModules: true});
-    projectFiles = projectFiles.pipe(plugins.cached());
-    util.log('Performing typeless TypeScript compile.');
-  } else {
-    tsProject = makeTsProject();
-    projectFiles = merge(typings, projectFiles);
-  }
+      // Only do a typed build every X builds, otherwise do a typeless build to speed things up
+      if (typedBuildCounter < Config.TYPED_COMPILE_INTERVAL) {
+        isFullCompile = false;
+        tsProject = makeTsProject({isolatedModules: true});
+        projectFiles = projectFiles.pipe(plugins.cached());
+        util.log('Performing typeless TypeScript compile.');
+      } else {
+        tsProject = makeTsProject();
+        projectFiles = merge(typings, projectFiles);
+      }
 
-  result = projectFiles
-    .pipe(plugins.plumber())
-    .pipe(plugins.sourcemaps.init())
-    .pipe(tsProject())
-    .on('error', () => {
-      typedBuildCounter = Config.TYPED_COMPILE_INTERVAL;
-    });
+      result = projectFiles
+        .pipe(plugins.plumber())
+        .pipe(plugins.sourcemaps.init())
+        .pipe(tsProject())
+        .on('error', () => {
+          typedBuildCounter = Config.TYPED_COMPILE_INTERVAL;
+        });
 
-  if (isFullCompile) {
-    typedBuildCounter = 0;
-  } else {
-    typedBuildCounter++;
-  }
+      if (isFullCompile) {
+        typedBuildCounter = 0;
+      } else {
+        typedBuildCounter++;
+      }
 
-  return result.js
-    .pipe(plugins.sourcemaps.write())
-// Use for debugging with Webstorm/IntelliJ
-// https://github.com/mgechev/angular2-seed/issues/1220
-//    .pipe(plugins.sourcemaps.write('.', {
-//      includeContent: false,
-//      sourceRoot: (file: any) =>
-//        relative(file.path, PROJECT_ROOT + '/' + APP_SRC).replace(sep, '/') + '/' + APP_SRC
-//    }))
-    .pipe(plugins.template(Object.assign(
-      templateLocals(), {
-        SYSTEM_CONFIG_DEV: jsonSystemConfig
+      return result.js
+        .pipe(plugins.sourcemaps.write())
+        // Use for debugging with Webstorm/IntelliJ
+        // https://github.com/mgechev/angular2-seed/issues/1220
+        //    .pipe(plugins.sourcemaps.write('.', {
+        //      includeContent: false,
+        //      sourceRoot: (file: any) =>
+        //        relative(file.path, PROJECT_ROOT + '/' + APP_SRC).replace(sep, '/') + '/' + APP_SRC
+        //    }))
+        .pipe(plugins.template(Object.assign(
+          templateLocals(), {
+            SYSTEM_CONFIG_DEV: jsonSystemConfig
+          }
+         )))
+        .pipe(gulp.dest(Config.APP_DEST));
       }
-     )))
-    .pipe(gulp.dest(Config.APP_DEST));
-};
+  };
+

tools/tasks/task.ts

@@ -0,0 +1,25 @@
+/**
+ * Base class for all tasks.
+ */
+export abstract class Task {
+  /**
+   * Override this task if you want to implement some custom
+   * task activation mechanism. By default each task will be always executed.
+   *
+   * @param {string[]} files A list of files changed since the previous watch.
+   */
+  shallRun(files: string[]): boolean {
+    return true;
+  }
+
+  /**
+   * Implements your task behavior.
+   *
+   * @param {any} done A function which should be activated once your task completes.
+   * @return {ReadWriteStream | Promise<any> | void} This method can either return a promise
+   * which should be resolved once your task execution completes, a stream
+   * which should throw an end event once your task execution completes
+   * or nothing in case you will manually invoke the `done` method.
+   */
+  abstract run(done?: any): any | Promise<any> | void;
+}

tools/tasks/typescript_task.ts

@@ -0,0 +1,9 @@
+import { Task } from './task';
+
+export abstract class TypeScriptTask extends Task {
+  shallRun(files: String[]) {
+    return files.reduce((a, f) => {
+      return a || f.endsWith('.ts');
+    }, false);
+  }
+}

tools/utils/seed/code_change_tools.ts

@@ -3,6 +3,34 @@ import * as browserSync from 'browser-sync';
 
 import Config from '../../config';
 
+class ChangeFileManager {
+  private _files: string[] = [];
+  private _pristine = true;
+
+  get lastChangedFiles() {
+    return this._files.slice();
+  }
+
+  get pristine() {
+    return this._pristine;
+  }
+
+  addFile(file: string) {
+    this._pristine = false;
+    this._files.push(file);
+  }
+
+  addFiles(files: string[]) {
+    files.forEach(f => this.addFile(f));
+  }
+
+  clear() {
+    this._files = [];
+  }
+}
+
+export let changeFileManager = new ChangeFileManager();
+
 /**
  * Initialises BrowserSync with the configuration defined in seed.config.ts (or if overriden: project.config.ts).
  */

tools/utils/seed/tasks_tools.ts

@@ -5,6 +5,9 @@ import * as isstream from 'isstream';
 import { join } from 'path';
 import * as tildify from 'tildify';
 
+import { changeFileManager } from './code_change_tools';
+import { Task } from '../../tasks/task';
+
 /**
  * Loads the tasks within the given path.
  * @param {string} path - The path to load the tasks from.
@@ -14,6 +17,33 @@ export function loadTasks(path: string): void {
   readDir(path, taskname => registerTask(taskname, path));
 }
 
+function normalizeTask(task: any, taskName: string) {
+  if (task instanceof Task) {
+    return task;
+  }
+  if (task.prototype && task.prototype instanceof Task) {
+    return new task();
+  }
+  if (typeof task === 'function') {
+    return new class AnonTask extends Task {
+      run(done: any) {
+	if (task.length > 0) {
+	  return task(done);
+	}
+
+	const taskReturnedValue = task();
+	if (isstream(taskReturnedValue)) {
+	  return taskReturnedValue;
+	}
+
+	done();
+      }
+    };
+  }
+  throw new Error(taskName + ' should be instance of the class ' +
+    'Task, a function or a class which extends Task.');
+}
+
 /**
  * Registers the task by the given taskname and path.
  * @param {string} taskname - The name of the task.
@@ -24,19 +54,13 @@ function registerTask(taskname: string, path: string): void {
   util.log('Registering task', util.colors.yellow(tildify(TASK)));
 
   gulp.task(taskname, (done: any) => {
-    const task = require(TASK);
-    if (task.length > 0) {
-      return task(done);
-    }
+    const task = normalizeTask(require(TASK), TASK);
 
-    const taskReturnedValue = task();
-    if (isstream(taskReturnedValue)) {
-      return taskReturnedValue;
+    if (changeFileManager.pristine || task.shallRun(changeFileManager.lastChangedFiles)) {
+      return task.run(done);
+    } else {
+      done();
     }
-
-    // TODO: add promise handling if needed at some point.
-
-    done();
   });
 }
 

tools/utils/seed/watch.ts

@@ -3,6 +3,7 @@ import { join } from 'path';
 import * as runSequence from 'run-sequence';
 
 import Config from '../../config';
+import { changeFileManager } from './code_change_tools';
 import { notifyLiveReload } from '../../utils';
 
 const plugins = <any>gulpLoadPlugins();
@@ -17,8 +18,13 @@ export function watch(taskname: string) {
       join(Config.APP_SRC,'**')
     ].concat(Config.TEMP_FILES.map((p) => { return '!'+p; }));
 
-    plugins.watch(paths, (e:any) =>
-      runSequence(taskname, () => notifyLiveReload(e))
-    );
+    plugins.watch(paths, (e: any) => {
+      changeFileManager.addFile(e.path);
+
+      runSequence(taskname, () => {
+	changeFileManager.clear();
+	notifyLiveReload(e);
+      });
+    });
   };
 }