Add enabled toggle to both GulpTask and IExecutable (microsoft#113)

* Adds an enabled toggle to both the IExecutable and Gulptask

* Changefile

* Lint errors

Author: Nicholas Pape

common/changes/nickpape-add-is-enabled-toggle-instead-of-override_2017-02-16-23-48.json

@@ -0,0 +1,10 @@
+{
+  "changes": [
+    {
+      "packageName": "@microsoft/gulp-core-build",
+      "comment": "Add an enabled toggle to IExecutable and GulpTask. Using this toggle is now preferred to overriding the isEnabled function.",
+      "type": "minor"
+    }
+  ],
+  "email": "nickpape@users.noreply.github.com"
+}

common/reviews/api/gulp-core-build.api.ts

@@ -42,13 +42,14 @@ class GulpTask<TASK_CONFIG> implements IExecutable {
   public buildConfig: IBuildConfig;
   public cleanMatch: string[];
   public copyFile(localSourcePath: string, localDestPath?: string): void;
+  public enabled: boolean;
   public execute(config: IBuildConfig): Promise<void>;
   public abstract executeTask(gulp: gulp.Gulp | GulpProxy, completeCallback?: (result?: Object) => void): Promise<Object> | NodeJS.ReadWriteStream | void;
   public fileError(filePath: string, line: number, column: number, errorCode: string, message: string): void;
   public fileExists(localPath: string): boolean;
   public fileWarning(filePath: string, line: number, column: number, warningCode: string, message: string): void;
   public getCleanMatch(buildConfig: IBuildConfig, taskConfig: TASK_CONFIG = this.taskConfig): string[];
-  public isEnabled(buildConfig: IBuildConfig): boolean;
+  public isEnabled(config?: IBuildConfig): boolean;
   protected loadSchema(): Object;
   public log(message: string): void;
   public logError(message: string): void;
@@ -108,6 +109,8 @@ interface ICustomGulpTask {
 
 // (undocumented)
 interface IExecutable {
+  // (undocumented)
+  enabled?: boolean;
   execute: (config: IBuildConfig) => Promise<void>;
   getCleanMatch?: (config: IBuildConfig, taskConfig?: any) => string[];
   isEnabled?: (config?: IBuildConfig) => boolean;

gulp-core-build/src/IExecutable.ts

@@ -10,6 +10,8 @@ export interface IExecutable {
   /** Optional name to give the task. If no name is provided, the "Running subtask" logging will be silent. */
   name?: string;
 
+  enabled?: boolean;
+
   /** Optional callback to indicate if the task is enabled or not. */
   isEnabled?: (config?: IBuildConfig) => boolean;
 

gulp-core-build/src/tasks/GulpTask.ts

@@ -36,12 +36,27 @@ export abstract class GulpTask<TASK_CONFIG> implements IExecutable {
    * will return this value.
    */
   public cleanMatch: string[];
+  /**
+   * Indicates whether this task should be executed or not. This toggle is used by isEnabled() to determine
+   * if the task should run. Since some tasks have more complex logic to determine if they should run or
+   * not, the isEnabled() function can be overriden.
+   */
+  public enabled: boolean = true;
 
   /**
    * The memoized schema for this task. Should not be utilized by child classes, use schema property instead.
    */
   private _schema: Object;
 
+  /**
+   * Overridable function which returns true if this task should be executed, or false if it should be skipped.
+   * @param buildConfig - the build configuration which should be used when determining if the task is enabled
+   * @returns true if the build is not redundant and the enabled toggle is true
+   */
+  public isEnabled(config?: IBuildConfig): boolean {
+    return (!config || !config.isRedundantBuild) && this.enabled;
+  };
+
   /**
    * A JSON Schema object which will be used to validate this task's configuration file.
    * @returns a z-schema schema definition
@@ -110,15 +125,6 @@ export abstract class GulpTask<TASK_CONFIG> implements IExecutable {
     }
   }
 
-  /**
-   * Overridable function which returns true if this task should be executed, or false if it should be skipped.
-   * @param buildConfig - the build configuration which should be used when determining if the task is enabled
-   * @returns true if the build is not redundant
-   */
-  public isEnabled(buildConfig: IBuildConfig): boolean {
-    return (!buildConfig || !buildConfig.isRedundantBuild);
-  }
-
   /**
    * When the task is executed by the build system, this function is called once. Note that this function
    * must either return a Promise, a Stream, or call the completeCallback() parameter.