Write the TSLint configuration file to the temp directory during build. (microsoft#129)

* Write the TSLint configuration file when execute.

- The TSLint configuration file can be used for VSCode TSLint plugin.

* Run rush change.

* Replace with fs.writeFileSync

* Leverage the writeFileSync.

- Leave a TODO to improve the performance.

* Update the change set comment.

* Fix some problems

* Merge

Author: lijunle

common/changes/write-config_2017-03-12-14-57.json

@@ -0,0 +1,10 @@
+{
+  "changes": [
+    {
+      "packageName": "@microsoft/gulp-core-build-typescript",
+      "comment": "Write the TSLint configuration file after executing the task.",
+      "type": "minor"
+    }
+  ],
+  "email": "lijunle@users.noreply.github.com"
+}

gulp-core-build-typescript/src/TSLintTask.ts

@@ -1,11 +1,12 @@
-import { GulpTask } from '@microsoft/gulp-core-build';
+import { GulpTask, IBuildConfig } from '@microsoft/gulp-core-build';
 import gulpType = require('gulp');
 /* tslint:disable:typedef */
 const md5 = require('md5');
 const merge = require('lodash').merge;
 /* tslint:enable:typedef */
 import through2 = require('through2');
 import gutil = require('gulp-util');
+import * as fs from 'fs';
 import * as TSLint from 'tslint';
 import * as path from 'path';
 import * as ts from 'typescript';
@@ -115,6 +116,13 @@ export class TSLintTask extends GulpTask<ITSLintTaskConfig> {
     const taskScope: TSLintTask = this;
 
     const activeLintRules: any = taskScope._loadLintRules(); // tslint:disable-line:no-any
+
+    // Write out the active lint rules for easier debugging
+    if (!fs.existsSync(path.dirname(this._getTsLintFilepath()))) {
+      fs.mkdirSync(path.dirname(this._getTsLintFilepath()));
+    }
+    fs.writeFileSync(this._getTsLintFilepath(), JSON.stringify(activeLintRules, undefined, 2));
+
     const cached = require('gulp-cache'); // tslint:disable-line
 
     return gulp.src(this.taskConfig.sourceMatch)
@@ -181,6 +189,14 @@ export class TSLintTask extends GulpTask<ITSLintTaskConfig> {
       ));
   }
 
+  public getCleanMatch(buildConfig: IBuildConfig, taskConfig: ITSLintTaskConfig = this.taskConfig): string[] {
+    return [path.join(buildConfig.rootPath, buildConfig.tempFolder)];
+  }
+
+  private _getTsLintFilepath(): string {
+    return path.join(this.buildConfig.rootPath, this.buildConfig.tempFolder, 'tslint.json');
+  }
+
   private _loadLintRules(): any { // tslint:disable-line:no-any
     if (!this._defaultLintRules) {
       this._defaultLintRules = require('./defaultTslint.json');