<!DOCTYPE html>
<html>

  <head>
    <base href="." />
    <title>angular playground</title>
    <link rel="stylesheet" href="style.css" />
    <script src="https://unpkg.com/core-js@2.4.1/client/shim.min.js"></script>
    <script src="https://unpkg.com/zone.js/dist/zone.js"></script>
    <script src="https://unpkg.com/zone.js/dist/long-stack-trace-zone.js"></script>
    <script src="https://unpkg.com/reflect-metadata@0.1.3/Reflect.js"></script>
    <script src="https://unpkg.com/systemjs@0.19.31/dist/system.js"></script>
    <script src="config.js"></script>
    <script>
    System.import('app')
      .catch(console.error.bind(console));
  </script>
  </head>

  <body>
    
    <h2>Problem</h2>
    Preserve original console.log call position (file + linenumber).
    <my-app>
      loading...
    </my-app>
  </body>

</html>
/* Styles go here */

### Angular Starter Plunker - Typescript
System.config({
  //use typescript for compilation
  transpiler: 'typescript',
  //typescript compiler options
  typescriptOptions: {
    emitDecoratorMetadata: true
  },
  paths: {
    'npm:': 'https://unpkg.com/'
  },
  //map tells the System loader where to look for things
  map: {
    
    'app': './src',
    
    '@angular/core': 'npm:@angular/core/bundles/core.umd.js',
    '@angular/common': 'npm:@angular/common/bundles/common.umd.js',
    '@angular/compiler': 'npm:@angular/compiler/bundles/compiler.umd.js',
    '@angular/platform-browser': 'npm:@angular/platform-browser/bundles/platform-browser.umd.js',
    '@angular/platform-browser-dynamic': 'npm:@angular/platform-browser-dynamic/bundles/platform-browser-dynamic.umd.js',
    '@angular/http': 'npm:@angular/http/bundles/http.umd.js',
    '@angular/router': 'npm:@angular/router/bundles/router.umd.js',
    '@angular/forms': 'npm:@angular/forms/bundles/forms.umd.js',
    '@angular/animations': 'npm:@angular/animations/bundles/animations.umd.js',
    '@angular/platform-browser/animations': 'npm:@angular/platform-browser/bundles/platform-browser-animations.umd.js',
    '@angular/animations/browser': 'npm:@angular/animations/bundles/animations-browser.umd.js',
    
    '@angular/core/testing': 'npm:@angular/core/bundles/core-testing.umd.js',
    '@angular/common/testing': 'npm:@angular/common/bundles/common-testing.umd.js',
    '@angular/compiler/testing': 'npm:@angular/compiler/bundles/compiler-testing.umd.js',
    '@angular/platform-browser/testing': 'npm:@angular/platform-browser/bundles/platform-browser-testing.umd.js',
    '@angular/platform-browser-dynamic/testing': 'npm:@angular/platform-browser-dynamic/bundles/platform-browser-dynamic-testing.umd.js',
    '@angular/http/testing': 'npm:@angular/http/bundles/http-testing.umd.js',
    '@angular/router/testing': 'npm:@angular/router/bundles/router-testing.umd.js',
    
    'rxjs': 'npm:rxjs',
    'typescript': 'npm:typescript@2.2.1/lib/typescript.js'
  },
  //packages defines our app package
  packages: {
    app: {
      main: './main.ts',
      defaultExtension: 'ts'
    },
    rxjs: {
      defaultExtension: 'js'
    }
  }
});
//main entry point
import {enableProdMode} from '@angular/core';
import {platformBrowserDynamic} from '@angular/platform-browser-dynamic';
import {AppModule} from './app';

// Remove annoying log message
enableProdMode();

platformBrowserDynamic().bootstrapModule(AppModule)
//our root app component
import {Component, NgModule, VERSION} from '@angular/core'
import {BrowserModule} from '@angular/platform-browser'
import {Caller} from './caller';

@Component({
  selector: 'my-app',
  template: `
    <div>
      <span>Hello {{name}}</span>
      <p>{{msg}}</p>
      <button (click)="caller.loggingSequence()">Run sequence</button>      
    </div>
  `,
  providers: [Caller]
})
export class App {
  name:string;
  constructor(private caller: Caller) {
    this.name = `Angular v${VERSION.full}`;
    this.msg = `Please check the console.log for the output.`;
  }
}

@NgModule({
  imports: [ BrowserModule ],
  declarations: [ App ],
  bootstrap: [ App ]
})
export class AppModule {}
import { Injectable } from '@angular/core';
import { ConsoleLog as Console1 }  from './solution1';
import { ConsoleLog as Console2 }  from './solution2';

@Injectable()
export class Caller {
  
  private _cLog1: Console1;
  private _cLog2: Console2;
  
  constructor() {
    console.log('Caller init');
    this._cLog1 = new Console1();
    this._cLog2 = new Console2();
  }
  
  public loggingSequence() {
    
    console.log(`
      ------------------------------------
      Next 'solution' preserves the original call position. (caller.ts)
      But the content isn't dynamic (same random number).
      ------------------------------------
    `);
    
    this._cLog1.start();
    
    console.log('Foo');
    console.log('Bar');
    
    this._cLog1.stop();
    
    console.log(`
      ------------------------------------
      Next 'solution' is dynamic (changes random number).
      But doesn't preserves the original call position, but re-sets it to solution2.ts (apply)
      ------------------------------------
    `);
    
    this._cLog2.start();
    
    console.log('Foo');
    console.log('Bar');
    
    this._cLog2.stop();
    
    console.log(`
      ------------------------------------
      How can I combine both 'solutions'?
      ------------------------------------
    `);
    
  }
}
export class ConsoleLog {
  private _isActive = false;
  private _nativeLogFn: any;

  constructor() {

    // ----------------------
    // Store the native console.log function, so it can be restored later 
    // ----------------------

    this._nativeLogFn = console.log;

  }

  public start() {
    if (!this._isActive) {

      // ----------------------
      // Create a new function as replacement for the native console.log 
      // function. *** This will be the subject of my question ***
      // ----------------------

      console.log = console.log.bind(console, Math.random());

      this._isActive = true;
    }
  }

  public stop() {
    if (this._isActive) {
      // Restore to native function
      console.log = this._nativeLogFn;
      this._isActive = false;
    }
  }
}
export class ConsoleLog {
  private _isActive = false;
  private _nativeLogFn: any;

  constructor() {

    // ----------------------
    // Store the native console.log function, so it can be restored later 
    // ----------------------

    this._nativeLogFn = console.log;

  }

  public start() {
    if (!this._isActive) {

      // ----------------------
      // Create a new function as replacement for the native console.log 
      // function. *** This will be the subject of my question ***
      // ----------------------

      // console.log = console.log.bind(console, Math.random());

      const consolelog = console.log;
      console.log = function (...args) {
          return consolelog.apply(this, [Math.random()].concat(args));
      }


      this._isActive = true;
    }
  }

  public stop() {
    if (this._isActive) {
      // Restore to native function
      console.log = this._nativeLogFn;
      this._isActive = false;
    }
  }
}