how to implement regions/code collapse in javascript

Good news for developers who is working with latest version of visual studio

The Web Essentials are coming with this feature .

Check this out

Note: For VS 2017 use JavaScript Regions : https://marketplace.visualstudio.com/items?itemName=MadsKristensen.JavaScriptRegions

Microsoft now has an extension for VS 2010 that provides this functionality:

JScript Editor Extensions

Thats easy!

Mark the section you want to collapse and,

Ctrl+M+H

And to expand use '+' mark on its left.

For those about to use the visual studio 2012, exists the Web Essentials 2012

For those about to use the visual studio 2015, exists the Web Essentials 2015.3

The usage is exactly like @prasad asked

Blog entry here explains it and this MSDN question.

You have to use Visual Studio 2003/2005/2008 Macros.

Copy + Paste from Blog entry for fidelity sake:

1. Open Macro Explorer
2. Create a New Macro
3. Name it OutlineRegions
4. Click Edit macro and paste the following VB code:

Option Strict Off
Option Explicit Off

Imports System
Imports EnvDTE
Imports EnvDTE80
Imports System.Diagnostics
Imports System.Collections

Public Module JsMacros

    Sub OutlineRegions()
        Dim selection As EnvDTE.TextSelection = DTE.ActiveDocument.Selection

        Const REGION_START As String = "//#region"
        Const REGION_END As String = "//#endregion"

        selection.SelectAll()
        Dim text As String = selection.Text
        selection.StartOfDocument(True)

        Dim startIndex As Integer
        Dim endIndex As Integer
        Dim lastIndex As Integer = 0
        Dim startRegions As Stack = New Stack()

        Do
            startIndex = text.IndexOf(REGION_START, lastIndex)
            endIndex = text.IndexOf(REGION_END, lastIndex)

            If startIndex = -1 AndAlso endIndex = -1 Then
                Exit Do
            End If

            If startIndex <> -1 AndAlso startIndex < endIndex Then
                startRegions.Push(startIndex)
                lastIndex = startIndex + 1
            Else
                ' Outline region ...
                selection.MoveToLineAndOffset(CalcLineNumber(text, CInt(startRegions.Pop())), 1)
                selection.MoveToLineAndOffset(CalcLineNumber(text, endIndex) + 1, 1, True)
                selection.OutlineSection()

                lastIndex = endIndex + 1
            End If
        Loop

        selection.StartOfDocument()
    End Sub

    Private Function CalcLineNumber(ByVal text As String, ByVal index As Integer)
        Dim lineNumber As Integer = 1
        Dim i As Integer = 0

        While i < index
            If text.Chars(i) = vbCr Then
                lineNumber += 1
                i += 1
            End If

            i += 1
        End While

        Return lineNumber
    End Function

End Module

5. Save the Macro and Close the Editor
6. Now let's assign shortcut to the macro. Go to Tools->Options->Environment->Keyboard and search for your macro in "show commands containing" textbox
7. now in textbox under the "Press shortcut keys" you can enter the desired shortcut. I use Ctrl+M+E. I don't know why - I just entered it first time and use it now :)