System.Web.Optimization changes order of js files when minifying javascript

Question

I am observing a very peculiar behaviour when minifying files with System.Web.Optimization , I am already using IBundleOrderer that works fine in preserving file order when I am not minifying the files

public class RespectGivenBundleOrder : IBundleOrderer
{
    public IEnumerable<BundleFile> OrderFiles(BundleContext context, IEnumerable<BundleFile> files)
    {
        return files;
    }
}

public static void RegisterTestingBundle(BundleCollection bundles)
    {
        var bundle = new ScriptBundle("~/OnTheMoveWebFiles/bundles/Testing");
        bundle.Orderer = new RespectGivenBundleOrder();
        bundle.Include(
            string.Format("{0}jquery-{{version}}.js", baseJSFolder),
            string.Format("{0}ua-parser.js", baseJSFolder),
            string.Format("{0}OnTheMove_Core.js", baseJSFolder),
            string.Format("{0}OnTheMove_TheApplication.js", baseJSFolder),
            string.Format("{0}OnTheMove_JQMQueryString.js", baseJSFolder),
            string.Format("{0}OnTheMove_OfflineAuditing.js", baseJSFolder),
            string.Format("{0}OnTheMove_DatabaseManager.js", baseJSFolder),
            string.Format("{0}OnTheMove.js", baseJSFolder),
            string.Format("{0}OnTheMove_Offline.js", baseJSFolder),
            string.Format("{0}OnTheMove_DatabaseLoader.js", baseJSFolder),
            string.Format("{0}OnTheMove_DatabaseTestHelper.js", baseJSFolder),
            string.Format("{0}OnTheMove_SmartScriptPlayer.js", baseJSFolder),
            string.Format("{0}jasmine.js", baseJSFolder),
            string.Format("{0}jasmine-html.js", baseJSFolder),
            string.Format("{0}jasmine-jquery-{{version}}.js", baseJSFolder),
            string.Format("{0}jasmine-OnTheMove-GenericMocksAndHelpers.js", baseJSFolder),
            string.Format("{0}jasmine-OnTheMove-DatabaseManager-SiebelToSQL-Tests.js", baseJSFolder),
            string.Format("{0}jasmine-OnTheMove-TreeValidator-Tests.js", baseJSFolder),
            string.Format("{0}jasmine-OnTheMove-GlobalFunction-Tests.js", baseJSFolder),
            string.Format("{0}jasmine-OnTheMove-OnTheMove_BusinessComponent-Tests.js", baseJSFolder),
            string.Format("{0}jasmine-OnTheMove_DatabaseTestHelper-Tests.js", baseJSFolder),
            string.Format("{0}jasmine-OnTheMove_OfflineAuditing-Tests.js", baseJSFolder),
            string.Format("{0}jasmine-OnTheMove-JQueryExtension-Tests.js", baseJSFolder));
        bundles.Add(bundle);
    }

but when I do turn the minification on I am getting javascript errors and by inspecting the beginning of minified file in chrome developer tools I can immediately see that order is messed up.

In immediate window when I execute var cont = new BundleResolver(BundleTable.Bundles ).GetBundleContents("~/OnTheMoveWebFiles/bundles/Testing") I get

Count = 23
    [0]: "~/OnTheMoveWebFiles/js/jquery-1.7.1.js"
    [1]: "~/OnTheMoveWebFiles/js/ua-parser.js"
    [2]: "~/OnTheMoveWebFiles/js/OnTheMove_Core.js"
    [3]: "~/OnTheMoveWebFiles/js/OnTheMove_TheApplication.js"
    [4]: "~/OnTheMoveWebFiles/js/OnTheMove_JQMQueryString.js"
    [5]: "~/OnTheMoveWebFiles/js/OnTheMove_OfflineAuditing.js"
    [6]: "~/OnTheMoveWebFiles/js/OnTheMove_DatabaseManager.js"
    [7]: "~/OnTheMoveWebFiles/js/OnTheMove.js"
    [8]: "~/OnTheMoveWebFiles/js/OnTheMove_Offline.js"
    [9]: "~/OnTheMoveWebFiles/js/OnTheMove_DatabaseLoader.js"
    [10]: "~/OnTheMoveWebFiles/js/OnTheMove_DatabaseTestHelper.js"
    [11]: "~/OnTheMoveWebFiles/js/OnTheMove_SmartScriptPlayer.js"
    [12]: "~/OnTheMoveWebFiles/js/jasmine.js"
    [13]: "~/OnTheMoveWebFiles/js/jasmine-html.js"
    [14]: "~/OnTheMoveWebFiles/js/jasmine-jquery-1.7.0.js"
    [15]: "~/OnTheMoveWebFiles/js/jasmine-OnTheMove-GenericMocksAndHelpers.js"
    [16]: "~/OnTheMoveWebFiles/js/jasmine-OnTheMove-DatabaseManager-SiebelToSQL-Tests.js"
    [17]: "~/OnTheMoveWebFiles/js/jasmine-OnTheMove-TreeValidator-Tests.js"
    [18]: "~/OnTheMoveWebFiles/js/jasmine-OnTheMove-GlobalFunction-Tests.js"
    [19]: "~/OnTheMoveWebFiles/js/jasmine-OnTheMove-OnTheMove_BusinessComponent-Tests.js"
    [20]: "~/OnTheMoveWebFiles/js/jasmine-OnTheMove_DatabaseTestHelper-Tests.js"
    [21]: "~/OnTheMoveWebFiles/js/jasmine-OnTheMove_OfflineAuditing-Tests.js"
    [22]: "~/OnTheMoveWebFiles/js/jasmine-OnTheMove-JQueryExtension-Tests.js"

which shows that order is being preserved, however when I minify it on the fly ( var contents =BundleManager.GetBundleContents("~/OnTheMoveWebFiles/bundles/Testing"); ) I get

"function TheApplication(){return window.onTheMove.theApplication}function decodeQueryString(n,t,i,r){var f,u={},s,h,e,o;if(i||(i=function(){return}),...

Which is beginning of OnTheMove_TheApplication.js and not jquery-1.7.1.js that I am expecting. One solution I see is to split it apart into more bundles and try to handle it that way.
Why minifier is not preserving order? Is my expectation wrong?

Answer 1

I managed solving this issue by creating an extension :

public class AsIsBundleOrderer : IBundleOrderer
{
    public virtual IEnumerable<FileInfo> OrderFiles(BundleContext context, IEnumerable<FileInfo> files)
    {
        return files;
    }
}

internal static class BundleExtensions
{
    public static Bundle ForceOrdered(this Bundle sb)
    {
        sb.Orderer = new AsIsBundleOrderer();
        return sb;
    }
}

Then, you can register your bundle

bundles.Add(new ScriptBundle("~/bundles/home")
            .Include("~/Scripts/leaflet-0.6.4.js")
            .Include("~/Scripts/oms.js")
            .Include("~/Scripts/home.js").ForceOrdered()

        );