I always love Git documentation that includes warnings about destructive commands (like this one) because there’s no way to get this code back (aka a data loss scenario), unless the code happens to be in your favorite editor’s buffer or you still secretly use Ctrl+C Ctrl+V for emergencies – DONT JUDGE ME PEOPLE! =p For example, from unmodifying a modified file

It’s important to understand that git checkout -- [file] is a dangerous command. Any changes you made to that file are gone – you just copied another file over it. Don’t ever use this command unless you absolutely know that you don’t want the file.

I think to myself, “Um, Git, you know the code I’m writing… there’s a reason I never want to speak of this code again!!” It seems Git was designed for people who never have to StackOverflow with cut and paste attempts just to get something to compile and yet forgot to try on a throwaway branch first. It’s once I get it to compile I want to start over as if to convey in my logs, “yep I knew what I was doing all along…”

tl;dr – Today’s Git tip of the day is when you’re feeling, “um, yeah, let’s pretend that never happened.”

Undo changes in specific file in working directory using Team Explorer

In Visual Studio, let’s add a few lines of code in our Program.cs project and hit save. You’ll immediately see Team Explorer telling you that you have unstaged changes in your working directory. Note that I say “unstaged changes” and not “uncommited changes.” Remember, even though Team Explorer lets you jump over staging, there’s still a “middle layer” as seen in the past couple of tips.

Right-click Program.cs and click Undo.

Now you’ll be prompted “are you sure” because like the Git documentation says, you won’t be able to get these changes back.

Now we’re back to before we made any unstaged and/or uncommitted modifications. Even VS seems to know to pop these changes from its clipboard ring. Wow, I feel for whoever had to test those scenarios!

Undo changes in specific file in working directory using Command Line

I believe this is the command line equivalent of running git checkout — <filename> although I’m not sure what the actual underlying plumbing Team Explorer is doing.

If we want to rinse and repeat from the command line,

First, make some edits in Visual Studio and hit save. We can confirm these changes by doing a git status

Next we’ll run the dangerous (aka data loss) command git checkout — <filename>

 

Although Git is like “Meh”, Visual Studio grabs your attention immediately with the old-faithful FILES HAVE CHANGED FILE HAVE CHANGE OMG FILES HAVE CHANGED WHAT DO WE DO?!?! dialog.

Since we made these changes from the command line, Visual Studio needs to know what to do with the current text buffer. In this case, we purposefully made these changes, so we want to say Yes to All.

And we’ll see that we’re back to our baseline code and no more changes being tracked in Team Explorer.

and Git from the command prompt confirms it.

Aside: What if you had said “No” or “No to All”?

Well, I guess Git won’t be aware of what state your file really is in. If you try to git add or git commit the untracked changes in Program.cs, Git will ignore you. Literally. Git says “nothing to commit, working tree clean.” Team Explorer will also do the same by not giving you any options. But as soon as you hit Save in VS (even if the file is already saved) or even type another character in the text buffer, Git picks back up on the changes.

I guess the take-home message is to hit Yes to All. If you have a scenario where you’d want to say No to All in such a situation (perhaps making this “less dangerous” although there are many, many better ways), please let me know!

Why would you want to stage multiple commits of the same file? Actually, I have no idea. This is why I’m writing this series so I can ask you all questions 🙂 Maybe there is no good reason to stage, just like making your bed every morning. Biggest waste of time EVER. You’re just going to mess it up less than half a day later… but I digress…

TBH I originally wrote today’s tip convinced I had found a bug in Team Explorer. I wanted to see what the workflow was like in Visual Studio when staging multiple commits for the same file. However, I confused myself by pressing the Commit Staged button, thinking it was the equivalent of git add <filename> (it’s not). In Team Explorer, doing Context Menu – Stage is the equivalent of git add <filename>, as you’ll see below…

To explain, let’s start with the command line for the expected behavior, then we’ll rinse and repeat using Team Explorer.

Multiple Stages using Same File using Command Line

First, I’ve written my code to be in a “baseline” state, e.g.

Next, I’ll add a new line

and via the command line, I’ll run git add Program.cs (or git add . since it is the only file modified) to add it to staging.

Running a git status confirms it’s staged to be committed.

Don’t git commit yet! Let’s stage another changes to the same file.

Back in Visual Studio, let’s add a Console.ReadLine() to make sure the console window doesn’t go away…

Now let’s run git add Program.cs again. Running git status confirms it’s still staged to be added.

Now let’s commit by running git commit -m “two changes added”

Now let’s rinse and repeat using Team Explorer…

Multiple Stages using Same File using Team Explorer

First, let’s get back to our baseline of just having Hello World. And I’ll hit Commit All to commit those changes.

Next, let’s make that first line change of Console.WriteLine(MyStrings.message); but this time instead of hitting Commit All, you want to right click and hit “Stage”

Now you’ll see the change has been staged in TE.

 

Now let’s add our Console.ReadLine() line…

and stage that commit…

and now under Staged Changes (1), you can right click and hit Compare with Unmodified to see that the 2 new lines have been added to the staging area.

Clicking Commit Staging in Team Explorer will now add these two new lines to the log.

And now checking the history (Status Bar – Click Master (or whatever branch) then View History shows the two commits (baseline and the two new lines).