Month: April 2017

How to view your branches from the command line – 120

Now that you’ve seen how to do fetches, merges, and pulls from a remote tracking branch within Visual Studio, let’s rinse and repeat from the command line. Personally, it’s been easier to first grasp these concepts using Visual Studio, then rinse and repeat at the command line level.

I have to know the truth behind what the UI is doing 🙂

If you want to view the full list of remotes, similar to the full list shown in Team Explorer – Branches

list of branches in Team Explorer

From the command line, you can do

$ git branch -a

You’ll see the same list (well almost the same list. I’m not sure yet what the remotes/origin/HEAD is doing yet… stay tuned unless someone wants to beat me to the answer in the comments!)

Note how the local branch `for-review` is listed first (which kinda gets blended in color-wise with the command), then master, then the remote tracking branches.

git branch -a from command line

Something that has confused me for a long time until I wrote yesterday’s post was whether “remotes/origin/why-not” was the same as “origin/why-not” or even the made-up “remotes/why-not” (which I don’t think a branch is ever referred to as such). Now that I can visualize what both the command line and Visual Studio are doing, it’s easier to get my head wrapped around these remote tracking branches.

How to deal with a merge conflict when doing a Pull from a remote branch into a local branch in Visual Studio – 119

Suppose this time you have conflicts when you do a Pull, meaning your local branch had a conflicting change that was committed locally (but not yet pushed – see Outgoing Commits 1 in screenshot below) and someone else (let’s say you via GitHub.com UI) made a corresponding  conflicting change on the remote.

Here’s the UI setup in Team Explorer. Click on Pull.

Pull incoming commits

Git halts the pull operation (at the merge portion) when it detects the conflicting changes, as expected.

Resovle the conflicts scary TE screen

From here it should be familiar territory by now. Clicking conflicts brings you to a merge conflict screen.

Resolve Conflicts

Clicking Merge brings up the 3 way merge tool (or choose a take remote  or a keep local). If you go the Merge tool route, make sure you click “Accept Merge” at the top. Gets me every time.

merge tool accept merge button

Once you’ve accepted the merge (or choose to use the remote or local version), click Commit Merge.

Commit Merge in Resolve Conflicts in TE 

Now we have to commit those our resulting merge. Click Commit Staged in Changes pane in Team Explorer.

Commit Staged in Changes in TE

and you’re done! Reviewing the local master history shows the merge commit now as the tip.

master local history

Still thinking re yesterday how a Pull is different than a Fetch + Merge. I guess if you know you want to download changes, but not ready to deal with any potential conflicts at this time (e.g. going offline for a while or got other things to do right now), Fetch is the way to go. If you know you’re ready to start playing with the code on your local branch, then Pull is the way to go, I think.

How to download and merge commits from a remote branch on your local branch – 118

Today’s tip shows how to combine doing a Fetch and a Merge by using the Pull command.

Suppose you have some incoming commits that you’re ready to merge into your local branch. In this example, I’ve create a new file on master on GitHub and I want to bring that commit into my local master branch.

Instead of fetching to review the commits that are going to be applied, we’ll assume you’ve already looked at GitHub to see what will be merged in.

Pull incoming commits into local master branch

The result of the Pull command shows a message at the top of the Team Explorer.

Repository updated to commit ID

Viewing the history on the master branch shows the tip (the top of the branch) having the newly merged in commit from GitHub.

History for local master branch

This begs the question: Why use Fetch? Why not always do a Pull? I believe the answer is

    1. if you want to verify what commits have been downloaded
    2. if you want to know if you’ll run into any merge conflicts before doing the Pull (the merge portion of Pull). However, I’m not sure how you can know if you’re going to have any merge conflicts, if you haven’t first merged the commits somewhere. I guess you could manually review the changes. Perhaps someone reading this knows what I’m missing.

How to download changes from a remote branch (e.g. GitHub) into your local branch in Visual Studio – 117

In yesterday’s example, you saw how to create a local branch from a remote tracking branch. In today’s tip, you’ll download new changes from the server into your local branch.

Suppose you know there are changes on a GitHub repo (in today’s example) you want to download to your computer.

First, switch to the branch you want to pull down, e.g. `for-review` is the branch with the changes I want. You can go to Team Explorer – Sync pane and click Fetch under Incoming Commits (or at the top of the pane).

Fetch incoming commits from branch for-review

After fetching, the window will show the new commits that have been downloaded but not applied to my local branch. That’s why this says “Incoming Commits”. The remote tracking branch remotes/for-review has these two commits (downloaded somewhere – not sure exactly where) but they have not been merged into your local branch (because we only “Fetched” the incoming commits, but haven’t done anything with them yet.)

downloaded commits

Now suppose you are ready to do something with these “incoming commits”, i.e. get the into your local branch `for-review`. Remember, your local branch is a just branch of the remote tracking branch, so you need to merge these 2 commits from the remote tracking branch into your local branch.

merge from origin/for-review into for-review branch 

The only thing that should look differently is the from branch name “origin/for-review”.

Click Merge to merge in the two incoming commits from the remote branch.

Go to View history to see the resulting timeline.

for-review history shows the 2 incoming commits

Sync will show 0 incoming commits now that they have been merged.

Yep, I already know what you’re thinking. I’m breaking down the steps manually and there’s this thing call Pull. Stay tuned to tomorrow’s tip 🙂

How to create a local copy of a remote branch in Visual Studio – 116

Suppose you’ve cloned a project from a GitHub repo that contains multiple branches. By default, Git pulls down the main tracking branch (e.g. master in most cases). That’s why you see a local checked-out (bolded) master and a remotes/origin master branch.

For the other branches under remotes/origin, Git doesn’t automatically pull these down. The branches listed under remotes/origin are called “remote tracking branches”. I believe these are also referred to as “remote branches” but the “tracking” is implied. Can you have a remote branch that isn’t a remote tracking branch? I guess not. I guess even if you checked out a “remote tracking branch” without the tracking flag (or without the checkbox checked), you’d still have the original “remote tracking branch” alongside the local non-tracked branch.

Team Explorer - Branches showing remote tracking branches

You cannot check out these remote branches directly. I guess if you could, you’d be working directly on the server instead of your local machine, which wouldn’t make too much sense, and probably wouldn’t be possible since a bare git repo (aka the git server you’re checking out from) doesn’t have a concept of a working directory. No idea. Just thinking out loud here.

Suppose you want to checkout the `for-review` branch to do work. First you’d need to create a new branch. Note just like 13* we’re going the long way around, meaning we’re not going to choose the “checkout” command in the context menu. We’re going to manually create the local branch first, then checkout, to see the process.

First, right click on the remote branch, and select New Local Branch From on the context menu, just as if you were creating any other branch. The Create Branch window section will appear.

creating a local branch from a remote tracking branch

Note how Visual Studio auto-populates the name of the local branch as `for-review` You could change the local branch name. You could also do `private string @long`. I’m sure the `@long` is far worse.

Checking the Create Branch button creates the local `for review` branch. Because the default is the Checkout branch option checked, the `for-review` is bolded.

for-review local branch checked out

I believe the Checkout command on the context menu for a remote branch will perform the above steps, but I’m not sure if there are any differences. For example, I’d assume the checkout command keeps the defaults (e.g. Track remote branch and Checkout branch – of course). In any case, when I’m trying to learn something new, it is helpful for me to see what is going on step-by-step as much as possible.

If I have any of the above terminology wrong, please let me know!!

*Heaven Sent was one of the best Doctor Who episodes in a LONG time. Wow, just wow.

How to resolve a conflict during a rebase in Visual Studio – 115

Similar to yesterday’s tip, but today, you’ll see how to resolve a conflict when rebasing within Visual Studio.

Suppose you have the same line in the same file modified in different branches. Just something simple to trigger a merge conflict. Or more likely, you’ve added one file in master and you’ve added another file in an experiment branch. Then you get a conflict when rebasing because your project file needs help merging the two newly added files.

First, you’ll get the message that there are conflicts.

conflicts message in Team Explorer

Click on the Conflicts: 1 link.

resolve conflicts window in Team Explorer

Clicking on the Merge button will bring up the built-in merge tool.

Make whatever selections you want, and then hit Accept Merge.

Accept merge in VS tool

Now View Changes, as you’ve resolved the conflicts, but still need to finish the rebase.

resolve conflicts - view changes

And finally finish the rebase! (For some reason, I can’t stop hearing the Mortal Kombat game in my head.)

rebase in progress - continue

And now you’ll see that the experiment branch has been merged onto master.

experiment pointer above master pointer

How to do a rebase in Visual Studio – 114

Suppose you’ve added a new file to your solution in a branch called `experiment` for experimental purposes. You are happy with this new file and want to merge this back into master. Well, let’s say you (or someone like you*) made a change in master.

Since this is on your local machine, you can decide “do I want to have the history of the experiment branch or do I want a clean, linear timeline?” Guess which adventure you’re going to choose today 🙂

Here’s the visual setup.

experiment vs master branches histories side by side in VS

Notice how the tip of experiment has a commit that’s not in Master, and vice versa, the tip of master has a commit that’s not in experiment.

First, we’ll use Team Explorer to rebase experiment unto master. BTW I love how Team Explorer uses full sentences to confirm your intent.

rebase from the current branch experiment onto branch master

Now after the rebase, you’ll see two things:

    1. The commit from master is now shown in the experiment branch (recall the visualization from previous posts – the master pointer is now behind experimental pointer)
    2. The commit ID for “added experimental code” has changed (You can compare to the first image in this blog post to verify)

master pointer shown in experiment branch history

And lastly, let’s get master caught up to experiment by doing a merge. Yay for full sentences in the below image!

Merge from branch experiment into current branch master

And now when you refresh Master history, you’ll see the changes.

master pointer pointing to same commit as experiment

*I couldn’t resist. I listened to way too much Matchbox 20 in my youth, “I wish the real world would just stop hassling me .”