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All right, so we finally get to try the rebase command.

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I'm going to do exactly what I'm showing you in this diagram.

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Currently, I have my FT branch feature, whatever that feature is, where I have twice merged in changes

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from master.

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So my master branch still doesn't have any of the feature stuff.

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That's fine.

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I don't want to directly merge anything into master right now.

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Instead, I'm just concerned about getting the changes from my coworkers that are constantly adding

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to master, even if it's not constant.

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Let's just say frequently in a given week, updating master pole requests are merged in I need that

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work on my feature branch, so I merge from master into feature, but that gives me merge commits.

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So instead I'm going to rebase.

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And again when we use the git rebase command, we are rewriting history.

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So this is the actual history of our commits.

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But when I rebase, things get switched around a bit.

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In fact, we get new commits generated.

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So instead of creating merge commits for us when we use git rebase, it rewrites history.

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It creates brand new commits for each of the original feature branch commits.

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So the workflow here looks like this.

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I want to be on my feature branch and then I call or I run git rebase master.

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So this is not going to screw up or change the master branch.

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Instead, it's going to rewrite history by taking my feature branch commits, creating new ones that

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are based on the originals and putting them all at the tip of the master branch or starting them at

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the tip of the master branch.

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Re Basing them at the tip of this master.

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So all that work, however many commits I have on my feature branch, that work is not going to be destroyed

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or anything like that, but the commits are going to be recreated and they're going to be added to the

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tip of my master branch.

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So we end up with a linear structure.

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We still have two branches, of course, because a branch is just a pointer with just a reference.

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But now we don't have these merge commits where if we don't really need to go into it now, but each

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one of these merge commits has two parents here.

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Every commit has a single parent.

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Except I guess the first commit on the master branch.

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So let me demonstrate this.

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As we saw, we already have merge commits so we can rebase now.

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I'm showing you sort of merging first and then rebasing, but you can actually rebase instead of merging.

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I'll show that.

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So here's our structure right now.

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I'll zoom in as much as I can in post-production.

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So we have Master Branch here on the right feature here and we have these merge commits.

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So instead of this structure, I'm going to rebase.

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And I guess what I'll start with is I'll show you these commit hashes.

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Maybe I'll take a screenshot of them.

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Now I'm going to run this command.

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So I'm on the feature branch.

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Let's say I make sure I get the latest changes on the master branch.

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I pull down from GitHub on master.

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I've got the latest that whatever coworkers have merged their code in.

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Now I'm going to call get rebase.

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I can type it, master.

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And I'm calling this from my feature branch.

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Okay.

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So take a look at this output rewinding head to replay your work on top of it so on top of master and

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then it applies my commits, my three commits.

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So let's see what that looks like.

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So I'll zoom in here.

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Hopefully I do follow through and zoom in in post-production.

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And our structure has changed pretty radically.

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So all of my work is still here.

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We still have those three commits I made on feature.

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We just don't have those two merge commits.

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So now things are linear.

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We still have two branches of course, but we've created new commits or git has created new commits

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for us based upon the original commits on the feature branch.

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So if I type get logged now first I'll just show you.

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Still two branches master is unchanged, but now if I type get log I'll do one line.

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We have fewer commits because we don't have those merge commits and the commit hashes have changed because

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we actually end up with new commits.

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So the original commits on the master branch are unchanged to be to be three for f, three for f.

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Right.

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What else is on master add footer e19e19.

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Anyway, the three commits that I made on the feature branch, however, like begin feature if we take

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a look at it on the original screenshot, I took eight, eight, nine.

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Very different.

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It's a completely new commit 907 So I rewrote history, I made new commits, the work is still there.

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I still have those commits, the commit messages and actually the dates are still in there, the metadata,

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but they are in fact new commits.

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It's not just like an update to a committed, it's new history.

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So what this does, though, is hopefully you can see it cleans up my history for this feature branch

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significantly and it makes it easier to see what I've done, like the actual work on this branch because

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it's all here now.

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It's not mixed in with that work from master, even though the code is all there together, but the

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commits are all together.

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They're condensed down.

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So I can see, Oh, this is what I've done, right?

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Those are the commits I've made on this branch versus originally.

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Let me pull that screenshot up again.

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If we look here, we've got this from the master branch and then this in the Master Branch Feature Branch

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Feature Master.

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This is on feature, it's a merge commit feature master feature versus here it's just master master,

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master, master those four and then feature feature feature.

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Master, branch, master branch, master branch, master branch and then feature, feature, feature.

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So that is our first example of using Rebase.

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We've done exactly what these diagrams showed, but I also want to show that we can just use rebase

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instead of merging.

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For example, if we quickly make another change on the master branch.

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So we're on the master branch.

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What else is added login form?

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How about image gallery added?

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I don't know really.

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This is probably not how you would break up development, but anyway, let's just do something obvious

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like that.

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Image Gallery added.

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So I'm going to do a commit on the master branch add image gallery.

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So that's something a coworker does.

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I switch back to feature.

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I don't have that right.

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So now we've diverged again.

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We don't have this linear structure and if I want that work that I just got pulled down from GitHub,

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let's say that a coworker did.

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I want that on my feature branch that I'm currently developing.

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I want to stay up to date instead of merging.

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I'm now going to rebase and the end result will be what I just showed you in the previous example,

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where we've rebase the feature branch on top of master.

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So instead of merging and having a merge commit here on the feature branch are three feature branch

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commits are just moved on top of that last master branch commit.

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So we rebase it on the tip of the master branch.

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Okay.

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So I don't have this commit on my feature branch about what was it again.

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Image Gallery.

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I don't have that on feature branch, but I'm going to switch to it.

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I'm currently on it.

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So make sure if that we're on feature.

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Oh and if I want just to check in, what's the difference.

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I can do get diff feet master and quickly see I'm don't have this image gallery added I mean we know

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that but if there was more work I would see there's a bigger diff between feature and master or vice

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versa.

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So I'm going to rebase get rebase master.

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I'm on the feature branch.

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Okay.

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So this is the current structure, what we see.

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And get re master here we go rewinds head to replay our work and this is what we end up with.

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So even though there was just one new commit on master, right?

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This ad image gallery commit all of my commits on feature were recreated.

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There are new commits and I didn't take a screenshot of the commit hashes, but these are different

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from what they were just a moment ago because these are new commits based on the original commits.

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And so now we're back to this linear structure, right?

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So I can do this instead of merging.

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I don't need to merge.

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I can only rebase or I guess as I showed you originally, you can merge, merge, merge.

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And then at the end say, okay, I'm going to rebase now before I share this with people, I don't want

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them to see all my merge commits.

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It's really depends on the workflow and we'll talk more about the pros and cons and especially about

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the golden rule of rebasing, which is when not to rebase.

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So hopefully this is becoming a little bit clearer when we rebase a branch, we are basing that branch

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on the tip of another branch.

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So if we switch to whatever branch our feature branch, we rebase on to master.

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That's the part that sometimes a see students get confused about.

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They think get rebase master means you're actually rebasing the master branch, but in fact we are rebasing

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on to master in this case.

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So our feature branch commits are recreated, new history is made and it all begins at the tip of the

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master branch and we end up with this nice linear structure.