COMP1531

⚽️ Teamwork

9.3 - Git - Resets & Amending

Author: Hayden Smith 2021

In this lecture

Why?

Sometimes we make mistakes using git, and we need tools to be able to resolve them (carefully)

What?

Doing a hard reset to a point in time
Altering the git history
Amending a commit

Mistakes

Everything we've done until this point continues to build on the git history. But we've largely considered the git history immutable.
With git, sometimes we make mistakes. Sometimes we want to undo things, or change history.

Two ways we're going to discuss this are:

git resets
git commit amend

git reset

Atlassian has a very clear article about git reset. We will use this as guidance.
We will mainly discuss hard and soft resets through a demonstration

git reset --hard [hash]

Sets all of your code to a specific commit. This is used for saying "I want to go back in time, and I don't care about anything that's happened since that point I'm going back to"

git reset --soft [hash]

Keeps all of your current code the same, but just changes what commit you're pointing to. This is used for saying "I like the code I have, so let's not change anything, but I want to alter the history of commits that got me here"

git commit --amend

git commit --amend -m "Commit"

Sometimes we need to update our previous commit name. We can do that easily by making another commit that over-rides it.
The --amend flag will make the commit, but it will replace the most recent commit with the new commit instead of adding another commit to the history
Let's do a demonstration.