Git: commit partial changes

Question

There are multiple questions on Stack Overflow addressing the problem of staging and committing only parts from files. However, I can't make it work.

• How can I commit only part of a file in git

Let's say we want to implement a dummy math class in php (the language doesn't matter) with some basic methods like: add, subtract, multiply and divide.

Let's start with the class definition:

<?php     class Math {     } ?> 

Now:

$ git add math.php $ git commit -m "Create Math class." 

In the next step we implement both add and subtract four methods:

<?php     class Math {         public function add($a, $b) {             return $a + $b;         }          public function subtract($a, $b) {             return $a - $b;         }     } ?> 

But now we want to commit the implementation of the add and the subtract methods in separate commits.

Is this possible?

What I tried

$ git add -p

The following appears:

I would love to split the hunk into smaller hunks, so I press s, and the following appears:

It seems that git didn't split it into smaller hunks.

Let's try now to manually edit the current hunk. So I press: e.

My default text editor (sublime text) opens up, and here I can edit the hunk:

I try to simply delete line 8,9,10,11 - because I want to stage only the add function. I save, close the editor, but git says:

Your edited hunk does not apply. Edit again (saying "no" discards!) [y/n]?

I'm really new to git add -p and interactive staging, so maybe it's something I do wrong, or simply it's not possible what I want, and really hope some more experienced git users have some instructions maybe also a solution for me.

Thank you!

Answer 1

You are doing exactly what I've done in the past, and I even recreated your entire experiment on a UNIX machine and it worked just as expected.

I suspect your editor is changing the line endings in the diff hunk when it saves.