A journey into git diff

double-triple-dot-git-diffs.md

This is a lesson by way of a sandbox repository. We have a file at commit A that looks like:

# double-triple-dot-git

This line will be used for commit B: I am adding some text for commit B

This line will be used for commit C: I am adding some text for commit C

This line will be used for commit D: I am adding some text for commit D

We will have 6 additional commits. Across the following branches:

A - B        main
  \
   C - D     test

A - B'        main_minus
  \
   C' - D'     test_minus

A commit with just a letter adds to the related line whereas a commit with a prime (') will remove the text on the related line. See the commits here (these show you the difference to the parent, so do look at the diagram above):

• B;
• C;
• D;
• B';
• C';
• D'.

Here is our full repo history:

* d3a0377   D' (origin/test_minus)
|
* 5dd0906   C'
|
| * c41c8ef D  (origin/test)
| |
| * 232caf4 C
|/
| * dd9c11e B' (origin/main_minus)
|/
| * 29adf51 B  (origin/main)
|/
* fd3c4fb   A
|
* bf39729   Initial commit - Christopher Bull

Suggested links:

1. main..test;
2. main...test;
3. main_minus..test_minus;
4. main_minus...test_minus.

Note that PRs are based on 3 dot diffs. Note that in the 4th example above there's a possible gotcha on an actual merge! (All lines will be deleted).

Feel free to add to the explanations above and fork the repo'.