git add -p lets you stage some changes and not others

I use this if I want to commit my real changes, but not the random debugging code I added.

(this is one of the tasks GUIs and IDEs are best at, but I always use git add -p anyway)

what the interface looks like

--- a/package.json
+++ b/package.json 
@@  -1,7 +1,7 @@ 
    "name": "homepage", 
-   "version": "1.0.0", 
+   "version": "1.0.1", 
    "devDependencies": {
-   "dart-sass": "^1.25.0" 
+    "dart-sass": "^1.26.0",
(1/1) Stage this hunk
[y,n,q,a,d, s,e,?]?

package.json is the filename
lines 4-9 are the diff
[y,n,q,a,d, s,e,?] is your choice

y(es)/n(o)/q(uit)

y means “stage this change”

n means “don’t”

q quits, keeping what you did so far. pretty straightforward.

how to check your work

git diff --cached

will show your staged changes

s: split into two parts

s will split a diff into smaller diffs you can say y or n to individually, like this:

+++ b/package.json 
@@ -1,7 +1,7 @@
- "version": "1.0.0",
+ "version": "1.0.1", 
  "devDependencies": {

BUT! This only works if there’s a newline between the two parts.

how to split a diff if there’s no newline

You can use the e (“edit”) option to edit the diff manually: - to remove a - line, replace “-” with a space - to remove a + line, delete the whole line

version 1:

"name": "homepage", 
- "version": "1.0.0",
- "devDependencies": { "version": "1.0.1",
+ "devDependenciezzz'

version 2:

"name": "homepage",
- "version": "1.0.0",
+ "version": "1.0.1", 
[space] "devDependencies":
[space]

(or you can just say ‘n’ and edit your code! that’s what I do!)