pre-push hook in Git - Step-by-Step Execution

Process Flow - pre-push hook

User runs git push

↓

Git checks for pre-push hook script

Yes↓

Run pre-push hook script

↓

Hook passes

↓

Push proceeds

↓

End

When you run 'git push', Git looks for a pre-push hook script. If found, it runs it. If the script passes, push continues; if it fails, push stops.

Execution Sample

Git

#!/bin/sh
# pre-push hook example

if ! ./run-tests.sh; then
  echo "Tests failed, push aborted."
  exit 1
fi
exit 0

This pre-push hook runs tests before allowing a push. If tests fail, it stops the push.

Process Table

Step	Action	Script Output	Exit Code	Push Status
1	User runs 'git push'			Waiting for hooks
2	Git finds pre-push hook script			Running hook
3	Hook runs './run-tests.sh'	Tests passed	0	Hook passes
4	Hook exits with 0		0	Push proceeds
5	Push completes successfully			Push done

💡 Hook exits with 0, so push proceeds and completes

Status Tracker

Variable	Start	After Step 3	After Step 4	Final
Exit Code	N/A	0	0	0
Push Status	Waiting	Running hook	Push proceeds	Push done

Key Moments - 3 Insights

Why does the push stop if the hook script exits with a non-zero code?

Git treats any non-zero exit code from the pre-push hook as a failure, so it blocks the push to prevent bad code from being pushed. See execution_table step 3 for exit code effect.

What happens if there is no pre-push hook script?

Git skips the hook and pushes immediately. The hook only runs if the script file exists and is executable.

Can the hook script show messages to the user?

Yes, any output like 'Tests failed, push aborted.' is shown in the terminal to explain why the push stopped (see execution_table step 3).

Visual Quiz - 3 Questions

Look at the execution table, what is the exit code of the hook script at step 3?

A 0

B 1

C 255

D No exit code

💡 Hint

Check the 'Exit Code' column at step 3 in the execution_table.

At which step does the push actually proceed?

A Step 3

B Step 4

C Step 2

D Step 5

💡 Hint

Look for 'Push proceeds' in the 'Push Status' column.

If the tests fail and the hook exits with code 1, what would happen?

A Push proceeds anyway

B Git ignores the hook

C Push is blocked

D Push completes but with warnings

💡 Hint

Recall that non-zero exit codes block the push as explained in key_moments.

Concept Snapshot

pre-push hook is a Git script run before pushing.
If it exits 0, push continues.
If non-zero, push stops.
Use it to run tests or checks.
Place script in .git/hooks/pre-push and make executable.

Full Transcript

When you run 'git push', Git looks for a pre-push hook script in the .git/hooks directory. If it finds one, it runs the script before pushing. The script can run tests or checks. If the script exits with 0, Git continues the push. If it exits with a non-zero code, Git stops the push to prevent bad changes from being sent. The script can print messages to explain why the push stopped. If no hook script exists, Git pushes immediately. This helps keep code quality high by stopping pushes that fail tests or checks.