Git Bisect is a powerful command in Git used to efficiently find bugs or issues within a project’s history. It operates on the principle of binary search, allowing developers to pinpoint the exact commit that introduced a bug by systematically narrowing down the range of commits to test.
To begin using Git Bisect, start by identifying a known good commit (where the code was working) and a known bad commit (where the bug is present). Git Bisect will then automatically check out commits between these two points for you to test.
Here are some examples illustrating how Git Bisect can be used:
Example 1: Start the bisecting process
git bisect start
This command initializes the bisecting process.
Example 2: Mark the current commit as bad
git bisect bad
Marks the current commit as bad, indicating the bug is present here.
Example 3: Mark a specific commit as good
git bisect good 3a1b5e8
Marks commit 3a1b5e8 as good, indicating the bug is not present before this commit.
Example 4: Automatically test the middle commit
git bisect run npm test
Automatically runs the specified test command on each checked-out commit until it finds the one introducing the bug.
Example 5: Skip a commit during bisecting
git bisect skip
Skips the current commit during the bisecting process if it’s not relevant to the bug.
Example 6: Visualize the bisecting process
git bisect visualize
Opens a visualization tool (if configured) to see the commits being tested.
Example 7: Reset the bisecting process
git bisect reset
Ends the bisecting process and returns the repository to its original state.
Example 8: Specify a range for bisecting
git bisect start HEAD~10 HEAD
Starts bisecting between the current commit and 10 commits before HEAD.
Example 9: Automatically bisect using a script
git bisect start HEAD bad_commit good_commit
Automates the bisecting process using a custom script or command.
Example 10: View the bisecting log
git bisect log
Displays a log of the bisecting process, showing which commits were tested.
To verify if Git Bisect has correctly identified the bug-introducing commit, execute your test suite or verify the specific behavior that was problematic. For instance, if a certain feature was broken after a recent change, running tests related to that feature after completing the bisecting process should confirm whether the correct commit was identified as the culprit.
Discussion about this post