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Overview Maintaining a clean commit history isn't just about vanity; it's about communication. When you open a pull request, your history tells a story to the reviewer. Git Interactive Rebase is the ultimate tool for refining that story. It allows you to rewrite history by combining, renaming, or deleting commits before they ever touch the main branch. This process transforms a messy series of "work in progress" (WIP) snapshots into a logical progression of features and fixes. Prerequisites To get the most out of this tutorial, you should be comfortable with basic Git operations like `git add`, `git commit`, and `git log`. Familiarity with terminal-based text editors—specifically Vim—is helpful, as rebase opens an interactive todo list in your default shell editor. You should also understand the concept of a HEAD pointer and how branches diverge from a common ancestor. Key Libraries & Tools * **Git**: The core distributed version control system used for all commands. * **Vim**: A terminal-based text editor often used as the default interface for rebase todo lists. * **Z**: A command-line tool mentioned by Rissa Jackson for quickly navigating between project directories. Code Walkthrough: Cleaning Your History The Interactive Command To start a rebase, you need to point Git to the commit *before* the ones you want to edit. Using the tilde (`~`) notation is the most reliable method. ```bash git rebase -i [commit-hash]~ ``` This opens an interactive list. Each line starts with the word `pick`. To change the history, you replace `pick` with a specific command. Dropping and Rewording If you have a commit that should never have existed, like a test file you accidentally committed, use the `drop` command. For simple typos in a commit message, use `reword`. ```text Interactive Rebase Todo List reword a1b2c3d Fix typo in post model drop e5f6g7h Delete me: temporary debugging pick i9j0k1l Add actual feature logic ``` Squashing and Fixing Up These are the workhorses of a clean history. Both `squash` and `fixup` meld a "child" commit into the "parent" commit above it. The difference lies in the message: `squash` prompts you to combine both messages, while `fixup` discards the child’s message entirely. ```bash Using fixup to hide a small cleanup pick a1b2c3d Main feature work fixup e5f6g7h Oops, forgot a semicolon ``` Syntax Notes You don't need to use the full 40-character SHA-1 hash. Git usually understands the first seven characters. In the rebase editor, simply changing the command word at the start of the line (e.g., from `pick` to `f` for fixup) is sufficient to trigger the change upon saving and exiting. Tips & Gotchas Rebasing is a destructive action because it generates new commit hashes. **Never rebase commits that have already been pushed to a shared branch** where others are working; you will break their history. If you must push rebased code to your own feature branch, use `git push --force-with-lease`. This "Canadian Force" command ensures you don't accidentally overwrite someone else's work if they added commits to the branch while you were rebasing locally. If things get confusing, your emergency exit is `git rebase --abort`.