Notes/15_BranchesAndMerginingII_RewritingHistory.ipynb

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    "# Branching and Merging II: Rewriting History"
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    "## Rewriting History\n",
    "\n",
    "1. Amending a Commit\n",
    "    - You can change the most recent commit\n",
    "        - Change the commit message\n",
    "        - Change the project files\n",
    "    - This creates a new SHA-1 (rewrites history)\n",
    "    - `git commit --amend -m \"add fileC.txt\"`\n",
    "    - Optionally use the `--no edit` option to reuse the previous commit message\n",
    "    \n",
    "\n",
    "2. Interactive Rebase\n",
    "    - Interactive rebase lets you edit commit using commands \n",
    "        - The commits can belong to any branch\n",
    "        - **The commit history is changed -  do not use for shared commit**\n",
    "    - `git rebase -i <after-this-commit>`\n",
    "        - Commits in the current branch after `<after-this-commit>` are listed in an editor and can be modified\n",
    "    - <img src=\"./images/git_47.png\" width=\"400\">\n",
    "    - Interactive Rebase Option provides the following:\n",
    "        - <img src=\"./images/git_48.png\" width=\"200\">\n",
    "        - <img src=\"./images/git_49.png\" width=\"200\">\n",
    "    - Delete a Commit\n",
    "        - The commit's work is not used!\n",
    "    - Squash a Commit\n",
    "        - Applies a new (squashed) commit to an older commit\n",
    "        - Combines the commit messages\n",
    "        - Removes the newer commit\n",
    "        - *Note: A fixup is like a squash, but the squashed commit's message is discarded*\n",
    "    - Squash VS. Delete\n",
    "        - Squash: Combines this commit with the older commit, creating a single commit\n",
    "            - The work of both commits in included\n",
    "        - Delete: No changes from this commit are applied\n",
    "            - The diff thrown out\n",
    "            - The work of this commit is lost\n",
    "            - Greater change of a merge conflict\n",
    "\n",
    "\n",
    "3. Squash Merges\n",
    "    - Merges the tip of the feature branch (D) onto the top of the base branch (C) \n",
    "        - There is a chance of a merge conflict\n",
    "    - Places the results in the **staging area**\n",
    "    - The results can then be commited (E)\n",
    "    - <img src=\"./images/git_50.png\" width=\"200\">\n",
    "    - Feature Commits?\n",
    "        - After the **featureX** label is deleted, commits B and D are no longer part of any named branch\n",
    "        - A squash merge *rewrites the commit history*\n",
    "        - <img src=\"./images/git_51.png\" width=\"200\">\n",
    "    - Squash Merge Commands:\n",
    "        - `git checkout master` \n",
    "        - `git merge --squash featureX`\n",
    "        - `git commit`\n",
    "            - accept or modify the squash message\n",
    "        - `git branch -D featureX`\n",
    "    - Squash Merge with Fast-Forward\n",
    "        - `git checkout master`\n",
    "        - `git merge --squash featureX`\n",
    "        - `git commit`\n",
    "            - accept or modify the squash message\n",
    "        - `git branch -D featureX`\n",
    "        \n",
    "        \n",
    "- Review\n",
    "    - You can amend the most recent commit's message and/or commited files\n",
    "        - It creates a new SHA-1\n",
    "    - Interactive rebase allows you to rewrite the history of a branch\n",
    "    - A squash reduces multiple commits into a single commit"
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    "## Review: Rewriting History\n",
    "- You can amend the most recent commit's message and/or commited files\n",
    "    - It creates a new SHA-1\n",
    "- Interactive rebase allows you to rewrite the history of a branch\n",
    "- A squash reduces multiple commits into a single commit\n"
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