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![Dumb Bug Hunting
19
● Solution
○ Manual Bitsec
$ git bisect start
$ git bisect bad BAD_SHA1_HASH
$ git bisect good GOOD_SHA1_HASH
Bisecting: 6 revisions left to test after this
[b047b02ea83310a70fd603dc8cd7a6cd13d15c04] secure this thing](https://image.slidesharecdn.com/hownottogitpresentation-180310225721/85/How-Not-To-GIT-19-320.jpg)
![Dumb Bug Hunting
20
● Solution
○ Manual Bitsec
$ git bisect good
Bisecting: 3 revisions left to test after this
[b047b02ea83310a70fd603dc8cd7a6cd13d15c04] secure this thing
$ git bisect bad
Bisecting: 1 revisions left to test after this
[f71ce38690acf49c1f3c9bea38e09d82a5ce6014] drop exceptions table](https://image.slidesharecdn.com/hownottogitpresentation-180310225721/85/How-Not-To-GIT-20-320.jpg)
![Messing with History
33
$ git pull origin master
...
$ git log
...
$ git commit --amend
...
$ git push origin master
...
# ! [rejected] master -> master
(non-fast-forward)
...](https://image.slidesharecdn.com/hownottogitpresentation-180310225721/85/How-Not-To-GIT-33-320.jpg)
Uploaded byLucas Lira Gomes
How Not To GIT
The document discusses various "anti-patterns" when using Git, such as manually merging code instead of using pull requests, copying files instead of using the stash command, inefficiently hunting for bugs by diffing commits, poorly resolving conflicts, making large "jumbo" commits, messing with commit history, allowing the master branch to diverge from the remote, and self-reviewing pull requests instead of assigning them to others. It provides solutions for each anti-pattern, such as using the fork-and-pull model, stash, bisect, merge tools, smaller focused commits, revert instead of amending history, keeping master in sync, and assigning reviews.
How Not To GIT
- 1. How Not ToGIT Lucas Gomes <@x8lucas8x>
- 2. Agenda ● Who amI? ● GIT Anti-Patterns ○ Manual Merging ○ Copy-Paste Backup ○ Dumb Bug Hunting ○ Dumb Conflict Resolution ○ Jumbo Commit 2 ○ Messing with History ○ Divergent Master ○ Self Reviewing ● References ● Q & A
- 3. Software Engineer Passionate Hacker ArchLinuxZealot FOSS Enthusiast I’m fond of doing things that last and all that jazz. Lucas Lira Gomes 3 contact@x8lucas8x.com linkedin.com/in/x8lucas8x facebook.com/x8lucas8x youtube.com/X80lucas08X twitter.com/x8lucas8x x8lucas8x.com github.com/x8lucas8x
- 4.
- 5. Manual Merging 5 $ gitcheckout branchA ... $ git commit ... $ git pull origin master ... $ echo ‘No pull requests this time!’ ... $ git checkout master ... $ git rebase branchA ... $ git push origin master ...
- 6. Manual Merging 6 ● Problems ○“To Err is Human” ■ Automate what you can ○ Permission management ■ Higher friction ○ Jeopardise collaboration ■ Less code-review
- 7.
- 8.
- 9. Manual Merging 9 ● Solution ○Fork & Pull model ■ Use proper tools ○ Avoid manual merges/rebases ■ Default to pull requests
- 10. Manual Merging 10 ● Solution ○Fork to access ■ Create it first $ git clone git@server_url:my_fork/remote.git
- 11. Manual Merging 11 ● Solution ○For updates ■ Forbid pushes ■ Setup read-only remote $ git remote add central https://server_url/central/remote.git $ git remote set-url central --push "You shall NOT push!!!"
- 12. Copy-Paste Backup 12 $ gitstatus # On branch master # ... # modified: index.html # ... $ cp index.html backup_index.html ... $ git checkout -- index.html ... $ git checkout branchB Switched to a new branch 'branchB'
- 13. Copy-Paste Backup 13 ● Problems ○“To Err is Human” ■ Use proper tools
- 14. Copy-Paste Backup 14 ● Solution ○Stash it $ git stash Saved working directory and index state "WIP on master: 049d078 added the index file" HEAD is now at 049d078 added the index file (To restore them type "git stash apply")
- 15. Copy-Paste Backup 15 ● Solution ○Stash it $ git status # On branch master nothing to commit, working directory clean $ git stash list stash@{0}: WIP on master: 049d078 added the index file
- 16. Copy-Paste Backup 16 ● Solution ○Stash it $ git stash apply # On branch master # Changes not staged for commit: # (use "git add <file>..." to update what will be committed) # # modified: index.html $ git stash drop stash@{0} Dropped stash@{0} (364e91f3f268f0900bc3ee613f9f733e82aaed43)
- 17. Dumb Bug Hunting 17 $git commit ... $ git commit ... $ git commit ... $ run app.py FATAL ERROR Gonna cry? ... $ diff HEAD~12 ... $ vim app.py ...
- 18. Dumb Bug Hunting 18 ●Problems ○ Not efficient ○ The more code == The harder
- 19. Dumb Bug Hunting 19 ●Solution ○ Manual Bitsec $ git bisect start $ git bisect bad BAD_SHA1_HASH $ git bisect good GOOD_SHA1_HASH Bisecting: 6 revisions left to test after this [b047b02ea83310a70fd603dc8cd7a6cd13d15c04] secure this thing
- 20. Dumb Bug Hunting 20 ●Solution ○ Manual Bitsec $ git bisect good Bisecting: 3 revisions left to test after this [b047b02ea83310a70fd603dc8cd7a6cd13d15c04] secure this thing $ git bisect bad Bisecting: 1 revisions left to test after this [f71ce38690acf49c1f3c9bea38e09d82a5ce6014] drop exceptions table
- 21. Dumb Bug Hunting 21 ●Solution ○ Manual Bitsec $ git bisect good b047b02ea83310a70fd603dc8cd7a6cd13d15c04 is first bad commit commit b047b02ea83310a70fd603dc8cd7a6cd13d15c04 Author: User1 <user1@example.com> Date: Tue Jan 27 14:48:32 2015 -0800 ...
- 22. Dumb Bug Hunting 22 ●Solution ○ Automate Bitsec $ git bisect start BAD_SHA1_HASH GOOD_SHA1_HASH $ git bisect run make test arguments ...
- 23. Dumb Conflict Resolution 23 $git pull origin master ... $ git status # On branch branchA # You have unmerged paths. # ... # both modified: README.md # ... $ vim README.md ...
- 24. Dumb Conflict Resolution 24 ●Problems ○ Not efficient ○ Prone to typing errors
- 25. Dumb Conflict Resolution 25 ●Solution ○ Use a mergetool $ git config --global merge.tool YOUR_DIFF_VIEWER
- 26. Dumb Conflict Resolution 26 ●Solution ○ Use a mergetool $ git mergetool Merging the files: README Normal merge conflict for 'README': {local}: modified {remote}: modified Hit return to start merge resolution tool (kdiff3):
- 27. Dumb Conflict Resolution 27 ●Solution ○ Use a mergetool (KDiff3)
- 28. Dumb Conflict Resolution 28 ●Solution ○ Use a mergetool (Meld)
- 29. Dumb Conflict Resolution 29 ●Solution ○ Use a mergetool ■ emerge ■ gvimdiff ■ vimdiff ■ Your IDE’s differ
- 30. Jumbo Commit 30 $ gitadd src/views/. ... $ git add src/models/. ... $ git add src/delegates/. ... $ git add images/. ... $ git commit -a ‘Biggest commit ever!’ ...
- 31. Jumbo Commit 31 ● Problems ○Long-term results ■ Team ○ Review procrastination ■ Higher cognitive load ○ Pulls are more prone to conflict
- 32. Jumbo Commit 32 ● Solution ○Divide and conquer ■ Create granular commits
- 33. Messing with History 33 $git pull origin master ... $ git log ... $ git commit --amend ... $ git push origin master ... # ! [rejected] master -> master (non-fast-forward) ...
- 34. Messing with History 34 ●Problems ○ Cannot push ○ If forced (push -f) ■ Breaks others’ history ■ Lose commits
- 35. Messing with History 35 ●Solution ○ Avoid messing with pushed history ■ On shared repositories only
- 36. Messing with History 36 ●Solution ○ Use Git Revert $ git revert DESIRED_SHA1_HASH
- 37. Divergent Master 37 $ gitcheckout master ... $ git rebase branchA ... $ git status ... # Your branch and 'origin/master' have diverged ...
- 38. Divergent Master 38 ● Problems ○Prone to mixing commits of different branches ■ Master is the ramification point
- 39. Divergent Master 39 ● Solution ○Use master as a carbon copy $ git checkout -b branchA Switched to a new branch 'branchA' $ git branch -D master ...
- 40. Divergent Master 40 ● Solution ○Use master as a carbon copy $ git branch -a branchA remotes/central/master $ git checkout remotes/central/master ...
- 41. Divergent Master 41 ● Solution ○Use master as a carbon copy $ git checkout -b master Switched to a new branch ‘master’
- 42. Self Reviewing 42 $ gitpush origin branchA ... $ echo “Lets create a pull request!” ...
- 43. Self Reviewing 43 ● Problems ○Team specialisation ■ “Not my code" ○ Less opportunity ■ Learning ■ Training
- 44. Self Reviewing 44 ● Solution ○Assign pull requests to others
- 45.
- 46. How Not ToGIT Lucas Gomes <@x8lucas8x>