Git workshop

Transcript

1. @tombruijn Git workshop Tom de Bruijn tomdebruijn.com
2. @tombruijn Agenda • Why this workshop? • Git rebasing • Reviewing Pull/Merge Requests
3. @tombruijn Interactive workshop That means you get to ask questions and do things
4. @tombruijn This is a practical workshop Let's first discuss some theory And then apply it in practice
5. @tombruijn Goal of workshop • Introduction to rebasing • Why rebase? • Explain how to rebase • Encourage you to rebase more
6. @tombruijn Make notes! You know the best way to remember things In your own words
7. @tombruijn Ask questions! Any time is good
8. @tombruijn Questions so far? (This type of slide is also a hint for myself)
9. @tombruijn Don't be afraid of Git! We can restore things Things don't disappear never to be seen again
10. @tombruijn Rebasing Why? What? How? When?
11. @tombruijn Why rebase? • Updating branches on other branches • Include other people's bug fixes in your branch • Alternative to a merge commit
12. @tombruijn Why rebase? • Fixing small issues in previous commits • Squash your own bug and test fixes • Updating in commit messages • Fixing typos • Adding more content
13. @tombruijn Commits to avoid • WIP • Fix test/bug • Merge commits • Instead, rebase
14. @tombruijn In short: To create a more readable git history
15. @tombruijn Questions so far?
16. @tombruijn Why a readable history? • We do this for our team • We do this for our future selves From: Git is about communication presentation
17. @tombruijn ✅ Better communication • git blame, git log ✅ Better reviews ✅ Faster reviews ✅ Faster debugging From: Git is about communication presentation
18. @tombruijn Not a deep dive • Not a tutorial on how to write commit messages • Want to learn more about communication in git? • tomdebruijn.com/posts/git-is-about-communication/ Blog post and #NoRuKo talk
19. @tombruijn Rebasing on another branch Rebasing on the branch we branched off from Get the latest bug fixes and features
20. @tombruijn Rebasing goal • Rebase feature branch on main branch • To include bug fixes in our branch • Prevent merge conflicts when merging our feature branch ✅
21. @tombruijn A visual example Today we'll be using learngitbranching.js.org/?NODEMO
22. @tombruijn Demo and questions? https:/ /github.com/tombruijn/rebase-workshop-example-1
23. @tombruijn Feature branch rebasing How to tidy up a branch for review
24. @tombruijn Imagine...
25. @tombruijn You get assigned an issue to add a button to the user profile page
26. @tombruijn At the end of the day you commit everything you have so far and sign off
27. @tombruijn The next day you realize you better refactor the button component making it easier to use
28. @tombruijn There was also a change on the main branch you needed to continue ⚠
29. @tombruijn Rebasing goal • Tidy up our branch for review • Make it easier to review for our team • The merged result is readable 3+ months from now ✅
30. @tombruijn Questions so far? About our rebasing goals
31. @tombruijn Git history • WIP • Add button • Merge branch "main" • Refactor button component • Fix tests Older Newer
32. @tombruijn Before After • WIP • Add button • Merge branch "main" • Refactor button component • Fix tests • How would you present your commits? How to clean up this branch?
33. @tombruijn Before After • WIP • Add button • Merge branch "main" • Refactor button component • Fix tests • WIP • Add button to user profile page • Refactor button component • Fix tests Reduce noise commits: merge commits
34. @tombruijn Before After • WIP • Add button • Merge branch "main" • Refactor button component • Fix tests • Add button to user profile page • Refactor button component • Fix tests Reduce noise commits: WIP commits
35. @tombruijn Before After • WIP • Add button • Merge branch "main" • Refactor button component • Fix tests • Add button to user profile page • Refactor button component Squash "Fix" commits with the commits that broke things in the first place
36. @tombruijn Questions so far?
37. @tombruijn Bonus
38. @tombruijn Before After • WIP • Add button • Merge branch "main" • Refactor button component • Fix tests • Add button to user profile page • Refactor button component • Rewrite user profile page button Does the refactor commit also include a rewrite of the first commit?
39. @tombruijn Before After • WIP • Add button • Merge branch "main" • Refactor button component • Fix tests • Refactor button component - PR #1 • Add button to user profile page - PR #2 More readable history. No double implementation of the button Send in the refactor PR first so your team can start reviewing it already
40. @tombruijn Demo and questions? https:/ /github.com/tombruijn/rebase-workshop-example-2
41. @tombruijn How to rebase?
42. @tombruijn Today we'll be refactoring on the command line This way we know how git work
43. @tombruijn Interactive rebase Tell Git how to rebase git rebase --interactive <SHA/branch>
44. @tombruijn Interactive rebase options • pick • Keep commit for rebasing. (Default option) • drop • Remove commit from history. Delete it. • reword • Update commit message. • edit • Edit commit and message. Split commits. • Reordering commits • Change lines to reorder commits
45. @tombruijn Questions so far?
46. @tombruijn Squashing Merge two commits together and keep their messages. Used for: • merging WIP work across commits
47. @tombruijn Questions so far?
48. @tombruijn Fixup Merge two commits together, only keep the first message. Used for: • typos • test fixes
49. @tombruijn Let's practice rebasing https:/ /github.com/tombruijn/rebase-workshop-example-2
50. @tombruijn Tips! Make notes!
51. @tombruijn Gain confidence • Rebase more often • Rebase small • The smallest you can at a time
52. @tombruijn Abort? Abort!! • git rebase --abort • Run into merge conflicts and don't know how to solve? Abort! • (Revert changes you made during the rebase) ❌
53. @tombruijn Demo and questions?
54. @tombruijn Backup branches • git checkout -b backup-branch • git checkout - # Go to previous branch • # Rebase • # If it did not go well? • git checkout backup-branch
55. @tombruijn Demo and questions?
56. @tombruijn git reflog • git reflog • Ref[erence] log • See all your actions in git • In a semi-human-readable format
57. @tombruijn Demo and questions?
58. @tombruijn git fixup • What are "fixup!" commits? • Mark commits as fixup commits for future rebasing • So you don't need to rebase now
59. @tombruijn Demo and questions? https:/ /github.com/tombruijn/rebase-workshop-example-3
60. @tombruijn Reviewing MRs/PRs How to leave a better review
61. @tombruijn • We do this for our team • We do this for our future selves From: Git is about communication presentation
62. @tombruijn ✅ Better communication ✅ Better reviews ✅ Faster reviews ✅ Faster debugging From: Git is about communication presentation
63. @tombruijn Leave better reviews • Ask questions if you have any! • Worst case you learn something new
64. @tombruijn Review questions • Why is the change necessary? What's the problem? • Why was this solution chosen? • What alternative solutions were available? • Would anyone understand this 3 months from now? ❓
65. @tombruijn In a perfect world • Be able to understand what the MR is about, using only the MR contents • You need the whole team to work together for this!
66. @tombruijn Test the code • Check out the MR locally and test the changes • Click through the app / run the app • Verify if the change actually works • Verify if the tests actually test the changed logic
67. @tombruijn Boy scouting • When to fix style issues? • When to refactor?
68. @tombruijn Questions? Ask me things git! tomdebruijn.com - for articles about git The last slide!