Effective Git

Transcript

1. If that doesn't fix it, git.txt contains the phone number of a friend of mine who understands git. Just wait through a few minutes of 'It's really pretty simple, just think of branches as...' and eventually you'll learn the commands that will fix everything.
2. EFFECTIVE GIT Michael Cordell
3. GIT: THE BASICS git is a distributed version control system
4. EDITING class Startup def increase_roi step_one step_two “????” profit! end end
5. STAGING ƭ startup.rb git add startup.rb Index
6. COMMITTING ƭ startup.rb Index git commit -m “Add the startup!”
7. ƭ ƭ ƭ ƭ
8. BRANCHING master git checkout -b feature feature
9. BRANCHING master feature git commit
10. BRANCHING master feature git commit
11. BRANCHING feature git checkout master master
12. BRANCHING feature git commit master
13. BRANCHING feature git merge feature master
14. WHY
15. Code Editor || IDE VCS Build Tools
16. Build Tools Editor/IDE Now VCS
17. Since git deals with history, git’s effectiveness as a tool is directly related to how it has been used in the past
18. GUIDING PRINCIPLES
19. Short, focused commits
22. Short, focused commits
23. Meaningful commit messages
24. KEY GIT PROPERTIES
25. GIT HISTORY IS A GRAPH
26. git history is a directed acyclic graph
27. git history is a directed acyclic graph
28. git history is a directed acyclic graph X
29. Commits in git are immutable
30. Commits in git are immutable Attempting to change: • Message • Content (file objects) • Parent commit results in the creation of a new commit
31. In contrast, references in git are cheap and movable
32. IN PRACTICE
33. IN PRACTICE: CONFIGURATION Learn to use aliases for faster git commands In your shell config: In your ~/.gitconfig $ git status $ g s
36. IN PRACTICE: STAGING git add -p not git add . Use editor plugins for easy staging by hunk or line
39. IN PRACTICE: COMMITTING First line is capitalized, short (50 chars or less) summary Second line is blank Rest of commit message should explain why and other useful information about the change See Tim Pope’s blog post on commit messages
40. RE-WRITING HISTORY
41. AMENDING git commit --amend alias cam = git commit --amend --no-edit
42. REBASING master feature git merge feature
43. REBASING master git reset --hard HEAD~1 feature
44. REBASING master feature git checkout feature
45. REBASING master feature git rebase master
46. REBASING master git rebase master
47. REBASING git rebase master master
48. REBASING git rebase master master feature
49. master feature master feature f87cb a98fc cc47a 18dd2 744ee 8ca01 8ca01 ac871 ac871
50. master f87cb a98fc cc47a 18dd2 744ee 8ca01 feature ac871 git checkout feature
51. f87cb cc47a 18dd2 8ca01 ac871 master a98fc 744ee feature git reset --hard f87cb
52. INTERACTIVE REBASE git rebase -i master
54. rebase conflicts are the same as merge conflicts, resolve and git rebase -i master
55. git diff against the pre-rebase commit if you are worried about conflict mistakes
56. USING THE HISTORY
59. IN PRACTICE: BLAMING Use git blame to find why a line changed -w flag to ignore whitespace changes
63. GIT BISECT FOR BUG HUNTING master
64. GIT BISECT FOR BUG HUNTING master
65. GIT BISECT FOR BUG HUNTING master git bisect start
66. GIT BISECT FOR BUG HUNTING master git bisect good HEAD~7
67. GIT BISECT FOR BUG HUNTING master git bisect bad master
68. GIT BISECT FOR BUG HUNTING master git bisect
69. GIT BISECT FOR BUG HUNTING master git bisect bad
70. GIT BISECT FOR BUG HUNTING master
71. GIT BISECT FOR BUG HUNTING master git bisect good
72. GIT BISECT FOR BUG HUNTING master
73. GIT BISECT FOR BUG HUNTING master git bisect bad
74. MOVING/COMPARING CODE git checkout diff reset REF { }
75. MOVING/COMPARING CODE git checkout diff reset REF { } switch to that reference
76. MOVING/COMPARING CODE git checkout diff reset REF { } compare current against that reference
77. MOVING/COMPARING CODE git checkout diff reset REF { } get the files at that reference
78. MOVING/COMPARING CODE git checkout diff reset { }REF
79. MOVING/COMPARING CODE git checkout diff reset REF -- FILES { }
80. FIXING “MISTAKES”
81. In git, nothing added is ever “lost”
82. FIXING A BAD MERGE Usually this is as simple as backing the commit out by reseting one commit back git reset --hard HEAD~1 If you want to just fix a single badly merged file checkout the file you want git checkout GOOD_REF -- file
83. REFLOG FOR EVERYTHING ELSE git reflog keeps a reference of reach change in the HEAD reference (checkouts, rebase, cherry-picks, etc.) find the commit from before the change you want to fix and reset/checkout against it reflog expires after 90 days, but you can turn this off and have it never expire
87. git checkout diff reset b73c8c7 { }
88. LOST A STASH? git fsck can be used to find files that were at one time staged or perhaps stashed and dropped
89. REMOTES
90. REMOTES master
91. REMOTES master origin/master git pull
92. REMOTES master origin/master git pull
93. REMOTES master origin/master git pull
94. REMOTES master origin/master git pull
95. If you are going to force push prefer: git push --force-with-lease
96. End
97. FURTHER READING Think Like a Git Hartl’s Free eBook Cook’s Git from the inside out