This document discusses common Git anti-patterns and provides recommendations to avoid them. It begins by explaining how Git works under the hood in terms of files, folders, references, and objects. It then covers 15 specific anti-patterns to avoid, such as treating Git like Dropbox, having long-living topic branches, merging too late without validation, and being afraid to delete branches. For each anti-pattern, it provides alternatives and recommendations, such as splitting work into small tasks, committing early and often, rebasing rather than merging, and deleting merged branches. The overall message is how to use Git properly and cure common issues by following best practices.

1. GITANTI
PATTERNS
How To Mess Up With Git and Love It Again
LEMi ORHAN ERGiN
Agile Software Craftsman, iyzico
/lemiorhan
lemiorhanergin.com
@lemiorhan
28 common git anti-patterns

2. DISCLOSURE
There is no formula for using git efficiently.
Opinions are my own. It means the opposites
might work perfectly for your conditions.

3. git is powerful
but you have to know using it properly

4. Are you using git
if all you do is commit-push-pull
use dropbox instead
ANTIPATTERN DANGER
as if it is dropbox ?
1DROPBOX-ISH GIT ANTI-PATTERN

5. learn how git works
no worries, I will cover how git behaves

6. the way it keeps
FILES & FOLDERS
working copy
staging area
objects database
repository
the way it keeps
REFERENCES
directed acyclic graph
keeping snapshots
traversing graph
branches, tags, heads
git has 2 mechanisms

7. Source Code
Working Copy
you want to version changes

8. Source Code
Working Copy
$ git init
Object Database
.git Folder / Object Database
Cache
Staging Area / The Index
initializing repo

9. Source Code
Working Copy
$ git init --bare
Object Database
.git Folder / Object Database
Cache
Staging Area / The Index
Remote
Upstream Repo / Remote Repo
Server
initializing bare repo

10. Object Database
.git Folder / Object Database
Cache
Staging Area / The Index
Remote
Upstream Repo / Remote Repo
Server
Source Code
Working Copy
$ git add .
preparing commits

11. folder
folder
folder
file
file
file
$ git add .
preparing commits

12. Object Database
.git Folder / Object Database
Cache
Staging Area / The Index
Remote
Upstream Repo / Remote Repo
Server
Source Code
Working Copy
$ git add .
preparing commits

13. Object Database
.git Folder / Object Database
Cache
Staging Area / The Index
Remote
Upstream Repo / Remote Repo
Server
Source Code
Working Copy
$ git commit -m “initial commit”
commi!ing

14. $ git commit -m “initial commit”
commi!ing
folder
folder
folder
file
file
file
commit
branch
HEAD
For more details, refer to book
Git Internals by Scott Chacon

15. folder
folder
folder
file
file
file
commit
$ git commit -m “second commit”
commi!ing
folder
commit
branch
HEAD
folder
file
folder
For more details, refer to book
Git Internals by Scott Chacon

16. folder
folder
folder
file
file
file
commit
$ git commit -m “third commit”
commi!ing
folder
commit
folder
file
folder
folder
commit
branch
HEAD
file
For more details, refer to book
Git Internals by Scott Chacon

17. Object Database
.git Folder / Object Database
Cache
Staging Area / The Index
Remote
Upstream Repo / Remote Repo
Server
Source Code
Working Copy
$ git commit -m “initial commit”
commi!ing

18. Object Database
.git Folder / Object Database
Cache
Staging Area / The Index
Remote
Upstream Repo / Remote Repo
Server
Source Code
Working Copy
$ git remote add origin http://upstream.repo
$ git push -u origin master pushing to remote

19. Object Database
.git Folder / Object Database
Cache
Staging Area / The Index
Remote
Upstream Repo / Remote Repo
Server
Source Code
Working Copy
new changes from others are pushed

20. Object Database
.git Folder / Object Database
Cache
Staging Area / The Index
Remote
Upstream Repo / Remote Repo
Server
Source Code
Working Copy
$ git fetch
fetching changes

21. Object Database
.git Folder / Object Database
Cache
Staging Area / The Index
Remote
Upstream Repo / Remote Repo
Server
Source Code
Working Copy
$ git merge FETCHED_HEAD
updating working copy

22. Object Database
.git Folder / Object Database
Cache
Staging Area / The Index
Remote
Upstream Repo / Remote Repo
Server
Source Code
Working Copy
$ git pull
git fetch + git merge
ge!ing changes to source code

23. Object Database
.git Folder / Object Database
Cache
Staging Area / The Index
Remote
Upstream Repo / Remote Repo
Server
Source Code
Working Copy
want to update last commit

24. Object Database
.git Folder / Object Database
Cache
Staging Area / The Index
Remote
Upstream Repo / Remote Repo
Server
Source Code
Working Copy
$ git reset --soft $ git commit --amend/ so" reseting
cannot be reached
Only the cache for
the commit you reseted
is removed from staging area
for your current branch

25. folder
folder
folder
file
file
file
commit
folder
commit
folder
file
folder
folder
commit
branch
HEAD
file
For more details, refer to book
Git Internals by Scott Chacon
$ git reset --soft $ git commit --amend/ so" reseting

26. folder
folder
folder
file
file
file
commit
folder
commit
folder
file
folder
folder
commit
branch
HEAD
file
For more details, refer to book
Git Internals by Scott Chacon
$ git reset --soft $ git commit --amend/ so" reseting

27. Object Database
.git Folder / Object Database
Cache
Staging Area / The Index
Remote
Upstream Repo / Remote Repo
Server
Source Code
Working Copy
want to squash or change last commits

28. Object Database
.git Folder / Object Database
Cache
Staging Area / The Index
Remote
Upstream Repo / Remote Repo
Server
Source Code
Working Copy
$ git reset --mixed
mixed reseting
cannot be reached
entries for commits, files
and folders are removed
from staging area

29. Object Database
.git Folder / Object Database
Cache
Staging Area / The Index
Remote
Upstream Repo / Remote Repo
Server
Source Code
Working Copy
want to get rid of last commits

30. Object Database
.git Folder / Object Database
Cache
Staging Area / The Index
Remote
Upstream Repo / Remote Repo
Server
Source Code
Working Copy
$ git reset --hard
hard reseting
cannot be reached
removed from staging area
removed from working copy

31. are you brave enough to
jump to any commit ?
jump to a branch
create a branch from a commit
create a branch from a tag
ANTIPATTERN DANGER
$ git checkout feature/PA-121
$ git checkout -b fix/missing-sign-parameter 2449be8
$ git checkout -b hotfix/v1.1 tags/v1
2BROKEN TIME MACHINE ANTI-PATTERN

32. are you sure?
are you brave enough to
jump to any commit ?

33. do you have
loooooong living
topic branches ?
ANTIPATTERN DANGER
3LONG LIVING BRANCHES ANTI-PATTERN

34. do you have
loooooong living
topic branches ?
welcome to
merge hell

35. before merging
do you validate commits
back to source ?
ANTIPATTERN DANGER
code review, continuous integration, automated testing…
4TOO LATE TO VALIDATE ANTI-PATTERN

36. before merging
do you validate commits
back to source ? areyou
sure?

37. merge and unmerge
do you o!en want to
just before releases ?
ANTIPATTERN DANGER
5CHERRY-PICK OBSSESSION ANTI-PATTERN

38. merge and unmerge
do you o!en want to
just before releases ?
master
HEAD
TAG/v13
version 14
$ git cherry-pick Every-Single-Commit-We-Want-To-Deploy

39. the commit graph ?
do you fully understand
ANTIPATTERN DANGER
6DEATH ON COMMIT GRAPH ANTI-PATTERN

40. the commit graph ?
do you fully understand
topic and shared branches, tracking branches, tags, HEADs, merge commits, reverted commits…

41. Cure?

42. Commit Early, Commit O"en
Perfect Later, Publish Once

43. STEP 0
split your big feature into
mini shippable tasks
master
HEAD
TOPIC
ORIGIN/master
refactorings
tasks, like rest endpoints
testable, deployable
each task will have a
branch, not a feature

44. STEP 1
commit early
commit o!en
no need to compile
no need for CI
it’s only for versioning
do not push
master
HEAD
TOPIC
ORIGIN/master

45. always pull with rebase
$ git pull --rebase origin master
to get forced pushes securely
to rebase your commits
master
HEAD
TOPIC
STEP 2
ORIGIN/master

46. always pull with rebase
$ git pull --rebase origin master
to get forced pushes securely
to rebase your commits
master
HEAD
TOPIC
STEP 2
ORIGIN/master

47. always pull with rebase
$ git pull --rebase origin master
to get forced pushes securely
to rebase your commits
master
HEAD
TOPIC
STEP 2
ORIGIN/master
if you branch is pushed already
$ git push -f

48. always pull with rebase
$ git pull --rebase origin master
to get forced pushes securely
to rebase your commitsmaster
HEAD
TOPIC
STEP 2
ORIGIN/master
if you branch is pushed already
$ git push -f
Sync source branch a!erwards
$ git fetch origin master:master

49. perfect later
make it single commit
$ git reset HEAD~3
or
$ git rebase -i HEAD~3
HEAD
TOPIC
STEP 3
ORIGIN/master
tests are passing
app is working
code is reviewed (*)
master

50. $ git reset HEAD~3 (then commit)
or
$ git rebase -i HEAD~3
HEAD
TOPIC
STEP 3
ORIGIN/master
perfect later
make it single commit
tests are passing
app is working
code is reviewed (*)
master

51. Use feature flags/toggles
HEAD
TOPIC
STEP 4
ORIGIN/master
if feature should be disabled
merge back to source
$ git checkout master
$ git merge topic
master

52. Use feature flags/toggles
master
HEAD
TOPIC
STEP 4
ORIGIN/master
if feature should be disabled
merge back to source
$ git checkout master
$ git merge topic

53. Continuous Integration
validates master branch
continuouslymaster
HEAD
TOPIC
ORIGIN/master
Pull requests can be
used to review code
and to validate before
merging back to master
Scrum tasks are
mapped to commits,
not stories
Github Flow can be
used to govern overall
TAMING
THE POWER OF GIT
make git the king again
Feature flags should be
used whenever possible
Commit early & o"en
perfect later, publish
once philosophy
Deliver frequently
be prepared to send
every single commit
Deleting branches a"er
merge will make your
commit graph readable

54. use terminal
GUIs are prison balls of developers
it’s ok to use GUIs while checking diffs,
resolving conflicts and viewing commit graph
BUTTON ADDICT ANTI-PATTERN
7
ANTIPATTERN DANGER

55. do not lose
take extra care while using hard reset
$ git reset --merge HEAD~
Use stash $ git stash save “updates local settings to keep db safe”
$ git reset --hard HEAD~
$ git stash apply stash@{0}
Create a new branch $ git checkout -b feature/PA-121
$ git add settings.xml
$ git commit -m “adds new settings config”
Use hard reset
with merge
and commit into it
uncommited changes
CODE LOSING SYNDROME ANTI-PATTERN
8
ANTIPATTERN DANGER

56. TOPIC
HEAD
MASTER
$ git merge --squash fix
Squash commit -- not updating HEAD
Automatic merge went well; stopped before committing as requested
$ git add .
$ git commit -m “adds a feature”
$ git branch -D topic
TRASH HOUSE ANTI-PATTERN
9
long living branches with care
handle
ANTIPATTERN DANGER
Squash all commits in your topic branch and
make them available in working copy

57. long living branches with care
handle
TOPIC
HEAD
MASTER
$ git merge --squash fix
Squash commit -- not updating HEAD
Automatic merge went well; stopped before committing as requested
$ git add .
$ git commit -m “adds a feature”
$ git branch -D topic
Squash all commits in your topic branch and
make them available in working copy

58. stop adding
prevent commits from being big ball of muds
every change
OMNIBUS BILL ANTI-PATTERN
10
ANTIPATTERN DANGER

59. stop adding
prevent commits from being big ball of muds
every change
local change sets at JetBrains IDEs

60. stop adding every change
partial add

61. messages
are
read!
# WHAT
# <issue id> (this commit will...) <subject>
# WHY and HOW
# Explain why this change is being made
# RELATED
# Provide links or keys to any relevant issues or other resources
# REMEMBER
# use lower case in the subject line
# start with a verb in imperative tone in the subject line
# do not end the subject line with a period
# separate subject from body with a blank line
# use the body to explain what and why vs. how
# can use multiple lines with "-" for bullet points in body
$ git config --global commit.template ~/.git-commit-template.txt
$ git config --global commit.cleanup strip
use git commit
templates to
create be"er
commit messages
comtmi
F*CKING COMMIT MESSAGES ANTI-PATTERN
11
ANTIPATTERN DANGER

62. messages
are
read!
use git commit
templates to
create be"er
commit messages
comtmi

63. by adding new commits ?
do you rollback your mistakes
ANTIPATTERN DANGER
12MESS UP WITH THE ROLLBACK ANTI-PATTERN

64. hard reset the merge commit
$ git reset --hard HEAD~
if you haven't pushed yet
HEAD
MASTER
Bug fıx

65. never force push
and change the history
if you already pushed to shared branch
Bug fıx
HEAD
MASTER

66. revert the merge commit
$ git revert 8f937c6 -m 1
if you already pushed
Bug fıx
HEAD
MASTER

67. is not the only method
pushing commits to server
ANTIPATTERN DANGER
for sharing your code
13CENTRALIZED GIT ANTI-PATTERN

68. Git Pong Pairing
$ git remote add personA <URL>
$ git fetch personA
$ git checkout personA/master
$ git checkout -b feature/PA-231
add your changes and commit
$ git push personA feature/PA-231
A B
$ git checkout feature/PA-231
add your changes and commit
$ git pull personA feature/PA-231

69. with the ones in source
branch ?
how do you sync your commits
ANTIPATTERN DANGER
14MERGE FANATIC ANTI-PATTERN

70. Bug fıx
ladder pa!ern
occurs when premature merge happens
HEAD
MASTER

71. FIX
master
c1 c2 c3 c4 c7
HEAD
c5 c6c5 c6
use rebase $ git rebase master

72. FIX
master
c1 c2 c3 c4 c7
HEAD
c5 c6c5 c6
use rebase $ git rebase master

73. FIX
master
c1 c2 c3 c4 c7
HEAD
c5 c6c5 c6
use rebase $ git rebase master

74. FIX
master
c1 c2 c3 c4 c7
HEAD
c5 c6c5 c6
use rebase $ git rebase master
c5
REPLAY #1

75. FIX
master
c1 c2 c3 c4 c7
HEAD
c5 c6c5 c6
use rebase $ git rebase master
c5
REPLAY #2
c6c6

76. FIX
master
c1 c2 c3 c4 c7
HEAD
c5 c6c5 c6
use rebase $ git rebase master
c5
REWIND
c6c6

77. FIX
master
c1 c2 c3 c4 c7
HEAD
use rebase $ git rebase master
c5
FINALIZE
c6c6

78. deleting branches?
are you scared of
ANTIPATTERN DANGER
15BRANCH CEMETERY ANTI-PATTERN

79. delete merged local branches
$ git branch --merged | grep -v '^* master$' | grep -v '^ master$' | xargs git branch -d
delete remote branches
$ git branch -r --merged | grep -v master | sed 's/origin///'
| xargs -n 1 git push --delete origin

80. delete all merged local branches
$ git branch --merged | grep -v '^* master$' | grep -v '^ master$' | xargs git branch -d
delete all merged remote branches
$ git branch -r --merged | grep -v master | sed 's/origin///'
| xargs -n 1 git push --delete origin

81. wri!en in any form?
anyone can push any code
ANTIPATTERN DANGER
16UNCONTROLLED POWER ANTI-PATTERN

82. use
pre-receive
hooks

83. Depend on each other
Too many repositories
ANTIPATTERN DANGER
for sharing your code
17WEB OF REPOSITORIES ANTI-PATTERN

84. Mono Repository
System
Even though our services are still developed and deployed
independently, the code for all services lives in one
repository
The repository contains more than one logical project (e.g.
an iOS client and a web-application)
These projects are most likely unrelated, loosely
connected or can be connected by other means (e.g via
dependency management tools)
Twi#er, Facebook, Google, Digital Ocean,
Foursquare, Etsy, Shippable, Plataformatec, Ravelin

85. You can not do CI without using monorepos
- Xebia
“When you start a new project,” Potvin tells WIRED, “you
have a wealth of libraries already available to you. Almost
everything has already been done.”
- Rachel Potvin, Engineering Manager at Google
Our productivity has increased at least 5x.
- Shippable

86. v1, v2, v3…
having branch for every release
ANTIPATTERN DANGER
18ORACLE SYNDROME ANTI-PATTERN
at the same time

87. Commit early & o"en
perfect later, publish
once philosophy
Deploy frequently
be prepared to send
every single commit
Newer keep release
branches for a long time
master branch should be
enough for all your needs

88. to git repo
you pushed confidential info
ANTIPATTERN DANGER
19WAITING FOR HACKERS ANTI-PATTERN

89. Ref: https://help.github.com/articles/remove-sensitive-data/

90. Do you know what evil merge is?
ANTIPATTERN DANGER
20EVIL MERGE ANTI-PATTERN

92. do you use feature branches
when there is no product at all
ANTIPATTERN DANGER
21BRANCH OVERDOSE ANTI-PATTERN

93. use single branch
topic branches simply
make everything more
complex

94. Scared on using git commands
ANTIPATTERN DANGER
22CHUCKY THE COMMAND ANTI-PATTERN

95. push
add
dosya güncelleme
committed
Track ediliyor
untracked unmodified pushedmodified
staged
Staging Alanında Local Repoda Uzak Repoda
added
add
commitcommit

96. hard reset
committed
Track ediliyor
untracked unmodified pushedmodified
staged
Staging Alanında Local Repoda Uzak Repoda
added
hard reset
hard reset
mixed reset
mixed reset
soft reset
rm --cached
rm
x

97. h"ps://github.com/lemiorhan/git-kata

98. no one knows git perfect
do you suffer?
ANTIPATTERN DANGER
23NO HERO TO SAVE LIVES ANTI-PATTERN

99. have a git-man
at least one developer
should expertise on git
for supporting the
others

100. Having duplicate commits
&
Having irrelevant merge commits
if you haven’t pushed yet
ANTIPATTERN DANGER
24DUPLICATE COMMITS ANTI-PATTERN

102. UPSTREAM
LOCAL
master
c1 c2 c3 c4 c7
c5 c6c5 c6
FIX
HEAD
master
c1 c2 c3 c4 c7
c5 c6c5 c6
FIX
rebase and push

103. UPSTREAM
LOCAL
master
c1 c2 c3 c4 c7
c5 c6c5’ c6’
FIX
HEAD
master
c1 c2 c3 c4 c7
c5 c6c5 c6
FIX
$ git rebase master
rebase and push

104. UPSTREAM
LOCAL
master
c1 c2 c3 c4 c7
c5 c6c5’ c6’
FIX
HEAD
master
c1 c2 c3 c4 c7
c5 c6c5’ c6’
FIX
$ git push -f
rebase and push

105. UPSTREAM
LOCAL
master
c1 c2 c3 c4 c7
c5 c6c5 c6
FIX
HEAD
master
c1 c2 c3 c4 c7
c5 c6c5’ c6’
FIX
pull rebased branch

106. UPSTREAM
LOCAL
master
c1 c2 c3 c4 c7
c5 c6c5’ c6’
FIX
HEAD
master
c1 c2 c3 c4 c7
c5 c6c5’ c6’
FIX
$ git pull --rebase
pull rebased branch

107. UPSTREAM
LOCAL
master
c1 c2 c3 c4 c7
c5 c6c5 c6
FIX
HEAD
master
c1 c2 c3 c4 c7
c5 c6c5’ c6’
FIX
c5 c6c5’ c6’
ORIGIN/FIX
$ git pull
pull rebased branch:(

108. UPSTREAM
LOCAL
c1 c2 c3 c4 c7
c5 c6c5 c6
master
c1 c2 c3 c4 c7
c5 c6c5’ c6’
FIX
c5 c6c5’ c6’
c8
$ git pull
master
FIX
HEAD
ORIGIN/FIX
pull rebased branch:(

109. we commit when we have
something big
ANTIPATTERN DANGER
25BIG FAT COMMIT ANTI-PATTERN

110. use TDD style
whenever tests pass, commit
that makes you commit early and o!en

111. are you scared of using rebase?
ANTIPATTERN DANGER
26REBASE-FOBIA ANTI-PATTERN

112. rebasenot to merge your unpushed
commits with the fetched ones
use pull with
prepared by @lemiorhan
rebaseto get rebased commits
from upstream safely
use pull with
REBASEfeature branches to integrate
into public branches
that you pushed
or that you pulled
from another person
Never use Rebase
USE

113. do you know when we get
conflicts and how to resolve it?
ANTIPATTERN DANGER
27CONFLICT-FOBIA ANTI-PATTERN

116. RECAP
what was really
happened at that time?
LET’S

117. master
TAG/v1.1
login
HEAD
DETACHED HEAD STATE
$ git checkout cecd95914
Note: checking out 'cecd95914'.
You are in 'detached HEAD' state. You can look around, make experimental
changes and commit them, and you can discard any commits you make in this
state without impacting any branches by performing another checkout.
LIVING AT DETACHED HEAD STATE ANTI-PATTERN
28
ANTIPATTERN DANGER

118. master
TAG/v1.1
login
HEAD
DETACHED HEAD STATE
$ git rebase (and conflicts happen)
$ git checkout HEAD~2
$ git checkout 43e3ab01
$ git checkout tags/v1.1
WHEN IT HAPPENS

119. master
TAG/v1.1
login
HEAD
poor little developer...

120. master
TAG/v1.1
login
HEAD
$ git checkout master

121. master
TAG/v1.1
login
HEAD
$ git reflog
aa67e3a2c HEAD@{0}: rebase finished: returning to refs/heads/fix/java-sql-Date-violates-LSR
aa67e3a2c HEAD@{1}: rebase: fixes UnsupportedOperationException while calling toIstant() method of java.sql.Date
a45f3c4e5 HEAD@{2}: rebase: checkout develop
630ddad6e HEAD@{3}: checkout: moving from develop to fix/java-sql-Date-violates-LSR
b26cf7a1a HEAD@{4}: rebase: checkout develop
630ddad6e HEAD@{5}: checkout: moving from develop to fix/java-sql-Date-violates-LSR
b26cf7a1a HEAD@{6}: pull: Fast-forward
8b59f8f50 HEAD@{7}: checkout: moving from fix/java-sql-Date-violates-LSR to develop

122. $ git reflog
630ddad6e
the one we are
searching for
master
TAG/v1.1
login
HEAD
aa67e3a2c HEAD@{0}: rebase finished: returning to refs/heads/fix/java-sql-Date-violates-LSR
aa67e3a2c HEAD@{1}: rebase: fixes UnsupportedOperationException while calling toIstant() method of java.sql.Date
a45f3c4e5 HEAD@{2}: rebase: checkout develop
630ddad6e HEAD@{3}: checkout: moving from develop to fix/java-sql-Date-violates-LSR
b26cf7a1a HEAD@{4}: rebase: checkout develop
630ddad6e HEAD@{5}: checkout: moving from develop to fix/java-sql-Date-violates-LSR
b26cf7a1a HEAD@{6}: pull: Fast-forward
8b59f8f50 HEAD@{7}: checkout: moving from fix/java-sql-Date-violates-LSR to develop

123. master
typofix
TAG/v1.1
login
HEAD
$ git branch typofix 630ddad6e

124. master
typofix
TAG/v1.1
login
HEAD
$ git branch typofix 630ddad6e
KEEP CALM, NOTHING WILL BE LOST

125. LEMi ORHAN ERGiN
agile software craftsman @ iyzico
/lemiorhan
lemiorhanergin.com
@lemiorhan
ANTIPATTERN DANGER