Git, GitHub, & How I work

A talk I put together for Syracuse dev group (womenincoding.com)

Transcript

1. Women in Coding present: Git, GitHub, & How I work A session by Mike Vormwald
2. Sponsor THANKS HealtheConnections! ! "
3. Who am I? Mike Vormwald - Senior Software Engineer @ Stitch Fix - Instructor @ StartFastCODE - Organizer @ OpenHack Syracuse - Git / GitHub Enthusiast
4. Who are you? Say hello 1. What is your name? 2. A thing you like about the summer? ! ! ☀
5. What are we doing here? We are going to talk about git and GitHub
6. Disclaimer Git is a large topic. • There will be things we don't cover tonight. I'd love to talk to you afterwards • This is an interactive session... please ask questions as we go
7. Disclaimer #2 We are covering git on the command line You don't have to. You can use an App instead: • git kraken • source tree • github desktop • atom
8. Tonight's agenda 1. Why do I need git? 2. Cover the essential git commands and terms 3. [We handwave away a lot of edge cases / intermediate commands] 4. GitHub! 5. More advanced commands (How Mike works)
9. Actionable takeaways Tonight's Goal: • Never used git before? You see the benefits and feel comfortable using it in your own projects • Used git before? I hope you learn a useful trick or two
10. 0. Why do I need git? • Git is a Version Control System
11. 0. Why do I need git? • Git is a Version Control System • Git exists so you can modify/change/break/improve your code, secure in the knowledge that you can not ruin your work too badly because you created save points along the way.
12. 0. Why do I need git? • Git is a Version Control System • Git exists so you can modify/change/break/improve your code, secure in the knowledge that you can not ruin your work too badly because you created save points along the way • Git allows teams to work together on a common set of files without overwriting each other • Git allows you to see all your past changes and interact with them
13. 0. Why do I need git? When you're just starting out Git can seem like too much of a hassle to be worth using, BUT... • Team Projects may be where Git really shines, but its worth it for solo projects as well (e.g. If computer breaks your code will be safe) • Gives you a skill for working on collaborative projects in the future
14. 0. Why do I need git? Questions? !"
15. 1. Cover the essential git commands and terms
16. git init "Initialize", or put Git in this folder so that it keeps track of changes to files in this folder and subfolders git init We now have a new empty Git repository !
17. git status Show me which files have been changed and which ones are ready to be committed. You will use this command A LOT. git status
18. Terms Working Directory: the directory you’re writing code in Staging Area: files are in the staging area if the changes in them will be included in the next save point Repository: everything Git is keeping track of
19. git add Lets create a new file and add it to our repository echo "womenincoding.com" > event.txt git add event.txt Include the changes to this file in the next commit
20. git add Working Directory: the directory you’re writing code in ! Staging Area: files are in the staging area if the changes in them will be included in the next save point Repository: everything Git is keeping track of
21. git commit Wrap up all these changes from "the staging area" and save them together with a short description of the changes git commit -m “Add event description text”
22. git commit Working Directory: the directory you’re writing code in Staging Area: files are in the staging area if the changes in them will be included in the next save point ! Repository: everything Git is keeping track of
23. git log Show a history of all commits in the Repository git log
24. git diff Show what is different from the last commit line by line git diff
25. Branching
26. git branch What are all my branches? or what are all the names of the different versions of my code? git branch
27. git branch feature-name Make a new branch/version of my code with the name feature git branch my-new-branch
28. git checkout feature-name Move to that branch/version of my code so I can make changes to that branch/version of my code git checkout my-new-branch
29. master branch The name of the branch which should be the official, working, well documented, version of my code
30. git merge Combine the history of two branches so I can have the changes from both in one place
31. Merge conflict Git does not know how to combine two histories and needs human assistance • Open the conflicted file • Edit the combined text • Save the file • Commit your changes
32. On branching & GitHub Flow I generally follow GitHub flow, which basically says master branch is ready for production, other branches are for work (works well with teams) https:/ /guides.github.com/introduction/flow/
33. Remote repository A remote location that you can push your commits to GitHub is a popular repository host
34. git remote add origin address-of- remote Make address-of-remote a new place to store my code and call it “origin”
35. git remote -v To see what remote locations your local repo knows about git remote -v origin git@github.com:openhacksyr/openhacksyr.github.io.git (fetch) origin git@github.com:openhacksyr/openhacksyr.github.io.git (push)
36. git push -u origin master Push my code to the location origin points to, on the master branch, and also in the future I will pull code from this same location Terms: • Upstream: where I will pull code from in the future • Origin: where I put backups or share my code
37. Interacting with a remote • git pull: grab code from remote repository • git fetch: grab code from remote repository • git push: save my history and changes in another location
38. GitHub terms Fork: I want a GitHub repo that looks like someone else’s repo Pull Request: I made some changes that I would like you to include in your repository, please accept them git clone: give me the code at this location
39. When in doubt • git help • git help [command] • e.g. git help fetch
40. 1. Cover the essential git commands and terms Questions? !"
41. #2. Intermediate / advanced git commands AKA Mike handwaves this topic away • Try to learn the fundamentals listed above • Learn more advanced commands on a need-to-know basis Google is your friend. These are very common questions
43. #2. Intermediate / advanced git commands The nice thing about git is there is major value added to your life, just by using the basic commands • Commit your changes as you go • Push them to a remote repository • Repeat
44. #2. Intermediate / advanced git commands Questions? !"
45. #3. GitHub ... lets also handwave past GitHub basics Github is a hugely popular git repository hosting service / social network
46. GitHub We are going to look at a pull request I made on OpenHackSyr.com https:/ /github.com/openhacksyr/openhacksyr.github.io/pull/19
47. This Pull Request ... is silly, BUT: • It only solves one thing • It has well written commit messages • Includes checkboxes to indicate progress
48. Bad commit messages • Provide no context • Tell no story • Are bad Identifiable information has been redacted because my friend promises to write better messages in the future
49. Good commit messages Capitalized, short (50 chars or less) summary More detailed explanatory text, if necessary. Wrap it to about 72 characters or so. In some contexts, the first line is treated as the subject of an email and the rest of the text as the body. The blank line separating the summary from the body is critical (unless you omit the body entirely); tools like rebase can get confused if you run the two together. Encourached by GitHub http:/ /tbaggery.com/2008/04/19/a-note-about-git-commit-messages.html
50. How can we make it better? Whenever creating a Pull Request that changes the visible application • Add a screen shot of the visual changes • BONUS POINTS If possible add an animated gif of new behavior (lots of ways to do this. google "licecap")
51. Last Note on Pull Requests • Small, focused PRs are better, and get more helpful feedback • Anything that is merged into master should be immediately deployable
52. #3. GitHub Questions? !"
53. #4. How Mike works
54. #4. How Mike works A series of problems
55. #4. How Mike works Lets live code on OpenHackSyr TODO: 1. We realize we need to add April's event data 2. Then we should address feedback on Pull Request #19 3. Update the dog gifs in multiple commits 4. Push our commits to the PR
56. Problem 1/6 When I commit my code, it opens a weird editor ("vi") to enter my commit message Solution To encourage better more intentional commit message, lets set editor to nano git config --global core.editor "nano" git commit [Opens nano] control-x y (to save)
57. Problem 2/6 I want to get to know this repo, then add April's event information Solution • git log --oneline -n 5 • git show HEAD • git show HEAD~n • git add • git commit
58. Problem 3/6 I just commited changes to master !! ! Solution • git reset --soft HEAD~ • git branch add-april-event • git checkout add-april-event • git add . • git commit
59. Problem 4a/6 I'm working on multiple features at once, and have need to switch back and forth between branches Solution (stash) • git stash • git stash list • git stash show -v • git stash pop
60. Problem 4b/6 I'm working on multiple features at once, and have need to switch back and forth between branches Solution (WIP Commit) • git add . && git commit -m "WIP" • git log --oneline -n 5 • git show HEAD • git reset HEAD~
61. Problem 5/6 I need to find a string somewhere in the codebase Solution git grep -i mike
62. Problem 6/6 I need to get the dog gif page in its current state into a new branch Solution git checkout master git checkout -b a-new-dog-themed-branch git checkout dog-gifs -- top-5-dog-gifs.md
63. My fav commands • git status • git status, git status, git status • git commit --amend to add or rewrite • git add -p • git diff --cached • git commit -v
64. ~/.gitconfig ... [alias] s = status a = !git add . && git status au = !git add -u . && git status aa = !git add . && git add -u . && git status c = commit -v ac = !git add . && git commit acm = !git add . && git commit -m l = log --graph --all --pretty=format:'%C(yellow)%h%C(cyan)%d%Creset %s %C(white)- %an, %ar%Creset' lo = log --oneline ll = log --stat --abbrev-commit d = diff --color-words dc = diff --cached br = branch co = checkout master = checkout master g = grep --break --heading --line-number pf = push --force-with-lease
65. 4. How Mike works Questions? !"
66. Summary • Use branches for new work, keep master clean • Don't be afraid when commiting/undoing changes on a branch, everything* can be undone • Write nice commit messages, please • Commit your changes in small concise chunks
67. Learn more! • try.github.io/levels/1/challenges/1 • services.github.com/on-demand/downloads/github-git-cheat- sheet.pdf • confluence.atlassian.com/bitbucketserver/basic-git- commands-776639767.html • ohshitgit.com • robots.thoughtbot.com/git-interactive-rebase-squash-amend- rewriting-history
68. Teaching references A lot of information in this presentation came from these great posts • recompilermag.com/issues/issue-1/how-to-teach-git/ • medium.com/@the_taqquikarim/two-questions-to-consider- before-teaching-git-77f5f7eccaea
69. Thanks!