1. Basis
1-1. First of all
Check the "push mode" of your Git.
git config --global push.default
It doesn't show anything? It's fine. If it shows something other than "simple", let me know.
1-2. GitHub Flow
We follow GitHub Flow. Read through the page below.
https://guides.github.com/introduction/flow/
* Note that the contents are in a slider UI, so don't miss them.
If you have some experience of Git Flow and if you are curious about the difference between Git Flow and GitHub Flow (those two are very different), I recommend this. (But it's not necessary.)
http://scottchacon.com/2011/08/31/github-flow.html
The points of GitHub Flow are:
- Always make a branch from
master. - Keep branches, Pull Requests (PR) and tasks as small as possible.
- Commit often. Push often. And make a PR right after you push your first commit.
- You can make a PR before you finish your task. The sooner the better.
One thing that is different from GitHub Flow
With our rule, after you finish your task, you will merge your branch to master and deploy master.
With GitHub Flow, a developer will merge master to his/her branch and deploy the branch (not master). After that, the developer will merge the branch to master.
1-3. Never do this
Never use --force (or -f) option when you use git push.
* Actually I've already configured our GitHub repositories so that you can't use git push --force to master. But don't even use --force to any other branches also.
2. Our actual flow
2-1. Make a branch and a PR
Make a branch and checkout it from the latest master.
git checkout master
git pull # Update `master` on your local
git checkout -b my-branch
After you commit some codes, push it right away to GitHub. Commit often, push often is one of the GitHub ways.
git push origin my-branch
If you push with --set-upstream (or -u) option,
git push --set-upstream origin my-branch
then you can skip typing your branch name afterwards.
git push
Now you can (should) make a PR in GitHub and write the PR URL in the Trello card you are working with. Again I recommend you that you make a PR as soon as possible.
Make a PR with no changes
Some people make PRs even without changing anything. But you need to have at least one commit to do so. You can do this with an empty commit using --allow-empty option.
git commit --allow-empty -m "Your commit message here"
This is just a tip and it's not mandatory for our team. Anyway please think that a PR is like a web bulletin board. And you can open it or close it whenever you want.
2-2. Merge and deploy your branch
You can merge your PR by yourself without code review if the branch only includes text, HTML, CSS changes or some small PHP changes.
If you think the PHP changes are somewhat big, ask someone to review your code.
Don't forget to click the "Delete branch" button on GitHub after you merge or close your PR.
Next, update master on your local.
git checkout master
git pull
Then you will be able to delete your branch.
git branch -d my-branch
Now you can deploy master to our production servers.
2-3. Get someone else's PR to your local
When you review someone else's PR, normally you do it on the GitHub web pages. However, sometimes you will want to get the PR to your local. Or sometimes you will need to work on the PR with other developers.
First, update branches on your local with git fetch with --prune (or -p) option. The option will delete your local branches if they have been deleted on remote (= GitHub), so always use --prune option.
git fetch --prune
Check if you have successfully updated every branches on your local.
git branch --all # Or you can use `-a` instead.
Next, checkout the remote branch to your local.
# You can also do it only with `git checkout someone-branch`.
# It's the shortcut, same as the command below.
git checkout remotes/origin/someone-branch -b someone-branch
Now you can pull/push without the branch name.
git pull
git push
2-4. Undo what you have done
Undo what you have added
You can do it with this.
git reset
If you pass a commit ID parameter to git reset, you can change our Git history. But don't do this. If you want to change or undo what you have committed, read the following.
Undo what you have committed
It's so easy. Just manually write codes and commit them that can undo what you have done.
If it's a pain in the neck to write such codes, you can use git revert. But be careful when you use git revert.
When you just want to change the commit message that you've just written, for example when you misspelled, you can do with --amend option.
git commit --amend -m "New commit message"
3. Other useful Git commands
git diff
With git diff, you can check the difference between your working directory and what you added. With git diff HEAD, you can check the difference between your working directory and HEAD. (Normally, HEAD is the newest commit that you or someone made in your current branch).
By the way, I recommend that you use -b option instead of -w option when you want to ignore whitespace changes. Look this diff. Someone accidentally put a white space between / and usr. What a fiasco!
-sudo rm -rf /usr/local/bin/abc
+sudo rm -rf / usr/local/bin/abc
-w option ignores all whitespace changes so you won't see the diff above.
-b option only ignores changes only when the amount of whitespaces changed. For example, 2 spaces to 3, or 3 to 2, will be ignored. But 1 to 0, or 0 to 1, won't be ignored. So you will be able to spot the diff above.
git grep
I use this command a thousand times a day. I believe grep is the best tool on earth. Without this, I would quit my job and become a Uber driver.
-i option ignores upper and lower cases. -I option ignores differences in binary files.
git blame
This command is useful when you want to know who wrote a line of codes.
git blame [file]
Remember that git blame is not for "blaming" anyone. It's just for knowing the person who wrote the line especially when you want to ask him/her something about the code.
git log
The following command shows every commits with a neat graph view.
git log --all --graph --oneline
If you don't want to bother typing the command above many times a day, just set an alias in ~/.gitconfig.
[alias]
tree = log --all --graph --oneline
Now you can call the alias with this.
git tree