As the size of a dev team grows, so does the likelihood of someone doing a force push and overwriting someone else's code.
Here's what a force push looks like in Git:
$ git push --force origin master# `--force` can also be written as `-f`
This command can cause all kinds of problems. It basically tells Git that I don't care what is in origin/master. What I have is correct. Overwrite it.
So what happens if a co-worker had changes committed to a branch that you haven't pulled down into your own repo? It gets overwritten, and your co-worker potentially has to re-do their work (or resurrect a commit or two if they still have it locally).
But this whole mess can be easily avoided with a small change to how you use the
force flag. Instead of using
$ git push --force-with-lease origin master
To summarize Git's documentation, using
force-with-lease tells git to check whether the remote repo is the same as the one you're trying to push up. If it
isn't, git will throw an error instead of blindly overwriting the remote repo. This will save you from accidentally
overwriting work that you don't intend to.
I hate type
force-with-lease though — especially because I'm used to typeing
-f for force pushing. Thankfully, Git allow syou to add aliases to
make this quicker. I like to think that I'm asking Git if it's okay to force push,
so I've aliased
push -force-with-lease to
$ git please origin master
You can add an alias in git by typing this into your terminal:
$ git config --global alias.please `push --force-with-lease`
Or you can open up your
~/.gitconfig file and manually add the alias:
[alias]please = push --force-with-lease
There's always a caveat...
It's possible to trick force with lease however. When you use
git pull to get
updates from the origin, this is doing two commands at once. Git runs a
to pull down the references to all the changes. Then it runs a
merge to merge
the changes you just fetched into your current branch.
If you only do a
fetch to get the latest updates, you'll only be updating your
references — not actually merging the changes into your working copy. Then,
if you force push with lease, Git will look at those references and think that the
local copy is up to date with the remote, when in reality it isn't yet. This will
trick Git into overwriting the changes on the remote with your local copy,
without having the changes actually merged in.
The easiest way to avoid this problem is always to use
git pull to
merge at the same time. I've not run into any instances where I've needed to
merge manually, so I can't speak to those circumstances. Using
has always worked for me.
I hope you find
git please helpful and that, as a result, you never have to
recover from a force-push nightmare.