This is a pot-pourri of copy-pastes from chats and links to the phab discourse regarding the subject of:
> How do I ensure that what someone lands is what was reviewed in the corresponding diff?
Here is an [[ https://discourse.phabricator-community.org/t/block-unreviewed-code-from-landing-onto-master/4434 | older discussion ]] with some background, as well as some input from Evan.
Options some orgs have considered (non-exhaustive)
#### Landbot
`arc land` does not push anything: it triggers a bot somewhere to run `arc patch` and as many other checks one would like before handling the push.
This has some similarities with gitlab's release trains.
#### Pre-receive commit hook
Here, a pre-receive commit hook does the following:
- finds out the diff belonging to the commit,
- arc patches the diff to a separate, clean working copy,
- compares the diff of the patch with the diff of the commit,
- rejects the push if they differ.
This forces the dev to update his diff when what he would push differs from it. Then we have some rules around what areas of the repo have a sticky accept or not.
It does not solve for "diff breaks master after rebase" but at least you work around the problem of malicious or unintentionally borked pushes.
Here is a [[ https://gist.github.com/Shastick/dfdc42b49a4191e82ce1ed2853b561a4 | gist ]] for a partial implementation (it still attempts to compare patch files vs applying the changesets and comparing the output of `git diff`.
### Onwards
It would probably be worth thinking a bit about what uses cases we want to cover, but at least we can quickly have some hooks that are easy to install for users that know what they are doing.