Source forges like Gitlab, Gitea, Forgjo, Github, and others do not allow directly leaving comments on code. However, they all do allow leaving comments on pull/merge requests and individual commits. This unfortunately doesn't work for snippets like Gitlab Snippets, Github Gists, etc. .

We can however use these to our advantage and use workarounds in order to make certain parts of our code reviewable:

Snippets

Create a repository to host your snippets (if you don't have one already), add your snippet of code as one commit to the repository (can be in a throwaway branch, the master branch, whatever). Share that commit link!

Larger changes

If you have code that belongs together, it is already in your repository, and is spread out over multiple commits, fear not! Once again, you can use the power of temporary branches. With these methods you can even have your entire repo reviewed.

A commit to review

Create a new branch, delete the parts of the code you want reviewed, create a revert commit, and share that link!

A PR to review

This requires 2 branches. If you've read the steps above, you already know where this is going.

Create a branch (deleted), delete the code and commit it. Create a new branch (revert) from this point and revert the previous commit. Now you can push both branches to your source forge and create a new merge request to merge revert into deleted.

If you have other tips, share them!