We will pass these positions back to clients for rendering non-model items, and
it's important that clients can consistently rely on them no matter which
columns were removed.
We've been sometimes using lo and sometimes using my slices package, and we need to pick one
for consistency. Lo is more extensive and better maintained so we're going with that.
My slices package was a superset of go's own slices package so in some places I've just used
the official one (the methods were just wrappers anyway).
I've also moved the remaining methods into the utils package.
Afero is a package that lets you mock out a filesystem with an in-memory filesystem.
It allows us to easily create the files required for a given test without worrying about
a cleanup step or different tests tripping on eachother when run in parallel.
Later on I'll standardise on using afero over the vanilla os package
The assert package is already very good at displaying errors, including printing
a diff of expected and actual value, so there's no point in printing the same
information again ourselves.
This fixes two problems with the "amend commit with staged changes" command:
1. Amending to a fixup commit didn't work (this would create a commmit with the
title "fixup! fixup! original title" and keep that at the top of the branch)
2. Unrelated fixup commits would be squashed too.
The added integration test verifies that both of these problems are fixed.
Instead of passing a bunch of different options in
PrepareInteractiveRebaseCommandOpts, where it was unclear how they interact if
several are set, have only a single field "instruction" which can be set to one
of various different instructions.
The functionality of replacing the entire todo file with our own is no longer
available; it is only possible to prepend todos to the existing file.
Also, instead of using different env vars for the various rebase operations that
we want to tell the daemon to do, use a single one that contains a json-encoded
struct with all available instructions. This makes the protocol much clearer,
and makes it easier to extend in the future.
It used to work on the assumption that rebasing commits in lazygit's model
correspond one-to-one to lines in the git-rebase-todo file, which isn't
necessarily true (e.g. when users use "git rebase --edit-todo" at the custom
command prompt and add a "break" between lines).
