ci: rename update-scripts → ci

This changes how we think about this directory; it does not need to be
exclusively for scripts related to updates, but should be a place for
any scripts intended to be run by CI workflows.

This mindset should make it easier to develop and test the business
logic of workflows, without always needing to test "in production" on
the nixvim repo or a fork.

Author: MattSturgeon

.github/workflows/update.yml

@@ -132,15 +132,15 @@ jobs:
         id: update_flake_lock
         if: inputs.update_lock || github.event_name == 'schedule'
         run: |
-          nix-build ./update-scripts -A update
+          nix-build ./ci -A update
           ./result/bin/update --commit --github-output
 
       - name: Update generated files
         id: generate
         if: inputs.generate || github.event_name == 'schedule'
         run: |
           old=$(git show --no-patch --format=%h)
-          nix-build ./update-scripts -A generate
+          nix-build ./ci -A generate
           ./result/bin/generate --commit
           new=$(git show --no-patch --format=%h)
           if [ "$old" != "$new" ]; then

update-scripts/README.md renamed to ci/README.md

@@ -1,9 +1,7 @@
-# Update scripts
+# CI scripts
 
-This directory contains update scripts that are not part of the actual flake.
-
-These scripts are used by the `update` CI workflow, so you shouldn't need to run them manually.
-This workflow is found at `.github/workflows/update.yml`.
+This directory contains CI-related scripts that are not part of the actual flake.
+Unless developing or testing changes, you shouldn't need to run them manually.
 
 ## Developing
 
@@ -14,17 +12,20 @@ For example, `nix-build -A generate` will build `./generate.nix` into `./result/
 A `shell.nix` is available that will place `generate` on your PATH.
 
 You could use this directory's shell/packages from another working directory by supplying `nix-build` or `nix-shell` with a path.
-E.g. `nix-shell ./update-scripts`.
+E.g. `nix-shell ./ci`.
 
 ## Explanation
 
-These packages are not in the flake outputs for two main reasons:
+These packages are not in the flake outputs for three main reasons:
 - Packages built using the flake must follow the flake's `nixConfig`
 - Packages included in the flake's output are checked by `nix flake check`
+- Some of the packages should have no dependency on the flake at all,
+  allowing this directory to be [sparse checked out][sparse-checkout] by a workflow
 
-Being unable to bypass `nixConfig` is an issue because we want to disable [IFD] for the flake, but not for these generate scripts.
+Being unable to bypass `nixConfig` is an issue because we want to disable [IFD] for the flake, but not for these scripts.
 
 If something changes upstream that causes the builds to fail, we don't want this to block us updating `flake.lock`.
 We'd still be made aware of any issues by the `update` CI workflow failing.
 
+[sparse-checkout]: https://github.com/actions/checkout#scenarios
 [IFD]: https://nixos.org/manual/nix/stable/language/import-from-derivation