ci: add flake update action (#267)

* create flake update action

* what am i doing

* fix

* try nixpkgs.hyprland

* try flake

* use add

* try sway + cache nix

* use install

* fix pgrep

* fix sway exit

* screw sway ipc

* get ready for merge

* [CI] chore: update flake

* finally ready

1 files changed, 86 insertions, 0 deletions

diff --git a/.github/workflows/update-flake-inputs.yml b/.github/workflows/update-flake-inputs.yml
new file mode 100644
index 0000000..f304d6c
--- /dev/null
+++ b/.github/workflows/update-flake-inputs.yml
@@ -0,0 +1,86 @@
+name: Update flake inputs
+
+on:
+  workflow_dispatch:
+  push:
+    branches:
+      - main
+
+jobs:
+  update-flake:
+    runs-on: ubuntu-latest
+
+    permissions:
+      contents: write
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Install Nix
+        uses: nixbuild/nix-quick-install-action@v31
+        with:
+          nix_conf: |
+            keep-env-derivations = true
+            keep-outputs = true
+
+      - name: Restore and save Nix store
+        uses: nix-community/cache-nix-action@v6
+        with:
+          # restore and save a cache using this key
+          primary-key: nix-${{ hashFiles('**/*.nix', '**/flake.lock') }}
+          # if there's no cache hit, restore a cache by this prefix
+          restore-prefixes-first-match: nix-
+          # collect garbage until the Nix store size (in bytes) is at most this number
+          # before trying to save a new cache
+          # 1G = 1073741824
+          gc-max-store-size-linux: 1G
+          # do purge caches
+          purge: true
+          # purge all versions of the cache
+          purge-prefixes: nix-
+          # created more than this number of seconds ago
+          purge-created: 0
+          # or, last accessed more than this number of seconds ago
+          # relative to the start of the `Post Restore and save Nix store` phase
+          purge-last-accessed: 0
+          # except any version with the key that is the same as the `primary-key`
+          purge-primary-key: never
+
+      - name: Update flake inputs
+        run: nix flake update
+
+      - name: Attempt to build flake
+        run: nix build
+
+      - name: Test on Sway
+        env:
+          XDG_RUNTIME_DIR: /home/runner/runtime
+          WLR_BACKENDS: headless
+          WLR_LIBINPUT_NO_DEVICES: 1
+          WAYLAND_DISPLAY: wayland-1
+        run: |
+          mkdir $XDG_RUNTIME_DIR
+          chown $USER $XDG_RUNTIME_DIR
+          chmod 0700 $XDG_RUNTIME_DIR
+
+          nix profile install 'nixpkgs#sway'
+          sway &
+          sleep 3  # Give Sway some time to start
+          result/bin/caelestia-shell -d
+          sleep 3  # Give the shell some time to start (and die)
+          pgrep .quickshell-wra  # Fail job if shell died
+
+          result/bin/caelestia-shell kill
+          killall sway  # Screw using IPC
+
+      - name: Check for changes
+        id: check
+        run: echo modified=$(test -n "$(git status --porcelain)" && echo 'true' || echo 'false') >> $GITHUB_OUTPUT
+
+      - name: Commit and push changes
+        if: steps.check.outputs.modified == 'true'
+        uses: EndBug/add-and-commit@v9
+        with:
+          add: flake.lock
+          default_author: github_actions
+          message: "[CI] chore: update flake"