Actions workflow to format code on command (#5400)

* Add script to perform or check formatting

* Actions workflow to format code on command

Comment on a PR with /format

3 files changed, 162 insertions, 0 deletions

diff --git a/.github/workflows/format.yml b/.github/workflows/format.yml
new file mode 100644
index 000000000..4a68882ae
--- /dev/null
+++ b/.github/workflows/format.yml
@@ -0,0 +1,49 @@
+name: Format
+on:
+  repository_dispatch:
+    types: [format-command]
+jobs:
+  format:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          token: ${{ secrets.SLANGBOT_PAT }}
+          repository: ${{ github.event.client_payload.pull_request.head.repo.full_name }}
+          ref: ${{ github.event.client_payload.pull_request.head.ref }}
+
+      - run: pip3 install gersemi
+
+      - name: install clang-format
+        run: |
+          tmpdir=$(mktemp -d)
+          curl -L -H "Authorization: token ${{ secrets.SLANGBOT_PAT }}" \
+            -o "$tmpdir/clang-format" \
+            https://github.com/shader-slang/slang-binaries/raw/4e88845ec51641b4c92e68027e359090bdb219e0/clang-format/x86_64-linux/bin/clang-format
+          chmod +x "$tmpdir/clang-format"
+          echo "$tmpdir" >> $GITHUB_PATH
+
+      - run: ./extras/formatting.sh
+
+      - name: Configure Git commit signing
+        run: |
+          echo "${{ secrets.SLANGBOT_SIGNING_KEY }}" > "${{runner.temp}}"/signing_key
+          chmod 600 "${{runner.temp}}"/signing_key
+          git config commit.gpgsign true
+          git config gpg.format ssh
+          git config user.signingkey "${{runner.temp}}"/signing_key
+
+      - uses: EndBug/add-and-commit@v9
+        with:
+          fetch: false
+          message: "format code"
+          push: true
+
+      - name: Add reaction
+        uses: peter-evans/create-or-update-comment@v4
+        with:
+          token: ${{ secrets.SLANGBOT_PAT }}
+          repository: ${{ github.event.client_payload.github.payload.repository.full_name }}
+          comment-id: ${{ github.event.client_payload.github.payload.comment.id }}
+          reactions-edit-mode: replace
+          reactions: hooray
diff --git a/.github/workflows/slash-command-dispatch.yml b/.github/workflows/slash-command-dispatch.yml
new file mode 100644
index 000000000..fc357f89e
--- /dev/null
+++ b/.github/workflows/slash-command-dispatch.yml
@@ -0,0 +1,32 @@
+name: Slash Command Dispatch
+on:
+  issue_comment:
+    types: [created]
+jobs:
+  slashCommandDispatch:
+    runs-on: ubuntu-latest
+    steps:
+
+      - name: Slash Command Dispatch
+        id: scd
+        uses: peter-evans/slash-command-dispatch@v4
+        with:
+          token: ${{ secrets.SLANGBOT_PAT }}
+          reaction-token: ${{ secrets.SLANGBOT_PAT }}
+          config: >
+            [
+              {
+                "command": "format",
+                "permission": "none",
+                "issue_type": "pull-request"
+              }
+            ]
+
+      - name: Edit comment with error message
+        if: steps.scd.outputs.error-message
+        uses: peter-evans/create-or-update-comment@v4
+        with:
+          token: ${{ secrets.SLANGBOT_PAT }}
+          comment-id: ${{ github.event.comment.id }}
+          body: |
+            > ${{ steps.scd.outputs.error-message }}
diff --git a/extras/formatting.sh b/extras/formatting.sh
new file mode 100755
index 000000000..dc3bbc7ca
--- /dev/null
+++ b/extras/formatting.sh
@@ -0,0 +1,81 @@
+#!/usr/bin/env bash
+
+set -e
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" >/dev/null 2>&1 && pwd)"
+cd "$(git -C "$SCRIPT_DIR" rev-parse --show-toplevel)" || exit 1
+
+check_only=0
+
+while [[ "$#" -gt 0 ]]; do
+  case $1 in
+  -h | --help) help=1 ;;
+  --check-only) check_only=1 ;;
+  esac
+  shift
+done
+
+if [ "$help" ]; then
+  me=$(basename "$0")
+  cat <<EOF
+$me: Format or check formatting of files in this repo
+
+Usage: $me [--check-only]
+
+Options:
+    --check-only     Check formatting without modifying files
+EOF
+  exit 0
+fi
+
+require_bin() {
+  local name="$1"
+  local required="$2"
+  local version
+
+  if ! command -v "$name" &>/dev/null; then
+    echo "This script needs $name, but it isn't in \$PATH"
+    missing_bin=1
+    return
+  fi
+
+  version=$("$name" --version | grep -oP "$name(?:\s+version)?\s+\K\d+\.\d+\.?\d*")
+  if ! printf '%s\n%s\n' "$required" "$version" | sort -V -C; then
+    echo "$name version $version is too old. Version $required or newer is required."
+    missing_bin=1
+  fi
+}
+
+require_bin "git" "1.8"
+require_bin "gersemi" "0.16.2"
+
+if [ "${missing_bin:-}" = "1" ]; then
+  exit 1
+fi
+
+if [ "$missing_bin" ]; then
+  exit 1
+fi
+
+exit_code=0
+
+cmake_formatting() {
+  readarray -t files < <(git ls-files '*.cmake' 'CMakeLists.txt' '**/CMakeLists.txt')
+
+  common_args=(
+    # turn on warning when this is fixed https://github.com/BlankSpruce/gersemi/issues/39
+    --no-warn-about-unknown-commands
+    --definitions "${files[@]}"
+  )
+
+  if [ "$check_only" -eq 1 ]; then
+    gersemi "${common_args[@]}" --diff --color "${files[@]}"
+    gersemi "${common_args[@]}" --check "${files[@]}" || exit_code=1
+  else
+    gersemi "${common_args[@]}" --in-place "${files[@]}"
+  fi
+}
+
+cmake_formatting
+
+exit $exit_code