add ci prettier changed-file check

Issue: CLDSRV-587

Author: benzekrimaha

.github/workflows/tests.yaml

@@ -8,6 +8,10 @@ on:
     branches-ignore:
       - 'q/*/**'
 
+  pull_request:
+    branches-ignore:
+      - 'q/*/**'
+
 env:
   # Secrets
   azurebackend_AZURE_STORAGE_ACCESS_KEY: >-
@@ -80,6 +84,8 @@ jobs:
     steps:
     - name: Checkout
       uses: actions/checkout@v4
+      with:
+        fetch-depth: 0
     - uses: actions/setup-node@v4
       with:
         node-version: '22'
@@ -89,6 +95,12 @@ jobs:
       run: yarn global add typescript@4.9.5
     - name: install dependencies
       run: yarn install --frozen-lockfile --network-concurrency 1
+    - name: Prettier (changed files)
+      run: scripts/format-changed.sh
+      env:
+        BASE_SHA: ${{ github.event.pull_request.base.sha }}
+        BASE_REF: ${{ github.event.pull_request.base.ref }}
+      if: ${{ github.event_name == 'pull_request' }}
     - uses: actions/setup-python@v5
       with:
         python-version: '3.9'

scripts/format-changed.sh

@@ -0,0 +1,43 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# Run Prettier only on files changed against a base ref/commit
+ROOT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+cd "$ROOT_DIR"
+
+# Inputs that can be provided by CI
+BASE_SHA="${BASE_SHA:-}"
+BASE_REF="${BASE_REF:-${GITHUB_BASE_REF:-}}"
+DEFAULT_BASE="${DEFAULT_BASE:-origin/main}"
+
+if [[ -n "$BASE_SHA" ]]; then
+    DIFF_BASE="$BASE_SHA"
+elif [[ -n "$BASE_REF" ]]; then
+    DIFF_BASE="origin/${BASE_REF#origin/}"
+else
+    DIFF_BASE="$DEFAULT_BASE"
+fi
+
+# Ensure the base ref exists locally
+if ! git rev-parse --verify "${DIFF_BASE}^{commit}" >/dev/null 2>&1; then
+    git fetch --no-tags --prune --depth=1 origin "${DIFF_BASE#origin/}" >/dev/null 2>&1 || true
+fi
+
+# If still missing, bail out gracefully to avoid blocking CI
+if ! git rev-parse --verify "${DIFF_BASE}^{commit}" >/dev/null 2>&1; then
+    echo "Base ref ${DIFF_BASE} not found; skipping Prettier check." >&2
+    exit 0
+fi
+
+mapfile -t CHANGED < <(git diff --name-only "${DIFF_BASE}...HEAD" --diff-filter=ACMRT \
+    | grep -E '\\.(js|cjs|mjs|ts|tsx|json|ya?ml|md)$' || true)
+
+if [[ ${#CHANGED[@]} -eq 0 ]]; then
+    echo "No supported files changed; skipping Prettier check."
+    exit 0
+fi
+
+echo "Running Prettier check on ${#CHANGED[@]} file(s):"
+printf ' - %s\n' "${CHANGED[@]}"
+
+yarn run --silent prettier --check "${CHANGED[@]}"