Add prettier to project and actions (#85)

* Install prettier

* Rework github actions:

- Add prettier-check action
- Add caching
- Rename pnpm command

.github/workflows/css-selectors.yaml

@@ -16,7 +16,7 @@ jobs:
             - name: Install pnpm
               uses: pnpm/action-setup@v4
               with:
-                  version: 9
+                  version: 10
 
             - name: Setup node.js
               uses: actions/setup-node@v4

.github/workflows/prettier-check.yaml

@@ -0,0 +1,33 @@
+name: Prettier Check
+
+on:
+    pull_request:
+        branches:
+            - main
+    push:
+        branches:
+            - main
+
+jobs:
+    prettier:
+        runs-on: ubuntu-latest
+
+        steps:
+            - uses: actions/checkout@v4
+
+            - name: Install pnpm
+              uses: pnpm/action-setup@v4
+              with:
+                  version: 10
+
+            - name: Setup Node.js
+              uses: actions/setup-node@v4
+              with:
+                  node-version: lts/*
+                  cache: "pnpm"
+
+            - name: Install dependencies
+              run: pnpm install --frozen-lockfile
+
+            - name: Run Prettier check
+              run: pnpm run format:check

package.json

@@ -16,7 +16,9 @@
         "build:chrome": "TARGET=chrome vite build",
         "test": "playwright test --reporter=list",
         "test:ui": "playwright test --ui",
-        "test:detailed": "playwright test"
+        "test:detailed": "playwright test",
+        "format": "prettier --write src/",
+        "format:check": "prettier --check src/"
     },
     "repository": {
         "type": "git",
@@ -42,6 +44,7 @@
         "@types/firefox-webext-browser": "^120.0.4",
         "@types/node": "^22.13.1",
         "@types/webextension-polyfill": "^0.12.1",
+        "prettier": "^3.4.2",
         "typescript": "^5.7.3",
         "web-ext": "^8.3.0",
         "webextension-polyfill": "^0.12.0"