chore: add prettier (#7)

Add `prettier` as formatter to the project. Formatting will be checked
in the `CI` pipeline to enfore consistent formatting in all source
files.

.github/renovate.json

@@ -26,6 +26,10 @@
       "groupName": "eslint",
       "matchPackagePrefixes": ["@typescript-eslint/", "eslint"]
     },
+    {
+      "groupName": "prettier",
+      "matchPackagePrefixes": ["prettier"]
+    },
     {
       "groupName": "typescript",
       "matchPackageNames": ["typescript"]

.github/workflows/ci.yml

@@ -28,6 +28,27 @@ jobs:
       - name: Lint
         run: npx eslint .
 
+  format:
+    runs-on: ubuntu-latest
+    timeout-minutes: 5
+    name: 'Format: node-18, ubuntu-latest'
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v3
+        with:
+          fetch-depth: 0
+
+      - name: Set node version to 18
+        uses: actions/setup-node@v3
+        with:
+          node-version: 18
+
+      - name: Install deps
+        run: npm install
+
+      - name: Format
+        run: npx prettier src --check
+
   ts-check-tests:
     runs-on: ubuntu-latest
     timeout-minutes: 10

.prettierrc.json

@@ -0,0 +1,4 @@
+{
+  "trailingComma": "all",
+  "singleQuote": true
+}

package.json

@@ -5,6 +5,7 @@
   "main": "dist/index.js",
   "scripts": {
     "build": "tsc",
+    "format": "prettier src --write",
     "lint": "eslint .",
     "lint:fix": "eslint . --fix"
   },
@@ -31,6 +32,7 @@
     "@typescript-eslint/eslint-plugin": "^5.59.11",
     "@typescript-eslint/parser": "^5.59.11",
     "eslint": "^8.42.0",
+    "prettier": "^3.0.3",
     "typescript": "~5.0.4"
   }
 }

src/index.ts

@@ -1 +1 @@
-// todo write the application
+// todo write the application