chore: add prettier

.editorconfig

@@ -0,0 +1,9 @@
+root = true
+
+[*]
+charset = utf-8
+insert_final_newline = true
+end_of_line = lf
+indent_style = space
+indent_size = 2
+max_line_length = 80

.github/workflows/ci.yaml

@@ -0,0 +1,27 @@
+name: CI
+
+on:
+  pull_request:
+  merge_group:
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  prettier:
+    runs-on: ubuntu-24.04
+    steps:
+      - name: Checkout
+        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+
+      - name: Setup Node.js
+        uses: actions/setup-node@1d0ff469b7ec7b3cb9d8673fde0c81c44821de2a # v4.2.0
+        with:
+          node-version: 22.14.0
+          cache: pnpm
+
+      - name: Install dev dependencies
+        run: pnpm install --frozen-lockfile --dev
+
+      - run: pnpm run prettier:check

.gitignore

@@ -1 +1,2 @@
 .idea
+node_modules

.npmrc

@@ -0,0 +1,2 @@
+public-hoist-pattern[]=*eslint*
+public-hoist-pattern[]=*prettier*

.prettierignore

@@ -0,0 +1 @@
+pnpm-lock.yaml

.prettierrc.js

@@ -0,0 +1,10 @@
+/**
+ * @see https://prettier.io/docs/configuration
+ * TODO migrate to TS when node lts supports it without flags
+ * @type {import("prettier").Config}
+ */
+const config = {
+  plugins: ["prettier-plugin-sort-json"],
+};
+
+export default config;

package.json

@@ -0,0 +1,17 @@
+{
+  "name": "backstage-renovate-config",
+  "packageManager": "[email protected]",
+  "volta": {
+    "node": "22.14.0",
+    "pnpm": "10.4.1"
+  },
+  "type": "module",
+  "scripts": {
+    "prettier:check": "prettier --check .",
+    "prettier:fix": "prettier --write ."
+  },
+  "devDependencies": {
+    "prettier": "3.5.2",
+    "prettier-plugin-sort-json": "4.1.1"
+  }
+}