Add vitest setup and puzzleUtils tests

package.json

@@ -5,7 +5,8 @@
   "scripts": {
     "dev": "vite",
     "build": "vite build",
-    "preview": "vite preview"
+    "preview": "vite preview",
+    "test": "vitest"
   },
   "dependencies": {
     "fireworks-js": "^2.10.8",
@@ -16,7 +17,10 @@
   },
   "devDependencies": {
     "@vitejs/plugin-vue": "^5.0.4",
+    "@vue/test-utils": "^2.4.6",
+    "jsdom": "^28.0.0",
     "vite": "^5.1.4",
-    "vite-plugin-pwa": "^0.20.5"
+    "vite-plugin-pwa": "^0.20.5",
+    "vitest": "^4.0.18"
   }
 }

src/utils/puzzleUtils.spec.js

@@ -0,0 +1,51 @@
+import { describe, it, expect } from 'vitest'
+import { calculateHints } from './puzzleUtils'
+
+describe('puzzleUtils', () => {
+  it('calculateHints correctly calculates hints for a simple grid', () => {
+    const grid = [
+      [1, 0, 1],
+      [1, 1, 1],
+      [0, 1, 0]
+    ]
+    // Row 0: 1, then space, then 1 -> [1, 1]
+    // Row 1: 1, 1, 1 -> [3]
+    // Row 2: space, 1, space -> [1]
+    
+    // Col 0: 1, 1, 0 -> [2]
+    // Col 1: 0, 1, 1 -> [2] ? Wait. Col 1 is 0, 1, 1. So space, 1, 1 -> [2].
+    // Let's trace col 1 manually:
+    // r0,c1 = 0
+    // r1,c1 = 1 -> count=1
+    // r2,c1 = 1 -> count=2
+    // end -> push 2.
+    // So Col 1 is [2].
+    
+    // Wait, my manual trace above for col 1:
+    // grid[0][1] is 0.
+    // grid[1][1] is 1.
+    // grid[2][1] is 1.
+    // Yes, [2].
+    
+    // Col 2: 1, 1, 0 -> [2].
+    
+    const expected = {
+      rowHints: [[1, 1], [3], [1]],
+      colHints: [[2], [2], [2]]
+    }
+    expect(calculateHints(grid)).toEqual(expected)
+  })
+
+  it('calculateHints handles empty rows/cols', () => {
+    const grid = [
+      [0, 0, 0],
+      [0, 0, 0],
+      [0, 0, 0]
+    ]
+    const expected = {
+      rowHints: [[0], [0], [0]],
+      colHints: [[0], [0], [0]]
+    }
+    expect(calculateHints(grid)).toEqual(expected)
+  })
+})

vitest.config.js

@@ -0,0 +1,16 @@
+import { defineConfig } from 'vitest/config'
+import vue from '@vitejs/plugin-vue'
+import path from 'path'
+
+export default defineConfig({
+  plugins: [vue()],
+  test: {
+    globals: true,
+    environment: 'jsdom',
+  },
+  resolve: {
+    alias: {
+      '@': path.resolve(__dirname, './src')
+    }
+  }
+})