chore: extract vitest config into separate file

vite.config.ts

@@ -1,6 +1,4 @@
 import vue from "@vitejs/plugin-vue";
-/// <reference types="vite/client" />
-/// <reference types="vitest" />
 import { fileURLToPath, URL } from "url";
 import { defineConfig } from "vite";
 import dts from "vite-plugin-dts";
@@ -153,10 +151,4 @@ export default defineConfig({
       },
     },
   },
-  test: {
-    environment: "jsdom",
-    coverage: {
-      reporter: ["text", "json", "html"],
-    },
-  },
 });

vitest.config.ts

@@ -0,0 +1,18 @@
+import { fileURLToPath } from "node:url";
+import { mergeConfig, defineConfig, configDefaults } from "vitest/config";
+import viteConfig from "./vite.config";
+
+export default mergeConfig(
+  viteConfig,
+  defineConfig({
+    test: {
+      environment: "jsdom",
+      exclude: [...configDefaults.exclude, "tests/*"],
+      root: fileURLToPath(new URL("./", import.meta.url)),
+      coverage: {
+        provider: "v8",
+        reporter: ["text", "json", "html"],
+      },
+    },
+  }),
+);