feat: add vitest configuration file

- add vitest configuration
- update tsconfig.json so that test files does not throw error
with global definitions such as expect, test

tsconfig.json

@@ -12,9 +12,10 @@
     "experimentalDecorators": true,
     "esModuleInterop": true,
     "noUnusedLocals": true,
-    "moduleResolution": "node",
+    "moduleResolution": "Bundler",
     "declaration": true,
     "resolveJsonModule": true,
+    "types": ["vitest/globals"],
 
     // TODO: Enable the following options later.
     // "forceConsistentCasingInFileNames": true,

vitest.config.js

@@ -0,0 +1,31 @@
+import { defineConfig, mergeConfig } from 'vitest/config'
+import viteConfig from './vite.config'
+
+export default defineConfig(configEnv => mergeConfig(
+  viteConfig(configEnv),
+  defineConfig({
+  test: {
+    globals: true,
+    environment: 'jsdom',
+    alias: {
+      "\\.css$": "identity-obj-proxy",
+      "\\.svg\\?react$": "<rootDir>/test/mocks/svgr.ts",
+      "^\\./IndexedDBWorker\\?worker$": "<rootDir>/test/mocks/workerMock.ts",
+      "^\\./olm$": "<rootDir>/test/mocks/olmMock.ts"
+    },
+    css: {
+      modules: {
+        classNameStrategy: 'non-scoped'
+      }
+    },
+    include: [
+      "test/**/*-test.[jt]s?(x)"
+    ],
+    coverage: {
+      reporter: ['text', 'html'],
+      exclude: [
+        'node_modules/'
+      ]
+    }
+  }
+})))