diff --git a/src/config.test.ts b/src/config.test.ts
new file mode 100644
index 0000000..0184a50
--- /dev/null
+++ b/src/config.test.ts
@@ -0,0 +1,20 @@
+import { Kysely, MysqlDialect } from 'kysely'
+import { createPool } from 'mysql2'
+import { expect, test } from 'vitest'
+
+import { defineConfig } from './config.js'
+
+test('defineConfig', () => {
+  expect(
+    defineConfig({
+      db: new Kysely({
+        dialect: new MysqlDialect({ pool: createPool('mysql://') }),
+      }),
+      migrationFolder: 'src/db/migrations',
+      codegen: {
+        dialect: 'mysql',
+        out: 'src/db/types.ts',
+      },
+    }),
+  ).toBeDefined()
+})
diff --git a/src/utils/loadEnv.test.ts b/src/utils/loadEnv.test.ts
new file mode 100644
index 0000000..216e1b5
--- /dev/null
+++ b/src/utils/loadEnv.test.ts
@@ -0,0 +1,7 @@
+import { expect, test } from 'vitest'
+
+import { loadEnv } from './loadEnv.js'
+
+test('loadEnv', () => {
+  expect(loadEnv()).toMatchInlineSnapshot('{}')
+})