diff --git a/packages/blocknumber/.gitignore b/packages/blocknumber/.gitignore
new file mode 100644
index 0000000..7773828
--- /dev/null
+++ b/packages/blocknumber/.gitignore
@@ -0,0 +1 @@
+dist/
\ No newline at end of file
diff --git a/packages/blocknumber/package.json b/packages/blocknumber/package.json
index 49b5377..7df4b85 100644
--- a/packages/blocknumber/package.json
+++ b/packages/blocknumber/package.json
@@ -4,7 +4,7 @@
     "description": "",
     "main": "index.ts",
     "scripts": {
-        "build": "tsc",
+        "build": "tsc -p tsconfig.build.json",
         "lint": "eslint .",
         "lint:fix": "pnpm lint --fix",
         "format": "prettier --check .",
diff --git a/packages/blocknumber/src/helloWorld.spec.ts b/packages/blocknumber/src/helloWorld.spec.ts
index 7216041..f2cafa8 100644
--- a/packages/blocknumber/src/helloWorld.spec.ts
+++ b/packages/blocknumber/src/helloWorld.spec.ts
@@ -1,7 +1,11 @@
 import { describe, expect, it } from "vitest";
 
+import foo from "./helloWorld";
+
 describe("test", () => {
     it("pass", () => {
-        expect(1).toBe(1);
+        const result = foo();
+
+        expect(result).toBe("bar");
     });
 });
diff --git a/packages/blocknumber/src/helloWorld.ts b/packages/blocknumber/src/helloWorld.ts
new file mode 100644
index 0000000..0838c22
--- /dev/null
+++ b/packages/blocknumber/src/helloWorld.ts
@@ -0,0 +1,3 @@
+export default function foo() {
+    return "bar";
+}