🧪 add unit tests for sha256 function

functions/api/submit-gap.js

@@ -65,7 +65,7 @@ function json(obj, status, extra = {}) {
   return new Response(JSON.stringify(obj), { status, headers: { "Content-Type": "application/json", ...extra } });
 }
 
-async function sha256(str) {
+export async function sha256(str) {
   const buf = await crypto.subtle.digest("SHA-256", new TextEncoder().encode(str));
   return [...new Uint8Array(buf)].map((b) => b.toString(16).padStart(2, "0")).join("");
 }

functions/api/submit-gap.test.js

@@ -0,0 +1,35 @@
+import { describe, it, expect } from 'vitest';
+import { sha256 } from './submit-gap.js';
+
+describe('sha256', () => {
+  it('should compute the correct SHA-256 hash for a known IP string', async () => {
+    const input = '127.0.0.1';
+    // SHA-256 of "127.0.0.1"
+    const expected = '12ca17b49af2289436f303e0166030a21e525d266e209267433801a8fd4071a0';
+    const result = await sha256(input);
+    expect(result).toBe(expected);
+  });
+
+  it('should compute the correct SHA-256 hash for an empty string', async () => {
+    const input = '';
+    // SHA-256 of ""
+    const expected = 'e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855';
+    const result = await sha256(input);
+    expect(result).toBe(expected);
+  });
+
+  it('should correctly handle a string with non-ASCII characters', async () => {
+    const input = 'hello world 🚀';
+    // SHA-256 of "hello world 🚀"
+    const expected = '7794bdd7454346eb21712d6fa26d63df3db615cd34f20d9ad5cd455897d7ca8a';
+    const result = await sha256(input);
+    expect(result).toBe(expected);
+  });
+
+  it('should produce deterministic output for the same input', async () => {
+    const input = 'some random string to test determinism';
+    const result1 = await sha256(input);
+    const result2 = await sha256(input);
+    expect(result1).toBe(result2);
+  });
+});