feat: create fake token util function

#19

src/mocks/utils/token.ts

@@ -0,0 +1,70 @@
+import {faker} from '@faker-js/faker';
+
+import {Member} from '@/types';
+
+const SECRET_KEY = 'secret-key';
+
+function base64Encode(str: string) {
+  return Buffer.from(str).toString('base64');
+}
+
+function base64Decode(str: string) {
+  return Buffer.from(str, 'base64').toString('utf-8');
+}
+
+export function createFakeJWT(
+  payload: Member,
+  expiresInSeconds: number = 60 * 60,
+) {
+  const header = {
+    alg: 'HS256',
+    typ: 'JWT',
+  };
+
+  const encodedHeader = base64Encode(JSON.stringify(header));
+
+  const currentTime = Math.floor(Date.now() / 1000);
+  const encodedPayload = base64Encode(
+    JSON.stringify({
+      iat: currentTime,
+      exp: currentTime + expiresInSeconds,
+      noncee: faker.string.uuid(),
+      ...payload,
+    }),
+  );
+  const signature = base64Encode(
+    `${encodedHeader}.${encodedPayload}.${SECRET_KEY}`,
+  );
+
+  const token = `${encodedHeader}.${encodedPayload}.${signature}`;
+  return token;
+}
+
+export function verifyFakeJWT(token: string) {
+  try {
+    const parts = token.split('.');
+    if (parts.length !== 3) {
+      return false;
+    }
+
+    const [encodedHeader, encodedPayload, signature] = parts;
+    const validSignature = base64Encode(
+      `${encodedHeader}.${encodedPayload}.${SECRET_KEY}`,
+    );
+
+    if (signature !== validSignature) {
+      return false;
+    }
+
+    const payload = JSON.parse(base64Decode(encodedPayload));
+
+    const currentTime = Math.floor(Date.now() / 1000);
+    if (payload.exp && currentTime > payload.exp) {
+      return false; // 토큰이 만료됨
+    }
+
+    return true;
+  } catch (error) {
+    return false;
+  }
+}