Allow Gift Card balance lookup in the Storefront API (#193)

* feat: enable balance lookup for gift-cards

integration-tests/api/__tests__/store/cart.js

@@ -22,7 +22,7 @@ describe("/store/carts", () => {
 
   afterAll(async () => {
     dbConnection.close();
-    dropDatabase({ databaseName: "medusa-integration" });
+    await dropDatabase({ databaseName: "medusa-integration" });
 
     medusaProcess.kill();
   });

integration-tests/api/__tests__/store/gift-cards.js

@@ -0,0 +1,65 @@
+const { dropDatabase } = require("pg-god");
+const path = require("path");
+const { Region, GiftCard } = require("@medusajs/medusa");
+
+const setupServer = require("../../../helpers/setup-server");
+const { useApi } = require("../../../helpers/use-api");
+const { initDb } = require("../../../helpers/use-db");
+
+jest.setTimeout(30000);
+
+describe("/store/gift-cards", () => {
+  let medusaProcess;
+  let dbConnection;
+
+  beforeAll(async () => {
+    const cwd = path.resolve(path.join(__dirname, "..", ".."));
+    dbConnection = await initDb({ cwd });
+    medusaProcess = await setupServer({ cwd });
+  });
+
+  afterAll(async () => {
+    dbConnection.close();
+    await dropDatabase({ databaseName: "medusa-integration" });
+
+    medusaProcess.kill();
+  });
+
+  describe("GET /store/gift-cards/:code", () => {
+    beforeEach(async () => {
+      const manager = dbConnection.manager;
+      await manager.insert(Region, {
+        id: "region",
+        name: "Test Region",
+        currency_code: "usd",
+        tax_rate: 0,
+      });
+      await manager.insert(GiftCard, {
+        id: "gift_test",
+        code: "GC_TEST",
+        value: 200,
+        balance: 120,
+        region_id: "region",
+      });
+    });
+
+    afterEach(async () => {
+      const manager = dbConnection.manager;
+      await manager.query(`DELETE FROM "gift_card"`);
+      await manager.query(`DELETE FROM "region"`);
+    });
+
+    it("retrieves a gift card", async () => {
+      const api = useApi();
+
+      const response = await api.get("/store/gift-cards/GC_TEST");
+      expect(response.status).toEqual(200);
+      expect(response.data.gift_card).toEqual({
+        id: "gift_test",
+        code: "GC_TEST",
+        value: 200,
+        balance: 120,
+      });
+    });
+  });
+});