fix(bru-1447): json response formatting using fast-json-format library (#5932)

tests/response/json-with-bigint-response-formatting/fixtures/collection/bigint-request.bru

@@ -0,0 +1,17 @@
+meta {
+  name: bigint-request
+  type: http
+  seq: 1
+}
+
+post {
+  url: https://echo.usebruno.com
+  body: json
+  auth: none
+}
+
+body:json {
+  {
+    "data": 1736184243098437392
+  }
+}

tests/response/json-with-bigint-response-formatting/fixtures/collection/bruno.json

@@ -0,0 +1,9 @@
+{
+  "version": "1",
+  "name": "bigint-test",
+  "type": "collection",
+  "ignore": [
+    "node_modules",
+    ".git"
+  ]
+}

tests/response/json-with-bigint-response-formatting/init-user-data/collection-security.json

@@ -0,0 +1,10 @@
+{
+  "collections": [
+    {
+      "path": "{{projectRoot}}/tests/response/json-with-bigint-response-formatting/fixtures/collection",
+      "securityConfig": {
+        "jsSandboxMode": "safe"
+      }
+    }
+  ]
+}

tests/response/json-with-bigint-response-formatting/init-user-data/preferences.json

@@ -0,0 +1,6 @@
+{
+  "maximized": false,
+  "lastOpenedCollections": [
+    "{{projectRoot}}/tests/response/json-with-bigint-response-formatting/fixtures/collection"
+  ]
+}

tests/response/json-with-bigint-response-formatting/json-with-bigint-response-formatting.spec.ts

@@ -0,0 +1,35 @@
+import { test, expect } from '../../../playwright';
+import { closeAllCollections } from '../../utils/page';
+
+test.describe.serial('JSON Response Formatting with BigInt', () => {
+  test.afterAll(async ({ pageWithUserData: page }) => {
+    // cleanup: close all collections
+    await closeAllCollections(page);
+  });
+
+  test('should handle BigInt values in JSON response formatting', async ({ pageWithUserData: page }) => {
+    await test.step('Navigate to collection and request', async () => {
+      // Navigate to the test collection
+      await expect(page.locator('#sidebar-collection-name').getByText('bigint-test')).toBeVisible();
+      await page.locator('#sidebar-collection-name').getByText('bigint-test').click();
+
+      // Navigate to the bigint request
+      await page.getByRole('complementary').getByText('bigint-request').click();
+    });
+
+    await test.step('Send request and verify response', async () => {
+      // Send the request
+      await page.getByTestId('send-arrow-icon').click();
+
+      // Wait for response
+      await expect(page.getByTestId('response-status-code')).toContainText('200', { timeout: 15000 });
+
+      // Verify the response is properly formatted JSON
+      const responseBody = page.locator('.response-pane');
+      await expect(responseBody).toBeVisible();
+
+      // The response should echo back our request data
+      await expect(responseBody).toContainText('"data": 1736184243098437392');
+    });
+  });
+});