getsentry · s1gr1d · Oct 23, 2025 · Oct 23, 2025
diff --git a/packages/react-router/test/server/getMetaTagTransformer.test.ts b/packages/react-router/test/server/getMetaTagTransformer.test.ts
@@ -0,0 +1,127 @@
+import { getTraceMetaTags } from '@sentry/core';
+import { PassThrough } from 'stream';
+import { beforeEach, describe, expect, test, vi } from 'vitest';
+import { getMetaTagTransformer } from '../../src/server/getMetaTagTransformer';
+
+vi.mock('@opentelemetry/core', () => ({
+  RPCType: { HTTP: 'http' },
+  getRPCMetadata: vi.fn(),
+}));
+
+vi.mock('@sentry/core', () => ({
+  SEMANTIC_ATTRIBUTE_SENTRY_SOURCE: 'sentry.source',
+  SEMANTIC_ATTRIBUTE_SENTRY_ORIGIN: 'sentry.origin',
+  getActiveSpan: vi.fn(),
+  getRootSpan: vi.fn(),
+  getTraceMetaTags: vi.fn(),
+}));
+
+describe('getMetaTagTransformer', () => {
+  beforeEach(() => {
+    vi.clearAllMocks();
+    (getTraceMetaTags as unknown as ReturnType<typeof vi.fn>).mockReturnValue(
+      '<meta name="sentry-trace" content="test-trace-id">',
+    );
+  });
+
+  test('should inject meta tags before closing head tag', () =>
+    new Promise<void>((resolve, reject) => {
+      const bodyStream = new PassThrough();
+      const transformer = getMetaTagTransformer(bodyStream);
+
+      let outputData = '';
+      bodyStream.on('data', chunk => {
+        outputData += chunk.toString();
+      });
+
+      bodyStream.on('end', () => {
+        try {
+          expect(outputData).toContain('<meta name="sentry-trace" content="test-trace-id"></head>');
+          expect(outputData).not.toContain('</head></head>');
+          expect(getTraceMetaTags).toHaveBeenCalledTimes(1);
+          resolve();
+        } catch (e) {
+          reject(e);
+        }
+      });
+
+      transformer.write('<html><head></head><body>Test</body></html>');
+      transformer.end();
+    }));
+
+  test('should not modify chunks without head closing tag', () =>
+    new Promise<void>((resolve, reject) => {
+      const bodyStream = new PassThrough();
+      const transformer = getMetaTagTransformer(bodyStream);
+
+      let outputData = '';
+      bodyStream.on('data', chunk => {
+        outputData += chunk.toString();
+      });
+
+      bodyStream.on('end', () => {
+        try {
+          expect(outputData).toBe('<html><body>Test</body></html>');
+          expect(outputData).not.toContain('sentry-trace');
+          expect(getTraceMetaTags).not.toHaveBeenCalled();
+          resolve();
+        } catch (e) {
+          reject(e);
+        }
+      });
+
+      transformer.write('<html><body>Test</body></html>');
+      transformer.end();
+    }));
+
+  test('should handle buffer input', () =>
+    new Promise<void>((resolve, reject) => {
+      const bodyStream = new PassThrough();
+      const transformer = getMetaTagTransformer(bodyStream);
+
+      let outputData = '';
+      bodyStream.on('data', chunk => {
+        outputData += chunk.toString();
+      });
+
+      bodyStream.on('end', () => {
+        try {
+          expect(outputData).toContain('<meta name="sentry-trace" content="test-trace-id"></head>');
+          expect(getTraceMetaTags).toHaveBeenCalledTimes(1);
+          resolve();
+        } catch (e) {
+          reject(e);
+        }
+      });
+
+      transformer.write(Buffer.from('<html><head></head><body>Test</body></html>'));
+      transformer.end();
+    }));
+
+  test('should handle multiple chunks', () =>
+    new Promise<void>((resolve, reject) => {
+      const bodyStream = new PassThrough();
+      const transformer = getMetaTagTransformer(bodyStream);
+
+      let outputData = '';
+      bodyStream.on('data', chunk => {
+        outputData += chunk.toString();
+      });
+
+      bodyStream.on('end', () => {
+        try {
+          expect(outputData).toContain('<meta name="sentry-trace" content="test-trace-id"></head>');
+          expect(outputData).toContain('<body>Test content</body>');
+          expect(getTraceMetaTags).toHaveBeenCalledTimes(1);
+          resolve();
+        } catch (e) {
+          reject(e);
+        }
+      });
+
+      transformer.write('<html><head>');
+      transformer.write('</head><body>Test content</body>');
+      transformer.write('</html>');
+      transformer.end();
+    }));
+});
diff --git a/packages/react-router/test/server/getMetaTagTransformer.ts b/packages/react-router/test/server/getMetaTagTransformer.ts