From 82afc753505c5a83770a9aa66b81a43d906ff9de Mon Sep 17 00:00:00 2001
From: Tommaso Sciortino <sciortino@gmail.com>
Date: Tue, 1 Jul 2025 16:05:33 -0700
Subject: [PATCH] Special case mime type for ts file. (#2902)

---
 packages/core/src/utils/fileUtils.test.ts | 5 +++++
 packages/core/src/utils/fileUtils.ts      | 8 +++++++-
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/packages/core/src/utils/fileUtils.test.ts b/packages/core/src/utils/fileUtils.test.ts
index 0455b6e1..c1381e85 100644
--- a/packages/core/src/utils/fileUtils.test.ts
+++ b/packages/core/src/utils/fileUtils.test.ts
@@ -196,6 +196,11 @@ describe('fileUtils', () => {
       vi.restoreAllMocks(); // Restore spies on actualNodeFs
     });
 
+    it('should detect typescript type by extension (ts)', () => {
+      expect(detectFileType('file.ts')).toBe('text');
+      expect(detectFileType('file.test.ts')).toBe('text');
+    });
+
     it('should detect image type by extension (png)', () => {
       mockMimeLookup.mockReturnValueOnce('image/png');
       expect(detectFileType('file.png')).toBe('image');
diff --git a/packages/core/src/utils/fileUtils.ts b/packages/core/src/utils/fileUtils.ts
index 5a05d513..72f29436 100644
--- a/packages/core/src/utils/fileUtils.ts
+++ b/packages/core/src/utils/fileUtils.ts
@@ -100,8 +100,14 @@ export function detectFileType(
   filePath: string,
 ): 'text' | 'image' | 'pdf' | 'audio' | 'video' | 'binary' {
   const ext = path.extname(filePath).toLowerCase();
-  const lookedUpMimeType = mime.lookup(filePath); // Returns false if not found, or the mime type string
 
+  // The mimetype for "ts" is MPEG transport stream (a video format) but we want
+  // to assume these are typescript files instead.
+  if (ext === '.ts') {
+    return 'text';
+  }
+
+  const lookedUpMimeType = mime.lookup(filePath); // Returns false if not found, or the mime type string
   if (lookedUpMimeType) {
     if (lookedUpMimeType.startsWith('image/')) {
       return 'image';