fix: catch UnicodeDecodeError in _is_json to avoid crashing detect_filetype()

CHANGELOG.md

@@ -3,6 +3,7 @@
 ### Fixes
 
 - **Update README.md**: readme-only changes; added a link to Unstructured Pipelines to the README. No library behavior changes.
+- **Fix crash on non-UTF-8 bracket-prefixed text with no extension**: `detect_filetype()` called `json.load()` directly on the raw file bytes when probing whether `text/plain`-guessed content is actually JSON. If the content started with `[`/`{` but contained non-UTF-8 bytes, `json.load()` raised an uncaught `UnicodeDecodeError` (not the `json.JSONDecodeError` the code caught), crashing detection instead of falling back to `FileType.TXT`. Both exception types are now caught.
 
 ## 0.25.0
 

test_unstructured/file_utils/test_filetype.py

@@ -1342,6 +1342,15 @@ def test_json_content_type_is_disambiguated_for_ndjson():
     assert predicted_type == FileType.NDJSON
 
 
+def test_it_does_not_crash_on_non_utf8_bracket_prefixed_text_with_no_extension():
+    non_utf8_bytes = b"{not json at all just braces \xe9 text} and more padding to fill the head"
+
+    file_buffer = io.BytesIO(non_utf8_bytes)
+    predicted_type = detect_filetype(file=file_buffer)
+
+    assert predicted_type == FileType.TXT
+
+
 def test_office_files_when_document_archive_has_non_standard_prefix():
     predicted_type = detect_filetype(
         file_path=input_path("file_type/test_document_from_office365.docx")

unstructured/file_utils/filetype.py

@@ -960,7 +960,7 @@ def _is_json(self) -> bool:
             with self._ctx.open() as file:
                 json.load(file)
             return True
-        except json.JSONDecodeError:
+        except (json.JSONDecodeError, UnicodeDecodeError):
             return False