fix(upload): configure chat attachment size limit (#2439)

tests/test_chat_upload_limit_config.py

@@ -0,0 +1,64 @@
+import io
+
+import pytest
+from fastapi import HTTPException, UploadFile
+
+from src.chat_helpers import validate_file_upload
+from src.upload_handler import UploadHandler
+from src.upload_limits import (
+    DEFAULT_CHAT_UPLOAD_MAX_BYTES,
+    get_chat_upload_max_bytes,
+    read_byte_limit_env,
+)
+
+
+def _upload(name: str, data: bytes) -> UploadFile:
+    return UploadFile(filename=name, file=io.BytesIO(data))
+
+
+def test_chat_upload_limit_defaults_to_10mb(monkeypatch):
+    monkeypatch.delenv("ODYSSEUS_CHAT_UPLOAD_MAX_BYTES", raising=False)
+
+    assert get_chat_upload_max_bytes() == DEFAULT_CHAT_UPLOAD_MAX_BYTES
+
+
+def test_chat_upload_limit_uses_env_bytes(monkeypatch):
+    monkeypatch.setenv("ODYSSEUS_CHAT_UPLOAD_MAX_BYTES", "12345")
+
+    assert get_chat_upload_max_bytes() == 12345
+
+
+def test_chat_upload_limit_rejects_invalid_env(monkeypatch):
+    monkeypatch.setenv("ODYSSEUS_CHAT_UPLOAD_MAX_BYTES", "not-bytes")
+
+    with pytest.raises(ValueError, match="ODYSSEUS_CHAT_UPLOAD_MAX_BYTES"):
+        get_chat_upload_max_bytes()
+
+
+def test_read_byte_limit_env_rejects_non_positive(monkeypatch):
+    monkeypatch.setenv("ODYSSEUS_CHAT_UPLOAD_MAX_BYTES", "0")
+
+    with pytest.raises(ValueError, match="greater than 0"):
+        read_byte_limit_env("ODYSSEUS_CHAT_UPLOAD_MAX_BYTES", 10)
+
+
+def test_validate_file_upload_uses_configured_chat_limit(monkeypatch):
+    monkeypatch.setenv("ODYSSEUS_CHAT_UPLOAD_MAX_BYTES", "4")
+
+    with pytest.raises(HTTPException) as exc:
+        validate_file_upload(_upload("too-large.txt", b"abcde"))
+
+    assert exc.value.status_code == 400
+    assert exc.value.detail["error"] == "FILE_TOO_LARGE"
+    assert exc.value.detail["message"] == "File size exceeds 4 bytes limit"
+
+
+def test_upload_handler_uses_configured_chat_limit(monkeypatch, tmp_path):
+    monkeypatch.setenv("ODYSSEUS_CHAT_UPLOAD_MAX_BYTES", "4")
+    handler = UploadHandler(base_dir=str(tmp_path), upload_dir=str(tmp_path / "uploads"))
+
+    with pytest.raises(HTTPException) as exc:
+        handler.save_upload(_upload("too-large.txt", b"abcde"), client_ip="127.0.0.1")
+
+    assert exc.value.status_code == 400
+    assert exc.value.detail == "File size exceeds 4 bytes limit"