chore: import upstream snapshot with attribution

servers/fastapi/utils/validators.py

@@ -0,0 +1,48 @@
+from pathlib import Path
+from typing import List
+from fastapi import HTTPException
+
+from fastapi import UploadFile
+
+
+def _is_accepted_file_type(file: UploadFile, accepted_types: List[str]) -> bool:
+    accepted_mime_types = {t.lower() for t in accepted_types if not t.startswith(".")}
+    accepted_extensions = {t.lower() for t in accepted_types if t.startswith(".")}
+
+    content_type = (file.content_type or "").strip().lower()
+    if content_type in accepted_mime_types:
+        return True
+
+    extension = Path(file.filename or "").suffix.lower()
+    if extension in accepted_extensions:
+        return True
+
+    return False
+
+
+def validate_files(
+    field,
+    nullable: bool,
+    multiple: bool,
+    max_size: int,
+    accepted_types: List[str],
+):
+
+    if field:
+        files: List[UploadFile] = field if multiple else [field]
+        for each_file in files:
+            file_size = each_file.size or 0
+
+            if (max_size * 1024 * 1024) < file_size:
+                raise HTTPException(
+                    400,
+                    detail=f"File '{each_file.filename}' exceeded max upload size of {max_size} MB",
+                )
+            elif not _is_accepted_file_type(each_file, accepted_types):
+                raise HTTPException(
+                    400,
+                    detail=f"File '{each_file.filename}' not accepted. Accepted types: {accepted_types}",
+                )
+
+    elif not (field or nullable):
+        raise HTTPException(400, detail="File must be provided.")