file.py: added encodings params so it can be tested

test_file.py, extended TestSameContent TestCase with test_utf8_bom_content_decoding

frappe/core/doctype/file/file.py

@@ -515,7 +515,7 @@ def unzip(self) -> list["File"]:
 	def exists_on_disk(self):
 		return os.path.exists(self.get_full_path())
 
-	def get_content(self) -> bytes:
+	def get_content(self, encodings=None) -> bytes | str:
 		if self.is_folder:
 			frappe.throw(_("Cannot get file contents of a Folder"))
 
@@ -531,10 +531,12 @@ def get_content(self) -> bytes:
 			self.validate_file_url()
 		file_path = self.get_full_path()
 
+		if encodings is None:
+			encodings = ["utf-8-sig", "utf-8", "windows-1250", "windows-1252"]
 		# read file with proper encoding
 		with open(file_path, mode="rb") as f:
 			self._content = f.read()
-			encodings = ["utf-8-sig", "utf-8", "windows-1250", "windows-1252"]
+
 			for encoding in encodings:
 				try:
 					# for plain text files

frappe/core/doctype/file/test_file.py

@@ -111,7 +111,7 @@ class TestBase64File(FrappeTestCase):
 	def setUp(self):
 		self.attached_to_doctype, self.attached_to_docname = make_test_doc()
 		self.test_content = base64.b64encode(test_content1.encode("utf-8"))
-		_file: "File" = frappe.get_doc(
+		_file: frappe.Document = frappe.get_doc(
 			{
 				"doctype": "File",
 				"file_name": "test_base64.txt",
@@ -125,7 +125,7 @@ def setUp(self):
 		self.saved_file_url = _file.file_url
 
 	def test_saved_content(self):
-		_file = frappe.get_doc("File", {"file_url": self.saved_file_url})
+		_file: frappe.Document = frappe.get_doc("File", {"file_url": self.saved_file_url})
 		content = _file.get_content()
 		self.assertEqual(content, test_content1)
 
@@ -255,6 +255,25 @@ def test_attachment_limit(self):
 		limit_property.delete()
 		frappe.clear_cache(doctype="ToDo")
 
+	def test_utf8_bom_content_decoding(self):
+		utf8_bom_content = test_content1.encode("utf-8-sig")
+		_file: frappe.Document = frappe.get_doc(
+			{
+				"doctype": "File",
+				"file_name": "utf8bom.txt",
+				"attached_to_doctype": self.attached_to_doctype1,
+				"attached_to_name": self.attached_to_docname1,
+				"content": utf8_bom_content,
+				"decode": False,
+			}
+		)
+		_file.save()
+		saved_file = frappe.get_doc("File", _file.name)
+		file_content_decoded = saved_file.get_content(encodings=["utf-8"])
+		self.assertEqual(file_content_decoded[0], "\ufeff")
+		file_content_properly_decoded = saved_file.get_content(encodings=["utf-8-sig", "utf-8"])
+		self.assertEqual(file_content_properly_decoded, test_content1)
+
 
 class TestFile(FrappeTestCase):
 	def setUp(self):