test: print view should not show warning/errors (#14972)

frappe/tests/test_printview.py

@@ -0,0 +1,22 @@
+import unittest
+
+import frappe
+from frappe.www.printview import get_html_and_style
+
+
+class PrintViewTest(unittest.TestCase):
+	def test_print_view_without_errors(self):
+
+		user = frappe.get_last_doc("User")
+
+		messages_before = frappe.get_message_log()
+		ret = get_html_and_style(doc=user.as_json(), print_format="Standard", no_letterhead=1)
+		messages_after = frappe.get_message_log()
+
+		if len(messages_after) > len(messages_before):
+			new_messages = messages_after[len(messages_before):]
+			self.fail("Print view showing error/warnings: \n"
+					+ "\n".join(str(msg) for msg in new_messages))
+
+		# html should exist
+		self.assertTrue(bool(ret["html"]))