fix: Guess most likely exception source (#21827)

frappe/__init__.py

@@ -1460,13 +1460,11 @@ def get_all_apps(with_internal_apps=True, sites_path=None):
 
 
 @request_cache
-def get_installed_apps(*, _ensure_on_bench=False):
+def get_installed_apps(*, _ensure_on_bench=False) -> list[str]:
 	"""
 	Get list of installed apps in current site.
 
-	:param sort: [DEPRECATED] Sort installed apps based on the sequence in sites/apps.txt
-	:param frappe_last: [DEPRECATED] Keep frappe last. Do not use this, reverse the app list instead.
-	:param ensure_on_bench: Only return apps that are present on bench.
+	:param _ensure_on_bench: Only return apps that are present on bench.
 	"""
 	if getattr(flags, "in_install_db", True):
 		return []

frappe/core/doctype/error_log/test_error_log.py

@@ -1,10 +1,12 @@
 # Copyright (c) 2015, Frappe Technologies and Contributors
 # License: MIT. See LICENSE
+from unittest.mock import patch
+
 from ldap3.core.exceptions import LDAPException, LDAPInappropriateAuthenticationResult
 
 import frappe
 from frappe.tests.utils import FrappeTestCase
-from frappe.utils.error import _is_ldap_exception
+from frappe.utils.error import _is_ldap_exception, guess_exception_source
 
 # test_records = frappe.get_test_records('Error Log')
 
@@ -21,3 +23,44 @@ class TestErrorLog(FrappeTestCase):
 
 		for e in exc:
 			self.assertTrue(_is_ldap_exception(e()))
+
+
+_RAW_EXC = """
+   File "apps/frappe/frappe/model/document.py", line 1284, in runner
+     add_to_return_value(self, fn(self, *args, **kwargs))
+                               ^^^^^^^^^^^^^^^^^^^^^^^^^
+   File "apps/frappe/frappe/model/document.py", line 933, in fn
+     return method_object(*args, **kwargs)
+            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   File "apps/erpnext/erpnext/selling/doctype/sales_order/sales_order.py", line 58, in onload
+     raise Exception("what")
+ Exception: what
+"""
+
+_THROW_EXC = """
+   File "apps/frappe/frappe/model/document.py", line 933, in fn
+     return method_object(*args, **kwargs)
+            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   File "apps/erpnext/erpnext/selling/doctype/sales_order/sales_order.py", line 58, in onload
+     frappe.throw("what")
+   File "apps/frappe/frappe/__init__.py", line 550, in throw
+     msgprint(
+   File "apps/frappe/frappe/__init__.py", line 518, in msgprint
+     _raise_exception()
+   File "apps/frappe/frappe/__init__.py", line 467, in _raise_exception
+     raise raise_exception(msg)
+ frappe.exceptions.ValidationError: what
+"""
+
+TEST_EXCEPTIONS = {
+	"erpnext (app)": _RAW_EXC,
+	"erpnext (app)": _THROW_EXC,
+}
+
+
+class TestExceptionSourceGuessing(FrappeTestCase):
+	@patch.object(frappe, "get_installed_apps", return_value=["frappe", "erpnext", "3pa"])
+	def test_exc_source_guessing(self, _installed_apps):
+		for source, exc in TEST_EXCEPTIONS.items():
+			result = guess_exception_source(exc)
+			self.assertEqual(result, source)

frappe/public/js/frappe/request.js

@@ -604,7 +604,14 @@ frappe.request.report_error = function (xhr, request_opts) {
 
 		let parts = strip(exc).split("\n");
 
-		frappe.error_dialog.$body.html(parts[parts.length - 1]);
+		let dialog_html = parts[parts.length - 1];
+
+		if (data._exc_source) {
+			dialog_html += "<br>";
+			dialog_html += `Possible source of error: ${data._exc_source.bold()} `;
+		}
+
+		frappe.error_dialog.$body.html(dialog_html);
 		frappe.error_dialog.show();
 	}
 };

frappe/utils/error.py

@@ -3,6 +3,9 @@
 
 import functools
 import inspect
+import re
+from collections import Counter
+from contextlib import suppress
 
 import frappe
 
@@ -126,3 +129,33 @@ def raise_error_on_no_output(error_message, error_type=None, keep_quiet=None):
 		return wrapper_raise_error_on_no_output
 
 	return decorator_raise_error_on_no_output
+
+
+def guess_exception_source(exception: str) -> str | None:
+	"""Attempts to guess source of error based on traceback.
+
+	E.g.
+
+	- For unhandled exception last python file from apps folder is responsible.
+	- For frappe.throws the exception source is possibly present after skipping frappe.throw frames
+	- For server script the file name is `<serverscript>`
+
+	"""
+	with suppress(Exception):
+		installed_apps = frappe.get_installed_apps()
+		app_priority = {app: installed_apps.index(app) for app in installed_apps}
+
+		APP_NAME_REGEX = re.compile(r".*File.*apps/(?P<app_name>\w+)/\1/")
+		SERVER_SCRIPT_FRAME = re.compile(r".*<serverscript>")
+
+		apps = Counter()
+		for line in reversed(exception.splitlines()):
+			if SERVER_SCRIPT_FRAME.match(line):
+				return "Server Script"
+
+			if matches := APP_NAME_REGEX.match(line):
+				app_name = matches.group("app_name")
+				apps[app_name] += app_priority.get(app_name, 0)
+
+		if probably_source := apps.most_common(1):
+			return f"{probably_source[0][0]} (app)"

frappe/utils/response.py

@@ -133,10 +133,14 @@ def as_binary():
 
 def make_logs(response=None):
 	"""make strings for msgprint and errprint"""
+	from frappe.utils.error import guess_exception_source
+
 	if not response:
 		response = frappe.local.response
 
 	if frappe.error_log:
+		if source := guess_exception_source(frappe.local.error_log and frappe.local.error_log[0]["exc"]):
+			response["_exc_source"] = source
 		response["exc"] = json.dumps([frappe.utils.cstr(d["exc"]) for d in frappe.local.error_log])
 
 	if frappe.local.message_log: