No tracebacks on normal errors and prettier error pages (#1768)

* Default error handler now only logs traceback on 500 errors and all responses are HTML formatted.

* Tests passing.

* Ability to flag any exception object with self.quiet = True following @ashleysommer suggestion.

* Refactor HTML formatting into errorpages.py. String escapes for debug tracebacks.

* Remove extra includes

* Auto-set quiet flag also when decorator is used.

* Cleanup, make error pages (probably) HTML5-compliant and similar for debug and non-debug modes.

* Fix lookup of non-existant status codes

* No logging of 503 errors after all.

* lint

tests/test_app.py

@@ -105,10 +105,7 @@ def test_app_handle_request_handler_is_none(app, monkeypatch):
 
     request, response = app.test_client.get("/test")
 
-    assert (
-        response.text
-        == "Error: 'None' was returned while requesting a handler from the router"
-    )
+    assert "'None' was returned while requesting a handler from the router" in response.text
 
 
 @pytest.mark.parametrize("websocket_enabled", [True, False])
@@ -189,7 +186,7 @@ def test_handle_request_with_nested_sanic_exception(app, monkeypatch, caplog):
     with caplog.at_level(logging.ERROR):
         request, response = app.test_client.get("/")
     assert response.status == 500
-    assert response.text == "Error: Mock SanicException"
+    assert "Mock SanicException" in response.text
     assert (
         "sanic.root",
         logging.ERROR,

tests/test_bad_request.py

@@ -18,4 +18,4 @@ def test_bad_request_response(app):
 
     app.run(host="127.0.0.1", port=42101, debug=False)
     assert lines[0] == b"HTTP/1.1 400 Bad Request\r\n"
-    assert lines[-1] == b"Error: Bad Request"
+    assert b"Bad Request" in lines[-1]

tests/test_exceptions.py

@@ -172,7 +172,7 @@ def test_handled_unhandled_exception(exception_app):
     request, response = exception_app.test_client.get("/divide_by_zero")
     assert response.status == 500
     soup = BeautifulSoup(response.body, "html.parser")
-    assert soup.h1.text == "Internal Server Error"
+    assert "Internal Server Error" in soup.h1.text
 
     message = " ".join(soup.p.text.split())
     assert message == (
@@ -218,4 +218,4 @@ def test_abort(exception_app):
 
     request, response = exception_app.test_client.get("/abort/message")
     assert response.status == 500
-    assert response.text == "Error: Abort"
+    assert "Abort" in response.text

tests/test_exceptions_handler.py

@@ -86,7 +86,7 @@ def test_html_traceback_output_in_debug_mode():
 
     summary_text = " ".join(soup.select(".summary")[0].text.split())
     assert (
-        "NameError: name 'bar' " "is not defined while handling path /4"
+        "NameError: name 'bar' is not defined while handling path /4"
     ) == summary_text
 
 
@@ -112,7 +112,7 @@ def test_chained_exception_handler():
 
     summary_text = " ".join(soup.select(".summary")[0].text.split())
     assert (
-        "ZeroDivisionError: division by zero " "while handling path /6/0"
+        "ZeroDivisionError: division by zero while handling path /6/0"
     ) == summary_text
 
 

tests/test_middleware.py

@@ -2,7 +2,7 @@ import logging
 
 from asyncio import CancelledError
 
-from sanic.exceptions import NotFound
+from sanic.exceptions import NotFound, SanicException
 from sanic.request import Request
 from sanic.response import HTTPResponse, text
 
@@ -93,7 +93,7 @@ def test_middleware_response_raise_cancelled_error(app, caplog):
             "sanic.root",
             logging.ERROR,
             "Exception occurred while handling uri: 'http://127.0.0.1:42101/'",
-        ) in caplog.record_tuples
+        ) not in caplog.record_tuples
 
 
 def test_middleware_response_raise_exception(app, caplog):
@@ -102,14 +102,16 @@ def test_middleware_response_raise_exception(app, caplog):
         raise Exception("Exception at response middleware")
 
     with caplog.at_level(logging.ERROR):
-        reqrequest, response = app.test_client.get("/")
+        reqrequest, response = app.test_client.get("/fail")
 
     assert response.status == 404
+    # 404 errors are not logged
     assert (
         "sanic.root",
         logging.ERROR,
         "Exception occurred while handling uri: 'http://127.0.0.1:42101/'",
-    ) in caplog.record_tuples
+    ) not in caplog.record_tuples
+    # Middleware exception ignored but logged
     assert (
         "sanic.error",
         logging.ERROR,

tests/test_payload_too_large.py

@@ -27,7 +27,7 @@ def test_payload_too_large_at_data_received_default(app):
 
     response = app.test_client.get("/1", gather_request=False)
     assert response.status == 413
-    assert response.text == "Error: Payload Too Large"
+    assert "Payload Too Large" in response.text
 
 
 def test_payload_too_large_at_on_header_default(app):
@@ -40,4 +40,4 @@ def test_payload_too_large_at_on_header_default(app):
     data = "a" * 1000
     response = app.test_client.post("/1", gather_request=False, data=data)
     assert response.status == 413
-    assert response.text == "Error: Payload Too Large"
+    assert "Payload Too Large" in response.text

tests/test_request_stream.py

@@ -329,15 +329,12 @@ def test_request_stream_handle_exception(app):
     # 404
     request, response = app.test_client.post("/in_valid_post", data=data)
     assert response.status == 404
-    assert response.text == "Error: Requested URL /in_valid_post not found"
+    assert "Requested URL /in_valid_post not found" in response.text
 
     # 405
     request, response = app.test_client.get("/post/random_id")
     assert response.status == 405
-    assert (
-        response.text == "Error: Method GET not allowed for URL"
-        " /post/random_id"
-    )
+    assert "Method GET not allowed for URL /post/random_id" in response.text
 
 
 def test_request_stream_blueprint(app):

tests/test_request_timeout.py

@@ -102,7 +102,7 @@ def test_default_server_error_request_timeout():
     client = DelayableSanicTestClient(request_timeout_default_app, 2)
     request, response = client.get("/1")
     assert response.status == 408
-    assert response.text == "Error: Request Timeout"
+    assert "Request Timeout" in response.text
 
 
 def test_default_server_error_request_dont_timeout():
@@ -125,4 +125,4 @@ def test_default_server_error_websocket_request_timeout():
     request, response = client.get("/ws1", headers=headers)
 
     assert response.status == 408
-    assert response.text == "Error: Request Timeout"
+    assert "Request Timeout" in response.text

tests/test_response_timeout.py

@@ -40,7 +40,7 @@ async def handler_2(request):
 def test_default_server_error_response_timeout():
     request, response = response_timeout_default_app.test_client.get("/1")
     assert response.status == 503
-    assert response.text == "Error: Response Timeout"
+    assert "Response Timeout" in response.text
 
 
 response_handler_cancelled_app.flag = False
@@ -65,5 +65,5 @@ async def handler_3(request):
 def test_response_handler_cancelled():
     request, response = response_handler_cancelled_app.test_client.get("/1")
     assert response.status == 503
-    assert response.text == "Error: Response Timeout"
+    assert "Response Timeout" in response.text
     assert response_handler_cancelled_app.flag is False

tests/test_static.py

@@ -238,7 +238,7 @@ def test_static_content_range_invalid_unit(
     request, response = app.test_client.get("/testing.file", headers=headers)
 
     assert response.status == 416
-    assert response.text == "Error: {} is not a valid Range Type".format(unit)
+    assert f"{unit} is not a valid Range Type" in response.text
 
 
 @pytest.mark.parametrize("file_name", ["test.file", "decode me.txt"])
@@ -256,9 +256,7 @@ def test_static_content_range_invalid_start(
     request, response = app.test_client.get("/testing.file", headers=headers)
 
     assert response.status == 416
-    assert response.text == "Error: '{}' is invalid for Content Range".format(
-        start
-    )
+    assert f"'{start}' is invalid for Content Range" in response.text
 
 
 @pytest.mark.parametrize("file_name", ["test.file", "decode me.txt"])
@@ -276,9 +274,7 @@ def test_static_content_range_invalid_end(
     request, response = app.test_client.get("/testing.file", headers=headers)
 
     assert response.status == 416
-    assert response.text == "Error: '{}' is invalid for Content Range".format(
-        end
-    )
+    assert f"'{end}' is invalid for Content Range" in response.text
 
 
 @pytest.mark.parametrize("file_name", ["test.file", "decode me.txt"])
@@ -295,7 +291,7 @@ def test_static_content_range_invalid_parameters(
     request, response = app.test_client.get("/testing.file", headers=headers)
 
     assert response.status == 416
-    assert response.text == "Error: Invalid for Content Range parameters"
+    assert "Invalid for Content Range parameters" in response.text
 
 
 @pytest.mark.parametrize(
@@ -369,7 +365,7 @@ def test_file_not_found(app, static_file_directory):
     request, response = app.test_client.get("/static/not_found")
 
     assert response.status == 404
-    assert response.text == "Error: File not found"
+    assert "File not found" in response.text
 
 
 @pytest.mark.parametrize("static_name", ["_static_name", "static"])

tests/test_views.py

@@ -49,7 +49,7 @@ def test_unexisting_methods(app):
     request, response = app.test_client.get("/")
     assert response.text == "I am get method"
     request, response = app.test_client.post("/")
-    assert response.text == "Error: Method POST not allowed for URL /"
+    assert "Method POST not allowed for URL /" in response.text
 
 
 def test_argument_methods(app):