Current File : //lib/python3/dist-packages/twisted/logger/test/test_flatten.py
# Copyright (c) Twisted Matrix Laboratories.
# See LICENSE for details.
"""
Test cases for L{twisted.logger._format}.
"""
import json
from itertools import count
from typing import Any, Callable, Optional
try:
from time import tzset
except ImportError:
tzset = None # type: ignore[assignment]
from twisted.trial import unittest
from .._flatten import KeyFlattener, aFormatter, extractField, flattenEvent
from .._format import formatEvent
from .._interfaces import LogEvent
class FlatFormattingTests(unittest.TestCase):
"""
Tests for flattened event formatting functions.
"""
def test_formatFlatEvent(self) -> None:
"""
L{flattenEvent} will "flatten" an event so that, if scrubbed of all but
serializable objects, it will preserve all necessary data to be
formatted once serialized. When presented with an event thusly
flattened, L{formatEvent} will produce the same output.
"""
counter = count()
class Ephemeral:
attribute = "value"
event1 = dict(
log_format=(
"callable: {callme()} "
"attribute: {object.attribute} "
"numrepr: {number!r} "
"numstr: {number!s} "
"strrepr: {string!r} "
"unistr: {unistr!s}"
),
callme=lambda: next(counter),
object=Ephemeral(),
number=7,
string="hello",
unistr="ö",
)
flattenEvent(event1)
event2 = dict(event1)
del event2["callme"]
del event2["object"]
event3 = json.loads(json.dumps(event2))
self.assertEqual(
formatEvent(event3),
(
"callable: 0 "
"attribute: value "
"numrepr: 7 "
"numstr: 7 "
"strrepr: 'hello' "
"unistr: ö"
),
)
def test_formatFlatEventBadFormat(self) -> None:
"""
If the format string is invalid, an error is produced.
"""
event1 = dict(
log_format=("strrepr: {string!X}"),
string="hello",
)
flattenEvent(event1)
event2 = json.loads(json.dumps(event1))
self.assertTrue(formatEvent(event2).startswith("Unable to format event"))
def test_formatFlatEventWithMutatedFields(self) -> None:
"""
L{formatEvent} will prefer the stored C{str()} or C{repr()} value for
an object, in case the other version.
"""
class Unpersistable:
"""
Unpersitable object.
"""
destructed = False
def selfDestruct(self) -> None:
"""
Self destruct.
"""
self.destructed = True
def __repr__(self) -> str:
if self.destructed:
return "post-serialization garbage"
else:
return "un-persistable"
up = Unpersistable()
event1 = dict(log_format="unpersistable: {unpersistable}", unpersistable=up)
flattenEvent(event1)
up.selfDestruct()
self.assertEqual(formatEvent(event1), "unpersistable: un-persistable")
def test_keyFlattening(self) -> None:
"""
Test that L{KeyFlattener.flatKey} returns the expected keys for format
fields.
"""
def keyFromFormat(format: str) -> str:
for (
literalText,
fieldName,
formatSpec,
conversion,
) in aFormatter.parse(format):
assert fieldName is not None
return KeyFlattener().flatKey(fieldName, formatSpec, conversion)
assert False, "Unable to derive key from format: {format}"
# No name
try:
self.assertEqual(keyFromFormat("{}"), "!:")
except ValueError:
# In python 2.6, an empty field name causes Formatter.parse to
# raise ValueError.
# In Python 2.7, it's allowed, so this exception is unexpected.
raise
# Just a name
self.assertEqual(keyFromFormat("{foo}"), "foo!:")
# Add conversion
self.assertEqual(keyFromFormat("{foo!s}"), "foo!s:")
self.assertEqual(keyFromFormat("{foo!r}"), "foo!r:")
# Add format spec
self.assertEqual(keyFromFormat("{foo:%s}"), "foo!:%s")
self.assertEqual(keyFromFormat("{foo:!}"), "foo!:!")
self.assertEqual(keyFromFormat("{foo::}"), "foo!::")
# Both
self.assertEqual(keyFromFormat("{foo!s:%s}"), "foo!s:%s")
self.assertEqual(keyFromFormat("{foo!s:!}"), "foo!s:!")
self.assertEqual(keyFromFormat("{foo!s::}"), "foo!s::")
sameFlattener = KeyFlattener()
(
(
literalText,
fieldName,
formatSpec,
conversion,
),
) = aFormatter.parse("{x}")
assert fieldName is not None
self.assertEqual(
sameFlattener.flatKey(fieldName, formatSpec, conversion), "x!:"
)
self.assertEqual(
sameFlattener.flatKey(fieldName, formatSpec, conversion), "x!:/2"
)
def _test_formatFlatEvent_fieldNamesSame(
self, event: Optional[LogEvent] = None
) -> LogEvent:
"""
The same format field used twice in one event is rendered twice.
@param event: An event to flatten. If L{None}, create a new event.
@return: C{event} or the event created.
"""
if event is None:
counter = count()
class CountStr:
"""
Hack
"""
def __str__(self) -> str:
return str(next(counter))
event = dict(
log_format="{x} {x}",
x=CountStr(),
)
flattenEvent(event)
self.assertEqual(formatEvent(event), "0 1")
return event
def test_formatFlatEventFieldNamesSame(self) -> None:
"""
The same format field used twice in one event is rendered twice.
"""
self._test_formatFlatEvent_fieldNamesSame()
def test_formatFlatEventFieldNamesSameAgain(self) -> None:
"""
The same event flattened twice gives the same (already rendered)
result.
"""
event = self._test_formatFlatEvent_fieldNamesSame()
self._test_formatFlatEvent_fieldNamesSame(event)
def test_formatEventFlatTrailingText(self) -> None:
"""
L{formatEvent} will handle a flattened event with tailing text after
a replacement field.
"""
event = dict(
log_format="test {x} trailing",
x="value",
)
flattenEvent(event)
result = formatEvent(event)
self.assertEqual(result, "test value trailing")
def test_extractField(
self, flattenFirst: Callable[[LogEvent], LogEvent] = lambda x: x
) -> None:
"""
L{extractField} will extract a field used in the format string.
@param flattenFirst: callable to flatten an event
"""
class ObjectWithRepr:
def __repr__(self) -> str:
return "repr"
class Something:
def __init__(self) -> None:
self.number = 7
self.object = ObjectWithRepr()
def __getstate__(self) -> None:
raise NotImplementedError("Just in case.")
event = dict(
log_format="{something.number} {something.object}",
something=Something(),
)
flattened = flattenFirst(event)
def extract(field: str) -> Any:
return extractField(field, flattened)
self.assertEqual(extract("something.number"), 7)
self.assertEqual(extract("something.number!s"), "7")
self.assertEqual(extract("something.object!s"), "repr")
def test_extractFieldFlattenFirst(self) -> None:
"""
L{extractField} behaves identically if the event is explicitly
flattened first.
"""
def flattened(event: LogEvent) -> LogEvent:
flattenEvent(event)
return event
self.test_extractField(flattened)
def test_flattenEventWithoutFormat(self) -> None:
"""
L{flattenEvent} will do nothing to an event with no format string.
"""
inputEvent = {"a": "b", "c": 1}
flattenEvent(inputEvent)
self.assertEqual(inputEvent, {"a": "b", "c": 1})
def test_flattenEventWithInertFormat(self) -> None:
"""
L{flattenEvent} will do nothing to an event with a format string that
contains no format fields.
"""
inputEvent = {"a": "b", "c": 1, "log_format": "simple message"}
flattenEvent(inputEvent)
self.assertEqual(
inputEvent,
{
"a": "b",
"c": 1,
"log_format": "simple message",
},
)
def test_flattenEventWithNoneFormat(self) -> None:
"""
L{flattenEvent} will do nothing to an event with log_format set to
None.
"""
inputEvent = {"a": "b", "c": 1, "log_format": None}
flattenEvent(inputEvent)
self.assertEqual(
inputEvent,
{
"a": "b",
"c": 1,
"log_format": None,
},
)
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