| Viewing file:  test_flatten.py (8.51 KB)      -rw-r--r-- Select action/file-type:
 
  (+) |  (+) |  (+) | Code (+) | Session (+) |  (+) | SDB (+) |  (+) |  (+) |  (+) |  (+) |  (+) | 
 
# Copyright (c) Twisted Matrix Laboratories.# See LICENSE for details.
 
 """
 Test cases for L{twisted.logger._format}.
 """
 
 import sys
 from itertools import count
 import json
 
 try:
 from time import tzset
 # We should upgrade to a version of pyflakes that does not require this.
 tzset
 except ImportError:
 tzset = None
 
 from twisted.trial import unittest
 
 from .._format import formatEvent
 from .._flatten import (
 flattenEvent, extractField, KeyFlattener, aFormatter
 )
 
 
 
 class FlatFormattingTests(unittest.TestCase):
 """
 Tests for flattened event formatting functions.
 """
 
 def test_formatFlatEvent(self):
 """
 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(object):
 attribute = "value"
 
 event1 = dict(
 log_format=(
 "callable: {callme()} "
 "attribute: {object.attribute} "
 "numrepr: {number!r} "
 "numstr: {number!s} "
 "strrepr: {string!r}"
 ),
 callme=lambda: next(counter), object=Ephemeral(),
 number=7, string="hello",
 )
 
 flattenEvent(event1)
 
 event2 = dict(event1)
 del event2["callme"]
 del event2["object"]
 event3 = json.loads(json.dumps(event2))
 self.assertEqual(
 formatEvent(event3),
 (
 u"callable: 0 "
 "attribute: value "
 "numrepr: 7 "
 "numstr: 7 "
 "strrepr: 'hello'"
 )
 )
 
 
 def test_formatFlatEventBadFormat(self):
 """
 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(u"Unable to format event")
 )
 
 
 def test_formatFlatEventWithMutatedFields(self):
 """
 L{formatEvent} will prefer the stored C{str()} or C{repr()} value for
 an object, in case the other version.
 """
 class Unpersistable(object):
 """
 Unpersitable object.
 """
 destructed = False
 
 def selfDestruct(self):
 """
 Self destruct.
 """
 self.destructed = True
 
 def __repr__(self):
 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):
 """
 Test that L{KeyFlattener.flatKey} returns the expected keys for format
 fields.
 """
 
 def keyFromFormat(format):
 for (
 literalText,
 fieldName,
 formatSpec,
 conversion,
 ) in aFormatter.parse(format):
 return KeyFlattener().flatKey(
 fieldName, formatSpec, conversion
 )
 
 # No name
 try:
 self.assertEqual(keyFromFormat("{}"), "!:")
 except ValueError:
 if sys.version_info[:2] == (2, 6):
 # In python 2.6, an empty field name causes Formatter.parse to
 # raise ValueError.
 pass
 else:
 # 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::")
 [keyPlusLiteral] = aFormatter.parse("{x}")
 key = keyPlusLiteral[1:]
 sameFlattener = KeyFlattener()
 self.assertEqual(sameFlattener.flatKey(*key), "x!:")
 self.assertEqual(sameFlattener.flatKey(*key), "x!:/2")
 
 
 def _test_formatFlatEvent_fieldNamesSame(self, event=None):
 """
 The same format field used twice in one event is rendered twice.
 
 @param event: An event to flatten.  If C{None}, create a new event.
 @return: C{event} or the event created.
 """
 if event is None:
 counter = count()
 
 class CountStr(object):
 """
 Hack
 """
 def __str__(self):
 return str(next(counter))
 
 event = dict(
 log_format="{x} {x}",
 x=CountStr(),
 )
 
 flattenEvent(event)
 self.assertEqual(formatEvent(event), u"0 1")
 
 return event
 
 
 def test_formatFlatEventFieldNamesSame(self):
 """
 The same format field used twice in one event is rendered twice.
 """
 self._test_formatFlatEvent_fieldNamesSame()
 
 
 def test_formatFlatEventFieldNamesSameAgain(self):
 """
 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):
 """
 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, u"test value trailing")
 
 
 def test_extractField(self, flattenFirst=lambda x: x):
 """
 L{extractField} will extract a field used in the format string.
 
 @param flattenFirst: callable to flatten an event
 """
 class ObjectWithRepr(object):
 def __repr__(self):
 return "repr"
 
 class Something(object):
 def __init__(self):
 self.number = 7
 self.object = ObjectWithRepr()
 
 def __getstate__(self):
 raise NotImplementedError("Just in case.")
 
 event = dict(
 log_format="{something.number} {something.object}",
 something=Something(),
 )
 
 flattened = flattenFirst(event)
 
 def extract(field):
 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):
 """
 L{extractField} behaves identically if the event is explicitly
 flattened first.
 """
 def flattened(evt):
 flattenEvent(evt)
 return evt
 self.test_extractField(flattened)
 
 
 def test_flattenEventWithoutFormat(self):
 """
 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):
 """
 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',
 }
 )
 
 |