Implement dict_config, a function which configures twiggy from a dict…

…ionary.

Fixes #59

doc/api.rst

@@ -23,10 +23,17 @@ Global Objects
 
     the global :class:`emitters <.Emitter>` dictionary, tied to the :data:`.log`
 
+*************************
+Configuration
+*************************
+
 .. autofunction:: add_emitters
 
+.. autofunction:: dict_config
+
 .. autofunction:: quick_setup
 
+
 *************************
 Features
 *************************

doc/changelog.rst

@@ -12,6 +12,7 @@ Changelog
 - support {}, %, $ as style aliases.
 - PEP8 name compliance
 - add logging_compat module for compatibility with stdlib's logging
+- add dict_config to configure logging from user configuration
 
 ******************************
 0.4.7

test-requirements.txt

@@ -1,3 +1,4 @@
 pytest
 pytest-cov
+pytest-mock
 unittest2

tests/test_dict_config.py

@@ -0,0 +1,239 @@
+import copy
+import re
+
+import pytest
+from six import StringIO
+
+import twiggy
+
+#
+# Tests: dict_config
+#
+
+VALID_CONFIG = {
+    'version': '1.0',
+    'incremental': False,
+    'outputs': {
+        'out1': {
+            'output': 'twiggy.outputs.StreamOutput',
+            'kwargs': {'stream': 'testing1'},
+        },
+        'out2': {
+            'output': 'twiggy.outputs.StreamOutput',
+            'kwargs': {'stream': 'testing2'},
+            'format': 'twiggy.formats.shell_format'
+        },
+    },
+    'emitters': {
+        'all': {
+            'level': 'DEBUG',
+            'output_name': 'out1'
+        },
+        'some': {
+            'level': 'WARNING',
+            'filters': [
+                {'filter': 'twiggy.filters.names',
+                 'args': ['a', 'b'],
+                 'kwargs': {}
+                 },
+                {'filter': 'twiggy.filters.names',
+                 'args': ['c', 'd'],
+                 'kwargs': {}
+                 },
+            ],
+            'output_name': 'out2'
+        },
+    }
+}
+
+
+@pytest.fixture(autouse=True)
+def twiggy_globals():
+    twiggy._populate_globals()
+    yield
+    twiggy._del_globals()
+
+
+@pytest.fixture
+def internal_log():
+    output = twiggy.internal_log.output
+
+    buf = StringIO()
+    new_output = twiggy.outputs.StreamOutput(format=output._format, stream=buf)
+
+    twiggy.internal_log.output = new_output
+    yield buf
+    twiggy.internal_log.output = output
+
+
+def test_dict_config_invalid(internal_log):
+    twiggy.dict_config({})
+    assert re.search(r"WARNING:twiggy.internal|Error parsing twiggy setup: Config dict"
+                     " must contain a 'version' key", internal_log.getvalue())
+
+
+def test_dict_config_valid(mocker):
+    def return_how_called(*args, **kwargs):
+        return (args, kwargs)
+
+    cfg = copy.deepcopy(VALID_CONFIG)
+
+    add_emitters = mocker.patch('twiggy.add_emitters')
+    mocker.patch('twiggy.emitters')
+    emitters_dict_clear = mocker.patch('twiggy.emitters.clear')
+    mocker.patch('twiggy.filters.names', return_how_called)
+
+    twiggy.dict_config(cfg)
+
+    assert emitters_dict_clear.call_args_list == [mocker.call()]
+
+    assert len(add_emitters.call_args_list) == 1
+    assert len(add_emitters.call_args_list[0][0]) == 2
+
+    # call_args_list is nested like this: [call(positional_args(first_emitter)),]
+    # We expect to have called add_emitters once with two positional args which are
+    # themselves tuples
+    if add_emitters.call_args_list[0][0][0][0] == 'all':
+        all_emitter = add_emitters.call_args_list[0][0][0]
+        some_emitter = add_emitters.call_args_list[0][0][1]
+    else:
+        some_emitter = add_emitters.call_args_list[0][0][0]
+        all_emitter = add_emitters.call_args_list[0][0][1]
+
+    assert all_emitter[0] == 'all'
+    assert all_emitter[1] == twiggy.levels.DEBUG
+    assert all_emitter[2] is None
+    assert isinstance(all_emitter[3], twiggy.outputs.StreamOutput)
+    assert all_emitter[3]._format == twiggy.formats.line_format
+    assert all_emitter[3].stream == 'testing1'
+
+    assert some_emitter[0] == 'some'
+    assert some_emitter[1] == twiggy.levels.WARNING
+    assert some_emitter[2] == [(('a', 'b'), {}), (('c', 'd'), {})]
+    assert isinstance(some_emitter[3], twiggy.outputs.StreamOutput)
+    assert some_emitter[3]._format == twiggy.formats.shell_format
+    assert some_emitter[3].stream == 'testing2'
+
+
+def test_dict_config_incremental_true(mocker):
+    def return_how_called(*args, **kwargs):
+        return (args, kwargs)
+
+    cfg = copy.deepcopy(VALID_CONFIG)
+    del cfg['emitters']['some']
+    cfg['incremental'] = True
+
+    add_emitters = mocker.patch('twiggy.add_emitters')
+    mocker.patch('twiggy.emitters')
+    emitters_dict_clear = mocker.patch('twiggy.emitters.clear')
+    mocker.patch('twiggy.filters.names', return_how_called)
+
+    twiggy.dict_config(cfg)
+
+    assert emitters_dict_clear.call_args_list == []
+
+    assert len(add_emitters.call_args_list) == 1
+    assert len(add_emitters.call_args_list[0][0]) == 1
+
+    cfg = copy.deepcopy(VALID_CONFIG)
+    del cfg['emitters']['all']
+    cfg['incremental'] = True
+
+    twiggy.dict_config(cfg)
+
+    assert emitters_dict_clear.call_args_list == []
+
+    assert len(add_emitters.call_args_list) == 2
+    assert len(add_emitters.call_args_list[0][0]) == 1
+    assert len(add_emitters.call_args_list[1][0]) == 1
+
+    # call_args_list is nested like this: [call(positional_args(first_emitter)),]
+    # We expect to have called add_emitters twice with one positional arg each time
+    all_emitter = add_emitters.call_args_list[0][0][0]
+    some_emitter = add_emitters.call_args_list[1][0][0]
+
+    assert all_emitter[0] == 'all'
+    assert all_emitter[1] == twiggy.levels.DEBUG
+    assert all_emitter[2] is None
+    assert isinstance(all_emitter[3], twiggy.outputs.StreamOutput)
+    assert all_emitter[3]._format == twiggy.formats.line_format
+    assert all_emitter[3].stream == 'testing1'
+
+    assert some_emitter[0] == 'some'
+    assert some_emitter[1] == twiggy.levels.WARNING
+    assert some_emitter[2] == [(('a', 'b'), {}), (('c', 'd'), {})]
+    assert isinstance(some_emitter[3], twiggy.outputs.StreamOutput)
+    assert some_emitter[3]._format == twiggy.formats.shell_format
+    assert some_emitter[3].stream == 'testing2'
+
+
+def test_dict_config_incremental_false_order(mocker):
+    """
+    With incremental=false it is important that the dictionary is cleared before the emitter is
+    added.  We'll do this by testing the emitters dict instead of a mock
+    """
+    cfg = copy.deepcopy(VALID_CONFIG)
+    del cfg['emitters']['some']
+
+    twiggy.dict_config(cfg)
+
+    assert len(twiggy.emitters) == 1
+    assert 'all' in twiggy.emitters
+
+    cfg = copy.deepcopy(VALID_CONFIG)
+    del cfg['emitters']['all']
+
+    twiggy.dict_config(cfg)
+
+    assert len(twiggy.emitters) == 1
+    assert 'some' in twiggy.emitters
+
+
+def test_dict_config_incremental_false_contents(mocker):
+    def return_how_called(*args, **kwargs):
+        return (args, kwargs)
+
+    cfg = copy.deepcopy(VALID_CONFIG)
+    del cfg['emitters']['some']
+
+    add_emitters = mocker.patch('twiggy.add_emitters')
+    mocker.patch('twiggy.emitters')
+    emitters_dict_clear = mocker.patch('twiggy.emitters.clear')
+    mocker.patch('twiggy.filters.names', return_how_called)
+
+    twiggy.dict_config(cfg)
+
+    assert emitters_dict_clear.call_args_list == [mocker.call()]
+
+    assert len(add_emitters.call_args_list) == 1
+    assert len(add_emitters.call_args_list[0][0]) == 1
+
+    the_emitter = add_emitters.call_args_list[0][0][0]
+
+    assert the_emitter[0] == 'all'
+    assert the_emitter[1] == twiggy.levels.DEBUG
+    assert the_emitter[2] is None
+    assert isinstance(the_emitter[3], twiggy.outputs.StreamOutput)
+    assert the_emitter[3]._format == twiggy.formats.line_format
+    assert the_emitter[3].stream == 'testing1'
+
+    cfg = copy.deepcopy(VALID_CONFIG)
+    del cfg['emitters']['all']
+
+    twiggy.dict_config(cfg)
+
+    # Note: This does not check that the clear call happens before the add_emitters call.
+    # The test_dict_config_incremental_false_order() check takes care of that.
+    assert emitters_dict_clear.call_args_list == [mocker.call(), mocker.call()]
+
+    assert len(add_emitters.call_args_list) == 2
+    assert len(add_emitters.call_args_list[1][0]) == 1
+
+    the_emitter = add_emitters.call_args_list[1][0][0]
+
+    assert the_emitter[0] == 'some'
+    assert the_emitter[1] == twiggy.levels.WARNING
+    assert the_emitter[2] == [(('a', 'b'), {}), (('c', 'd'), {})]
+    assert isinstance(the_emitter[3], twiggy.outputs.StreamOutput)
+    assert the_emitter[3]._format == twiggy.formats.shell_format
+    assert the_emitter[3].stream == 'testing2'