feat(cli): support file configuration overrides -- @tonybaloney (#179)

* initial prototype for file configuration

* only load the radon.cfg if it exists

* add some basic tests and fix some erroneous behaviours

* Put the configuration in a module property so that it is used for the default values. Changing configuration once module is imported will not take effect

* Update documentation.

docs/commandline.rst

@@ -14,6 +14,28 @@ Radon currently has four commands:
     with Radon, you'll have to set the `RADONFILESENCODING` environment
     variable to `UTF-8`.
 
+Radon configuration files
+-------------------------
+
+When using radon regularly, you may want to specify default argument values in a configuration file.
+For example, all of the radon commands have a ``--exclude`` and ``--ignore`` argument on the command-line.
+
+Radon will look for the following files to determine default arguments:
+
+* ``radon.cfg``
+* ``setup.cfg``
+* ``~/.radon.cfg``
+
+Any radon configuration will be given in the INI-format, under the section ``[radon]``.
+
+For example:
+
+.. code-block:: ini
+
+   [radon]
+   exclude = test_*.py
+   cc_min = B
+
 The :command:`cc` command
 -------------------------
 
@@ -57,38 +79,52 @@ Options
 
 .. option:: -x, --max
 
-   Set the maximum complexity rank to display.
+   Set the maximum complexity rank to display, defaults to ``F``.
+
+   Value can be set in a configuration file using the ``cc_max`` property.
 
 .. option:: -n, --min
 
-   Set the minimum complexity rank to display.
+   Set the minimum complexity rank to display, defaults to ``A``.
+
+   Value can be set in a configuration file using the ``cc_min`` property.
 
 .. option:: -a, --average
 
    If given, at the end of the analysis show the average Cyclomatic
    Complexity. This option is influenced by :option:`-x, --max` and
    :option:`-n, --min` options.
 
+   Value can be set in a configuration file using the ``average`` property.
+
 .. option:: --total-average
 
    Like :option:`-a, --average`, but it is not influenced by `min` and `max`.
    Every analyzed block is counted, no matter whether it is displayed or not.
 
+   Value can be set in a configuration file using the ``total_average`` property.
+
 .. option:: -s, --show-complexity
 
    If given, show the complexity score along with its rank.
 
+   Value can be set in a configuration file using the ``show_complexity`` property.
+
 .. option:: -e, --exclude
 
    Exclude files only when their path matches one of these glob patterns.
    Usually needs quoting at the command line.
 
+   Value can be set in a configuration file using the ``exclude`` property.
+
 .. option:: -i, --ignore
 
    Ignore directories when their name matches one of these glob patterns: radon
    won't even descend into them. By default, hidden directories (starting with
    '.') are ignored.
 
+   Value can be set in a configuration file using the ``ignore`` property.
+
 .. option:: -o, --order
 
    The ordering function for the results. Can be one of:
@@ -97,6 +133,8 @@ Options
     * `LINES`: order by line numbers;
     * `ALPHA`: order by block names (alphabetically).
 
+   Value can be set in a configuration file using the ``order`` property.
+
 .. option:: -j, --json
 
    If given, the results will be converted into JSON. This is useful in case
@@ -112,6 +150,14 @@ Options
    Does not count assert statements when computing complexity. This is because
    Python can be run with an optimize flag which removes assert statements.
 
+   Value can be set in a configuration file using the ``no_assert`` property.
+
+.. option:: -O, --output-file
+
+   Save output to the specified output file.
+
+   Value can be set in a configuration file using the ``output_file`` property.
+
 Examples
 ++++++++
 
@@ -178,38 +224,56 @@ Options
 
 .. option:: -x, --max
 
-   Set the maximum MI to display.
+   Set the maximum MI to display. Expects a letter between A-F. Defaults to ``C``.
+
+   Value can be set in a configuration file using the ``mi_max`` property.
 
 .. option:: -n, --min
 
-   Set the minimum MI to display.
+   Set the minimum MI to display. Expects a letter between A-F. Defaults to ``A``.
+
+   Value can be set in a configuration file using the ``mi_min`` property.
 
 .. option:: -e, --exclude
 
    Exclude files only when their path matches one of these glob patterns.
    Usually needs quoting at the command line.
 
+   Value can be set in a configuration file using the ``exclude`` property.
+
 .. option:: -i, --ignore
 
    Ignore directories when their name matches one of these glob patterns: radon
    won't even descend into them. By default, hidden directories (starting with
    '.') are ignored.
 
+   Value can be set in a configuration file using the ``ignore`` property.
+
 .. option:: -m, --multi
 
    If given, Radon will not count multiline strings as comments.
    Most of the time this is safe since multiline strings are used as functions
    docstrings, but one should be aware that their use is not limited to that
    and sometimes it would be wrong to count them as comment lines.
 
+   Value can be set in a configuration file using the ``multi`` property.
+
 .. option:: -s, --show
 
    If given, the actual MI value is shown in results, alongside the rank.
 
+   Value can be set in a configuration file using the ``show_mi`` property.
+
 .. option:: -j, --json
 
    Format results in JSON.
 
+.. option:: -O, --output-file
+
+   Save output to the specified output file.
+
+   Value can be set in a configuration file using the ``output_file`` property.
+
 
 Examples
 ++++++++
@@ -267,12 +331,16 @@ Options
    Exclude files only when their path matches one of these glob patterns.
    Usually needs quoting at the command line.
 
+   Value can be set in a configuration file using the ``exclude`` property.
+
 .. option:: -i, --ignore
 
    Ignore directories when their name matches one of these glob patterns: radon
    won't even descend into them. By default, hidden directories (starting with
    '.') are ignored.
 
+   Value can be set in a configuration file using the ``ignore`` property.
+
 .. option:: -s, --summary
 
    If given, at the end of the analysis a summary of the gathered
@@ -282,6 +350,13 @@ Options
 
    If given, the results will be converted into JSON.
 
+.. option:: -O, --output-file
+
+   Save output to the specified output file.
+
+   Value can be set in a configuration file using the ``output_file`` property.
+
+
 Examples
 ++++++++
 
@@ -301,7 +376,7 @@ matches ``path1/tests/*``.
 
 
 The :command:`hal` command
--------------------------
+--------------------------
 
 .. program:: hal
 
@@ -318,24 +393,35 @@ Options
 
 .. option:: -f, --functions
 
-    Compute the metrics on the *function* level, as opposed to the *file*
-    level.
+   Compute the metrics on the *function* level, as opposed to the *file* level.
+
+   Value can be set in a configuration file using the ``functions`` property.
 
 .. option:: -e, --exclude
 
    Exclude files when their path matches one of these glob patterns. Usually
    needs quoting at the command line.
 
+   Value can be set in a configuration file using the ``exclude`` property.
+
 .. option:: -i, --ignore
 
    Refuse to descend into directories that match any of these glob patterns. By
    default, hidden directories (starting with '.') are ignored.
 
+   Value can be set in a configuration file using the ``ignore`` property.
+
 .. option:: -j, --json
 
    Convert results into JSON. This is useful for exporting results to another
    application.
 
+.. option:: -O, --output-file
+
+   Save output to the specified output file.
+
+   Value can be set in a configuration file using the ``output_file`` property.
+
 
 Examples
 ++++++++

radon/cli/__init__.py

@@ -4,21 +4,65 @@
 import inspect
 from contextlib import contextmanager
 from mando import Program
+import configparser
+import os
 
 import radon.complexity as cc_mod
 from radon.cli.colors import BRIGHT, RED, RESET
 from radon.cli.harvest import CCHarvester, RawHarvester, MIHarvester, HCHarvester
 
 
+CONFIG_SECTION_NAME = 'radon'
+
+
+class FileConfig(object):
+    '''
+    Yield default options by reading local configuration files.
+    '''
+    def __init__(self):
+        self.file_cfg = self.file_config()
+
+    def get_value(self, key, type, default):
+        if not self.file_cfg.has_option(CONFIG_SECTION_NAME, key):
+            return default
+        if type == int:
+            return self.file_cfg.getint(CONFIG_SECTION_NAME, key, fallback=default)
+        if type == bool:
+            return self.file_cfg.getboolean(CONFIG_SECTION_NAME, key, fallback=default)
+        else:
+            return self.file_cfg.get(CONFIG_SECTION_NAME, key, fallback=default)
+
+    @staticmethod
+    def file_config():
+        '''Return any file configuration discovered'''
+        config = configparser.ConfigParser()
+        if os.path.exists('radon.cfg'):
+            config.read_file(open('radon.cfg'))
+        config.read(['setup.cfg', os.path.expanduser('~/.radon.cfg')])
+        return config
+
+
+_cfg = FileConfig()
+
 program = Program(version=sys.modules['radon'].__version__)
 
 
 @program.command
 @program.arg('paths', nargs='+')
-def cc(paths, min='A', max='F', show_complexity=False, average=False,
-       exclude=None, ignore=None, order='SCORE', json=False, no_assert=False,
-       show_closures=False, total_average=False, xml=False, codeclimate=False,
-       output_file=None, ):
+def cc(paths, min=_cfg.get_value('cc_min', str, 'A'),
+       max=_cfg.get_value('cc_max', str, 'F'),
+       show_complexity=_cfg.get_value('show_complexity', bool, False),
+       average=_cfg.get_value('average', bool, False),
+       exclude=_cfg.get_value('exclude', str, None),
+       ignore=_cfg.get_value('ignore', str, None),
+       order=_cfg.get_value('order', str, 'SCORE'),
+       json=False,
+       no_assert=_cfg.get_value('no_assert', bool, False),
+       show_closures=_cfg.get_value('show_closures', bool, False),
+       total_average=_cfg.get_value('total_average', bool, False),
+       xml=False,
+       codeclimate=False,
+       output_file=_cfg.get_value('output_file', str, None), ):
     '''Analyze the given Python modules and compute Cyclomatic
     Complexity (CC).
 
@@ -71,8 +115,12 @@ def cc(paths, min='A', max='F', show_complexity=False, average=False,
 
 @program.command
 @program.arg('paths', nargs='+')
-def raw(paths, exclude=None, ignore=None, summary=False, json=False,
-        output_file=None):
+def raw(paths,
+        exclude=_cfg.get_value('exclude', str, None),
+        ignore=_cfg.get_value('ignore', str, None),
+        summary=False,
+        json=False,
+        output_file=_cfg.get_value('output_file', str, None), ):
     '''Analyze the given Python modules and compute raw metrics.
 
     :param paths: The paths where to find modules or packages to analyze. More
@@ -99,8 +147,16 @@ def raw(paths, exclude=None, ignore=None, summary=False, json=False,
 
 @program.command
 @program.arg('paths', nargs='+')
-def mi(paths, min='A', max='C', multi=True, exclude=None, ignore=None,
-       show=False, json=False, sort=False, output_file=None):
+def mi(paths,
+       min=_cfg.get_value('mi_min', str, 'A'),
+       max=_cfg.get_value('mi_max', str, 'C'),
+       multi=_cfg.get_value('multi', bool, True),
+       exclude=_cfg.get_value('exclude', str, None),
+       ignore=_cfg.get_value('ignore', str, None),
+       show=_cfg.get_value('show_mi', bool, False),
+       json=False,
+       sort=False,
+       output_file=_cfg.get_value('output_file', str, None), ):
     '''Analyze the given Python modules and compute the Maintainability Index.
 
     The maintainability index (MI) is a compound metric, with the primary aim
@@ -140,8 +196,12 @@ def mi(paths, min='A', max='C', multi=True, exclude=None, ignore=None,
 
 @program.command
 @program.arg("paths", nargs="+")
-def hal(paths, exclude=None, ignore=None, json=False, functions=False,
-        output_file=None):
+def hal(paths,
+        exclude=_cfg.get_value('exclude', str, None),
+        ignore=_cfg.get_value('ignore', str, None),
+        json=False,
+        functions=_cfg.get_value('functions', bool, False),
+        output_file=_cfg.get_value('output_file', str, None), ):
     """
     Analyze the given Python modules and compute their Halstead metrics.
 

radon/tests/conftest.py

@@ -0,0 +1,25 @@
+import pytest
+import textwrap
+import os
+
+
+class RadonConfig(object):
+    def __init__(self):
+        self._fname = os.path.join(os.path.dirname(__file__), 'radon.cfg')
+
+    def write(self, text):
+        _cfg = textwrap.dedent(text)
+        with open(self._fname, 'w') as cfg_f:
+            cfg_f.write("# Autogenerated from pytest \n[radon]\n")
+            cfg_f.write(_cfg)
+
+    def __del__(self):
+        with open(self._fname, 'w') as cfg_f:
+            cfg_f.write('# Session completed')
+
+
+@pytest.fixture(scope="session")
+def radon_config():
+    r = RadonConfig()
+    yield r
+    del r