Merge pull request #135 from farmersez/exclude-all-errors

Supporting an empty list in the `--select=` option.

Author: Nurdok

docs/release_notes.rst

@@ -12,6 +12,11 @@ New Features
   previously resulted in D100 errors ("Missing docstring in public module")
   will now result in D104 (#105, #127).
 
+* Support the option to exclude all error codes. Running pep257 with
+  `--select=` (or `select=` in the configuration file) will exclude all errors
+  which could then be added one by one using `add-select`. Useful for projects
+  new to pep257 (#132, #135).
+
 Bug Fixes
 
 * On Python 2.x, D302 ("Use u""" for Unicode docstrings") is not reported

src/pep257.py

@@ -692,15 +692,15 @@ def get_option_parser():
            help='show explanation of each error')
     option('-s', '--source', action='store_true',
            help='show source for each error')
-    option('--select', metavar='<codes>', default='',
+    option('--select', metavar='<codes>', default=None,
            help='choose the basic list of checked errors by specifying which '
                 'errors to check for (with a list of comma-separated error '
                 'codes). for example: --select=D101,D202')
-    option('--ignore', metavar='<codes>', default='',
+    option('--ignore', metavar='<codes>', default=None,
            help='choose the basic list of checked errors by specifying which '
                 'errors to ignore (with a list of comma-separated error '
                 'codes). for example: --ignore=D101,D202')
-    option('--convention', metavar='<name>', default='',
+    option('--convention', metavar='<name>', default=None,
            help='choose the basic list of checked errors by specifying an '
                 'existing convention. Possible conventions: {0}'
                 .format(', '.join(conventions)))
@@ -858,11 +858,11 @@ def filter(self, record):
 
 def get_checked_error_codes(options):
     codes = set(ErrorRegistry.get_error_codes())
-    if options.ignore:
+    if options.ignore is not None:
         checked_codes = codes - set(options.ignore.split(','))
-    elif options.select:
+    elif options.select is not None:
         checked_codes = set(options.select.split(','))
-    elif options.convention:
+    elif options.convention is not None:
         checked_codes = getattr(conventions, options.convention)
     else:
         checked_codes = conventions.pep257

src/tests/test_pep257.py

@@ -168,7 +168,7 @@ def foo():
 
 
 def test_select_cli():
-    """Test choosing error codes with --select in the CLI."""
+    """Test choosing error codes with `--select` in the CLI."""
     with Pep257Env() as env:
         with env.open('example.py', 'wt') as example:
             example.write(textwrap.dedent("""\
@@ -183,7 +183,7 @@ def foo():
 
 
 def test_select_config():
-    """Test choosing error codes with --select in the config file."""
+    """Test choosing error codes with `select` in the config file."""
     with Pep257Env() as env:
         with env.open('example.py', 'wt') as example:
             example.write(textwrap.dedent("""\
@@ -302,3 +302,47 @@ def test_illegal_convention():
         assert code == 2
         assert "Illegal convention 'illegal_conv'." in err
         assert 'Possible conventions: pep257' in err
+
+
+def test_empty_select_cli():
+    """Test excluding all error codes with `--select=` in the CLI."""
+    with Pep257Env() as env:
+        with env.open('example.py', 'wt') as example:
+            example.write(textwrap.dedent("""\
+                def foo():
+                    pass
+            """))
+
+        _, _, code = env.invoke_pep257(args="--select=")
+        assert code == 0
+
+
+def test_empty_select_config():
+    """Test excluding all error codes with `select=` in the config file."""
+    with Pep257Env() as env:
+        with env.open('example.py', 'wt') as example:
+            example.write(textwrap.dedent("""\
+                def foo():
+                    pass
+            """))
+
+        env.write_config(select="")
+        _, _, code = env.invoke_pep257()
+        assert code == 0
+
+
+def test_empty_select_with_added_error():
+    """Test excluding all errors but one."""
+    with Pep257Env() as env:
+        with env.open('example.py', 'wt') as example:
+            example.write(textwrap.dedent("""\
+                def foo():
+                    pass
+            """))
+
+        env.write_config(select="")
+        _, err, code = env.invoke_pep257(args="--add-select=D100")
+        assert code == 1
+        assert 'D100' in err
+        assert 'D101' not in err
+        assert 'D103' not in err