Fix issue #890

5 files changed, 28 insertions, 2 deletions

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 48c2d77e..a73e70c4 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -15,6 +15,7 @@ Planned:
 ### 4.3.13 - March 6, 2019 - hot fix release
 - Fixed the inability to accurately determine import section when a mix of conda and virtual environments are used.
 - Fixed some output being printed even when --quiet mode is enabled.
+- Fixed issue #890 interoperability with PyCharm by allowing case sensitive non type grouped sorting
 
 ### 4.3.12 - March 6, 2019 - hot fix release
 - Fix error caused when virtual environment not detected
diff --git a/isort/isort.py b/isort/isort.py
index 5b35b0d5..19bdceb2 100644
--- a/isort/isort.py
+++ b/isort/isort.py
@@ -302,7 +302,8 @@ class SortImports(object):
                 prefix = "B"
             else:
                 prefix = "C"
-        module_name = module_name.lower()
+        if not config['case_sensitive']:
+            module_name = module_name.lower()
         if section_name is None or 'length_sort_' + str(section_name).lower() not in config:
             length_sort = config['length_sort']
         else:
diff --git a/isort/main.py b/isort/main.py
index 767927d4..3cc00c30 100644
--- a/isort/main.py
+++ b/isort/main.py
@@ -291,6 +291,8 @@ def parse_args(argv: Optional[Sequence[str]] = None) -> Dict[str, Any]:
     parser.add_argument('--unsafe', dest='unsafe', action='store_true',
                         help='Tells isort to look for files in standard library directories, etc. '
                              'where it may not be safe to operate in')
+    parser.add_argument('--case-sensitive', dest='case_sensitive', action='store_true',
+                        help='Tells isort to include casing when sorting module names')
     parser.add_argument('files', nargs='*', help='One or more Python source files that need their imports sorted.')
 
     arguments = {key: value for key, value in vars(parser.parse_args(argv)).items() if value}
diff --git a/isort/settings.py b/isort/settings.py
index 43a0f2a4..6504be53 100644
--- a/isort/settings.py
+++ b/isort/settings.py
@@ -167,7 +167,8 @@ default = {'force_to_top': [],
            'no_lines_before': [],
            'no_inline_sort': False,
            'ignore_comments': False,
-           'safety_excludes': True}
+           'safety_excludes': True,
+           'case_sensitive': False}
 
 
 @lru_cache()
diff --git a/test_isort.py b/test_isort.py
index 9b3c1e42..fce3e3f0 100644
--- a/test_isort.py
+++ b/test_isort.py
@@ -2880,3 +2880,24 @@ def test_extract_multiline_output_wrap_setting_from_a_config_file(tmpdir: py.pat
 
     config = settings.from_path(str(tmpdir))
     assert config['multi_line_output'] == WrapModes.VERTICAL_GRID_GROUPED
+
+
+def test_ensure_support_for_non_typed_but_cased_alphabetic_sort_issue_890():
+    test_input = ('from pkg import BALL\n'
+                  'from pkg import RC\n'
+                  'from pkg import Action\n'
+                  'from pkg import Bacoo\n'
+                  'from pkg import RCNewCode\n'
+                  'from pkg import actual\n'
+                  'from pkg import rc\n'
+                  'from pkg import recorder\n')
+    expected_output = ('from pkg import Action\n'
+                       'from pkg import BALL\n'
+                       'from pkg import Bacoo\n'
+                       'from pkg import RC\n'
+                       'from pkg import RCNewCode\n'
+                       'from pkg import actual\n'
+                       'from pkg import rc\n'
+                       'from pkg import recorder\n')
+    assert SortImports(file_contents=test_input, case_sensitive=True, order_by_type=False,
+                       force_single_line=True).output == expected_output