fix: not capitalizing first word when summary ends in period (#185)

* fix: not capitalizing first word in summary with period

* test: for capitalizing first word in summary with period

src/docformatter/strings.py

@@ -23,6 +23,8 @@
 # SOFTWARE.
 """This module provides docformatter string functions."""
 
+
+import contextlib
 # Standard Library Imports
 import re
 
@@ -110,7 +112,13 @@ def normalize_summary(summary: str) -> str:
         and (not summary.startswith("#"))
     ):
         summary += "."
-        summary = summary[0].upper() + summary[1:]
+
+    with contextlib.suppress(IndexError):
+        # Look for underscores in the first word, this would typically
+        # indicate the first word is a variable name or some other
+        # non-standard English word.
+        if "_" not in summary.split(" ", 1)[0]:
+            summary = summary[0].upper() + summary[1:]
 
     return summary
 

tests/test_string_functions.py

@@ -206,6 +206,29 @@ def test_normalize_summary_capitalize_first_letter(self):
             "don't lower case I'm"
         )
 
+    @pytest.mark.unit
+    def test_normalize_summary_capitalize_first_letter_with_period(self):
+        """Capitalize the first letter of the summary even when ends in period.
+
+        See issue #184. See requirement docformatter_4.5.1.
+        """
+        assert (
+            "This is a summary that needs to be capped."
+            == docformatter.normalize_summary(
+                "this is a summary that needs to be capped."
+            )
+        )
+
+    @pytest.mark.unit
+    def test_normalize_summary_dont_capitalize_first_letter_if_variable(self):
+        """Capitalize the first word unless it looks like a variable."""
+        assert (
+            "num_iterations should not be capitalized in this summary."
+            == docformatter.normalize_summary(
+                "num_iterations should not be capitalized in this summary"
+            )
+        )
+
 
 class TestSplitters:
     """Class for testing the string splitting function.