Enhance split words

Keep "Response200" as "response_200", but don't make "s3config" become
"s_3_config". :)

Author: ramnes

Diff for: openapi_python_client/utils.py

@@ -12,8 +12,11 @@ def sanitize(value: str) -> str:
 
 
 def split_words(value: str) -> List[str]:
-    """Split a string on non-capital letters and known delimiters"""
-    value = " ".join(re.split("([A-Z]?[a-z]+)", value))
+    """Split a string on words and known delimiters"""
+    # Put a space between lowercase letters and capital letters or numbers
+    value = re.sub(r"([a-z])([A-Z0-9])", r"\1 \2", value)
+    # Separate acronyms from words
+    value = re.sub(r"([A-Z0-9]+)([A-Z][a-z]+)", r"\1 \2", value)
     return re.findall(rf"[^{delimiters}]+", value)
 
 

Diff for: tests/test_utils.py

@@ -3,6 +3,22 @@
 from openapi_python_client import utils
 
 
+@pytest.mark.parametrize(
+    "before, after",
+    [
+        ("connectionID", ["connection", "ID"]),
+        ("connection_id", ["connection", "id"]),
+        ("connection-id", ["connection", "id"]),
+        ("Response200", ["Response", "200"]),
+        ("Response200Okay", ["Response", "200", "Okay"]),
+        ("S3Config", ["S3", "Config"]),
+        ("s3config", ["s3config"]),
+    ],
+)
+def test_split_words(before, after):
+    assert utils.split_words(before) == after
+
+
 def test_snake_case_uppercase_str():
     assert utils.snake_case("HTTP") == "http"
     assert utils.snake_case("HTTP RESPONSE") == "http_response"