Add test

Author: AdrienVannson

tests/test_casing.py

@@ -0,0 +1,32 @@
+def test_snake_case() -> None:
+    from betterproto2_compiler.casing import snake_case
+
+    # Simple renaming
+    assert snake_case("methodName") == "method_name"
+    assert snake_case("MethodName") == "method_name"
+
+    # Don't break acronyms
+    assert snake_case("HTTPRequest") == "http_request"
+    assert snake_case("RequestHTTP") == "request_http"
+    assert snake_case("HTTPRequest2") == "http_request_2"
+    assert snake_case("RequestHTTP2") == "request_http_2"
+    assert snake_case("GetAResponse") == "get_a_response"
+
+    # Split digits
+    assert snake_case("Get2025Results") == "get_2025_results"
+    assert snake_case("Get10yResults") == "get_10y_results"
+
+    # If the name already contains an underscore or is lowercase, don't change it at all.
+    # There is a risk of breaking names otherwise.
+    assert snake_case("aaa_123_bbb") == "aaa_123_bbb"
+    assert snake_case("aaa_123bbb") == "aaa_123bbb"
+    assert snake_case("aaa123_bbb") == "aaa123_bbb"
+    assert snake_case("get_HTTP_response") == "get_HTTP_response"
+    assert snake_case("_methodName") == "_methodName"
+    assert snake_case("make_gRPC_request") == "make_gRPC_request"
+
+    assert snake_case("value1") == "value1"
+    assert snake_case("value1string") == "value1string"
+
+    # It is difficult to cover all the cases with a simple algorithm...
+    # "GetValueAsUInt32" -> "get_value_as_u_int_32"