detect go.mod files as Go language

Author: alanhamlett

tests/samples/codefiles/go.mod

@@ -274,3 +274,9 @@ def test_mjs_javascript_module_extension_detected(self):
             expected_language='JavaScript',
             entity='javascript_module.mjs',
         )
+
+    def test_go_mod_detected(self):
+        self.shared(
+            expected_language='Go',
+            entity='go.mod',
+        )

tests/test_languages.py

@@ -169,6 +169,10 @@ def get_language_from_extension(file_name):
     """
 
     filepart, extension = os.path.splitext(file_name)
+    pathpart, filename = os.path.split(file_name)
+
+    if filename == 'go.mod':
+        return 'Go'
 
     if re.match(r'\.h.*$', extension, re.IGNORECASE) or re.match(r'\.c.*$', extension, re.IGNORECASE):