test: add tests for autogen-snippets option (#1055)

Follow up to #1044

Author: busunkim96

tests/unit/generator/test_options.py

@@ -141,9 +141,7 @@ def test_options_service_config(fs):
 
 
 def test_options_bool_flags():
-    # All these options are default False.
-    # If new options violate this assumption,
-    # this test may need to be tweaked.
+    # Most options are default False.
     # New options should follow the dash-case/snake_case convention.
     opt_str_to_attr_name = {
         name: re.sub(r"-", "_", name)
@@ -161,3 +159,22 @@ def test_options_bool_flags():
 
         options = Options.build(opt)
         assert getattr(options, attr)
+
+    # Check autogen-snippets separately, as it is default True
+    options = Options.build("")
+    assert options.autogen_snippets
+
+    options = Options.build("autogen-snippets=False")
+    assert not options.autogen_snippets
+
+
+def test_options_autogen_snippets_false_for_old_naming():
+    # NOTE: Snippets are not currently correct for the alternative (Ads) templates
+    # so always disable snippetgen in that case
+    # https://github.com/googleapis/gapic-generator-python/issues/1052
+    options = Options.build("old-naming")
+    assert not options.autogen_snippets
+
+    # Even if autogen-snippets is set to True, do not enable snippetgen
+    options = Options.build("old-naming,autogen-snippets=True")
+    assert not options.autogen_snippets