fix: module names can no longer collide with keywords or builtinsg

E.g. protobuf/any.proto will be imported as

from google.protobuf import any_pb2 as gp_any # Was previously 'as any'

gapic/schema/metadata.py

@@ -34,6 +34,7 @@
 from gapic.schema import imp
 from gapic.schema import naming
 from gapic.utils import cached_property
+from gapic.utils import RESERVED_NAMES
 
 
 @dataclasses.dataclass(frozen=True)
@@ -48,6 +49,9 @@ class Address:
     )
     collisions: FrozenSet[str] = dataclasses.field(default_factory=frozenset)
 
+    def __post_init__(self):
+        super().__setattr__("collisions", self.collisions | RESERVED_NAMES)
+
     def __eq__(self, other) -> bool:
         return all([getattr(self, i) == getattr(other, i) for i
                     in ('name', 'module', 'module_path', 'package', 'parent')])

gapic/utils/reserved_names.py

@@ -12,7 +12,18 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import builtins
+import itertools
 import keyword
 
 
-RESERVED_NAMES = frozenset(keyword.kwlist)
+# The filter and map builtins are a historical artifact;
+# they are not used in modern, idiomatic python,
+# nor are they used in the gapic surface.
+# They are too useful to reserve.
+RESERVED_NAMES = frozenset(
+    itertools.chain(
+        keyword.kwlist,
+        set(dir(builtins)) - {"filter", "map"},
+    )
+)

tests/unit/schema/test_metadata.py

@@ -20,6 +20,7 @@
 
 from gapic.schema import metadata
 from gapic.schema import naming
+from gapic.utils import RESERVED_NAMES
 
 
 def test_address_str():
@@ -160,11 +161,31 @@ def test_address_subpackage_empty():
 
 def test_metadata_with_context():
     meta = metadata.Metadata()
-    assert meta.with_context(
+    collisions = meta.with_context(
         collisions={'foo', 'bar'},
-    ).address.collisions == {'foo', 'bar'}
+    ).address.collisions - RESERVED_NAMES
+    assert collisions == {'foo', 'bar'}
 
 
+
+def test_address_name_builtin_keyword():
+    addr_builtin = metadata.Address(
+        name="Any",
+        module="any",
+        package=("google", "protobuf"),
+        api_naming=naming.NewNaming(proto_package="foo.bar.baz.v1"),
+    )
+    assert addr_builtin.module_alias == "gp_any"
+
+    addr_kword = metadata.Address(
+        name="Class",
+        module="class",
+        package=("google", "protobuf"),
+        api_naming=naming.NewNaming(proto_package="foo.bar.baz.v1"),
+    )
+    assert addr_kword.module_alias == "gp_class"
+
+
 def test_doc_nothing():
     meta = metadata.Metadata()
     assert meta.doc == ''