Fix erroneous codec cache invalidation on internal codec aliasing.

set_builtin_type_codec() flushes the codec cache, so internal codec
aliasing (for enums and fallback) must use a version that doesn't
kill the cache.

Fixes: #133, #122.

Author: elprans

asyncpg/protocol/codecs/base.pyx

@@ -468,6 +468,10 @@ cdef class DataCodecConfig:
                 self._type_codecs_cache[oid, elem_format] = \
                     Codec.new_range_codec(oid, name, schema, elem_codec)
 
+            elif ti['kind'] == b'e':
+                # Enum types are essentially text
+                self._set_builtin_type_codec(oid, name, schema, 'scalar',
+                                             TEXTOID, PG_FORMAT_ANY)
             else:
                 self.declare_fallback_codec(oid, name, schema)
 
@@ -481,8 +485,8 @@ cdef class DataCodecConfig:
 
         self.clear_type_cache()
 
-    def set_builtin_type_codec(self, typeoid, typename, typeschema, typekind,
-                               alias_to, format=PG_FORMAT_ANY):
+    def _set_builtin_type_codec(self, typeoid, typename, typeschema, typekind,
+                                alias_to, format=PG_FORMAT_ANY):
         cdef:
             Codec codec
             Codec target_codec
@@ -517,6 +521,10 @@ cdef class DataCodecConfig:
                 (typeoid, PG_FORMAT_TEXT) not in self._local_type_codecs):
             raise ValueError('unknown alias target: {}'.format(alias_to))
 
+    def set_builtin_type_codec(self, typeoid, typename, typeschema, typekind,
+                               alias_to, format=PG_FORMAT_ANY):
+        self._set_builtin_type_codec(typeoid, typename, typeschema, typekind,
+                                     alias_to, format)
         self.clear_type_cache()
 
     def clear_type_cache(self):
@@ -545,8 +553,8 @@ cdef class DataCodecConfig:
             # can avoid this by specifying a codec for this type
             # using Connection.set_type_codec().
             #
-            self.set_builtin_type_codec(oid, name, schema, 'scalar',
-                                        TEXTOID, PG_FORMAT_TEXT)
+            self._set_builtin_type_codec(oid, name, schema, 'scalar',
+                                         TEXTOID, PG_FORMAT_TEXT)
 
             codec = self.get_codec(oid, PG_FORMAT_TEXT)
 

tests/test_codecs.py

@@ -1166,15 +1166,43 @@ async def test_enum_in_array(self):
         await self.con.execute('''
             CREATE TYPE enum_t AS ENUM ('abc', 'def', 'ghi');
         ''')
-        result = await self.con.fetchrow('''SELECT $1::enum_t[];''',
-                                         ['abc'])
-        self.assertEqual(result, (['abc'],))
 
-        result = await self.con.fetchrow('''SELECT ARRAY[$1::enum_t];''',
-                                         'abc')
+        try:
+            result = await self.con.fetchrow('''SELECT $1::enum_t[];''',
+                                             ['abc'])
+            self.assertEqual(result, (['abc'],))
+
+            result = await self.con.fetchrow('''SELECT ARRAY[$1::enum_t];''',
+                                             'abc')
+
+            self.assertEqual(result, (['abc'],))
 
-        self.assertEqual(result, (['abc'],))
+        finally:
+            await self.con.execute('''
+                DROP TYPE enum_t;
+            ''')
 
+    async def test_enum_and_range(self):
         await self.con.execute('''
-            DROP TYPE enum_t;
+            CREATE TYPE enum_t AS ENUM ('abc', 'def', 'ghi');
+            CREATE TABLE testtab (
+                a int4range,
+                b enum_t
+            );
+
+            INSERT INTO testtab VALUES (
+                '[10, 20)', 'abc'
+            );
         ''')
+
+        try:
+            result = await self.con.fetchrow('''
+                SELECT testtab.a FROM testtab WHERE testtab.b = $1
+            ''', 'abc')
+
+            self.assertEqual(result, (asyncpg.Range(10, 20),))
+        finally:
+            await self.con.execute('''
+                DROP TABLE testtab;
+                DROP TYPE enum_t;
+            ''')