Support target_session_attrs in URL format, add tests (#1073)

Author: elprans

asyncpg/connect_utils.py

@@ -378,6 +378,13 @@ def _parse_connect_dsn_and_args(*, dsn, host, port, user,
                     'ssl_max_protocol_version'
                 )
 
+            if 'target_session_attrs' in query:
+                dsn_target_session_attrs = query.pop(
+                    'target_session_attrs'
+                )
+                if target_session_attrs is None:
+                    target_session_attrs = dsn_target_session_attrs
+
             if query:
                 if server_settings is None:
                     server_settings = query

tests/test_connect.py

@@ -563,6 +563,42 @@ class TestConnectParams(tb.TestCase):
             })
         },
 
+        {
+            'name': 'target_session_attrs',
+            'dsn': 'postgresql://user@host1:1111,host2:2222/db'
+                   '?target_session_attrs=read-only',
+            'result': ([('host1', 1111), ('host2', 2222)], {
+                'database': 'db',
+                'user': 'user',
+                'target_session_attrs': 'read-only',
+            })
+        },
+
+        {
+            'name': 'target_session_attrs_2',
+            'dsn': 'postgresql://user@host1:1111,host2:2222/db'
+                   '?target_session_attrs=read-only',
+            'target_session_attrs': 'read-write',
+            'result': ([('host1', 1111), ('host2', 2222)], {
+                'database': 'db',
+                'user': 'user',
+                'target_session_attrs': 'read-write',
+            })
+        },
+
+        {
+            'name': 'target_session_attrs_3',
+            'dsn': 'postgresql://user@host1:1111,host2:2222/db',
+            'env': {
+                'PGTARGETSESSIONATTRS': 'read-only',
+            },
+            'result': ([('host1', 1111), ('host2', 2222)], {
+                'database': 'db',
+                'user': 'user',
+                'target_session_attrs': 'read-only',
+            })
+        },
+
         {
             'name': 'dsn_ipv6_multi_host',
             'dsn': 'postgresql://user@[2001:db8::1234%25eth0],[::1]/db',