Studio: pin search_path so empty_database CREATE EXTENSION works

Author: PierreSenellart

studio/provsql_studio/db.py

@@ -693,6 +693,14 @@ def empty_database(pool: ConnectionPool) -> list[str]:
         # Pre-PG15 default grants on public, so unqualified CREATE TABLE
         # keeps working for every role that could before.
         cur.execute("GRANT USAGE, CREATE ON SCHEMA public TO PUBLIC")
+        # CREATE EXTENSION installs into the first existing schema on the
+        # session search_path. That search_path is inherited from the
+        # database default, which may point at a user schema we just
+        # dropped above (e.g. the regression fixture sets the DB-level
+        # search_path to provsql_test) -- leaving no valid creation
+        # target and a "no schema has been selected for creation" error.
+        # Pin it to the public schema we just recreated.
+        cur.execute("SET search_path TO public")
         cur.execute("CREATE EXTENSION IF NOT EXISTS provsql CASCADE")
     return schemas
 

studio/tests/e2e/test_notebook_ui.py

@@ -901,17 +901,34 @@ def test_empty_db_button_confirms_and_wipes(
         import psycopg
         from pathlib import Path
         repo = Path(__file__).resolve().parents[3]
+        # The fixture script expects a virgin database (plain CREATE EXTENSION
+        # and CREATE SCHEMA provsql_test); the wipe reinstalled provsql and
+        # leaves provsql_test (the active search_path schema) in place, so shed
+        # both first. The database-level search_path that the original setup.sql
+        # established (ALTER DATABASE ... SET search_path = provsql_test) must
+        # also be reset: once provsql_test is dropped it points at a missing
+        # schema, so the fresh sessions below would have no valid creation
+        # target and setup.sql's CREATE EXTENSION would fail with "no schema
+        # selected". setup.sql re-establishes the search_path itself.
         with psycopg.connect(test_dsn, autocommit=True) as conn:
-            # The fixture script expects a virgin database (plain
-            # CREATE EXTENSION); the wipe reinstalled provsql, so shed
-            # it first.
             conn.execute("DROP EXTENSION IF EXISTS provsql CASCADE")
             conn.execute("DROP SCHEMA IF EXISTS provsql CASCADE")
-            for fname in ("setup.sql", "add_provenance.sql"):
-                sql_text = "\n".join(
-                    line for line in
-                    (repo / "test" / "sql" / fname).read_text().splitlines()
-                    if not line.startswith("\\"))
+            conn.execute("DROP SCHEMA IF EXISTS provsql_test CASCADE")
+            conn.execute(
+                "DO $$ BEGIN EXECUTE format("
+                "'ALTER DATABASE %I RESET search_path', current_database());"
+                " END $$")
+        # Each file gets its own connection: setup.sql sets the search_path at
+        # the database level (ALTER DATABASE), which only takes effect for
+        # sessions opened afterwards, so add_provenance.sql must run in a fresh
+        # one to resolve the provsql schema -- the same reason conftest seeds
+        # per file.
+        for fname in ("setup.sql", "add_provenance.sql"):
+            sql_text = "\n".join(
+                line for line in
+                (repo / "test" / "sql" / fname).read_text().splitlines()
+                if not line.startswith("\\"))
+            with psycopg.connect(test_dsn, autocommit=True) as conn:
                 conn.execute(sql_text)
         # The restore re-created the extension behind the server's back;
         # bounce its pool (same-database connection switch) so later