test(c/driver/postgresql): add test for composite type behavior

c/driver/postgresql/postgresql_test.cc

@@ -1825,6 +1825,84 @@ TEST_F(PostgresStatementTest, SqlQueryInt2vector) {
   ASSERT_EQ(reader.array->release, nullptr);
 }
 
+TEST_F(PostgresStatementTest, PostgresCompositeTypeTest) {
+  ASSERT_THAT(AdbcStatementNew(&connection, &statement, &error), IsOkStatus(&error));
+  {
+    adbc_validation::StreamReader reader;
+
+    // Types are cached on the AdbcDatabase so this test has to totally recreate
+    // its AdbcDatabase (see the call to ResetTest in the body here).
+
+    // Cleanup. We have to drop the table before we drop the type.
+    ASSERT_THAT(
+        AdbcStatementSetSqlQuery(
+            &statement, "DROP TABLE IF EXISTS adbc_postgresql_composite_type_test_table;",
+            &error),
+        IsOkStatus(&error));
+    ASSERT_THAT(AdbcStatementExecuteQuery(&statement, &reader.stream.value,
+                                          &reader.rows_affected, &error),
+                IsOkStatus(&error));
+    ASSERT_THAT(AdbcStatementSetSqlQuery(
+                    &statement, "DROP TYPE IF EXISTS my_composite_type;", &error),
+                IsOkStatus(&error));
+    ASSERT_THAT(AdbcStatementExecuteQuery(&statement, &reader.stream.value,
+                                          &reader.rows_affected, &error),
+                IsOkStatus(&error));
+
+    // Create type and table, fill with data
+    ASSERT_THAT(
+        AdbcStatementSetSqlQuery(
+            &statement, "CREATE TYPE my_composite_type AS (x integer, y text);", &error),
+        IsOkStatus(&error));
+    ASSERT_THAT(AdbcStatementExecuteQuery(&statement, &reader.stream.value,
+                                          &reader.rows_affected, &error),
+                IsOkStatus(&error));
+
+    ASSERT_THAT(
+        AdbcStatementSetSqlQuery(&statement,
+                                 "CREATE TABLE adbc_postgresql_composite_type_test_table "
+                                 "(a my_composite_type);",
+                                 &error),
+        IsOkStatus(&error));
+    ASSERT_THAT(AdbcStatementExecuteQuery(&statement, &reader.stream.value,
+                                          &reader.rows_affected, &error),
+                IsOkStatus(&error));
+
+    ASSERT_THAT(AdbcStatementSetSqlQuery(
+                    &statement,
+                    "INSERT INTO adbc_postgresql_composite_type_test_table "
+                    "(a) VALUES (ROW(1, 'a')), (ROW(2,' b')), (ROW(3,' c'));",
+                    &error),
+                IsOkStatus(&error));
+    ASSERT_THAT(AdbcStatementExecuteQuery(&statement, &reader.stream.value,
+                                          &reader.rows_affected, &error),
+                IsOkStatus(&error));
+
+    // AdbcDatabase currently caches types so we need to recreate it
+    // https://github.com/apache/arrow-adbc/pull/3196#pullrequestreview-3103472826
+    ResetTest();
+
+    ASSERT_THAT(AdbcStatementNew(&connection, &statement, &error), IsOkStatus(&error));
+    ASSERT_THAT(AdbcStatementSetSqlQuery(
+                    &statement,
+                    "SELECT * FROM adbc_postgresql_composite_type_test_table;", &error),
+                IsOkStatus(&error));
+    ASSERT_THAT(AdbcStatementExecuteQuery(&statement, &reader.stream.value,
+                                          &reader.rows_affected, &error),
+                IsOkStatus(&error));
+
+    ASSERT_NO_FATAL_FAILURE(reader.GetSchema());
+    ASSERT_EQ(reader.schema->n_children, 1);
+    ASSERT_STREQ(reader.schema->children[0]->name, "a");
+    ASSERT_STREQ(reader.schema->children[0]->format, "+s");
+    ASSERT_EQ(reader.schema->children[0]->n_children, 2);
+    ASSERT_STREQ(reader.schema->children[0]->children[0]->name, "x");
+    ASSERT_STREQ(reader.schema->children[0]->children[0]->format, "i");
+    ASSERT_STREQ(reader.schema->children[0]->children[1]->name, "y");
+    ASSERT_STREQ(reader.schema->children[0]->children[1]->format, "u");
+  }
+}
+
 TEST_F(PostgresStatementTest, UnknownOid) {
   // Regression test for https://github.com/apache/arrow-adbc/issues/2448
   ASSERT_THAT(AdbcStatementNew(&connection, &statement, &error), IsOkStatus(&error));

c/validation/adbc_validation.h

@@ -359,6 +359,7 @@ class StatementTest {
 
   void SetUpTest();
   void TearDownTest();
+  void ResetTest();
 
   // Test methods
   void TestNewInit();

c/validation/adbc_validation_statement.cc

@@ -62,6 +62,11 @@ void StatementTest::TearDownTest() {
   }
 }
 
+void StatementTest::ResetTest() {
+  TearDownTest();
+  SetUpTest();
+}
+
 void StatementTest::TestNewInit() {
   ASSERT_THAT(AdbcStatementNew(&connection, &statement, &error), IsOkStatus(&error));
   ASSERT_THAT(AdbcStatementRelease(&statement, &error), IsOkStatus(&error));