fix namespace function error

Author: brennanjl

node/engine/functions.go

@@ -279,18 +279,25 @@ var (
 		},
 		"array_length": &ScalarFunctionDefinition{
 			ValidateArgsFunc: func(args []*types.DataType) (*types.DataType, error) {
-				if len(args) != 1 {
-					return nil, wrapErrArgumentNumber(1, len(args))
+				if len(args) < 1 || len(args) > 2 {
+					return nil, fmt.Errorf("invalid number of arguments: expected 1 or 2, got %d", len(args))
 				}
 
 				if !args[0].IsArray {
 					return nil, fmt.Errorf("%w: expected argument to be an array, got %s", ErrType, args[0].String())
 				}
 
+				if len(args) == 2 && !args[1].Equals(types.IntType) {
+					return nil, wrapErrArgumentType(types.IntType, args[1])
+				}
+
 				return types.IntType, nil
 			},
 			PGFormatFunc: func(inputs []string) (string, error) {
-				return fmt.Sprintf("array_length(%s, 1)", inputs[0]), nil
+				if len(inputs) == 1 {
+					return fmt.Sprintf("array_length(%s, 1)", inputs[0]), nil
+				}
+				return fmt.Sprintf("array_length(%s, %s)", inputs[0], inputs[1]), nil
 			},
 		},
 		"array_remove": &ScalarFunctionDefinition{

node/engine/interpreter/interpreter_test.go

@@ -1761,6 +1761,17 @@ func Test_Actions(t *testing.T) {
 			action: "call_get_null",
 		},
 		// TODO: test that actions returning nulls to other actions does not error
+		{
+			// this is a regression test
+			name: "special functions called in new namespaces works as expected",
+			stmt: []string{
+				`CREATE NAMESPACE test;`,
+				`{test} create action get_uuid() public view returns (uuid) {return uuid_generate_kwil('a');}`,
+			},
+			namespace: "test",
+			action:    "get_uuid",
+			results:   [][]any{{mustUUID("819ab751-e64c-5259-bbae-4d36f25bdd84")}},
+		},
 	}
 
 	db, err := newTestDB()

node/engine/interpreter/planner.go

@@ -1956,7 +1956,7 @@ func (i *interpreterPlanner) VisitCreateNamespaceStatement(p0 *parse.CreateNames
 		}
 
 		exec.interpreter.namespaces[p0.Namespace] = &namespace{
-			availableFunctions: make(map[string]*executable),
+			availableFunctions: copyBuiltinExecutables(),
 			tables:             make(map[string]*engine.Table),
 			onDeploy:           func(*executionContext) error { return nil },
 			onUndeploy:         func(*executionContext) error { return nil },