ISE caused by an object-returning function wrapped into a SELECT

• Error Message:

InternalServerError: there is no range var for (__derived__::expr~6) source in <pg.SelectStmt at 0x7efbfbfa67c0>
Hint: This is most likely a bug in EdgeDB. Please consider opening an issue ticket...

• EdgeDB Version: 1.0a2-2020012220~buster
• OS Version: Debian 10

Steps to Reproduce: 0. Create the database and module.

CREATE DATABASE name;

\c name;
...
CREATE MODULE api;

1. Create the schema (shown at the bottom).
2. Add the following DDL functions. The error occurs after attempting to run CREATE FUNCTION api::LoginCredentialSession.

WITH MODULE api
CREATE FUNCTION validate_credentials(EMAIL: str, PASS: str) -> SET OF api::User
USING EdgeQL $$
    WITH MODULE api
    SELECT
        User
    FILTER
        .email = EMAIL
        AND
        .password = PASS
    LIMIT 1
$$;

WITH MODULE api
CREATE FUNCTION random_big_str_id() -> str
USING EdgeQL $$
    SELECT 
        std::re_replace(
            r'^[ \t]+',
            r'',
            (
                SELECT std::to_str(
                    random() * 10 ^ 256, 
                    '999999999999999999999\
                     999999999999999999999\
                     999999999999999999999\
                     999999999999999999999\
                     999999999999999999999\
                     999999999999999999999\
                     999999999999999999999\
                     999999999999999999999\
                     999999999999999999999\
                     999999999999999999999\
                     999999999999999999999\
                     999999999999999999999\
                     99999'
                )
            )
        )
$$;

WITH MODULE api
CREATE FUNCTION create_new_session(EMAIL: str, PASS: str) -> api::Session
USING EdgeQL $$
    WITH MODULE api
    INSERT Session {
        token := <str>(SELECT api::random_big_str_id()),
        sessionID := <str>(SELECT api::random_big_str_id()),
        user := (SELECT api::validate_credentials(EMAIL, PASS) LIMIT 1)
    }
$$;
WITH MODULE api
CREATE FUNCTION LoginCredentialSession(EMAIL: str, PASS: str) -> SET OF api::Session
USING EdgeQL $$
    # First case to split on is whether the user
    # authenticates correctly:
    WITH MODULE api
    SELECT ( 
        SELECT Session
        FILTER .sessionID = (
            SELECT (SELECT api::create_new_session(EMAIL, PASS))
            ).sessionID
        )
    )
    IF
    (
        SELECT api::validate_credentials(EMAIL, PASS)) ?!= <Session>{}
    )
    ELSE <Session>{}
$$;

Schema:

CREATE MIGRATION %s TO {
    module api {
        type Session {
            property token -> str;
            required link user -> User;
            required property sessionID -> str;
            required property createdAt -> datetime {
                default := datetime_current();
            }
            required property allottedDuration -> duration {
                default := <duration>'24 hours';
            }
        }
        type User {
            required property name -> str;
            property isDevice -> bool {
                default := False
            }
            link device -> Device;
            multi link devices -> Device;
            property phone_1 -> str {
                default := '';
            }
            property phone_2 -> str {
                default := '';
            }
            property email -> str;
            property storageDirectory := ('/' ++ __source__.email ++ '/');
            property _storageDirectory := ('/ware/blob' ++ __source__.storageDirectory);
            property password -> str;
            property isAdmin -> bool {
                default := False;
            }
            required property isGuest -> bool {
                default := False;
            }
            multi link files -> File;
            multi link widgets -> Widget;
        }
        type Device {
            property device_name -> str;
            property ipv4_address -> str;
            property ipv6_address -> str;
            property mac_address -> str;
            property online -> bool;
        }
        type Widget {
            required property name -> str;
            property path -> str;
            property executable_name -> str;
            property indexHtmlPath -> str;
            property runCommand -> str;
        }
        type File {
            required property filename -> str;
            required property path -> str;
            required property readable -> bool {
                default := True;
            }
            required property writeable -> bool {
                default := True;
            }
            required property executable -> bool {
                default := False;
            }
            required property isDirectory -> bool {
                default := False;
            }
            required property isPublic -> bool {
                default := False;
            }
            required property isDownloadable -> bool {
                default := True;
            }
            property uploadedBy -> str;
            property uploadedAt -> datetime {
                default := datetime_current();
            }
            required property temporary -> bool {
                default := False;
            }
        }
    }
};
COMMIT MIGRATION %s;

[elprans]

The syntax is FOR variable IN { <set> }, where <set> is an arbitrary expression of type T, and variable would hold a singleton value of the type T on every “iteration”. The curly brackets in this case are needed for grammar disambiguation.

[elprans]

Actually, there’s a way to do this using a FOR statement. Here’s the solution:

WITH MODULE api
FOR user IN {api::validate_credentials(EMAIL, PASSWORD)}
 UNION (
     INSERT Session { user := user, sessionID := ... }
);