CustomAttributeType reduces union type to primitive type

[zirkelc]

When I give the CustomAttributeType() a union type like this:

type PersonnelRole = 
| string
| {
    type: 'contractor';
    contractStartDate: string;
    contractEndDate: string;
};

The resulting type on the entity is reduces to the primitive type string. See this ElectroDB example

I checked the implementation of CustomAttributeType and it always takes the primitive type if available:

declare function CustomAttributeType<T>(
    base: T extends string ? 'string'
        : T extends number ? 'number'
        : T extends boolean ? 'boolean'
        : 'any'
): T extends string | number | boolean
    ? OpaquePrimitiveTypeName<T>
    : CustomAttributeTypeName<T>;

Is there a specific reason for this or could it be changed to handle union types?

[tywalch]

Hi @zirkelc 👋

This is a necessity simply because of how TypeScript widens types. You can definitely roll your own option here to avoid the trappings of your union with string:

https://electrodb.fun/?#code/PQKgBAsg9gJgpgGzARwK5wE4Es4GcA0YuccYGeqCALgUQBYCG5YA7llXWAGbZwB2MXGBDAAUKKwBbAA5QMVMAG8wAUT5V2AT0IBlTADcsAYziEAwqlxUokgIJUq2AEaoqcACqbpcAHINJpAC+3Bg2YABEiHBGjrBO4QDc4kZQfFZgVAxOCKQAvBGaUKgYAPqZ2XAlfP5wieJUXqQACpi4qXyIAEpQOWD5ogA+RI5YfADmg0qiYDMZjQBcYADkKeoYDDFyS0mzYKuOG1Q6mfIAIgxui1bY4zuz++sxajDnl8M3Y0mBSaKr6d4YNp8DoIbo5TzePoRBh8TThMAMISoPgAaz4UBYfARQgsVhs9hGLjcEN8NQAPC1Ae0uj04AA+H6gMDuREooRqDQNYRiP4KNz+CBwSROVpQjosVTqLQACmmU12klgiEWijlu34nM0i3CmVwbPC+DVs30rSwqW1AEYDUaZsQMIYTNrdSiGNJpOEjYFDbsLoTXHgVTaMnB-IHdrsGt5tddRmNreHZuQ0FhyDBFo50EGvUHLJgwwm5lGIjHxvGC0nUCm4GmMhhMwnswnQjl8wnI3BFgCgSCwR5GlnPd7ZqN4AAPAPy8MBYWtVvh6QoucJrg4BA18ILssFvY2WS4dgdsAAbR1Ick4QAukGZo2C3ql+GV4h13qtwXgMA9uQLqQUjIoPubhgCicCaEIXByGA0hMBoDBIG08jAaBKDoLwuDXvcu4AQeiwnrmGCXhhgRZkON5yreyjlL0xEAJQ-KI-KSIKM6AgAdNIrjSqqMyMdqWRGGW+HavAXBls2h7hCWYwlPocHoB6gQ0axYxQNKdH1GezEimxHFUFxcq8dCTgCUOQkRCJYm0nODyHM8rwSQATAADA5ADMAC0FpOZ5ACsb42TExwwfZ2rOW57lORaEVWqRhYSQF1gEUOxGKcpqnqUAA

[zirkelc]

Great! Thanks for the quick reply!