API reference › @evolu/common › Type › Typed

Defined in: packages/common/src/Type.ts:8882

A structurally tagged value created by typed.

Typed unions model mutually exclusive states as separate variants instead of combinations of flags and optional properties. TypeScript narrows a union by its literal type property. To enforce exhaustive handling, return from every case of a value-producing switch or assert that the remaining value is never in the default case of a side-effecting switch.

Example

import { type Typed } from "@evolu/common";

type Status = Typed<"Pending"> | Typed<"Completed">;

const getStatusMessage = (status: Status): string => {
  switch (status.type) {
    case "Pending":
      return "Waiting";
    case "Completed":
      return "Done";
  }
};

expect(getStatusMessage({ type: "Pending" })).toBe("Waiting");

Extended by

Properties

type

readonly type: Tag;

Defined in: packages/common/src/Type.ts:8883

Markdown for LLMs