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Snapshot And Throw Matchers ​

toMatchSnapshot ​

Snapshot assertions compare the serialized current value to a saved snapshot entry.

ts
expect(payload).toMatchSnapshot();
expect(payload).toMatchSnapshot("payload");

Unnamed calls use an incrementing key within the current test. Named calls append the provided suffix.

See Snapshots for snapshot file behavior and CLI flags.

toThrow ​

toThrow() is delegated to try-as when it is installed and enabled.

ts
import "try-as";
import { expect, test } from "as-test";

test("throws", () => {
  expect((): void => {
    unreachable();
  }).toThrow();
});

Notes:

  • if try-as is unavailable, toThrow() is treated as disabled and emits a warning once
  • use --enable try-as or matching config when you want the throw path active
  • toThrow() depends on the try-as instrumentation model, not a JavaScript exception bridge