tryRun

Runs a function (synchronously), expecting it to throw an error.

tryRun(f: () => void): unknown

Summary

This method runs the provided function within a try-catch statement. If the function throws an error or if the test case fails otherwise, the error that was caught is returned and the test case doesn’t fail. If the function doesn’t throw an error, this method returns undefined.

Parameters

f — The function to run

Return value

The error that was caught, or undefined otherwise

Errors

This method throws the current error, if the test case already failed before (e.g. using fail())

Example

describe("My scope", () => {
  test("Try to run a bad function", (t) => {
    function bad() { let x = undefined; return x["foo"]; }
    let error = t.tryRun(bad);
    expect(error).toBeDefined();
  });
});