`expect.throws`

Use Case

Expect that a code block throws an error.

Proposed Solution

Proposed API:

inflight throws(block: inflight (): void, contains: str?);
throws(block: (): void, contains: str?);

The contains will partial match against the error message text (e.g. contains()).

We need a separate API for inflight and preflight because if this is an inflight closure it
is implicitly asynchronous, so it cannot be called preflight.

Example:

bring expect;

// this is the preflight version
expect.throws(() => { throw "my"; }); // `contains` is optional

test "an error is thrown" {
  // this is the inflight version
  expect.throws(() => {
    throw "i am an error";
  }, contains: "error");
}

Implementation Notes

No response

Component

No response

Community Notes

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The issue names no files, tests, or entry points. Start by reviewing the proposed preflight and inflight APIs and the surrounding expect functionality, then determine the finalized behavior for optional partial message matching. Done means both forms are specified and implemented with coverage for the shown synchronous and asynchronous examples.