Function _assertResultFound

src/cdk/testing/harness-environment.ts:494–506

Verifies that there is at least one result in an array.

(
  results: Promise<T[]>,
  queryDescriptions: string[],
)

/** Verifies that there is at least one result in an array. */
async function _assertResultFound<T>(
  results: Promise<T[]>,
  queryDescriptions: string[],
): Promise<T> {
  const result = (await results)[0];
  if (result == undefined) {
    throw Error(
      `Failed to find element matching one of the following queries:\n` +
        queryDescriptions.map(desc => `(${desc})`).join(',\n'),
    );
  }
  return result;
}

/** Gets a list of description strings from a list of queries. */
function _getDescriptionForLocatorForQueries(queries: (string | HarnessQuery<any>)[]) {