export declare type TestDefinition = {
    description: string;
    /** Execute the test logic. DOES NOT THROW. */
    run: () => PromiseLike<TestResult>;
};
export declare type TestResult = {
    runtimeMs: number;
    /** If the test failed, error will not be null. */
    error: Error | null;
};
/** Register a test to run. */
export declare function test(description: string, exercise: () => void | PromiseLike<void>): void;
/**
 * Create shorthand function for defining tests in a group.
 *
 * This is really just a wrapper around {@link test} that applies a common prefix string.
 */
export declare function defineTestGroup(groupDescriptionPrefix: string): typeof test;