interface Describe {
    /**
     * Defines a group of tests.
     *
     * @param name - The name of the group.
     * @param callback - The function to create a scope for a group of tests.
     */
    (name: string, callback: () => void | Promise<void>): void;
    /**
     * Marks a group of tests as focused.
     *
     * @param name - The name of the group.
     * @param callback - The function to create a scope for a group of tests.
     */
    only: (name: string, callback: () => void | Promise<void>) => void;
    /**
     * Marks a group of tests as skipped.
     *
     * @param name - The name of the group.
     * @param callback - The function to create a scope for a group of tests.
     */
    skip: (name: string, callback: () => void | Promise<void>) => void;
    /**
     * Marks a group of tests as yet to be implemented.
     *
     * @param name - The name of the group.
     * @param callback - The function to create a scope for a group of tests.
     */
    todo: (name: string, callback?: () => void | Promise<void>) => void;
}
interface Test {
    /**
     * Defines a single test.
     *
     * @param name - The name of the test.
     * @param callback - The function with a code snippet and assertions.
     */
    (name: string, callback: () => void | Promise<void>): void;
    /**
     * Marks a test as focused.
     *
     * @param name - The name of the test.
     * @param callback - The function with a code snippet and assertions.
     */
    only: (name: string, callback: () => void | Promise<void>) => void;
    /**
     * Marks a test as skipped.
     *
     * @param name - The name of the test.
     * @param callback - The function with a code snippet and assertions.
     */
    skip: (name: string, callback: () => void | Promise<void>) => void;
    /**
     * Marks a test as yet to be implemented.
     *
     * @param name - The name of the test.
     * @param callback - The function with a code snippet and assertions.
     */
    todo: (name: string, callback?: () => void | Promise<void>) => void;
}
interface Matchers {
    /**
     * Checks if the `any` type is identical to the source type.
     */
    toBeAny: () => void;
    /**
     * Checks if the target type is assignable to the source type.
     */
    toBeAssignable: {
        /**
         * Checks if the target type is assignable to the source type.
         */
        <Target>(): void;
        /**
         * Checks if type of the target expression is assignable to the source type.
         */
        (target: unknown): void;
    };
    /**
     * Checks if the `bigint` type is identical to the source type.
     */
    toBeBigInt: () => void;
    /**
     * Checks if the `boolean` type is identical to the source type.
     */
    toBeBoolean: () => void;
    /**
     * Checks if the `never` type is identical to the source type.
     */
    toBeNever: () => void;
    /**
     * Checks if the `null` type is identical to the source type.
     */
    toBeNull: () => void;
    /**
     * Checks if the `number` type is identical to the source type.
     */
    toBeNumber: () => void;
    /**
     * Checks if the `string` type is identical to the source type.
     */
    toBeString: () => void;
    /**
     * Checks if the `symbol` type is identical to the source type.
     */
    toBeSymbol: () => void;
    /**
     * Checks if the `undefined` type is identical to the source type.
     */
    toBeUndefined: () => void;
    /**
     * Checks if the `unique symbol` type is identical to the source type.
     */
    toBeUniqueSymbol: () => void;
    /**
     * Checks if the `unknown` type is identical to the source type.
     */
    toBeUnknown: () => void;
    /**
     * Checks if the `void` type is identical to the source type.
     */
    toBeVoid: () => void;
    /**
     * Check if the target type is identical to the source type.
     */
    toEqual: {
        /**
         * Checks if the target type is identical to the source type.
         */
        <Target>(): void;
        /**
         * Checks if type of the target expression is identical to the source type.
         */
        (target: unknown): void;
    };
    /**
     * Checks if a property key exists on the source type.
     */
    toHaveProperty: (key: string | number | symbol) => void;
    /**
     * Checks if the target type is a subtype the source type.
     */
    toMatch: {
        /**
         * Checks if the target type is a subtype the source type.
         */
        <Target>(): void;
        /**
         * Checks if type of the target expression is a subtype the source type.
         */
        (target: unknown): void;
    };
    /**
     * Checks if the source type raises an error.
     */
    toRaiseError: (...target: Array<string | number>) => void;
}
interface Modifier {
    /**
     * Passes the source type to the matcher.
     */
    type: Matchers & {
        /**
         * Negates the assertion.
         */
        not: Matchers;
    };
}
interface Expect {
    /**
     * Builds an assertion.
     *
     * @template Source - The type against which the assertion will be made.
     */
    <Source>(): Modifier;
    /**
     * Builds an assertion.
     *
     * @param source - The expression against which type the assertion will be made.
     */
    (source: unknown): Modifier;
    fail: {
        /**
         * Mark an assertion as supposed to fail.
         *
         * @template Source - The type against which the assertion will be made.
         */
        <Source>(): Modifier;
        /**
         * Mark an assertion as supposed to fail.
         *
         * @param source - The expression against which type the assertion will be made.
         */
        (source: unknown): Modifier;
    };
    /**
     * Marks an assertion as focused.
     */
    only: {
        /**
         * Marks an assertion as focused.
         *
         * @template Source - The type against which the assertion will be made.
         */
        <Source>(): Modifier;
        /**
         * Marks an assertion as focused.
         *
         * @param source - The expression against which type the assertion will be made.
         */
        (source: unknown): Modifier;
        fail: {
            /**
             * Mark an assertion as supposed to fail.
             *
             * @template Source - The type against which the assertion will be made.
             */
            <Source>(): Modifier;
            /**
             * Mark an assertion as supposed to fail.
             *
             * @param source - The expression against which type the assertion will be made.
             */
            (source: unknown): Modifier;
        };
    };
    /**
     * Marks an assertion as skipped.
     */
    skip: {
        /**
         * Marks an assertion as skipped.
         *
         * @template Source - The type against which the assertion will be made.
         */
        <Source>(): Modifier;
        /**
         * Marks an assertion as skipped.
         *
         * @param source - The expression against which type the assertion will be made.
         */
        (source: unknown): Modifier;
        fail: {
            /**
             * Marks an assertion as supposed to fail.
             *
             * @template Source - The type against which the assertion will be made.
             */
            <Source>(): Modifier;
            /**
             * Marks an assertion as supposed to fail.
             *
             * @param source - The expression against which type the assertion will be made.
             */
            (source: unknown): Modifier;
        };
    };
}
/**
 * Defines a test group.
 */
declare const describe: Describe;
/**
 * Defines a single test.
 */
declare const test: Test;
/**
 * Defines a single test.
 */
declare const it: Test;
/**
 * Builds an assertion.
 */
declare const expect: Expect;

export { describe, expect, it, test };