alsatian-test/alsatian

import {
    ContainerMatcher,
    EmptyMatcher,
    FunctionMatcher,
    Matcher,
    NumberMatcher,
    PropertyMatcher,
    StringMatcher
} from "../matchers";
import { FunctionSpy, PropertySpy } from "../spying";
import { AnyFunction } from "../_interfaces";

/**
 * Enables actual vs expected comparisons
 */
export interface IExpect {
    /**
     * Allows checking of test outcomes
     * @param actualValue - the value or function under test
     */
    <T>(actualValue: Array<T>): ContainerMatcher<Array<T>, T>;
    <T extends AnyFunction>(
        actualValue: FunctionSpy | T
    ): FunctionMatcher<T>;
    (actualValue: number): NumberMatcher;
    <T>(actualValue: PropertySpy<T>): PropertyMatcher<T>;
    (actualValue: object): EmptyMatcher<object>;
    (actualValue: string): StringMatcher;
    <T>(actualValue: T): Matcher<T>;

    /**
     * Fails the test with the given message
     * @param message - the message that will be shown in the failure
     */
    fail(message: string): void;

    extend<ExpectedType, MatcherType extends Matcher<ExpectedType>>(
        type: new (...args: Array<any>) => ExpectedType,
        matcher: new (value: ExpectedType, testItem: any) => MatcherType
    ): IExtendedExpect<ExpectedType, MatcherType> & this;
}

export type IExtendedExpect<
    ExpectType,
    MatcherType extends Matcher<ExpectType>
> = <T extends ExpectType>(actualValue: T) => Matcher<T> & MatcherType;