test/operators/start_with.cpp

#include "../test.h"
#include <rxcpp/operators/rx-start_with.hpp>

SCENARIO("start_with - source never emits or completes", "[start_with][operators]"){
    GIVEN("a source"){
        auto sc = rxsc::make_test();
        auto w = sc.create_worker();
        const rxsc::test::messages<int> on;

        auto xs = sc.make_hot_observable({
            on.next(150, 1)
        });

        WHEN("start_with one value"){

            auto res = w.start(
                [xs]() {
                    return xs
                        | rxo::start_with(1)
                        // forget type to workaround lambda deduction bug on msvc 2013
                        | rxo::as_dynamic();
                }
            );

            THEN("the output contains start_with value"){
                auto required = rxu::to_vector({
                    on.next(200, 1)
                });
                auto actual = res.get_observer().messages();
                REQUIRE(required == actual);
            }

            THEN("there was 1 subscription/unsubscription to the source"){
                auto required = rxu::to_vector({
                    on.subscribe(200, 1000)
                });
                auto actual = xs.subscriptions();
                REQUIRE(required == actual);
            }
        }
    }
}

SCENARIO("start_with - source completes without emitting items", "[start_with][operators]"){
    GIVEN("a source"){
        auto sc = rxsc::make_test();
        auto w = sc.create_worker();
        const rxsc::test::messages<int> on;

        auto xs = sc.make_hot_observable({
            on.next(150, 1),
            on.completed(250)
        });

        WHEN("start_with one value"){

            auto res = w.start(
                [xs]() {
                    return xs
                        .start_with(5)
                        // forget type to workaround lambda deduction bug on msvc 2013
                        .as_dynamic();
                }
            );

            THEN("the output contains start_with item and complete message"){
                auto required = rxu::to_vector({
                    on.next(200, 5),
                    on.completed(250)
                });
                auto actual = res.get_observer().messages();
                REQUIRE(required == actual);
            }

            THEN("there was 1 subscription/unsubscription to the source"){
                auto required = rxu::to_vector({
                    on.subscribe(200, 250)
                });
                auto actual = xs.subscriptions();
                REQUIRE(required == actual);
            }

        }
    }
}

SCENARIO("start_with - source emits and completes", "[start_with][operators]"){
    GIVEN("a source"){
        auto sc = rxsc::make_test();
        auto w = sc.create_worker();
        const rxsc::test::messages<int> on;

        auto xs = sc.make_hot_observable({
            on.next(150, 1),
            on.next(210, 2),
            on.completed(250)
        });

        WHEN("start_with one value"){

            auto res = w.start(
                [xs]() {
                    return xs
                        .start_with(5)
                        // forget type to workaround lambda deduction bug on msvc 2013
                        .as_dynamic();
                }
            );

            THEN("the output contains start_with item and the items sent while subscribed"){
                auto required = rxu::to_vector({
                    on.next(200, 5),
                    on.next(210, 2),
                    on.completed(250)
                });
                auto actual = res.get_observer().messages();
                REQUIRE(required == actual);
            }

            THEN("there was 1 subscription/unsubscription to the source"){
                auto required = rxu::to_vector({
                    on.subscribe(200, 250)
                });
                auto actual = xs.subscriptions();
                REQUIRE(required == actual);
            }

        }
    }
}

SCENARIO("start_with - sources terminates with an error", "[start_with][operators]"){
    GIVEN("a source"){
        auto sc = rxsc::make_test();
        auto w = sc.create_worker();
        const rxsc::test::messages<int> on;

        std::runtime_error ex("start_with on_error from source");

        auto xs = sc.make_hot_observable({
            on.next(150, 1),
            on.error(250, ex)
        });

        WHEN("start_with one value"){

            auto res = w.start(
                [xs]() {
                    return xs
                        .start_with(5)
                        // forget type to workaround lambda deduction bug on msvc 2013
                        .as_dynamic();
                }
            );

            THEN("the output contains start_with item and an error"){
                auto required = rxu::to_vector({
                    on.next(200, 5),
                    on.error(250, ex)
                });
                auto actual = res.get_observer().messages();
                REQUIRE(required == actual);
            }

            THEN("there was 1 subscription/unsubscription to the source"){
                auto required = rxu::to_vector({
                    on.subscribe(200, 250)
                });
                auto actual = xs.subscriptions();
                REQUIRE(required == actual);
            }

        }
    }
}

SCENARIO("start_with several items - source emits and completes", "[start_with][operators]"){
    GIVEN("a source"){
        auto sc = rxsc::make_test();
        auto w = sc.create_worker();
        const rxsc::test::messages<int> on;

        auto xs = sc.make_hot_observable({
            on.next(150, 1),
            on.next(210, 2),
            on.completed(250)
        });

        WHEN("start_with one value"){

            auto res = w.start(
                [xs]() {
                    return xs
                        .start_with(5, 6)
                        // forget type to workaround lambda deduction bug on msvc 2013
                        .as_dynamic();
                }
            );

            THEN("the output contains start_with item and the items sent while subscribed"){
                auto required = rxu::to_vector({
                    on.next(200, 5),
                    on.next(200, 6),
                    on.next(210, 2),
                    on.completed(250)
                });
                auto actual = res.get_observer().messages();
                REQUIRE(required == actual);
            }

            THEN("there was 1 subscription/unsubscription to the source"){
                auto required = rxu::to_vector({
                    on.subscribe(200, 250)
                });
                auto actual = xs.subscriptions();
                REQUIRE(required == actual);
            }

        }
    }
}