test/operators/element_at.cpp

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

SCENARIO("element_at - never", "[element_at][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("element_at is taken"){

            auto res = w.start(
                [xs]() {
                    return xs | rxo::element_at(3);
                }
            );

            THEN("the output is empty"){
                auto required = std::vector<rxsc::test::messages<int>::recorded_type>();
                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("element_at - empty", "[element_at][operators]"){
    GIVEN("a source"){
        auto sc = rxsc::make_test();
        auto w = sc.create_worker();
        const rxsc::test::messages<int> on;

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

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

        WHEN("element_at is taken"){

            auto res = w.start(
                [xs]() {
                    return xs.element_at(0);
                }
            );

            THEN("the output only contains an error"){
                auto required = rxu::to_vector({
                    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("element_at - first", "[element_at][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("element_at is taken"){

            auto res = w.start(
                [xs]() {
                    return xs.element_at(0);
                }
            );

            THEN("the output contains the first element"){
                auto required = rxu::to_vector({
                    on.next(210, 2),
                    on.completed(210)
                });
                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, 210)
                });
                auto actual = xs.subscriptions();
                REQUIRE(required == actual);
            }

        }
    }
}

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

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

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

        WHEN("element_at is taken"){

            auto res = w.start(
                [xs]() {
                    return xs.element_at(3);
                }
            );

            THEN("the output contains an error"){
                auto required = rxu::to_vector({
                    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("element_at - non-first", "[element_at][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.next(220, 3),
            on.next(230, 4), //
            on.next(240, 5),
            on.completed(250)
        });

        WHEN("element_at is taken"){

            auto res = w.start(
                [xs]() {
                    return xs.element_at(2);
                }
            );

            THEN("the output contains the element at requested index"){
                auto required = rxu::to_vector({
                    on.next(230, 4),
                    on.completed(230)
                });
                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, 230)
                });
                auto actual = xs.subscriptions();
                REQUIRE(required == actual);
            }

        }
    }
}

SCENARIO("element_at - last in a sequence", "[element_at][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.next(220, 3),
            on.next(230, 4),
            on.next(240, 5), //
            on.completed(250)
        });

        WHEN("element_at is taken"){

            auto res = w.start(
                [xs]() {
                    return xs.element_at(3);
                }
            );

            THEN("the output contains the element at requested index"){
                auto required = rxu::to_vector({
                    on.next(240, 5),
                    on.completed(240)
                });
                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, 240)
                });
                auto actual = xs.subscriptions();
                REQUIRE(required == actual);
            }

        }
    }
}

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

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

        auto xs = sc.make_hot_observable({
            on.next(150, 1),
            on.next(210, 2), // #0
            on.next(220, 3), // #1
            on.next(230, 4), // #2
            on.next(240, 5), // #3
            on.completed(250)
        });

        WHEN("element_at is taken"){

            auto res = w.start(
                [xs]() {
                    return xs.element_at(4);
                }
            );

            THEN("the output contains an error"){
                auto required = rxu::to_vector({
                    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);
            }

        }
    }
}