tests/testthat/test-1-events.R

In ElianHugh/emitters: NodeJS-inspired events and io streams.

test_that(
    "1.1 Event loop phases are run in the correct order.",
    code = {
        phase_tracker <- list()

        track_phases <- function() {
            append_to_tracker <- function(phase) {
                phase_tracker <<- append(phase_tracker, phase)
            }

            .add_to_callback(function() append_to_tracker(.event_loop$current_phase))
            .add_to_close(function() append_to_tracker(.event_loop$current_phase))
            set_timeout(function() append_to_tracker(.event_loop$current_phase), 0)
            .add_to_poll(function() append_to_tracker(.event_loop$current_phase))
            set_immediate(function() append_to_tracker(.event_loop$current_phase))
        }

        track_phases()

        while (length(phase_tracker) != 5) {
            later::run_now()
        }

        expect_true(identical(phase_tracker[[1]], .event_loop$loops$timer))
        expect_true(identical(phase_tracker[[2]], .event_loop$loops$callback))
        expect_true(identical(phase_tracker[[3]], .event_loop$loops$poll))
        expect_true(identical(phase_tracker[[4]], .event_loop$loops$check))
        expect_true(identical(phase_tracker[[5]], .event_loop$loops$close))
    }
)


test_that(
    "1.2 Next tick appropriately goes to next phase",
    code = {

        next_phase_poll <- FALSE

        # next tick phase should be .next_tick_poll
        .add_to_poll(function() {
             next_tick(
                function() {
                    next_phase_poll <<- {
                            identical(.event_loop$current_phase, .event_loop$loops$check)
                    }
                }
            )
        }
        )

        wait_for_change("next_phase_poll", FALSE)
        expect_true(next_phase_poll)
    }
)