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Fix debounce emitting End after Close signal (#49)
* Fix debounce emitting End after Close
Since there was no difference between "ended"
and "closed" in the debounce operator, after
the timeout completed it would emit an End
event even if the source has been closed.
* Add test for debounced End
authored by
Phil Plückthun
and committed by
GitHub
592c41ea
dcbdaf50
+45
-19
+32
-18
src/web/wonkaJs.re
+32
-18
src/web/wonkaJs.re
···
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/* operators */
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+
type debounceStateT = {
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mutable id: option(Js.Global.timeoutId),
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mutable deferredEnded: bool,
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mutable ended: bool,
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};
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+
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[@genType]
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let debounce = (f: (. 'a) => int): operatorT('a, 'a) =>
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curry(source =>
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curry(sink => {
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let gotEndSignal = ref(false);
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let id: ref(option(Js.Global.timeoutId)) = ref(None);
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let state: debounceStateT = {
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id: None,
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deferredEnded: false,
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ended: false,
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};
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let clearTimeout = () =>
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switch (id^) {
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switch (state.id) {
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| Some(timeoutId) =>
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id := None;
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state.id = None;
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Js.Global.clearTimeout(timeoutId);
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| None => ()
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};
···
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sink(.
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Start(
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(. signal) =>
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switch (signal) {
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| Close =>
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clearTimeout();
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tb(. Close);
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| _ => tb(. signal)
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if (!state.ended) {
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switch (signal) {
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| Close =>
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state.ended = true;
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state.deferredEnded = false;
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clearTimeout();
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tb(. Close);
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| Pull => tb(. Pull)
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};
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},
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),
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)
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| Push(x) =>
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| Push(x) when !state.ended =>
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clearTimeout();
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id :=
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state.id =
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Some(
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Js.Global.setTimeout(
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() => {
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id := None;
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state.id = None;
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sink(. signal);
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if (gotEndSignal^) {
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if (state.deferredEnded) {
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sink(. End);
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};
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},
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f(. x),
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),
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);
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| End =>
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gotEndSignal := true;
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-
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switch (id^) {
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| Push(_) => ()
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| End when !state.ended =>
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state.ended = true;
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switch (state.id) {
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| Some(_) => state.deferredEnded = true
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| None => sink(. End)
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| _ => ()
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};
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| End => ()
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}
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);
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})
+13
-1
src/wonka_operators.test.ts
+13
-1
src/wonka_operators.test.ts
···
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passesSinkClose(noop);
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passesSourceEnd(noop);
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passesSingleStart(noop);
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-
// TODO: passesStrictEnd(noop);
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passesStrictEnd(noop);
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passesAsyncSequence(noop);
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it('waits for a specified amount of silence before emitting the last value', () => {
···
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jest.advanceTimersByTime(1);
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expect(fn).toHaveBeenCalledWith(2);
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});
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+
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it('emits debounced value with delayed End signal', () => {
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const { source, next, complete } = sources.makeSubject<number>();
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const fn = jest.fn();
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sinks.forEach(fn)(web.debounce(() => 100)(source));
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next(1);
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complete();
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jest.advanceTimersByTime(100);
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expect(fn).toHaveBeenCalled();
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});
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});
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