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promise_test(async () => {
const source = new Observable(subscriber => {
subscriber.next("good");
subscriber.next("good");
subscriber.next("good");
subscriber.complete();
});
const result = await source.every((value) => value === "good");
assert_true(result, "Promise resolves with true if all values pass the predicate");
}, "every(): Promise resolves to true if all values pass the predicate");
promise_test(async () => {
const source = new Observable(subscriber => {
subscriber.next("good");
subscriber.next("good");
subscriber.next("bad");
subscriber.complete();
});
const result = await source.every((value) => value === "good");
assert_false(result, "Promise resolves with false if any value fails the predicate");
}, "every(): Promise resolves to false if any value fails the predicate");
promise_test(async () => {
let tornDown = false;
let subscriberActiveAfterFailingPredicate = true;
const source = new Observable(subscriber => {
subscriber.addTeardown(() => tornDown = true);
subscriber.next("good");
subscriber.next("good");
subscriber.next("bad");
subscriberActiveAfterFailingPredicate = subscriber.active;
subscriber.next("good");
subscriber.complete();
});
const result = await source.every((value) => value === "good");
assert_false(result, "Promise resolves with false if any value fails the predicate");
assert_false(subscriberActiveAfterFailingPredicate,
"Subscriber becomes inactive because every() unsubscribed");
}, "every(): Abort the subscription to the source if the predicate does not pass");
promise_test(async () => {
const logs = [];
const source = createTestSubject({
onSubscribe: () => logs.push("subscribed to source"),
onTeardown: () => logs.push("teardown"),
});
const resultPromise = source.every((value, index) => {
logs.push(`Predicate called with ${value}, ${index}`);
return true;
});
let promiseResolved = false;
resultPromise.then(() => promiseResolved = true);
assert_array_equals(logs, ["subscribed to source"],
"calling every() subscribes to the source immediately");
source.next("a");
assert_array_equals(logs, [
"subscribed to source",
"Predicate called with a, 0"
], "Predicate called with the value and the index");
source.next("b");
assert_array_equals(logs, [
"subscribed to source",
"Predicate called with a, 0",
"Predicate called with b, 1",
], "Predicate called with the value and the index");
// wait a tick, just to prove that you have to wait for complete to be called.
await Promise.resolve();
assert_false(promiseResolved,
"Promise should not resolve until after the source completes");
source.complete();
assert_array_equals(logs, [
"subscribed to source",
"Predicate called with a, 0",
"Predicate called with b, 1",
"teardown",
], "Teardown function called immediately after the source completes");
const result = await resultPromise;
assert_true(result,
"Promise resolves with true if all values pass the predicate");
}, "every(): Lifecycle checks when all values pass the predicate");
promise_test(async () => {
const logs = [];
const source = createTestSubject({
onSubscribe: () => logs.push("subscribed to source"),
onTeardown: () => logs.push("teardown"),
});
const resultPromise = source.every((value, index) => {
logs.push(`Predicate called with ${value}, ${index}`);
return value === "good";
});
let promiseResolved = false;
resultPromise.then(() => promiseResolved = true);
assert_array_equals(logs, ["subscribed to source"],
"calling every() subscribes to the source immediately");
source.next("good");
source.next("good");
assert_array_equals(logs, [
"subscribed to source",
"Predicate called with good, 0",
"Predicate called with good, 1",
], "Predicate called with the value and the index");
assert_false(promiseResolved, "Promise should not resolve until after the predicate fails");
source.next("bad");
assert_array_equals(logs, [
"subscribed to source",
"Predicate called with good, 0",
"Predicate called with good, 1",
"Predicate called with bad, 2",
"teardown",
], "Predicate called with the value and the index, failing predicate immediately aborts subscription to source");
const result = await resultPromise;
assert_false(result, "Promise resolves with false if any value fails the predicate");
}, "every(): Lifecycle checks when any value fails the predicate");
promise_test(async () => {
const source = new Observable(subscriber => {
subscriber.complete();
});
const result = await source.every(() => true);
assert_true(result,
"Promise resolves with true if the observable completes without " +
"emitting a value");
}, "every(): Resolves with true if the observable completes without " +
"emitting a value");
promise_test(async t => {
const error = new Error("error from source");
const source = new Observable(subscriber => {
subscriber.error(error);
});
promise_rejects_exactly(t, error, source.every(() => true),
"Promise rejects with the error emitted from the source observable");
}, "every(): Rejects with any error emitted from the source observable");
promise_test(async t => {
const source = new Observable(subscriber => {
subscriber.next(1);
subscriber.next(2);
subscriber.next(3);
subscriber.complete();
});
const error = new Error("bad value");
const promise = source.every(value => {
if (value <= 2) return true;
throw error;
});
promise_rejects_exactly(t, error, promise, "Promise rejects with the " +
"error thrown from the predicate");
}, "every(): Rejects with any error thrown from the predicate");
promise_test(async () => {
const indices = [];
const source = new Observable(subscriber => {
subscriber.next("a");
subscriber.next("b");
subscriber.next("c");
subscriber.complete();
});
const value = await source.every((value, index) => {
indices.push(index);
return true;
});
assert_array_equals(indices, [0, 1, 2]);
assert_true(value,
"Promise resolves with true if all values pass the predicate");
}, "every(): Index is passed into the predicate");
promise_test(async t => {
const source = new Observable(subscriber => {});
const controller = new AbortController();
const promise = source.every(() => true, { signal: controller.signal });
controller.abort();
promise_rejects_dom(t, 'AbortError', promise, "Promise rejects with a " +
"DOMException if the source Observable is aborted");
}, "every(): Rejects with a DOMException if the source Observable is aborted");
function createTestSubject(options) {
const onTeardown = options?.onTeardown;
const subscribers = new Set();
const subject = new Observable(subscriber => {
options?.onSubscribe?.();
subscribers.add(subscriber);
subscriber.addTeardown(() => subscribers.delete(subscriber));
if (onTeardown) {
subscriber.addTeardown(onTeardown);
}
});
subject.next = (value) => {
for (const subscriber of Array.from(subscribers)) {
subscriber.next(value);
}
};
subject.error = (error) => {
for (const subscriber of Array.from(subscribers)) {
subscriber.error(error);
}
};
subject.complete = () => {
for (const subscriber of Array.from(subscribers)) {
subscriber.complete();
}
};
subject.subscriberCount = () => {
return subscribers.size;
};
return subject;
}
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