1 files changed, 108 insertions, 0 deletions
diff --git a/testing/web-platform/tests/dom/observable/tentative/observable-take.any.js b/testing/web-platform/tests/dom/observable/tentative/observable-take.any.js
new file mode 100644
index 0000000000..8350d0214c
--- /dev/null
+++ b/testing/web-platform/tests/dom/observable/tentative/observable-take.any.js
@@ -0,0 +1,108 @@
+test(() => {
+  const results = [];
+  const source = new Observable(subscriber => {
+    subscriber.addTeardown(() => results.push("source teardown"));
+    subscriber.next(1);
+    subscriber.next(2);
+    subscriber.next(3);
+    subscriber.complete();
+  });
+
+  const result = source.take(2);
+
+  result.subscribe({
+    next: v => results.push(v),
+    error: e => results.push(e),
+    complete: () => results.push("complete"),
+  });
+
+  assert_array_equals(results, [1, 2, "source teardown", "complete"]);
+}, "take(): Takes the first N values from the source observable, then completes");
+
+test(() => {
+  const results = [];
+  const source = new Observable(subscriber => {
+    subscriber.addTeardown(() => results.push("source teardown"));
+    subscriber.next(1);
+    subscriber.next(2);
+    subscriber.next(3);
+    subscriber.complete();
+  });
+
+  const result = source.take(5);
+
+  result.subscribe({
+    next: v => results.push(v),
+    error: e => results.push(e),
+    complete: () => results.push("complete"),
+  });
+
+  assert_array_equals(results, [1, 2, 3, "source teardown", "complete"],
+      "complete() is immediately forwarded");
+}, "take(): Forwards complete()s that happen before the take count is met, " +
+   "and unsubscribes from source Observable");
+
+test(() => {
+  const results = [];
+  const error = new Error('source error');
+  const source = new Observable(subscriber => {
+    subscriber.next(1);
+    subscriber.error(error);
+  });
+
+  const result = source.take(100);
+
+  result.subscribe({
+    next: v => results.push(v),
+    error: e => results.push(e),
+    complete: () => results.push("complete"),
+  });
+
+  assert_array_equals(results, [1, error], "Errors are forwarded");
+}, "take(): Should forward errors from the source observable");
+
+test(() => {
+  const results = [];
+  const source = new Observable((subscriber) => {
+    results.push("source subscribe");
+    subscriber.next(1);
+    subscriber.next(2);
+    subscriber.next(3);
+    subscriber.complete();
+  });
+
+  const result = source.take(0);
+
+  result.subscribe({
+    next: v => results.push(v),
+    error: e => results.push(e),
+    complete: () => results.push("complete"),
+  });
+
+  assert_array_equals(results, ["complete"]);
+}, "take(): take(0) should not subscribe to the source observable, and " +
+   "should return an observable that immediately completes");
+
+test(() => {
+  const results = [];
+  const source = new Observable((subscriber) => {
+    results.push("source subscribe");
+    subscriber.next(1);
+    subscriber.next(2);
+    subscriber.next(3);
+    subscriber.complete();
+  });
+
+  // Per WebIDL, `-1` passed into an `unsigned long long` gets wrapped around
+  // into the maximum value (18446744073709551615), which means the `result`
+  // Observable captures everything that `source` does.
+  const result = source.take(-1);
+
+  result.subscribe({
+    next: v => results.push(v),
+    error: e => results.push(e),
+    complete: () => results.push("complete"),
+  });
+
+  assert_array_equals(results, ["source subscribe", 1, 2, 3, "complete"]);
+}, "take(): Negative count is treated as maximum value");