1 files changed, 85 insertions, 0 deletions
diff --git a/testing/web-platform/tests/dom/observable/tentative/observable-find.any.js b/testing/web-platform/tests/dom/observable/tentative/observable-find.any.js
new file mode 100644
index 0000000000..0e09060fc5
--- /dev/null
+++ b/testing/web-platform/tests/dom/observable/tentative/observable-find.any.js
@@ -0,0 +1,85 @@
+promise_test(async () => {
+  let inactiveAfterB = false;
+  const source = new Observable(subscriber => {
+    subscriber.next("a");
+    subscriber.next("b");
+    inactiveAfterB = !subscriber.active;
+    subscriber.next("c");
+    subscriber.complete();
+  });
+
+  const value = await source.find((value) => value === "b");
+
+  assert_equals(value, "b", "Promise resolves with the first value that passes the predicate");
+
+  assert_true(inactiveAfterB, "subscriber is inactive after the first value that passes the predicate");
+}, "find(): Promise resolves with the first value that passes the predicate");
+
+promise_test(async () => {
+  const source = new Observable(subscriber => {
+    subscriber.next("a");
+    subscriber.next("b");
+    subscriber.next("c");
+    subscriber.complete();
+  });
+
+  const value = await source.find(() => false);
+
+  assert_equals(value, undefined, "Promise resolves with undefined if no value passes the predicate");
+}, "find(): Promise resolves with undefined if no value passes the predicate");
+
+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.find(() => true), "Promise " +
+      "rejects with the error emitted from the source Observable");
+}, "find(): Promise rejects with the error emitted from the source Observable");
+
+promise_test(async t => {
+  const source = new Observable(subscriber => {
+    subscriber.next("ignored");
+  });
+
+  const error = new Error("thrown from predicate");
+  promise_rejects_exactly(t, error, source.find(() => {throw error}),
+      "Promise rejects with any error thrown from the predicate");
+}, "find(): Promise rejects with any error thrown from the predicate");
+
+promise_test(async () => {
+  let indices = [];
+
+  const source = new Observable(subscriber => {
+    subscriber.next("a");
+    subscriber.next("b");
+    subscriber.next("c");
+    subscriber.complete();
+  });
+
+  const value = await source.find((value, index) => {
+    indices.push(index);
+    return false;
+  });
+
+  assert_equals(value, undefined, "Promise resolves with undefined if no value passes the predicate");
+
+  assert_array_equals(indices, [0, 1, 2], "find(): Passes the index of the value to the predicate");
+}, "find(): Passes the index of the value to the predicate");
+
+promise_test(async t => {
+  const controller = new AbortController();
+  const source = new Observable(subscriber => {
+    subscriber.next("a");
+    subscriber.next("b");
+    subscriber.next("c");
+    subscriber.complete();
+  });
+
+  controller.abort();
+  const promise = source.find(() => true, { signal: controller.signal });
+
+  promise_rejects_dom(t, 'AbortError', promise, "Promise rejects with " +
+      "DOMException when the signal is aborted");
+}, "find(): Rejects with AbortError when the signal is aborted");