1 files changed, 231 insertions, 0 deletions
diff --git a/cli/tests/unit/event_target_test.ts b/cli/tests/unit/event_target_test.ts
new file mode 100644
index 000000000..0c4eb4d0d
--- /dev/null
+++ b/cli/tests/unit/event_target_test.ts
@@ -0,0 +1,231 @@
+// Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.
+import { unitTest, assertEquals } from "./test_util.ts";
+
+unitTest(function addEventListenerTest(): void {
+  const document = new EventTarget();
+
+  // @ts-ignore tests ignoring the type system for resilience
+  assertEquals(document.addEventListener("x", null, false), undefined);
+  // @ts-ignore
+  assertEquals(document.addEventListener("x", null, true), undefined);
+  // @ts-ignore
+  assertEquals(document.addEventListener("x", null), undefined);
+});
+
+unitTest(function constructedEventTargetCanBeUsedAsExpected(): void {
+  const target = new EventTarget();
+  const event = new Event("foo", { bubbles: true, cancelable: false });
+  let callCount = 0;
+
+  const listener = (e: Event): void => {
+    assertEquals(e, event);
+    ++callCount;
+  };
+
+  target.addEventListener("foo", listener);
+
+  target.dispatchEvent(event);
+  assertEquals(callCount, 1);
+
+  target.dispatchEvent(event);
+  assertEquals(callCount, 2);
+
+  target.removeEventListener("foo", listener);
+  target.dispatchEvent(event);
+  assertEquals(callCount, 2);
+});
+
+unitTest(function anEventTargetCanBeSubclassed(): void {
+  class NicerEventTarget extends EventTarget {
+    on(
+      type: string,
+      callback: ((e: Event) => void) | null,
+      options?: AddEventListenerOptions
+    ): void {
+      this.addEventListener(type, callback, options);
+    }
+
+    off(
+      type: string,
+      callback: ((e: Event) => void) | null,
+      options?: EventListenerOptions
+    ): void {
+      this.removeEventListener(type, callback, options);
+    }
+  }
+
+  const target = new NicerEventTarget();
+  new Event("foo", { bubbles: true, cancelable: false });
+  let callCount = 0;
+
+  const listener = (): void => {
+    ++callCount;
+  };
+
+  target.on("foo", listener);
+  assertEquals(callCount, 0);
+
+  target.off("foo", listener);
+  assertEquals(callCount, 0);
+});
+
+unitTest(function removingNullEventListenerShouldSucceed(): void {
+  const document = new EventTarget();
+  // @ts-ignore
+  assertEquals(document.removeEventListener("x", null, false), undefined);
+  // @ts-ignore
+  assertEquals(document.removeEventListener("x", null, true), undefined);
+  // @ts-ignore
+  assertEquals(document.removeEventListener("x", null), undefined);
+});
+
+unitTest(function constructedEventTargetUseObjectPrototype(): void {
+  const target = new EventTarget();
+  const event = new Event("toString", { bubbles: true, cancelable: false });
+  let callCount = 0;
+
+  const listener = (e: Event): void => {
+    assertEquals(e, event);
+    ++callCount;
+  };
+
+  target.addEventListener("toString", listener);
+
+  target.dispatchEvent(event);
+  assertEquals(callCount, 1);
+
+  target.dispatchEvent(event);
+  assertEquals(callCount, 2);
+
+  target.removeEventListener("toString", listener);
+  target.dispatchEvent(event);
+  assertEquals(callCount, 2);
+});
+
+unitTest(function toStringShouldBeWebCompatible(): void {
+  const target = new EventTarget();
+  assertEquals(target.toString(), "[object EventTarget]");
+});
+
+unitTest(function dispatchEventShouldNotThrowError(): void {
+  let hasThrown = false;
+
+  try {
+    const target = new EventTarget();
+    const event = new Event("hasOwnProperty", {
+      bubbles: true,
+      cancelable: false,
+    });
+    const listener = (): void => {};
+    target.addEventListener("hasOwnProperty", listener);
+    target.dispatchEvent(event);
+  } catch {
+    hasThrown = true;
+  }
+
+  assertEquals(hasThrown, false);
+});
+
+unitTest(function eventTargetThisShouldDefaultToWindow(): void {
+  const {
+    addEventListener,
+    dispatchEvent,
+    removeEventListener,
+  } = EventTarget.prototype;
+  let n = 1;
+  const event = new Event("hello");
+  const listener = (): void => {
+    n = 2;
+  };
+
+  addEventListener("hello", listener);
+  window.dispatchEvent(event);
+  assertEquals(n, 2);
+  n = 1;
+  removeEventListener("hello", listener);
+  window.dispatchEvent(event);
+  assertEquals(n, 1);
+
+  window.addEventListener("hello", listener);
+  dispatchEvent(event);
+  assertEquals(n, 2);
+  n = 1;
+  window.removeEventListener("hello", listener);
+  dispatchEvent(event);
+  assertEquals(n, 1);
+});
+
+unitTest(function eventTargetShouldAcceptEventListenerObject(): void {
+  const target = new EventTarget();
+  const event = new Event("foo", { bubbles: true, cancelable: false });
+  let callCount = 0;
+
+  const listener = {
+    handleEvent(e: Event): void {
+      assertEquals(e, event);
+      ++callCount;
+    },
+  };
+
+  target.addEventListener("foo", listener);
+
+  target.dispatchEvent(event);
+  assertEquals(callCount, 1);
+
+  target.dispatchEvent(event);
+  assertEquals(callCount, 2);
+
+  target.removeEventListener("foo", listener);
+  target.dispatchEvent(event);
+  assertEquals(callCount, 2);
+});
+
+unitTest(function eventTargetShouldAcceptAsyncFunction(): void {
+  const target = new EventTarget();
+  const event = new Event("foo", { bubbles: true, cancelable: false });
+  let callCount = 0;
+
+  const listener = (e: Event): void => {
+    assertEquals(e, event);
+    ++callCount;
+  };
+
+  target.addEventListener("foo", listener);
+
+  target.dispatchEvent(event);
+  assertEquals(callCount, 1);
+
+  target.dispatchEvent(event);
+  assertEquals(callCount, 2);
+
+  target.removeEventListener("foo", listener);
+  target.dispatchEvent(event);
+  assertEquals(callCount, 2);
+});
+
+unitTest(
+  function eventTargetShouldAcceptAsyncFunctionForEventListenerObject(): void {
+    const target = new EventTarget();
+    const event = new Event("foo", { bubbles: true, cancelable: false });
+    let callCount = 0;
+
+    const listener = {
+      handleEvent(e: Event): void {
+        assertEquals(e, event);
+        ++callCount;
+      },
+    };
+
+    target.addEventListener("foo", listener);
+
+    target.dispatchEvent(event);
+    assertEquals(callCount, 1);
+
+    target.dispatchEvent(event);
+    assertEquals(callCount, 2);
+
+    target.removeEventListener("foo", listener);
+    target.dispatchEvent(event);
+    assertEquals(callCount, 2);
+  }
+);