deno/tests/unit/event_test.ts

// Copyright 2018-2024 the Deno authors. All rights reserved. MIT license.
import { assertEquals, assertStringIncludes } from "./test_util.ts";

Deno.test(function eventInitializedWithType() {
  const type = "click";
  const event = new Event(type);

  assertEquals(event.isTrusted, false);
  assertEquals(event.target, null);
  assertEquals(event.currentTarget, null);
  assertEquals(event.type, "click");
  assertEquals(event.bubbles, false);
  assertEquals(event.cancelable, false);
});

Deno.test(function eventInitializedWithTypeAndDict() {
  const init = "submit";
  const eventInit = { bubbles: true, cancelable: true } as EventInit;
  const event = new Event(init, eventInit);

  assertEquals(event.isTrusted, false);
  assertEquals(event.target, null);
  assertEquals(event.currentTarget, null);
  assertEquals(event.type, "submit");
  assertEquals(event.bubbles, true);
  assertEquals(event.cancelable, true);
});

Deno.test(function eventComposedPathSuccess() {
  const type = "click";
  const event = new Event(type);
  const composedPath = event.composedPath();

  assertEquals(composedPath, []);
});

Deno.test(function eventStopPropagationSuccess() {
  const type = "click";
  const event = new Event(type);

  assertEquals(event.cancelBubble, false);
  event.stopPropagation();
  assertEquals(event.cancelBubble, true);
});

Deno.test(function eventStopImmediatePropagationSuccess() {
  const type = "click";
  const event = new Event(type);

  assertEquals(event.cancelBubble, false);
  event.stopImmediatePropagation();
  assertEquals(event.cancelBubble, true);
});

Deno.test(function eventPreventDefaultSuccess() {
  const type = "click";
  const event = new Event(type);

  assertEquals(event.defaultPrevented, false);
  event.preventDefault();
  assertEquals(event.defaultPrevented, false);

  const eventInit = { bubbles: true, cancelable: true } as EventInit;
  const cancelableEvent = new Event(type, eventInit);
  assertEquals(cancelableEvent.defaultPrevented, false);
  cancelableEvent.preventDefault();
  assertEquals(cancelableEvent.defaultPrevented, true);
});

Deno.test(function eventInitializedWithNonStringType() {
  // deno-lint-ignore no-explicit-any
  const type: any = undefined;
  const event = new Event(type);

  assertEquals(event.isTrusted, false);
  assertEquals(event.target, null);
  assertEquals(event.currentTarget, null);
  assertEquals(event.type, "undefined");
  assertEquals(event.bubbles, false);
  assertEquals(event.cancelable, false);
});

Deno.test(function eventInspectOutput() {
  // deno-lint-ignore no-explicit-any
  const cases: Array<[any, (event: any) => string]> = [
    [
      new Event("test"),
      (event: Event) =>
        `Event {\n  bubbles: false,\n  cancelable: false,\n  composed: false,\n  currentTarget: null,\n  defaultPrevented: false,\n  eventPhase: 0,\n  srcElement: null,\n  target: null,\n  returnValue: true,\n  timeStamp: ${event.timeStamp},\n  type: "test"\n}`,
    ],
    [
      new ErrorEvent("error"),
      (event: Event) =>
        `ErrorEvent {\n  bubbles: false,\n  cancelable: false,\n  composed: false,\n  currentTarget: null,\n  defaultPrevented: false,\n  eventPhase: 0,\n  srcElement: null,\n  target: null,\n  returnValue: true,\n  timeStamp: ${event.timeStamp},\n  type: "error",\n  message: "",\n  filename: "",\n  lineno: 0,\n  colno: 0,\n  error: undefined\n}`,
    ],
    [
      new CloseEvent("close"),
      (event: Event) =>
        `CloseEvent {\n  bubbles: false,\n  cancelable: false,\n  composed: false,\n  currentTarget: null,\n  defaultPrevented: false,\n  eventPhase: 0,\n  srcElement: null,\n  target: null,\n  returnValue: true,\n  timeStamp: ${event.timeStamp},\n  type: "close",\n  wasClean: false,\n  code: 0,\n  reason: ""\n}`,
    ],
    [
      new CustomEvent("custom"),
      (event: Event) =>
        `CustomEvent {\n  bubbles: false,\n  cancelable: false,\n  composed: false,\n  currentTarget: null,\n  defaultPrevented: false,\n  eventPhase: 0,\n  srcElement: null,\n  target: null,\n  returnValue: true,\n  timeStamp: ${event.timeStamp},\n  type: "custom",\n  detail: undefined\n}`,
    ],
    [
      new ProgressEvent("progress"),
      (event: Event) =>
        `ProgressEvent {\n  bubbles: false,\n  cancelable: false,\n  composed: false,\n  currentTarget: null,\n  defaultPrevented: false,\n  eventPhase: 0,\n  srcElement: null,\n  target: null,\n  returnValue: true,\n  timeStamp: ${event.timeStamp},\n  type: "progress",\n  lengthComputable: false,\n  loaded: 0,\n  total: 0\n}`,
    ],
  ];

  for (const [event, outputProvider] of cases) {
    assertEquals(Deno.inspect(event), outputProvider(event));
  }
});

Deno.test(function inspectEvent() {
  // has a customInspect implementation that previously would throw on a getter
  assertEquals(
    Deno.inspect(Event.prototype),
    `Event {
  bubbles: [Getter],
  cancelable: [Getter],
  composed: [Getter],
  currentTarget: [Getter],
  defaultPrevented: [Getter],
  eventPhase: [Getter],
  srcElement: [Getter/Setter],
  target: [Getter],
  returnValue: [Getter/Setter],
  timeStamp: [Getter],
  type: [Getter]
}`,
  );

  // ensure this still works
  assertStringIncludes(
    Deno.inspect(new Event("test")),
    // check a substring because one property is a timestamp
    `Event {\n  bubbles: false,\n  cancelable: false,`,
  );
});

Deno.test("default argument is null prototype", () => {
  const event = new Event("test");
  assertEquals(event.bubbles, false);

  // @ts-ignore this is on purpose to check if overriding prototype
  // has effect on `Event.
  Object.prototype.bubbles = true;
  const event2 = new Event("test");
  assertEquals(event2.bubbles, false);

  // @ts-ignore this is done on purpose
  delete Object.prototype.bubbles;
});