"use strict";

add_task(async function test_background_reload_and_unload() {
  let events = [];
  {
    let {Management} = ChromeUtils.import("resource://gre/modules/Extension.jsm", {});
    let record = (type, extensionContext) => {
      let eventType = type == "proxy-context-load" ? "load" : "unload";
      let url = extensionContext.uri.spec;
      let extensionId = extensionContext.extension.id;
      events.push({eventType, url, extensionId});
    };

    Management.on("proxy-context-load", record);
    Management.on("proxy-context-unload", record);
    registerCleanupFunction(() => {
      Management.off("proxy-context-load", record);
      Management.off("proxy-context-unload", record);
    });
  }

  let extension = ExtensionTestUtils.loadExtension({
    background() {
      browser.test.onMessage.addListener(msg => {
        browser.test.assertEq("reload-background", msg);
        location.reload();
      });
      browser.test.sendMessage("background-url", location.href);
    },
  });

  await extension.startup();
  let backgroundUrl = await extension.awaitMessage("background-url");

  let contextEvents = events.splice(0);
  equal(contextEvents.length, 1,
        "ExtensionContext state change after loading an extension");
  equal(contextEvents[0].eventType, "load");
  equal(contextEvents[0].url, backgroundUrl,
        "The ExtensionContext should be the background page");

  extension.sendMessage("reload-background");
  await extension.awaitMessage("background-url");

  contextEvents = events.splice(0);
  equal(contextEvents.length, 2,
        "ExtensionContext state changes after reloading the background page");
  equal(contextEvents[0].eventType, "unload",
        "Unload ExtensionContext of background page");
  equal(contextEvents[0].url, backgroundUrl, "ExtensionContext URL = background");
  equal(contextEvents[1].eventType, "load",
        "Create new ExtensionContext for background page");
  equal(contextEvents[1].url, backgroundUrl, "ExtensionContext URL = background");

  await extension.unload();

  contextEvents = events.splice(0);
  equal(contextEvents.length, 1,
        "ExtensionContext state change after unloading the extension");
  equal(contextEvents[0].eventType, "unload",
        "Unload ExtensionContext for background page after extension unloads");
  equal(contextEvents[0].url, backgroundUrl, "ExtensionContext URL = background");
});
