1 files changed, 113 insertions, 0 deletions
diff --git a/devtools/shared/commands/resource/tests/browser_resources_unwatch_early.js b/devtools/shared/commands/resource/tests/browser_resources_unwatch_early.js
new file mode 100644
index 0000000000..e3890cf970
--- /dev/null
+++ b/devtools/shared/commands/resource/tests/browser_resources_unwatch_early.js
@@ -0,0 +1,113 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Test that calling unwatchResources before watchResources could resolve still
+// removes watcher entries correctly.
+
+const ResourceCommand = require("resource://devtools/shared/commands/resource/resource-command.js");
+
+const TEST_URI = "data:text/html;charset=utf-8,";
+
+add_task(async function () {
+  const tab = await addTab(TEST_URI);
+
+  const { client, resourceCommand, targetCommand } = await initResourceCommand(
+    tab
+  );
+  const { CONSOLE_MESSAGE, ROOT_NODE } = resourceCommand.TYPES;
+
+  info("Use console.log in the content page");
+  await logInTab(tab, "msg-1");
+
+  info("Call watchResources with various configurations");
+
+  // Watcher 1 only watches for CONSOLE_MESSAGE.
+  // For this call site, unwatchResource will be called before onAvailable has
+  // resolved.
+  const messages1 = [];
+  const onAvailable1 = createMessageCallback(messages1);
+  const onWatcher1Ready = resourceCommand.watchResources([CONSOLE_MESSAGE], {
+    onAvailable: onAvailable1,
+  });
+  resourceCommand.unwatchResources([CONSOLE_MESSAGE], {
+    onAvailable: onAvailable1,
+  });
+
+  info(
+    "Calling unwatchResources for an already unregistered callback should be a no-op"
+  );
+  // and more importantly, it should not throw
+  resourceCommand.unwatchResources([CONSOLE_MESSAGE], {
+    onAvailable: onAvailable1,
+  });
+
+  // Watcher 2 watches for CONSOLE_MESSAGE & another resource (ROOT_NODE).
+  // Again unwatchResource will be called before onAvailable has resolved.
+  // But unwatchResource is only called for CONSOLE_MESSAGE, not for ROOT_NODE.
+  const messages2 = [];
+  const onAvailable2 = createMessageCallback(messages2);
+  const onWatcher2Ready = resourceCommand.watchResources(
+    [CONSOLE_MESSAGE, ROOT_NODE],
+    {
+      onAvailable: onAvailable2,
+    }
+  );
+  resourceCommand.unwatchResources([CONSOLE_MESSAGE], {
+    onAvailable: onAvailable2,
+  });
+
+  // Watcher 3 watches for CONSOLE_MESSAGE, but we will not call unwatchResource
+  // explicitly for it before the end of test. Used as a reference.
+  const messages3 = [];
+  const onAvailable3 = createMessageCallback(messages3);
+  const onWatcher3Ready = resourceCommand.watchResources([CONSOLE_MESSAGE], {
+    onAvailable: onAvailable3,
+  });
+
+  info("Call unwatchResources for CONSOLE_MESSAGE on watcher 1 & 2");
+
+  info("Wait for all watchers `watchResources` to resolve");
+  await Promise.all([onWatcher1Ready, onWatcher2Ready, onWatcher3Ready]);
+  ok(!hasMessage(messages1, "msg-1"), "Watcher 1 did not receive msg-1");
+  ok(!hasMessage(messages2, "msg-1"), "Watcher 2 did not receive msg-1");
+  ok(hasMessage(messages3, "msg-1"), "Watcher 3 received msg-1");
+
+  info("Log a new message");
+  await logInTab(tab, "msg-2");
+
+  info("Wait until watcher 3 received the new message");
+  await waitUntil(() => hasMessage(messages3, "msg-2"));
+
+  ok(!hasMessage(messages1, "msg-2"), "Watcher 1 did not receive msg-2");
+  ok(!hasMessage(messages2, "msg-2"), "Watcher 2 did not receive msg-2");
+
+  targetCommand.destroy();
+  await client.close();
+});
+
+function logInTab(tab, message) {
+  return ContentTask.spawn(tab.linkedBrowser, message, function (_message) {
+    content.console.log(_message);
+  });
+}
+
+function hasMessage(messageResources, text) {
+  return messageResources.find(
+    resource => resource.message.arguments[0] === text
+  );
+}
+
+// All resource command callbacks share the same pattern here: they add all
+// console message resources to a provided `messages` array.
+function createMessageCallback(messages) {
+  const { CONSOLE_MESSAGE } = ResourceCommand.TYPES;
+  return async resources => {
+    for (const resource of resources) {
+      if (resource.resourceType === CONSOLE_MESSAGE) {
+        messages.push(resource);
+      }
+    }
+  };
+}