1 files changed, 214 insertions, 0 deletions
diff --git a/devtools/shared/commands/target/tests/browser_target_command_watchTargets.js b/devtools/shared/commands/target/tests/browser_target_command_watchTargets.js
new file mode 100644
index 0000000000..516780be01
--- /dev/null
+++ b/devtools/shared/commands/target/tests/browser_target_command_watchTargets.js
@@ -0,0 +1,214 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Test the TargetCommand's `watchTargets` function
+
+const TEST_URL =
+  "data:text/html;charset=utf-8," + encodeURIComponent(`<div id="test"></div>`);
+
+add_task(async function () {
+  // Enabled fission's pref as the TargetCommand is almost disabled without it
+  await pushPref("devtools.browsertoolbox.scope", "everything");
+  // Disable the preloaded process as it gets created lazily and may interfere
+  // with process count assertions
+  await pushPref("dom.ipc.processPrelaunch.enabled", false);
+  // This preference helps destroying the content process when we close the tab
+  await pushPref("dom.ipc.keepProcessesAlive.web", 1);
+
+  await testWatchTargets();
+  await testThrowingInOnAvailable();
+});
+
+async function testWatchTargets() {
+  info("Test TargetCommand watchTargets function");
+
+  const commands = await CommandsFactory.forMainProcess();
+  const targetCommand = commands.targetCommand;
+  const { TYPES } = targetCommand;
+
+  await targetCommand.startListening();
+
+  // Note that ppmm also includes the parent process, which is considered as a frame rather than a process
+  const originalProcessesCount = Services.ppmm.childCount - 1;
+
+  info(
+    "Check that onAvailable is called for processes already created *before* the call to watchTargets"
+  );
+  const targets = new Set();
+  const topLevelTarget = targetCommand.targetFront;
+  const onAvailable = ({ targetFront }) => {
+    if (targets.has(targetFront)) {
+      ok(false, "The same target is notified multiple times via onAvailable");
+    }
+    is(
+      targetFront.targetType,
+      TYPES.PROCESS,
+      "We are only notified about process targets"
+    );
+    ok(
+      targetFront == topLevelTarget
+        ? targetFront.isTopLevel
+        : !targetFront.isTopLevel,
+      "isTopLevel property is correct"
+    );
+    targets.add(targetFront);
+  };
+  const onDestroyed = ({ targetFront }) => {
+    if (!targets.has(targetFront)) {
+      ok(
+        false,
+        "A target is declared destroyed via onDestroyed without being notified via onAvailable"
+      );
+    }
+    is(
+      targetFront.targetType,
+      TYPES.PROCESS,
+      "We are only notified about process targets"
+    );
+    ok(
+      !targetFront.isTopLevel,
+      "We are not notified about the top level target destruction"
+    );
+    targets.delete(targetFront);
+  };
+  await targetCommand.watchTargets({
+    types: [TYPES.PROCESS],
+    onAvailable,
+    onDestroyed,
+  });
+  is(
+    targets.size,
+    originalProcessesCount,
+    "retrieved the expected number of processes via watchTargets"
+  );
+  // Start from 1 in order to ignore the parent process target, which is considered as a frame rather than a process
+  for (let i = 1; i < Services.ppmm.childCount; i++) {
+    const process = Services.ppmm.getChildAt(i);
+    const hasTargetWithSamePID = [...targets].find(
+      processTarget => processTarget.targetForm.processID == process.osPid
+    );
+    ok(
+      hasTargetWithSamePID,
+      `Process with PID ${process.osPid} has been reported via onAvailable`
+    );
+  }
+
+  info(
+    "Check that onAvailable is called for processes created *after* the call to watchTargets"
+  );
+  const previousTargets = new Set(targets);
+  const onProcessCreated = new Promise(resolve => {
+    const onAvailable2 = ({ targetFront }) => {
+      if (previousTargets.has(targetFront)) {
+        return;
+      }
+      targetCommand.unwatchTargets({
+        types: [TYPES.PROCESS],
+        onAvailable: onAvailable2,
+      });
+      resolve(targetFront);
+    };
+    targetCommand.watchTargets({
+      types: [TYPES.PROCESS],
+      onAvailable: onAvailable2,
+    });
+  });
+  const tab1 = await BrowserTestUtils.openNewForegroundTab({
+    gBrowser,
+    url: TEST_URL,
+    forceNewProcess: true,
+  });
+  const createdTarget = await onProcessCreated;
+
+  // For some reason, creating a new tab purges processes created from previous tests
+  // so it is not reasonable to assert the side of `targets` as it may be lower than expected.
+  ok(targets.has(createdTarget), "The new tab process is in the list");
+
+  const processCountAfterTabOpen = targets.size;
+
+  // Assert that onDestroyed is called for destroyed processes
+  const onProcessDestroyed = new Promise(resolve => {
+    const onAvailable3 = () => {};
+    const onDestroyed3 = ({ targetFront }) => {
+      resolve(targetFront);
+      targetCommand.unwatchTargets({
+        types: [TYPES.PROCESS],
+        onAvailable: onAvailable3,
+        onDestroyed: onDestroyed3,
+      });
+    };
+    targetCommand.watchTargets({
+      types: [TYPES.PROCESS],
+      onAvailable: onAvailable3,
+      onDestroyed: onDestroyed3,
+    });
+  });
+
+  BrowserTestUtils.removeTab(tab1);
+
+  const destroyedTarget = await onProcessDestroyed;
+  is(
+    targets.size,
+    processCountAfterTabOpen - 1,
+    "The closed tab's process has been reported as destroyed"
+  );
+  ok(
+    !targets.has(destroyedTarget),
+    "The destroyed target is no longer in the list"
+  );
+  is(
+    destroyedTarget,
+    createdTarget,
+    "The destroyed target is the one that has been reported as created"
+  );
+
+  targetCommand.unwatchTargets({
+    types: [TYPES.PROCESS],
+    onAvailable,
+    onDestroyed,
+  });
+
+  targetCommand.destroy();
+
+  await commands.destroy();
+}
+
+async function testThrowingInOnAvailable() {
+  info(
+    "Test TargetCommand watchTargets function when an exception is thrown in onAvailable callback"
+  );
+
+  const commands = await CommandsFactory.forMainProcess();
+  const targetCommand = commands.targetCommand;
+  const { TYPES } = targetCommand;
+
+  await targetCommand.startListening();
+
+  // Note that ppmm also includes the parent process, which is considered as a frame rather than a process
+  const originalProcessesCount = Services.ppmm.childCount - 1;
+
+  info(
+    "Check that onAvailable is called for processes already created *before* the call to watchTargets"
+  );
+  const targets = new Set();
+  let thrown = false;
+  const onAvailable = ({ targetFront }) => {
+    if (!thrown) {
+      thrown = true;
+      throw new Error("Force an exception when processing the first target");
+    }
+    targets.add(targetFront);
+  };
+  await targetCommand.watchTargets({ types: [TYPES.PROCESS], onAvailable });
+  is(
+    targets.size,
+    originalProcessesCount - 1,
+    "retrieved the expected number of processes via onAvailable. All but the first one where we have thrown."
+  );
+
+  targetCommand.destroy();
+
+  await commands.destroy();
+}