// Copyright 2020 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "src/devices/bin/driver_manager/driver_runner.h"

#include <fuchsia/driver/framework/cpp/fidl_test_base.h>
#include <fuchsia/io/cpp/fidl_test_base.h>
#include <fuchsia/sys2/cpp/fidl_test_base.h>
#include <lib/async-loop/cpp/loop.h>
#include <lib/async-loop/default.h>
#include <lib/fidl/cpp/binding.h>
#include <lib/fit/defer.h>
#include <lib/gtest/test_loop_fixture.h>
#include <lib/inspect/cpp/reader.h>
#include <lib/inspect/testing/cpp/inspect.h>
#include <lib/sys/cpp/testing/component_context_provider.h>

#include <gtest/gtest.h>

#include "src/devices/bin/driver_manager/fake_driver_index.h"

namespace fdata = fuchsia_data;
namespace fdf = fuchsia::driver::framework;
namespace fio = fuchsia::io;
namespace frunner = fuchsia_component_runner;
namespace fsys = fuchsia::sys2;

using namespace testing;
using namespace inspect::testing;

class fake_context : public fit::context {
 public:
  fit::executor* executor() const override {
    EXPECT_TRUE(false);
    return nullptr;
  }

  fit::suspended_task suspend_task() override {
    EXPECT_TRUE(false);
    return fit::suspended_task();
  }
};

class UnbindWatcher : public fidl::WireAsyncEventHandler<frunner::ComponentController> {
 public:
  UnbindWatcher(size_t index, std::vector<size_t>& indices) : index_(index), indices_(indices) {}

  void Unbound(fidl::UnbindInfo) override { indices_.emplace_back(index_); }

 private:
  const size_t index_;
  std::vector<size_t>& indices_;
};

class TestRealm : public fsys::testing::Realm_TestBase {
 public:
  using BindChildHandler =
      fit::function<void(fsys::ChildRef child, fidl::InterfaceRequest<fio::Directory> exposed_dir)>;
  using CreateChildHandler =
      fit::function<void(fsys::CollectionRef collection, fsys::ChildDecl decl)>;
  using DestroyChildHandler = fit::function<void(fsys::ChildRef child)>;

  void SetBindChildHandler(BindChildHandler bind_child_handler) {
    bind_child_handler_ = std::move(bind_child_handler);
  }

  void SetCreateChildHandler(CreateChildHandler create_child_handler) {
    create_child_handler_ = std::move(create_child_handler);
  }

  void SetDestroyChildHandler(DestroyChildHandler destroy_child_handler) {
    destroy_child_handler_ = std::move(destroy_child_handler);
  }

 private:
  void BindChild(fsys::ChildRef child, fidl::InterfaceRequest<fio::Directory> exposed_dir,
                 BindChildCallback callback) override {
    bind_child_handler_(std::move(child), std::move(exposed_dir));
    callback(fsys::Realm_BindChild_Result(fit::ok()));
  }

  void CreateChild(fsys::CollectionRef collection, fsys::ChildDecl decl,
                   CreateChildCallback callback) override {
    create_child_handler_(std::move(collection), std::move(decl));
    callback(fsys::Realm_CreateChild_Result(fit::ok()));
  }

  void DestroyChild(fsys::ChildRef child, DestroyChildCallback callback) override {
    destroy_child_handler_(std::move(child));
    callback(fsys::Realm_DestroyChild_Result(fit::ok()));
  }

  void NotImplemented_(const std::string& name) override {
    printf("Not implemented: Realm::%s\n", name.data());
  }

  BindChildHandler bind_child_handler_;
  CreateChildHandler create_child_handler_;
  DestroyChildHandler destroy_child_handler_ = [](auto) {};
};

class TestDirectory : public fio::testing::Directory_TestBase {
 public:
  using OpenHandler =
      fit::function<void(std::string path, fidl::InterfaceRequest<fio::Node> object)>;

  void SetOpenHandler(OpenHandler open_handler) { open_handler_ = std::move(open_handler); }

 private:
  void Clone(uint32_t flags, fidl::InterfaceRequest<fio::Node> object) override {
    EXPECT_EQ(ZX_FS_FLAG_CLONE_SAME_RIGHTS, flags);
  }

  void Open(uint32_t flags, uint32_t mode, std::string path,
            fidl::InterfaceRequest<fio::Node> object) override {
    open_handler_(std::move(path), std::move(object));
  }

  void NotImplemented_(const std::string& name) override {
    printf("Not implemented: Directory::%s\n", name.data());
  }

  OpenHandler open_handler_;
};

class TestDriverHost : public fdf::testing::DriverHost_TestBase {
 public:
  using StartHandler = fit::function<void(fdf::DriverStartArgs start_args,
                                          fidl::InterfaceRequest<fdf::Driver> driver)>;

  void SetStartHandler(StartHandler start_handler) { start_handler_ = std::move(start_handler); }

 private:
  void Start(fdf::DriverStartArgs start_args, fidl::InterfaceRequest<fdf::Driver> driver) override {
    start_handler_(std::move(start_args), std::move(driver));
  }

  void NotImplemented_(const std::string& name) override {
    printf("Not implemented: DriverHost::%s\n", name.data());
  }

  StartHandler start_handler_;
};

class TestTransaction : public fidl::Transaction {
 public:
  TestTransaction(bool close) : close_(close) {}

 private:
  std::unique_ptr<Transaction> TakeOwnership() override {
    EXPECT_TRUE(false);
    return nullptr;
  }

  zx_status_t Reply(fidl::OutgoingMessage* message) override {
    EXPECT_TRUE(false);
    return ZX_OK;
  }

  void Close(zx_status_t epitaph) override { EXPECT_TRUE(close_); }

  bool close_;
};

struct Driver {
  std::string url;
  std::string binary;
  bool colocate = false;
  bool close = false;
};

class DriverRunnerTest : public gtest::TestLoopFixture {
 public:
  void SetUp() override {
    TestLoopFixture::SetUp();
    fidl::InterfaceRequestHandler<fsys::Realm> handler = [this](auto request) {
      EXPECT_EQ(ZX_OK, realm_binding_.Bind(std::move(request), loop_.dispatcher()));
    };
    ASSERT_EQ(ZX_OK, provider_.context()->outgoing()->AddPublicService(std::move(handler)));
  }

 protected:
  inspect::Inspector* inspector() { return &inspector_; }
  async::Loop& loop() { return loop_; }
  TestRealm& realm() { return realm_; }
  TestDirectory& driver_host_dir() { return driver_host_dir_; }
  TestDriverHost& driver_host() { return driver_host_; }
  fidl::Binding<fio::Directory>& driver_dir_binding() { return driver_dir_binding_; }

  zx::channel ConnectToRealm() {
    fsys::RealmPtr realm;
    provider_.ConnectToPublicService(realm.NewRequest(loop_.dispatcher()));
    return realm.Unbind().TakeChannel();
  }

  FakeDriverIndex CreateDriverIndex() {
    return FakeDriverIndex(loop().dispatcher(),
                           [](auto args) -> zx::status<FakeDriverIndex::MatchResult> {
                             std::string_view name(args.name().data(), args.name().size());
                             if (name == "second") {
                               return zx::ok(FakeDriverIndex::MatchResult{
                                   .url = "fuchsia-boot:///#meta/second-driver.cm",
                                   .matched_args = std::move(args),
                               });
                             } else {
                               return zx::error(ZX_ERR_NOT_FOUND);
                             }
                           });
  }

  void StartDriverHost(std::string coll, std::string name) {
    realm().SetCreateChildHandler(
        [coll, name](fsys::CollectionRef collection, fsys::ChildDecl decl) {
          EXPECT_EQ(coll, collection.name);
          EXPECT_EQ(name, decl.name());
          EXPECT_EQ("fuchsia-boot:///#meta/driver_host2.cm", decl.url());
        });
    realm().SetBindChildHandler([this, coll, name](fsys::ChildRef child, auto exposed_dir) {
      EXPECT_EQ(coll, child.collection.value_or(""));
      EXPECT_EQ(name, child.name);
      EXPECT_EQ(ZX_OK, driver_host_dir_binding_.Bind(std::move(exposed_dir), loop_.dispatcher()));
    });
    driver_host_dir().SetOpenHandler([this](std::string path, auto object) {
      EXPECT_EQ(fdf::DriverHost::Name_, path);
      EXPECT_EQ(ZX_OK, driver_host_binding_.Bind(object.TakeChannel(), loop_.dispatcher()));
    });
  }

  zx::channel StartDriver(DriverRunner* driver_runner, Driver driver) {
    fidl::FidlAllocator allocator;

    fidl::VectorView<fdata::wire::DictionaryEntry> program_entries(allocator, 2);
    program_entries[0].key.Set(allocator, "binary");
    program_entries[0].value.set_str(allocator, allocator, driver.binary);
    program_entries[1].key.Set(allocator, "colocate");
    program_entries[1].value.set_str(allocator, allocator, driver.colocate ? "true" : "false");

    fdata::wire::Dictionary program(allocator);
    program.set_entries(allocator, std::move(program_entries));

    auto outgoing_endpoints = fidl::CreateEndpoints<fuchsia_io::Directory>();
    EXPECT_EQ(ZX_OK, outgoing_endpoints.status_value());

    frunner::wire::ComponentStartInfo start_info(allocator);
    start_info.set_resolved_url(allocator, allocator, driver.url)
        .set_program(allocator, std::move(program))
        .set_ns(allocator)
        .set_outgoing_dir(allocator, std::move(outgoing_endpoints->server));

    zx::channel controller_client_end, controller_server_end;
    EXPECT_EQ(ZX_OK, zx::channel::create(0, &controller_client_end, &controller_server_end));
    TestTransaction transaction(driver.close);
    {
      fidl::WireInterface<frunner::ComponentRunner>::StartCompleter::Sync completer(&transaction);
      static_cast<fidl::WireInterface<frunner::ComponentRunner>*>(driver_runner)
          ->Start(std::move(start_info), std::move(controller_server_end), completer);
    }
    loop().RunUntilIdle();
    return controller_client_end;
  }

  zx::status<zx::channel> StartRootDriver(std::string url, DriverRunner* driver_runner) {
    realm().SetCreateChildHandler([](fsys::CollectionRef collection, fsys::ChildDecl decl) {
      EXPECT_EQ("boot-drivers", collection.name);
      EXPECT_EQ("root", decl.name());
      EXPECT_EQ("fuchsia-boot:///#meta/root-driver.cm", decl.url());
    });
    realm().SetBindChildHandler([this](fsys::ChildRef child, auto exposed_dir) {
      EXPECT_EQ("boot-drivers", child.collection);
      EXPECT_EQ("root", child.name);
      EXPECT_EQ(ZX_OK, driver_dir_binding_.Bind(std::move(exposed_dir), loop_.dispatcher()));
    });
    auto start = driver_runner->StartRootDriver(std::move(url));
    if (start.is_error()) {
      return start.take_error();
    }
    loop().RunUntilIdle();

    StartDriverHost("driver_hosts", "driver_host-0");
    zx::channel controller =
        StartDriver(driver_runner, {
                                       .url = "fuchsia-boot:///#meta/root-driver.cm",
                                       .binary = "driver/root-driver.so",
                                   });
    return zx::ok(std::move(controller));
  }

  void Unbind() {
    driver_host_binding_.Unbind();
    loop().RunUntilIdle();
  }

  void Emplace(fidl::InterfaceRequest<fdf::Driver> request) {
    requests_.emplace_back(std::move(request));
  }

  inspect::Hierarchy Inspect(DriverRunner* driver_runner) {
    fake_context context;
    auto inspector = driver_runner->Inspect()(context).take_value();
    return inspect::ReadFromInspector(inspector)(context).take_value();
  }

 private:
  TestRealm realm_;
  TestDirectory driver_host_dir_;
  TestDirectory driver_dir_;
  TestDriverHost driver_host_;
  fidl::Binding<fsys::Realm> realm_binding_{&realm_};
  fidl::Binding<fio::Directory> driver_host_dir_binding_{&driver_host_dir_};
  fidl::Binding<fio::Directory> driver_dir_binding_{&driver_dir_};
  fidl::Binding<fdf::DriverHost> driver_host_binding_{&driver_host_};
  std::vector<fidl::InterfaceRequest<fdf::Driver>> requests_;

  inspect::Inspector inspector_;
  async::Loop loop_{&kAsyncLoopConfigNoAttachToCurrentThread};
  sys::testing::ComponentContextProvider provider_{loop_.dispatcher()};
};

// Start the root driver.
TEST_F(DriverRunnerTest, StartRootDriver) {
  auto driver_index = CreateDriverIndex();
  auto driver_index_client = driver_index.Connect();
  ASSERT_EQ(driver_index_client.status_value(), ZX_OK);
  DriverRunner driver_runner(ConnectToRealm(), std::move(driver_index_client.value()), inspector(),
                             loop().dispatcher());

  auto defer = fit::defer([this] { Unbind(); });

  driver_host().SetStartHandler([this](fdf::DriverStartArgs start_args, auto request) {
    Emplace(std::move(request));
    auto& entries = start_args.program().entries();
    EXPECT_EQ(2u, entries.size());
    EXPECT_EQ("binary", entries[0].key);
    EXPECT_EQ("driver/root-driver.so", entries[0].value->str());
    EXPECT_EQ("colocate", entries[1].key);
    EXPECT_EQ("false", entries[1].value->str());
  });
  ASSERT_TRUE(StartRootDriver("fuchsia-boot:///#meta/root-driver.cm", &driver_runner).is_ok());
}

// Start the root driver, and add a child node owned by the root driver.
TEST_F(DriverRunnerTest, StartRootDriver_AddOwnedChild) {
  auto driver_index = CreateDriverIndex();
  auto driver_index_client = driver_index.Connect();
  ASSERT_EQ(driver_index_client.status_value(), ZX_OK);
  DriverRunner driver_runner(ConnectToRealm(), std::move(driver_index_client.value()), inspector(),
                             loop().dispatcher());
  auto defer = fit::defer([this] { Unbind(); });

  driver_host().SetStartHandler([this](fdf::DriverStartArgs start_args, auto request) {
    Emplace(std::move(request));
    auto& entries = start_args.program().entries();
    EXPECT_EQ(2u, entries.size());
    EXPECT_EQ("binary", entries[0].key);
    EXPECT_EQ("driver/root-driver.so", entries[0].value->str());
    EXPECT_EQ("colocate", entries[1].key);
    EXPECT_EQ("false", entries[1].value->str());

    fdf::NodePtr root_node;
    EXPECT_EQ(ZX_OK, root_node.Bind(std::move(*start_args.mutable_node()), loop().dispatcher()));
    fdf::NodeAddArgs args;
    args.set_name("second");
    fdf::NodeControllerPtr node_controller;
    fdf::NodePtr second_node;
    root_node->AddChild(std::move(args), node_controller.NewRequest(loop().dispatcher()),
                        second_node.NewRequest(loop().dispatcher()),
                        [](auto result) { EXPECT_FALSE(result.is_err()); });
  });
  auto root_driver = StartRootDriver("fuchsia-boot:///#meta/root-driver.cm", &driver_runner);
  ASSERT_TRUE(root_driver.is_ok());
}

// Start the root driver, add a child node, then remove it.
TEST_F(DriverRunnerTest, StartRootDriver_RemoveOwnedChild) {
  auto driver_index = CreateDriverIndex();
  auto driver_index_client = driver_index.Connect();
  ASSERT_EQ(driver_index_client.status_value(), ZX_OK);
  DriverRunner driver_runner(ConnectToRealm(), std::move(driver_index_client.value()), inspector(),
                             loop().dispatcher());
  auto defer = fit::defer([this] { Unbind(); });

  fdf::NodeControllerPtr node_controller;
  fdf::NodePtr root_node, second_node;
  driver_host().SetStartHandler([this, &node_controller, &root_node, &second_node](
                                    fdf::DriverStartArgs start_args, auto request) {
    Emplace(std::move(request));
    auto& entries = start_args.program().entries();
    EXPECT_EQ(2u, entries.size());
    EXPECT_EQ("binary", entries[0].key);
    EXPECT_EQ("driver/root-driver.so", entries[0].value->str());
    EXPECT_EQ("colocate", entries[1].key);
    EXPECT_EQ("false", entries[1].value->str());

    EXPECT_EQ(ZX_OK, root_node.Bind(std::move(*start_args.mutable_node()), loop().dispatcher()));
    fdf::NodeAddArgs args;
    args.set_name("second");
    root_node->AddChild(std::move(args), node_controller.NewRequest(loop().dispatcher()),
                        second_node.NewRequest(loop().dispatcher()),
                        [](auto result) { EXPECT_FALSE(result.is_err()); });
  });
  auto root_driver = StartRootDriver("fuchsia-boot:///#meta/root-driver.cm", &driver_runner);
  ASSERT_TRUE(root_driver.is_ok());

  node_controller->Remove();
  loop().RunUntilIdle();
  EXPECT_FALSE(second_node.is_bound());
  EXPECT_TRUE(root_node.is_bound());
}

// Start the root driver, and add a child node with an invalid name.
TEST_F(DriverRunnerTest, StartRootDriver_AddOwnedChild_InvalidName) {
  auto driver_index = CreateDriverIndex();
  auto driver_index_client = driver_index.Connect();
  ASSERT_EQ(driver_index_client.status_value(), ZX_OK);
  DriverRunner driver_runner(ConnectToRealm(), std::move(driver_index_client.value()), inspector(),
                             loop().dispatcher());
  auto defer = fit::defer([this] { Unbind(); });

  fdf::NodePtr root_node, invalid_node;
  driver_host().SetStartHandler([this, &root_node, &invalid_node](fdf::DriverStartArgs start_args,
                                                                  auto request) {
    Emplace(std::move(request));

    EXPECT_EQ(ZX_OK, root_node.Bind(std::move(*start_args.mutable_node()), loop().dispatcher()));
    fdf::NodeAddArgs args;
    args.set_name("second.invalid");
    fdf::NodeControllerPtr node_controller;
    root_node->AddChild(std::move(args), node_controller.NewRequest(loop().dispatcher()),
                        invalid_node.NewRequest(loop().dispatcher()),
                        [](auto result) { EXPECT_TRUE(result.is_err()); });
  });
  auto root_driver = StartRootDriver("fuchsia-boot:///#meta/root-driver.cm", &driver_runner);
  ASSERT_TRUE(root_driver.is_ok());

  loop().RunUntilIdle();
  EXPECT_FALSE(invalid_node.is_bound());
  EXPECT_TRUE(root_node.is_bound());
}

// Start the root driver, and add two child nodes with duplicate names.
TEST_F(DriverRunnerTest, StartRootDriver_AddOwnedChild_DuplicateNames) {
  auto driver_index = CreateDriverIndex();
  auto driver_index_client = driver_index.Connect();
  ASSERT_EQ(driver_index_client.status_value(), ZX_OK);
  DriverRunner driver_runner(ConnectToRealm(), std::move(driver_index_client.value()), inspector(),
                             loop().dispatcher());
  auto defer = fit::defer([this] { Unbind(); });

  fdf::NodePtr root_node, second_node, invalid_node;
  driver_host().SetStartHandler([this, &root_node, &second_node, &invalid_node](
                                    fdf::DriverStartArgs start_args, auto request) {
    Emplace(std::move(request));

    EXPECT_EQ(ZX_OK, root_node.Bind(std::move(*start_args.mutable_node()), loop().dispatcher()));
    fdf::NodeAddArgs args;
    args.set_name("second");
    fdf::NodeControllerPtr node_controller;
    root_node->AddChild(std::move(args), node_controller.NewRequest(loop().dispatcher()),
                        second_node.NewRequest(loop().dispatcher()),
                        [](auto result) { EXPECT_FALSE(result.is_err()); });
    args.set_name("second");
    root_node->AddChild(std::move(args), node_controller.NewRequest(loop().dispatcher()),
                        invalid_node.NewRequest(loop().dispatcher()),
                        [](auto result) { EXPECT_TRUE(result.is_err()); });
  });
  auto root_driver = StartRootDriver("fuchsia-boot:///#meta/root-driver.cm", &driver_runner);
  ASSERT_TRUE(root_driver.is_ok());

  loop().RunUntilIdle();
  EXPECT_FALSE(invalid_node.is_bound());
  EXPECT_TRUE(second_node.is_bound());
  EXPECT_TRUE(root_node.is_bound());
}

// Start the root driver, and add a child node with duplicate symbols. The child
// node is unowned, so if we did not have duplicate symbols, the second driver
// would bind to it.
TEST_F(DriverRunnerTest, StartRootDriver_AddUnownedChild_DuplicateSymbols) {
  auto driver_index = CreateDriverIndex();
  auto driver_index_client = driver_index.Connect();
  ASSERT_EQ(driver_index_client.status_value(), ZX_OK);
  DriverRunner driver_runner(ConnectToRealm(), std::move(driver_index_client.value()), inspector(),
                             loop().dispatcher());
  auto defer = fit::defer([this] { Unbind(); });

  fdf::NodeControllerPtr node_controller;
  driver_host().SetStartHandler([this, &node_controller](fdf::DriverStartArgs start_args,
                                                         auto request) {
    Emplace(std::move(request));

    fdf::NodePtr root_node;
    EXPECT_EQ(ZX_OK, root_node.Bind(std::move(*start_args.mutable_node()), loop().dispatcher()));
    fdf::NodeAddArgs args;
    args.set_name("second");
    args.mutable_symbols()->emplace_back(
        std::move(fdf::NodeSymbol().set_name("sym").set_address(0xfeed)));
    args.mutable_symbols()->emplace_back(
        std::move(fdf::NodeSymbol().set_name("sym").set_address(0xf00d)));
    root_node->AddChild(std::move(args), node_controller.NewRequest(loop().dispatcher()), {},
                        [](auto result) { EXPECT_TRUE(result.is_err()); });
  });
  auto root_driver = StartRootDriver("fuchsia-boot:///#meta/root-driver.cm", &driver_runner);
  ASSERT_TRUE(root_driver.is_ok());

  loop().RunUntilIdle();
  ASSERT_FALSE(node_controller.is_bound());
}

// Start the root driver, and add a child node that has a symbol without an
// address.
TEST_F(DriverRunnerTest, StartRootDriver_AddUnownedChild_SymbolMissingAddress) {
  auto driver_index = CreateDriverIndex();
  auto driver_index_client = driver_index.Connect();
  ASSERT_EQ(driver_index_client.status_value(), ZX_OK);
  DriverRunner driver_runner(ConnectToRealm(), std::move(driver_index_client.value()), inspector(),
                             loop().dispatcher());
  auto defer = fit::defer([this] { Unbind(); });

  fdf::NodeControllerPtr node_controller;
  driver_host().SetStartHandler([this, &node_controller](fdf::DriverStartArgs start_args,
                                                         auto request) {
    Emplace(std::move(request));

    fdf::NodePtr root_node;
    EXPECT_EQ(ZX_OK, root_node.Bind(std::move(*start_args.mutable_node()), loop().dispatcher()));
    fdf::NodeAddArgs args;
    args.set_name("second");
    args.mutable_symbols()->emplace_back(std::move(fdf::NodeSymbol().set_name("sym")));
    root_node->AddChild(std::move(args), node_controller.NewRequest(loop().dispatcher()), {},
                        [](auto result) { EXPECT_TRUE(result.is_err()); });
  });
  auto root_driver = StartRootDriver("fuchsia-boot:///#meta/root-driver.cm", &driver_runner);
  ASSERT_TRUE(root_driver.is_ok());

  loop().RunUntilIdle();
  ASSERT_FALSE(node_controller.is_bound());
}

// Start the root driver, and add a child node that has a symbol without a name.
TEST_F(DriverRunnerTest, StartRootDriver_AddUnownedChild_SymbolMissingName) {
  auto driver_index = CreateDriverIndex();
  auto driver_index_client = driver_index.Connect();
  ASSERT_EQ(driver_index_client.status_value(), ZX_OK);
  DriverRunner driver_runner(ConnectToRealm(), std::move(driver_index_client.value()), inspector(),
                             loop().dispatcher());
  auto defer = fit::defer([this] { Unbind(); });

  fdf::NodeControllerPtr node_controller;
  driver_host().SetStartHandler([this, &node_controller](fdf::DriverStartArgs start_args,
                                                         auto request) {
    Emplace(std::move(request));

    fdf::NodePtr root_node;
    EXPECT_EQ(ZX_OK, root_node.Bind(std::move(*start_args.mutable_node()), loop().dispatcher()));
    fdf::NodeAddArgs args;
    args.set_name("second");
    args.mutable_symbols()->emplace_back(std::move(fdf::NodeSymbol().set_address(0xfeed)));
    root_node->AddChild(std::move(args), node_controller.NewRequest(loop().dispatcher()), {},
                        [](auto result) { EXPECT_TRUE(result.is_err()); });
  });
  auto root_driver = StartRootDriver("fuchsia-boot:///#meta/root-driver.cm", &driver_runner);
  ASSERT_TRUE(root_driver.is_ok());

  loop().RunUntilIdle();
  ASSERT_FALSE(node_controller.is_bound());
}

// Start the root driver, and then start a second driver in a new driver host.
TEST_F(DriverRunnerTest, StartSecondDriver_NewDriverHost) {
  auto driver_index = CreateDriverIndex();
  auto driver_index_client = driver_index.Connect();
  ASSERT_EQ(driver_index_client.status_value(), ZX_OK);
  DriverRunner driver_runner(ConnectToRealm(), std::move(driver_index_client.value()), inspector(),
                             loop().dispatcher());
  auto defer = fit::defer([this] { Unbind(); });

  driver_host().SetStartHandler([this](fdf::DriverStartArgs start_args, auto request) {
    Emplace(std::move(request));
    auto& entries = start_args.program().entries();
    EXPECT_EQ(2u, entries.size());
    EXPECT_EQ("binary", entries[0].key);
    EXPECT_EQ("driver/root-driver.so", entries[0].value->str());
    EXPECT_EQ("colocate", entries[1].key);
    EXPECT_EQ("false", entries[1].value->str());

    realm().SetCreateChildHandler([](fsys::CollectionRef collection, fsys::ChildDecl decl) {
      EXPECT_EQ("boot-drivers", collection.name);
      EXPECT_EQ("root.second", decl.name());
      EXPECT_EQ("fuchsia-boot:///#meta/second-driver.cm", decl.url());
    });
    realm().SetBindChildHandler([this](fsys::ChildRef child, auto exposed_dir) {
      EXPECT_EQ("boot-drivers", child.collection);
      EXPECT_EQ("root.second", child.name);
      EXPECT_EQ(ZX_OK, driver_dir_binding().Bind(std::move(exposed_dir), loop().dispatcher()));
    });

    fdf::NodePtr root_node;
    EXPECT_EQ(ZX_OK, root_node.Bind(std::move(*start_args.mutable_node()), loop().dispatcher()));
    fdf::NodeAddArgs args;
    args.set_name("second");
    args.mutable_offers()->emplace_back("fuchsia.package.Protocol");
    args.mutable_symbols()->emplace_back(
        std::move(fdf::NodeSymbol().set_name("sym").set_address(0xfeed)));
    fdf::NodeControllerPtr node_controller;
    root_node->AddChild(std::move(args), node_controller.NewRequest(loop().dispatcher()), {},
                        [](auto result) { EXPECT_FALSE(result.is_err()); });
  });
  ASSERT_TRUE(StartRootDriver("fuchsia-boot:///#meta/root-driver.cm", &driver_runner).is_ok());

  driver_host().SetStartHandler([this](fdf::DriverStartArgs start_args, auto request) {
    Emplace(std::move(request));
    auto& offers = start_args.offers();
    EXPECT_EQ(1u, offers.size());
    EXPECT_EQ("fuchsia.package.Protocol", offers[0]);
    EXPECT_TRUE(start_args.symbols().empty());
    auto& entries = start_args.program().entries();
    EXPECT_EQ(2u, entries.size());
    EXPECT_EQ("binary", entries[0].key);
    EXPECT_EQ("driver/second-driver.so", entries[0].value->str());
    EXPECT_EQ("colocate", entries[1].key);
    EXPECT_EQ("false", entries[1].value->str());
    EXPECT_TRUE(start_args.exposed_dir().is_valid());
  });
  StartDriverHost("driver_hosts", "driver_host-1");
  StartDriver(&driver_runner, {
                                  .url = "fuchsia-boot:///#meta/second-driver.cm",
                                  .binary = "driver/second-driver.so",
                              });
}

// Start the root driver, and then start a second driver in the same driver
// host.
TEST_F(DriverRunnerTest, StartSecondDriver_SameDriverHost) {
  auto driver_index = CreateDriverIndex();
  auto driver_index_client = driver_index.Connect();
  ASSERT_EQ(driver_index_client.status_value(), ZX_OK);
  DriverRunner driver_runner(ConnectToRealm(), std::move(driver_index_client.value()), inspector(),
                             loop().dispatcher());
  auto defer = fit::defer([this] { Unbind(); });

  driver_host().SetStartHandler([this](fdf::DriverStartArgs start_args, auto request) {
    Emplace(std::move(request));
    auto& entries = start_args.program().entries();
    EXPECT_EQ(2u, entries.size());
    EXPECT_EQ("binary", entries[0].key);
    EXPECT_EQ("driver/root-driver.so", entries[0].value->str());
    EXPECT_EQ("colocate", entries[1].key);
    EXPECT_EQ("false", entries[1].value->str());

    realm().SetCreateChildHandler([](fsys::CollectionRef collection, fsys::ChildDecl decl) {
      EXPECT_EQ("boot-drivers", collection.name);
      EXPECT_EQ("root.second", decl.name());
      EXPECT_EQ("fuchsia-boot:///#meta/second-driver.cm", decl.url());
    });
    realm().SetBindChildHandler([this](fsys::ChildRef child, auto exposed_dir) {
      EXPECT_EQ("boot-drivers", child.collection);
      EXPECT_EQ("root.second", child.name);
      EXPECT_EQ(ZX_OK, driver_dir_binding().Bind(std::move(exposed_dir), loop().dispatcher()));
    });

    fdf::NodePtr root_node;
    EXPECT_EQ(ZX_OK, root_node.Bind(std::move(*start_args.mutable_node()), loop().dispatcher()));
    fdf::NodeAddArgs args;
    args.set_name("second");
    args.mutable_offers()->emplace_back("fuchsia.package.Protocol");
    args.mutable_symbols()->emplace_back(
        std::move(fdf::NodeSymbol().set_name("sym").set_address(0xfeed)));
    fdf::NodeControllerPtr node_controller;
    root_node->AddChild(std::move(args), node_controller.NewRequest(loop().dispatcher()), {},
                        [](auto result) { EXPECT_FALSE(result.is_err()); });
  });
  ASSERT_TRUE(StartRootDriver("fuchsia-boot:///#meta/root-driver.cm", &driver_runner).is_ok());

  driver_host().SetStartHandler([this](fdf::DriverStartArgs start_args, auto request) {
    Emplace(std::move(request));
    auto& offers = start_args.offers();
    EXPECT_EQ(1u, offers.size());
    EXPECT_EQ("fuchsia.package.Protocol", offers[0]);
    auto& symbols = start_args.symbols();
    EXPECT_EQ(1u, symbols.size());
    EXPECT_EQ("sym", symbols[0].name());
    EXPECT_EQ(0xfeedu, symbols[0].address());
    auto& entries = start_args.program().entries();
    EXPECT_EQ(2u, entries.size());
    EXPECT_EQ("binary", entries[0].key);
    EXPECT_EQ("driver/second-driver.so", entries[0].value->str());
    EXPECT_EQ("colocate", entries[1].key);
    EXPECT_EQ("true", entries[1].value->str());
    EXPECT_TRUE(start_args.exposed_dir().is_valid());
  });
  StartDriver(&driver_runner, {
                                  .url = "fuchsia-boot:///#meta/second-driver.cm",
                                  .binary = "driver/second-driver.so",
                                  .colocate = true,
                              });
}

// Start the root driver, and then start a second driver that we match based on
// node properties.
TEST_F(DriverRunnerTest, StartSecondDriver_UseProperties) {
  FakeDriverIndex driver_index(
      loop().dispatcher(), [](auto args) -> zx::status<FakeDriverIndex::MatchResult> {
        if (args.has_properties() && args.properties()[0].key() == 0x1985 &&
            args.properties()[0].value() == 0x2301) {
          return zx::ok(FakeDriverIndex::MatchResult{
              .url = "fuchsia-boot:///#meta/second-driver.cm",
              .matched_args = std::move(args),
          });
        } else {
          return zx::error(ZX_ERR_NOT_FOUND);
        }
      });
  auto driver_index_client = driver_index.Connect();
  ASSERT_EQ(driver_index_client.status_value(), ZX_OK);
  DriverRunner driver_runner(ConnectToRealm(), std::move(driver_index_client.value()), inspector(),
                             loop().dispatcher());
  auto defer = fit::defer([this] { Unbind(); });

  driver_host().SetStartHandler([this](fdf::DriverStartArgs start_args, auto request) {
    Emplace(std::move(request));
    auto& entries = start_args.program().entries();
    EXPECT_EQ(2u, entries.size());
    EXPECT_EQ("binary", entries[0].key);
    EXPECT_EQ("driver/root-driver.so", entries[0].value->str());
    EXPECT_EQ("colocate", entries[1].key);
    EXPECT_EQ("false", entries[1].value->str());

    realm().SetCreateChildHandler([](fsys::CollectionRef collection, fsys::ChildDecl decl) {
      EXPECT_EQ("boot-drivers", collection.name);
      EXPECT_EQ("root.second", decl.name());
      EXPECT_EQ("fuchsia-boot:///#meta/second-driver.cm", decl.url());
    });
    realm().SetBindChildHandler([this](fsys::ChildRef child, auto exposed_dir) {
      EXPECT_EQ("boot-drivers", child.collection);
      EXPECT_EQ("root.second", child.name);
      EXPECT_EQ(ZX_OK, driver_dir_binding().Bind(std::move(exposed_dir), loop().dispatcher()));
    });

    fdf::NodePtr root_node;
    EXPECT_EQ(ZX_OK, root_node.Bind(std::move(*start_args.mutable_node()), loop().dispatcher()));
    fdf::NodeAddArgs args;
    args.set_name("second");
    args.mutable_properties()->emplace_back(
        std::move(fdf::NodeProperty().set_key(0x1985).set_value(0x2301)));
    fdf::NodeControllerPtr node_controller;
    root_node->AddChild(std::move(args), node_controller.NewRequest(loop().dispatcher()), {},
                        [](auto result) { EXPECT_FALSE(result.is_err()); });
  });
  ASSERT_TRUE(StartRootDriver("fuchsia-boot:///#meta/root-driver.cm", &driver_runner).is_ok());

  driver_host().SetStartHandler([this](fdf::DriverStartArgs start_args, auto request) {
    Emplace(std::move(request));
    auto& entries = start_args.program().entries();
    EXPECT_EQ(2u, entries.size());
    EXPECT_EQ("binary", entries[0].key);
    EXPECT_EQ("driver/second-driver.so", entries[0].value->str());
    EXPECT_EQ("colocate", entries[1].key);
    EXPECT_EQ("true", entries[1].value->str());
    EXPECT_TRUE(start_args.exposed_dir().is_valid());
  });
  StartDriver(&driver_runner, {
                                  .url = "fuchsia-boot:///#meta/second-driver.cm",
                                  .binary = "driver/second-driver.so",
                                  .colocate = true,
                              });
}

// Start the root driver, and then add a child node that does not bind to a
// second driver.
TEST_F(DriverRunnerTest, StartSecondDriver_UnknownNode) {
  auto driver_index = CreateDriverIndex();
  auto driver_index_client = driver_index.Connect();
  ASSERT_EQ(driver_index_client.status_value(), ZX_OK);
  DriverRunner driver_runner(ConnectToRealm(), std::move(driver_index_client.value()), inspector(),
                             loop().dispatcher());
  auto defer = fit::defer([this] { Unbind(); });

  driver_host().SetStartHandler([this](fdf::DriverStartArgs start_args, auto request) {
    Emplace(std::move(request));
    auto& entries = start_args.program().entries();
    EXPECT_EQ(2u, entries.size());
    EXPECT_EQ("binary", entries[0].key);
    EXPECT_EQ("driver/root-driver.so", entries[0].value->str());
    EXPECT_EQ("colocate", entries[1].key);
    EXPECT_EQ("false", entries[1].value->str());

    fdf::NodePtr root_node;
    EXPECT_EQ(ZX_OK, root_node.Bind(std::move(*start_args.mutable_node()), loop().dispatcher()));
    fdf::NodeAddArgs args;
    args.set_name("unknown-node");
    fdf::NodeControllerPtr node_controller;
    root_node->AddChild(std::move(args), node_controller.NewRequest(loop().dispatcher()), {},
                        [](auto result) { EXPECT_FALSE(result.is_err()); });
  });
  ASSERT_TRUE(StartRootDriver("fuchsia-boot:///#meta/root-driver.cm", &driver_runner).is_ok());

  StartDriver(&driver_runner, {.close = true});
}

// Start the second driver, and then unbind its associated node.
TEST_F(DriverRunnerTest, StartSecondDriver_UnbindSecondNode) {
  auto driver_index = CreateDriverIndex();
  auto driver_index_client = driver_index.Connect();
  ASSERT_EQ(driver_index_client.status_value(), ZX_OK);
  DriverRunner driver_runner(ConnectToRealm(), std::move(driver_index_client.value()), inspector(),
                             loop().dispatcher());
  auto defer = fit::defer([this] { Unbind(); });

  fdf::NodePtr root_node;
  driver_host().SetStartHandler([this, &root_node](fdf::DriverStartArgs start_args, auto request) {
    Emplace(std::move(request));
    realm().SetCreateChildHandler([](fsys::CollectionRef collection, fsys::ChildDecl decl) {});
    realm().SetBindChildHandler([this](fsys::ChildRef child, auto exposed_dir) {
      EXPECT_EQ(ZX_OK, driver_dir_binding().Bind(std::move(exposed_dir), loop().dispatcher()));
    });

    EXPECT_EQ(ZX_OK, root_node.Bind(std::move(*start_args.mutable_node()), loop().dispatcher()));
    fdf::NodeAddArgs args;
    args.set_name("second");
    fdf::NodeControllerPtr node_controller;
    root_node->AddChild(std::move(args), node_controller.NewRequest(loop().dispatcher()), {},
                        [](auto result) { EXPECT_FALSE(result.is_err()); });
  });
  auto root_driver = StartRootDriver("fuchsia-boot:///#meta/root-driver.cm", &driver_runner);
  ASSERT_TRUE(root_driver.is_ok());

  fdf::NodePtr second_node;
  driver_host().SetStartHandler([this, &second_node](fdf::DriverStartArgs start_args,
                                                     auto request) {
    Emplace(std::move(request));
    EXPECT_EQ(ZX_OK, second_node.Bind(std::move(*start_args.mutable_node()), loop().dispatcher()));
  });

  StartDriverHost("driver_hosts", "driver_host-1");
  zx::channel second_driver =
      StartDriver(&driver_runner, {
                                      .url = "fuchsia-boot:///#meta/second-driver.cm",
                                      .binary = "driver/second-driver.so",
                                  });

  // Unbinding the second node stops the driver bound to it.
  second_node.Unbind();
  realm().SetDestroyChildHandler([](fsys::ChildRef child) {
    EXPECT_EQ("root.second", child.name);
    EXPECT_EQ("boot-drivers", child.collection);
  });
  loop().RunUntilIdle();
  zx_signals_t signals = 0;
  ASSERT_EQ(ZX_OK, second_driver.wait_one(ZX_CHANNEL_PEER_CLOSED, zx::time::infinite(), &signals));
  ASSERT_TRUE(signals & ZX_CHANNEL_PEER_CLOSED);

  // On destruction, we unbind the root node, which stops the root driver.
  realm().SetDestroyChildHandler([](fsys::ChildRef child) {
    EXPECT_EQ("root", child.name);
    EXPECT_EQ("boot-drivers", child.collection);
  });
}

// Start the second driver, and then close the associated Driver protocol
// channel.
TEST_F(DriverRunnerTest, StartSecondDriver_CloseSecondDriver) {
  auto driver_index = CreateDriverIndex();
  auto driver_index_client = driver_index.Connect();
  ASSERT_EQ(driver_index_client.status_value(), ZX_OK);
  DriverRunner driver_runner(ConnectToRealm(), std::move(driver_index_client.value()), inspector(),
                             loop().dispatcher());
  auto defer = fit::defer([this] { Unbind(); });

  fdf::NodePtr root_node;
  driver_host().SetStartHandler([this, &root_node](fdf::DriverStartArgs start_args, auto request) {
    Emplace(std::move(request));
    realm().SetCreateChildHandler([](fsys::CollectionRef collection, fsys::ChildDecl decl) {});
    realm().SetBindChildHandler([this](fsys::ChildRef child, auto exposed_dir) {
      EXPECT_EQ(ZX_OK, driver_dir_binding().Bind(std::move(exposed_dir), loop().dispatcher()));
    });

    EXPECT_EQ(ZX_OK, root_node.Bind(std::move(*start_args.mutable_node()), loop().dispatcher()));
    fdf::NodeAddArgs args;
    args.set_name("second");
    fdf::NodeControllerPtr node_controller;
    root_node->AddChild(std::move(args), node_controller.NewRequest(loop().dispatcher()), {},
                        [](auto result) { EXPECT_FALSE(result.is_err()); });
  });
  auto root_driver = StartRootDriver("fuchsia-boot:///#meta/root-driver.cm", &driver_runner);
  ASSERT_TRUE(root_driver.is_ok());

  fdf::NodePtr second_node;
  fidl::InterfaceRequest<fdf::Driver> second_request;
  driver_host().SetStartHandler([this, &second_node, &second_request](
                                    fdf::DriverStartArgs start_args, auto request) {
    second_request = std::move(request);
    EXPECT_EQ(ZX_OK, second_node.Bind(std::move(*start_args.mutable_node()), loop().dispatcher()));
  });

  StartDriverHost("driver_hosts", "driver_host-1");
  zx::channel second_driver =
      StartDriver(&driver_runner, {
                                      .url = "fuchsia-boot:///#meta/second-driver.cm",
                                      .binary = "driver/second-driver.so",
                                  });

  // Closing the Driver protocol channel of the second driver causes the driver
  // to be stopped.
  second_request.TakeChannel();
  loop().RunUntilIdle();
  zx_signals_t signals = 0;
  ASSERT_EQ(ZX_OK, second_driver.wait_one(ZX_CHANNEL_PEER_CLOSED, zx::time::infinite(), &signals));
  ASSERT_TRUE(signals & ZX_CHANNEL_PEER_CLOSED);
}

// Start a chain of drivers, and then unbind the second driver's node.
TEST_F(DriverRunnerTest, StartDriverChain_UnbindSecondNode) {
  FakeDriverIndex driver_index(loop().dispatcher(),
                               [](auto args) -> zx::status<FakeDriverIndex::MatchResult> {
                                 std::string name(args.name().data(), args.name().size());
                                 return zx::ok(FakeDriverIndex::MatchResult{
                                     .url = "fuchsia-boot:///#meta/" + name + "-driver.cm",
                                     .matched_args = std::move(args),
                                 });
                               });
  auto driver_index_client = driver_index.Connect();
  ASSERT_EQ(driver_index_client.status_value(), ZX_OK);
  DriverRunner driver_runner(ConnectToRealm(), std::move(driver_index_client.value()), inspector(),
                             loop().dispatcher());
  auto defer = fit::defer([this] { Unbind(); });

  fdf::NodePtr root_node;
  driver_host().SetStartHandler([this, &root_node](fdf::DriverStartArgs start_args, auto request) {
    Emplace(std::move(request));
    realm().SetCreateChildHandler([](fsys::CollectionRef collection, fsys::ChildDecl decl) {});
    realm().SetBindChildHandler([this](fsys::ChildRef child, auto exposed_dir) {
      EXPECT_EQ(ZX_OK, driver_dir_binding().Bind(std::move(exposed_dir), loop().dispatcher()));
    });

    EXPECT_EQ(ZX_OK, root_node.Bind(std::move(*start_args.mutable_node()), loop().dispatcher()));
    fdf::NodeAddArgs args;
    args.set_name("node-0");
    fdf::NodeControllerPtr node_controller;
    root_node->AddChild(std::move(args), node_controller.NewRequest(loop().dispatcher()), {},
                        [](auto result) { EXPECT_FALSE(result.is_err()); });
  });
  auto root_driver = StartRootDriver("fuchsia-boot:///#meta/root-driver.cm", &driver_runner);
  ASSERT_TRUE(root_driver.is_ok());

  constexpr size_t kMaxNodes = 10;
  std::vector<fdf::NodePtr> nodes;
  std::vector<zx::channel> drivers;
  for (size_t i = 1; i <= kMaxNodes; i++) {
    driver_host().SetStartHandler([this, &nodes, i](fdf::DriverStartArgs start_args, auto request) {
      Emplace(std::move(request));
      realm().SetCreateChildHandler([](fsys::CollectionRef collection, fsys::ChildDecl decl) {});
      realm().SetBindChildHandler([this](fsys::ChildRef child, auto exposed_dir) {
        EXPECT_EQ(ZX_OK, driver_dir_binding().Bind(std::move(exposed_dir), loop().dispatcher()));
      });

      auto& node = nodes.emplace_back();
      EXPECT_EQ(ZX_OK, node.Bind(std::move(*start_args.mutable_node()), loop().dispatcher()));
      // Only add a node that a driver will be bound to.
      if (i != kMaxNodes) {
        fdf::NodeAddArgs args;
        args.set_name("node-" + std::to_string(i));
        fdf::NodeControllerPtr node_controller;
        node->AddChild(std::move(args), node_controller.NewRequest(loop().dispatcher()), {},
                       [](auto result) { EXPECT_FALSE(result.is_err()); });
      }
    });

    StartDriverHost("driver_hosts", "driver_host-" + std::to_string(i));
    drivers.emplace_back(
        StartDriver(&driver_runner,
                    {
                        .url = "fuchsia-boot:///#meta/node-" + std::to_string(i - 1) + "-driver.cm",
                        .binary = "driver/driver.so",
                    }));
  }

  // Unbinding the second node stops all drivers bound in the sub-tree, in a
  // depth-first order.
  std::vector<size_t> indices;
  std::vector<fidl::Client<frunner::ComponentController>> clients;
  for (auto& driver : drivers) {
    clients.emplace_back(std::move(driver), loop().dispatcher(),
                         std::make_shared<UnbindWatcher>(clients.size() + 1, indices));
  }
  nodes.front().Unbind();
  loop().RunUntilIdle();
  EXPECT_THAT(indices, ElementsAre(10, 9, 8, 7, 6, 5, 4, 3, 2, 1));
}

// Start the second driver, and then unbind the root node.
TEST_F(DriverRunnerTest, StartSecondDriver_UnbindRootNode) {
  auto driver_index = CreateDriverIndex();
  auto driver_index_client = driver_index.Connect();
  ASSERT_EQ(driver_index_client.status_value(), ZX_OK);
  DriverRunner driver_runner(ConnectToRealm(), std::move(driver_index_client.value()), inspector(),
                             loop().dispatcher());
  auto defer = fit::defer([this] { Unbind(); });

  fdf::NodePtr root_node;
  driver_host().SetStartHandler([this, &root_node](fdf::DriverStartArgs start_args, auto request) {
    Emplace(std::move(request));
    realm().SetCreateChildHandler([](fsys::CollectionRef collection, fsys::ChildDecl decl) {});
    realm().SetBindChildHandler([this](fsys::ChildRef child, auto exposed_dir) {
      EXPECT_EQ(ZX_OK, driver_dir_binding().Bind(std::move(exposed_dir), loop().dispatcher()));
    });

    EXPECT_EQ(ZX_OK, root_node.Bind(std::move(*start_args.mutable_node()), loop().dispatcher()));
    fdf::NodeAddArgs args;
    args.set_name("second");
    fdf::NodeControllerPtr node_controller;
    root_node->AddChild(std::move(args), node_controller.NewRequest(loop().dispatcher()), {},
                        [](auto result) { EXPECT_FALSE(result.is_err()); });
  });
  auto root_driver = StartRootDriver("fuchsia-boot:///#meta/root-driver.cm", &driver_runner);
  ASSERT_TRUE(root_driver.is_ok());

  fdf::NodePtr second_node;
  driver_host().SetStartHandler([this, &second_node](fdf::DriverStartArgs start_args,
                                                     auto request) {
    Emplace(std::move(request));
    EXPECT_EQ(ZX_OK, second_node.Bind(std::move(*start_args.mutable_node()), loop().dispatcher()));
  });

  StartDriverHost("driver_hosts", "driver_host-1");
  zx::channel second_driver =
      StartDriver(&driver_runner, {
                                      .url = "fuchsia-boot:///#meta/second-driver.cm",
                                      .binary = "driver/second-driver.so",
                                  });

  // Unbinding the root node stops all drivers.
  std::vector<size_t> indices;
  fidl::Client<frunner::ComponentController> root_client(
      std::move(root_driver.value()), loop().dispatcher(),
      std::make_shared<UnbindWatcher>(0, indices));
  fidl::Client<frunner::ComponentController> second_client(
      std::move(second_driver), loop().dispatcher(), std::make_shared<UnbindWatcher>(1, indices));
  root_node.Unbind();
  loop().RunUntilIdle();
  EXPECT_THAT(indices, ElementsAre(1, 0));
}

// Start the second driver, and then stop the root driver.
TEST_F(DriverRunnerTest, StartSecondDriver_StopRootDriver) {
  auto driver_index = CreateDriverIndex();
  auto driver_index_client = driver_index.Connect();
  ASSERT_EQ(driver_index_client.status_value(), ZX_OK);
  DriverRunner driver_runner(ConnectToRealm(), std::move(driver_index_client.value()), inspector(),
                             loop().dispatcher());
  auto defer = fit::defer([this] { Unbind(); });

  fdf::NodePtr root_node;
  driver_host().SetStartHandler([this, &root_node](fdf::DriverStartArgs start_args, auto request) {
    Emplace(std::move(request));
    realm().SetCreateChildHandler([](fsys::CollectionRef collection, fsys::ChildDecl decl) {});
    realm().SetBindChildHandler([this](fsys::ChildRef child, auto exposed_dir) {
      EXPECT_EQ(ZX_OK, driver_dir_binding().Bind(std::move(exposed_dir), loop().dispatcher()));
    });

    EXPECT_EQ(ZX_OK, root_node.Bind(std::move(*start_args.mutable_node()), loop().dispatcher()));
    fdf::NodeAddArgs args;
    args.set_name("second");
    fdf::NodeControllerPtr node_controller;
    root_node->AddChild(std::move(args), node_controller.NewRequest(loop().dispatcher()), {},
                        [](auto result) { EXPECT_FALSE(result.is_err()); });
  });
  auto root_driver = StartRootDriver("fuchsia-boot:///#meta/root-driver.cm", &driver_runner);
  ASSERT_TRUE(root_driver.is_ok());
  zx::unowned_channel unowned_root_driver(root_driver.value());

  driver_host().SetStartHandler(
      [this](fdf::DriverStartArgs start_args, auto request) { Emplace(std::move(request)); });

  StartDriverHost("driver_hosts", "driver_host-1");
  zx::channel second_driver =
      StartDriver(&driver_runner, {
                                      .url = "fuchsia-boot:///#meta/second-driver.cm",
                                      .binary = "driver/second-driver.so",
                                  });

  // Stopping the root driver stops all drivers.
  std::vector<size_t> indices;
  fidl::Client<frunner::ComponentController> root_client(
      std::move(root_driver.value()), loop().dispatcher(),
      std::make_shared<UnbindWatcher>(0, indices));
  fidl::Client<frunner::ComponentController> second_client(
      std::move(second_driver), loop().dispatcher(), std::make_shared<UnbindWatcher>(1, indices));
  root_client->Stop();
  loop().RunUntilIdle();
  EXPECT_THAT(indices, ElementsAre(1, 0));
}

// Start a driver and inspect the driver runner.
TEST_F(DriverRunnerTest, StartAndInspect) {
  auto driver_index = CreateDriverIndex();
  auto driver_index_client = driver_index.Connect();
  ASSERT_EQ(driver_index_client.status_value(), ZX_OK);
  DriverRunner driver_runner(ConnectToRealm(), std::move(driver_index_client.value()), inspector(),
                             loop().dispatcher());
  auto defer = fit::defer([this] { Unbind(); });

  driver_host().SetStartHandler([this](fdf::DriverStartArgs start_args, auto request) {
    Emplace(std::move(request));
    realm().SetCreateChildHandler([](fsys::CollectionRef collection, fsys::ChildDecl decl) {});
    realm().SetBindChildHandler([this](fsys::ChildRef child, auto exposed_dir) {
      EXPECT_EQ(ZX_OK, driver_dir_binding().Bind(std::move(exposed_dir), loop().dispatcher()));
    });

    fdf::NodePtr root_node;
    EXPECT_EQ(ZX_OK, root_node.Bind(std::move(*start_args.mutable_node()), loop().dispatcher()));
    fdf::NodeAddArgs args;
    args.set_name("second");
    args.mutable_offers()->emplace_back("fuchsia.package.ProtocolA");
    args.mutable_offers()->emplace_back("fuchsia.package.ProtocolB");
    args.mutable_symbols()->emplace_back(
        std::move(fdf::NodeSymbol().set_name("symbol-A").set_address(0x2301)));
    args.mutable_symbols()->emplace_back(
        std::move(fdf::NodeSymbol().set_name("symbol-B").set_address(0x1985)));
    fdf::NodeControllerPtr node_controller;
    root_node->AddChild(std::move(args), node_controller.NewRequest(loop().dispatcher()), {},
                        [](auto result) { EXPECT_FALSE(result.is_err()); });
  });
  ASSERT_TRUE(StartRootDriver("fuchsia-boot:///#meta/root-driver.cm", &driver_runner).is_ok());

  EXPECT_THAT(
      Inspect(&driver_runner),
      AllOf(NodeMatches(NameMatches("root")),
            ChildrenMatch(UnorderedElementsAre(AllOf(
                NodeMatches(NameMatches("root")),
                ChildrenMatch(UnorderedElementsAre(AllOf(NodeMatches(AllOf(
                    NameMatches("second"),
                    PropertyList(UnorderedElementsAre(
                        StringIs("offers", "fuchsia.package.ProtocolA, fuchsia.package.ProtocolB"),
                        StringIs("symbols", "symbol-A, symbol-B")))))))))))));
}