src/lib/component/serve_test.go - fuchsia - Git at Google

 // 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.

 //go:build !build_with_native_toolchain
 // +build !build_with_native_toolchain

 package component_test

 import (
 	"context"
 	"errors"
 	"sync"
 	"syscall/zx"
 	"syscall/zx/fidl"
 	"syscall/zx/zxwait"
 	"testing"
 	"time"

 	"go.fuchsia.dev/fuchsia/src/lib/component"

 	"fidl/bindingstest"
 )

 var _ bindingstest.Test1WithCtx = (*test1Impl)(nil)

 type test1Impl struct{}

 func (*test1Impl) Echo(_ fidl.Context, s *string) (*string, error) {
 	return s, nil
 }

 func (*test1Impl) NoResponse(fidl.Context) error {
 	return nil
 }

 func (*test1Impl) EmptyResponse(fidl.Context) error {
 	return nil
 }

 func (*test1Impl) TooManyBytesInResponse(fidl.Context) ([]uint8, error) {
 	return make([]uint8, zx.ChannelMaxMessageBytes+1), nil
 }

 func (*test1Impl) TooManyHandlesInResponse(fidl.Context) ([]zx.Handle, error) {
 	out := make([]zx.Handle, zx.ChannelMaxMessageHandles+1)
 	for i := range out {
 		out[i] = 1 // to avoid zx.HandleInvalid(0).
 	}
 	return out, nil
 }

 func (*test1Impl) EchoHandleRights(_ fidl.Context, h zx.Port) (uint32, error) {
 	infoHandleBasic, err := h.Handle().GetInfoHandleBasic()
 	if err != nil {
 		return 0, err
 	}
 	return uint32(infoHandleBasic.Rights), h.Close()
 }

 func TestEmptyWriteErrors(t *testing.T) {
 	var wg sync.WaitGroup

 	ch, sh, err := zx.NewChannel(0)
 	if err != nil {
 		t.Fatal(err)
 	}
 	defer func() {
 		if err := ch.Close(); err != nil {
 			t.Error(err)
 		}
 		// Wait for the serving goroutine to exit, then confirm that Serve
 		// closed the channel.
 		wg.Wait()
 		err := sh.Close()
 		if err, ok := err.(*zx.Error); ok && err.Status == zx.ErrBadHandle {
 			return
 		}
 		t.Errorf("got sh.Close() = %v, want %q", err, zx.ErrBadHandle)
 	}()

 	errChan := make(chan error, 1)

 	wg.Add(1)
 	go func() {
 		defer wg.Done()
 		component.Serve(context.Background(), &bindingstest.Test1WithCtxStub{
 			Impl: &test1Impl{},
 		}, sh, component.ServeOptions{
 			OnError: func(err error) {
 				errChan <- err
 			},
 		})
 	}()

 	if err := ch.Write(nil, nil, 0); err != nil {
 		t.Fatal(err)
 	}

 	if _, err := zxwait.WaitContext(context.Background(), zx.Handle(ch), zx.SignalChannelPeerClosed); err != nil {
 		t.Fatal(err)
 	}

 	close(errChan)
 	for err := range errChan {
 		if !errors.Is(err, fidl.ErrPayloadTooSmall) {
 			t.Errorf("got Serve error = %v, want %q", err, fidl.ErrPayloadTooSmall)
 		}
 	}
 }

 func TestEcho(t *testing.T) {
 	var wg sync.WaitGroup

 	ch, sh, err := zx.NewChannel(0)
 	if err != nil {
 		t.Fatal(err)
 	}
 	defer func() {
 		// Expect the final test to have closed the client.
 		func() {
 			err := ch.Close()
 			if err, ok := err.(*zx.Error); ok && err.Status == zx.ErrBadHandle {
 				return
 			}
 			t.Errorf("got ch.Close() = %v, want %q", err, zx.ErrBadHandle)
 		}()
 		// Wait for the serving goroutine to exit, then confirm that Serve
 		// closed the channel.
 		wg.Wait()
 		func() {
 			err := sh.Close()
 			if err, ok := err.(*zx.Error); ok && err.Status == zx.ErrBadHandle {
 				return
 			}
 			t.Errorf("got sh.Close() = %v, want %q", err, zx.ErrBadHandle)
 		}()
 	}()

 	wg.Add(1)
 	go func() {
 		defer wg.Done()
 		component.Serve(context.Background(), &bindingstest.Test1WithCtxStub{
 			Impl: &test1Impl{},
 		}, sh, component.ServeOptions{
 			OnError: func(err error) {
 				t.Error(err)
 			},
 		})
 	}()

 	client := bindingstest.Test1WithCtxInterface{Channel: ch}

 	t.Run("Basic", func(t *testing.T) {
 		str := "Hello World!"
 		r, err := client.Echo(context.Background(), &str)
 		if err != nil {
 			t.Fatal(err)
 		}
 		if r == nil {
 			t.Fatalf("got Echo(%q) = nil", str)
 		}
 		if *r != str {
 			t.Fatalf("got Echo(%q) = %q", str, *r)
 		}
 	})

 	t.Run("NoResponse", func(t *testing.T) {
 		if err := client.NoResponse(context.Background()); err != nil {
 			t.Fatal(err)
 		}
 	})

 	t.Run("EmptyResponse", func(t *testing.T) {
 		if err := client.EmptyResponse(context.Background()); err != nil {
 			t.Fatal(err)
 		}
 	})

 	t.Run("Event", func(t *testing.T) {
 		const str = "Surprise!"
 		pxy := bindingstest.Test1EventProxy{Channel: sh}
 		if err := pxy.Surprise(str); err != nil {
 			t.Fatal(err)
 		}
 		s, err := client.ExpectSurprise(context.Background())
 		if err != nil {
 			t.Fatal(err)
 		}
 		if s != str {
 			t.Fatalf("got Event = %q, want %q", str, s)
 		}
 	})

 	t.Run("ReducingHandleRights", func(t *testing.T) {
 		const expectedRights = zx.RightTransfer | zx.RightDuplicate | zx.RightRead
 		port, err := zx.NewPort(0)
 		if err != nil {
 			t.Fatal(err)
 		}
 		defer func() {
 			err := port.Close()
 			// Ownership should have moved to the server, and it should have closed
 			// the handle.
 			if err, ok := err.(*zx.Error); ok && err.Status == zx.ErrBadHandle {
 				return
 			}
 			t.Errorf("got port.Close() = %v, want %q", err, zx.ErrBadHandle)
 		}()
 		handleInfo, err := port.Handle().GetInfoHandleBasic()
 		if err != nil {
 			t.Fatal(err)
 		}
 		if !handleInfo.Rights.StrictSupersetOf(expectedRights) {
 			t.Fatalf("got !(%b).StrictSupersetOf(%b)", handleInfo.Rights, expectedRights)
 		}
 		rights, err := client.EchoHandleRights(context.Background(), port)
 		if err != nil {
 			t.Fatal(err)
 		}
 		if rights := zx.Rights(rights); rights != expectedRights {
 			t.Fatalf("got EchoHandleRights(...) = %b, want %b", rights, expectedRights)
 		}
 	})

 	t.Run("MissingExpectedRightsSendingSide", func(t *testing.T) {
 		// This test tests the sending side when there are missing expected rights.
 		// The receiving side is harder to test because there needs to be a
 		// mismatch of rights on the sending and receiving side.
 		port, err := zx.NewPort(0)
 		if err != nil {
 			t.Fatal(err)
 		}
 		defer func() {
 			err := port.Close()
 			// This handle should have been consumed by the replace below.
 			if err, ok := err.(*zx.Error); ok && err.Status == zx.ErrBadHandle {
 				return
 			}
 			t.Errorf("got port.Close() = %v, want %q", err, zx.ErrBadHandle)
 		}()
 		const reducedRights = zx.RightTransfer | zx.RightDuplicate
 		h, err := port.Handle().Replace(reducedRights)
 		if err != nil {
 			t.Fatal(err)
 		}
 		defer func() {
 			err := h.Close()
 			// Ownership should have moved to the server, and it should have closed
 			// the handle.
 			if err, ok := err.(*zx.Error); ok && err.Status == zx.ErrBadHandle {
 				return
 			}
 			t.Errorf("got h.Close() = %v, want %q", err, zx.ErrBadHandle)
 		}()
 		handleInfo, err := h.GetInfoHandleBasic()
 		if err != nil {
 			t.Fatal(err)
 		}
 		if handleInfo.Rights != reducedRights {
 			t.Fatalf("got Rights = %b, want %b", handleInfo.Rights, reducedRights)
 		}
 		{
 			_, err := client.EchoHandleRights(context.Background(), zx.Port(h))
 			if err, ok := err.(*zx.Error); ok && err.Status == zx.ErrInvalidArgs {
 				return
 			}
 			t.Fatalf("got EchoHandleRights(reducedRights) = %v, want %q", err, zx.ErrInvalidArgs)
 		}
 	})
 }

 func TestRespondErrors(t *testing.T) {
 	tests := []struct {
 		name              string
 		call              func(*bindingstest.Test1WithCtxInterface) error
 		expectErr         zx.Status
 		expectErrOnServer error
 	}{
 		{
 			name: "TooManyBytes",
 			call: func(client *bindingstest.Test1WithCtxInterface) error {
 				_, err := client.TooManyBytesInResponse(context.Background())
 				return err
 			},
 			expectErr:         zx.ErrPeerClosed,
 			expectErrOnServer: component.ErrTooManyBytesInResponse,
 		},
 		{
 			name: "TooManyHandles",
 			call: func(client *bindingstest.Test1WithCtxInterface) error {
 				_, err := client.TooManyHandlesInResponse(context.Background())
 				return err
 			},
 			expectErr:         zx.ErrPeerClosed,
 			expectErrOnServer: component.ErrTooManyHandlesInResponse,
 		},
 	}

 	for _, test := range tests {
 		t.Run(test.name, func(t *testing.T) {
 			var wg sync.WaitGroup
 			defer wg.Wait()

 			ch, sh, err := zx.NewChannel(0)
 			if err != nil {
 				t.Fatal(err)
 			}

 			errChan := make(chan error, 1)
 			wg.Add(1)
 			go func() {
 				defer wg.Done()
 				component.Serve(context.Background(), &bindingstest.Test1WithCtxStub{
 					Impl: &test1Impl{},
 				}, sh, component.ServeOptions{
 					OnError: func(err error) {
 						errChan <- err
 					},
 				})
 			}()

 			err = test.call(&bindingstest.Test1WithCtxInterface{Channel: ch})
 			if err, ok := err.(*zx.Error); !ok || err.Status != test.expectErr {
 				t.Errorf("got err = %q", err)
 			}

 			select {
 			case err := <-errChan:
 				if !errors.Is(err, test.expectErrOnServer) {
 					t.Errorf("got err = %s, want %q", err, test.expectErrOnServer)
 				}
 			default:
 				t.Error("got no error on server")
 			}
 		})
 	}
 }

 func TestServe_MagicNumberCheck(t *testing.T) {
 	var wg sync.WaitGroup

 	ch, sh, err := zx.NewChannel(0)
 	if err != nil {
 		t.Fatal(err)
 	}
 	defer func() {
 		if err := ch.Close(); err != nil {
 			t.Error(err)
 		}
 		// Wait for the serving goroutine to exit, then confirm that Serve
 		// closed the channel.
 		wg.Wait()
 		err := sh.Close()
 		if err, ok := err.(*zx.Error); ok && err.Status == zx.ErrBadHandle {
 			return
 		}
 		t.Errorf("got sh.Close() = %v, want %q", err, zx.ErrBadHandle)
 	}()

 	errChan := make(chan error, 1)

 	wg.Add(1)
 	go func() {
 		defer wg.Done()
 		component.Serve(context.Background(), &bindingstest.Test1WithCtxStub{
 			Impl: &test1Impl{},
 		}, sh, component.ServeOptions{
 			OnError: func(err error) {
 				errChan <- err
 			},
 		})
 	}()

 	// Send an event with an unknown magic number. The method ordinal and message
 	// body can also be invalid but magic numbers are checked first.
 	request := []byte{
 		0, 0, 0, 0, // txid
 		0, 0, 0, // flags
 		0,                      // magic number
 		0, 0, 0, 0, 0, 0, 0, 1, // method ordinal
 		0, 0, 0, 0, 0, 0, 0, 0, // empty struct data
 	}

 	if err := ch.Write(request, nil, 0); err != nil {
 		t.Fatal(err)
 	}

 	if _, err := zxwait.WaitContext(context.Background(), zx.Handle(ch), zx.SignalChannelPeerClosed); err != nil {
 		t.Fatal(err)
 	}

 	close(errChan)
 	for err := range errChan {
 		if !errors.Is(err, fidl.ErrUnknownMagic) {
 			t.Errorf("got Serve error = %v, want %q", err, fidl.ErrUnknownMagic)
 		}
 	}
 }

 var _ bindingstest.Test1WithCtx = (*hangingImpl)(nil)

 type hangingImpl struct {
 	test1Impl

 	// Used to coordinate blocking.
 	sem chan struct{}
 }

 func (impl *hangingImpl) NoResponse(ctx fidl.Context) error {
 	defer func() {
 		<-impl.sem
 	}()

 	for {
 		select {
 		case <-impl.sem:
 		case <-ctx.Done():
 			return ctx.Err()
 		}
 	}
 }

 func TestServeConcurrent(t *testing.T) {
 	ch, sh, err := zx.NewChannel(0)
 	if err != nil {
 		t.Fatal(err)
 	}
 	defer func() {
 		if err := ch.Close(); err != nil {
 			t.Error(err)
 		}
 	}()

 	impl := hangingImpl{
 		sem: make(chan struct{}),
 	}
 	defer close(impl.sem)

 	errChan := make(chan error, 1)

 	done := make(chan struct{})
 	go func() {
 		defer close(done)
 		component.Serve(context.Background(), &bindingstest.Test1WithCtxStub{
 			Impl: &impl,
 		}, sh, component.ServeOptions{
 			Concurrent: true,
 			OnError: func(err error) {
 				errChan <- err
 			},
 		})
 	}()

 	client := bindingstest.Test1WithCtxInterface{Channel: ch}
 	if err := client.NoResponse(context.Background()); err != nil {
 		t.Fatal(err)
 	}

 	// Ensure the handler is blocked.
 	impl.sem <- struct{}{}

 	// Closing the channel cancels the handler's context.
 	if err := ch.Close(); err != nil {
 		t.Fatal(err)
 	}

 	// Handler should now be blocked on deferred channel read.
 	select {
 	case <-done:
 		t.Error("serving returned while handler running")
 	case <-time.After(100 * time.Millisecond):
 	}

 	impl.sem <- struct{}{}
 	<-done

 	// Serving should have closed the channel.
 	func() {
 		err := sh.Close()
 		if err, ok := err.(*zx.Error); ok && err.Status == zx.ErrBadHandle {
 			return
 		}
 		t.Errorf("got sh.Close() = %v, want %q", err, zx.ErrBadHandle)
 	}()

 	close(errChan)
 	for err := range errChan {
 		if err != nil {
 			t.Errorf("Serve(...) = %s", err)
 		}
 	}
 }

 func TestKeepChannelAlive(t *testing.T) {
 	tests := []struct {
 		name      string
 		keepAlive bool
 	}{
 		{
 			name:      "keep alive",
 			keepAlive: true,
 		},
 		{
 			name:      "close",
 			keepAlive: false,
 		},
 	}
 	for _, testCase := range tests {
 		t.Run(testCase.name, func(t *testing.T) {
 			client, server, err := zx.NewChannel(0)
 			if err != nil {
 				t.Fatal(err)
 			}
 			defer func() {
 				if err := client.Close(); err != nil {
 					t.Errorf("client.Close() = %s", err)
 				}
 			}()

 			ctx, cancel := context.WithCancel(context.Background())
 			cancel()
 			component.Serve(ctx, &bindingstest.Test1WithCtxStub{
 				Impl: &test1Impl{},
 			}, server, component.ServeOptions{
 				KeepChannelAlive: testCase.keepAlive,
 				OnError: func(err error) {
 					t.Error(err)
 				},
 			})

 			err = server.Close()
 			if testCase.keepAlive {
 				if err != nil {
 					t.Fatalf("server.Close() = %s", err)
 				}
 			} else {
 				var zxErr *zx.Error
 				if !errors.As(err, &zxErr) {
 					t.Fatalf("expected %s to be %T", err, zxErr)
 				}
 				if got, want := zxErr.Status, zx.ErrBadHandle; got != want {
 					t.Fatalf("zxErr.status = %s, want %s", got, want)
 				}
 			}
 		})
 	}

 }
	// 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.

	//go:build !build_with_native_toolchain
	// +build !build_with_native_toolchain

	package component_test

	import (
	"context"
	"errors"
	"sync"
	"syscall/zx"
	"syscall/zx/fidl"
	"syscall/zx/zxwait"
	"testing"
	"time"

	"go.fuchsia.dev/fuchsia/src/lib/component"

	"fidl/bindingstest"
	)

	var _ bindingstest.Test1WithCtx = (*test1Impl)(nil)

	type test1Impl struct{}

	func (test1Impl) Echo(_ fidl.Context, s string) (*string, error) {
	return s, nil
	}

	func (*test1Impl) NoResponse(fidl.Context) error {
	return nil
	}

	func (*test1Impl) EmptyResponse(fidl.Context) error {
	return nil
	}

	func (*test1Impl) TooManyBytesInResponse(fidl.Context) ([]uint8, error) {
	return make([]uint8, zx.ChannelMaxMessageBytes+1), nil
	}

	func (*test1Impl) TooManyHandlesInResponse(fidl.Context) ([]zx.Handle, error) {
	out := make([]zx.Handle, zx.ChannelMaxMessageHandles+1)
	for i := range out {
	out[i] = 1 // to avoid zx.HandleInvalid(0).
	}
	return out, nil
	}

	func (*test1Impl) EchoHandleRights(_ fidl.Context, h zx.Port) (uint32, error) {
	infoHandleBasic, err := h.Handle().GetInfoHandleBasic()
	if err != nil {
	return 0, err
	}
	return uint32(infoHandleBasic.Rights), h.Close()
	}

	func TestEmptyWriteErrors(t *testing.T) {
	var wg sync.WaitGroup

	ch, sh, err := zx.NewChannel(0)
	if err != nil {
	t.Fatal(err)
	}
	defer func() {
	if err := ch.Close(); err != nil {
	t.Error(err)
	}
	// Wait for the serving goroutine to exit, then confirm that Serve
	// closed the channel.
	wg.Wait()
	err := sh.Close()
	if err, ok := err.(*zx.Error); ok && err.Status == zx.ErrBadHandle {
	return
	}
	t.Errorf("got sh.Close() = %v, want %q", err, zx.ErrBadHandle)
	}()

	errChan := make(chan error, 1)

	wg.Add(1)
	go func() {
	defer wg.Done()
	component.Serve(context.Background(), &bindingstest.Test1WithCtxStub{
	Impl: &test1Impl{},
	}, sh, component.ServeOptions{
	OnError: func(err error) {
	errChan <- err
	},
	})
	}()

	if err := ch.Write(nil, nil, 0); err != nil {
	t.Fatal(err)
	}

	if _, err := zxwait.WaitContext(context.Background(), zx.Handle(ch), zx.SignalChannelPeerClosed); err != nil {
	t.Fatal(err)
	}

	close(errChan)
	for err := range errChan {
	if !errors.Is(err, fidl.ErrPayloadTooSmall) {
	t.Errorf("got Serve error = %v, want %q", err, fidl.ErrPayloadTooSmall)
	}
	}
	}

	func TestEcho(t *testing.T) {
	var wg sync.WaitGroup

	ch, sh, err := zx.NewChannel(0)
	if err != nil {
	t.Fatal(err)
	}
	defer func() {
	// Expect the final test to have closed the client.
	func() {
	err := ch.Close()
	if err, ok := err.(*zx.Error); ok && err.Status == zx.ErrBadHandle {
	return
	}
	t.Errorf("got ch.Close() = %v, want %q", err, zx.ErrBadHandle)
	}()
	// Wait for the serving goroutine to exit, then confirm that Serve
	// closed the channel.
	wg.Wait()
	func() {
	err := sh.Close()
	if err, ok := err.(*zx.Error); ok && err.Status == zx.ErrBadHandle {
	return
	}
	t.Errorf("got sh.Close() = %v, want %q", err, zx.ErrBadHandle)
	}()
	}()

	wg.Add(1)
	go func() {
	defer wg.Done()
	component.Serve(context.Background(), &bindingstest.Test1WithCtxStub{
	Impl: &test1Impl{},
	}, sh, component.ServeOptions{
	OnError: func(err error) {
	t.Error(err)
	},
	})
	}()

	client := bindingstest.Test1WithCtxInterface{Channel: ch}

	t.Run("Basic", func(t *testing.T) {
	str := "Hello World!"
	r, err := client.Echo(context.Background(), &str)
	if err != nil {
	t.Fatal(err)
	}
	if r == nil {
	t.Fatalf("got Echo(%q) = nil", str)
	}
	if *r != str {
	t.Fatalf("got Echo(%q) = %q", str, *r)
	}
	})

	t.Run("NoResponse", func(t *testing.T) {
	if err := client.NoResponse(context.Background()); err != nil {
	t.Fatal(err)
	}
	})

	t.Run("EmptyResponse", func(t *testing.T) {
	if err := client.EmptyResponse(context.Background()); err != nil {
	t.Fatal(err)
	}
	})

	t.Run("Event", func(t *testing.T) {
	const str = "Surprise!"
	pxy := bindingstest.Test1EventProxy{Channel: sh}
	if err := pxy.Surprise(str); err != nil {
	t.Fatal(err)
	}
	s, err := client.ExpectSurprise(context.Background())
	if err != nil {
	t.Fatal(err)
	}
	if s != str {
	t.Fatalf("got Event = %q, want %q", str, s)
	}
	})

	t.Run("ReducingHandleRights", func(t *testing.T) {
	const expectedRights = zx.RightTransfer \| zx.RightDuplicate \| zx.RightRead
	port, err := zx.NewPort(0)
	if err != nil {
	t.Fatal(err)
	}
	defer func() {
	err := port.Close()
	// Ownership should have moved to the server, and it should have closed
	// the handle.
	if err, ok := err.(*zx.Error); ok && err.Status == zx.ErrBadHandle {
	return
	}
	t.Errorf("got port.Close() = %v, want %q", err, zx.ErrBadHandle)
	}()
	handleInfo, err := port.Handle().GetInfoHandleBasic()
	if err != nil {
	t.Fatal(err)
	}
	if !handleInfo.Rights.StrictSupersetOf(expectedRights) {
	t.Fatalf("got !(%b).StrictSupersetOf(%b)", handleInfo.Rights, expectedRights)
	}
	rights, err := client.EchoHandleRights(context.Background(), port)
	if err != nil {
	t.Fatal(err)
	}
	if rights := zx.Rights(rights); rights != expectedRights {
	t.Fatalf("got EchoHandleRights(...) = %b, want %b", rights, expectedRights)
	}
	})

	t.Run("MissingExpectedRightsSendingSide", func(t *testing.T) {
	// This test tests the sending side when there are missing expected rights.
	// The receiving side is harder to test because there needs to be a
	// mismatch of rights on the sending and receiving side.
	port, err := zx.NewPort(0)
	if err != nil {
	t.Fatal(err)
	}
	defer func() {
	err := port.Close()
	// This handle should have been consumed by the replace below.
	if err, ok := err.(*zx.Error); ok && err.Status == zx.ErrBadHandle {
	return
	}
	t.Errorf("got port.Close() = %v, want %q", err, zx.ErrBadHandle)
	}()
	const reducedRights = zx.RightTransfer \| zx.RightDuplicate
	h, err := port.Handle().Replace(reducedRights)
	if err != nil {
	t.Fatal(err)
	}
	defer func() {
	err := h.Close()
	// Ownership should have moved to the server, and it should have closed
	// the handle.
	if err, ok := err.(*zx.Error); ok && err.Status == zx.ErrBadHandle {
	return
	}
	t.Errorf("got h.Close() = %v, want %q", err, zx.ErrBadHandle)
	}()
	handleInfo, err := h.GetInfoHandleBasic()
	if err != nil {
	t.Fatal(err)
	}
	if handleInfo.Rights != reducedRights {
	t.Fatalf("got Rights = %b, want %b", handleInfo.Rights, reducedRights)
	}
	{
	_, err := client.EchoHandleRights(context.Background(), zx.Port(h))
	if err, ok := err.(*zx.Error); ok && err.Status == zx.ErrInvalidArgs {
	return
	}
	t.Fatalf("got EchoHandleRights(reducedRights) = %v, want %q", err, zx.ErrInvalidArgs)
	}
	})
	}

	func TestRespondErrors(t *testing.T) {
	tests := []struct {
	name string
	call func(*bindingstest.Test1WithCtxInterface) error
	expectErr zx.Status
	expectErrOnServer error
	}{
	{
	name: "TooManyBytes",
	call: func(client *bindingstest.Test1WithCtxInterface) error {
	_, err := client.TooManyBytesInResponse(context.Background())
	return err
	},
	expectErr: zx.ErrPeerClosed,
	expectErrOnServer: component.ErrTooManyBytesInResponse,
	},
	{
	name: "TooManyHandles",
	call: func(client *bindingstest.Test1WithCtxInterface) error {
	_, err := client.TooManyHandlesInResponse(context.Background())
	return err
	},
	expectErr: zx.ErrPeerClosed,
	expectErrOnServer: component.ErrTooManyHandlesInResponse,
	},
	}

	for _, test := range tests {
	t.Run(test.name, func(t *testing.T) {
	var wg sync.WaitGroup
	defer wg.Wait()

	ch, sh, err := zx.NewChannel(0)
	if err != nil {
	t.Fatal(err)
	}

	errChan := make(chan error, 1)
	wg.Add(1)
	go func() {
	defer wg.Done()
	component.Serve(context.Background(), &bindingstest.Test1WithCtxStub{
	Impl: &test1Impl{},
	}, sh, component.ServeOptions{
	OnError: func(err error) {
	errChan <- err
	},
	})
	}()

	err = test.call(&bindingstest.Test1WithCtxInterface{Channel: ch})
	if err, ok := err.(*zx.Error); !ok \|\| err.Status != test.expectErr {
	t.Errorf("got err = %q", err)
	}

	select {
	case err := <-errChan:
	if !errors.Is(err, test.expectErrOnServer) {
	t.Errorf("got err = %s, want %q", err, test.expectErrOnServer)
	}
	default:
	t.Error("got no error on server")
	}
	})
	}
	}

	func TestServe_MagicNumberCheck(t *testing.T) {
	var wg sync.WaitGroup

	ch, sh, err := zx.NewChannel(0)
	if err != nil {
	t.Fatal(err)
	}
	defer func() {
	if err := ch.Close(); err != nil {
	t.Error(err)
	}
	// Wait for the serving goroutine to exit, then confirm that Serve
	// closed the channel.
	wg.Wait()
	err := sh.Close()
	if err, ok := err.(*zx.Error); ok && err.Status == zx.ErrBadHandle {
	return
	}
	t.Errorf("got sh.Close() = %v, want %q", err, zx.ErrBadHandle)
	}()

	errChan := make(chan error, 1)

	wg.Add(1)
	go func() {
	defer wg.Done()
	component.Serve(context.Background(), &bindingstest.Test1WithCtxStub{
	Impl: &test1Impl{},
	}, sh, component.ServeOptions{
	OnError: func(err error) {
	errChan <- err
	},
	})
	}()

	// Send an event with an unknown magic number. The method ordinal and message
	// body can also be invalid but magic numbers are checked first.
	request := []byte{
	0, 0, 0, 0, // txid
	0, 0, 0, // flags
	0, // magic number
	0, 0, 0, 0, 0, 0, 0, 1, // method ordinal
	0, 0, 0, 0, 0, 0, 0, 0, // empty struct data
	}

	if err := ch.Write(request, nil, 0); err != nil {
	t.Fatal(err)
	}

	if _, err := zxwait.WaitContext(context.Background(), zx.Handle(ch), zx.SignalChannelPeerClosed); err != nil {
	t.Fatal(err)
	}

	close(errChan)
	for err := range errChan {
	if !errors.Is(err, fidl.ErrUnknownMagic) {
	t.Errorf("got Serve error = %v, want %q", err, fidl.ErrUnknownMagic)
	}
	}
	}

	var _ bindingstest.Test1WithCtx = (*hangingImpl)(nil)

	type hangingImpl struct {
	test1Impl

	// Used to coordinate blocking.
	sem chan struct{}
	}

	func (impl *hangingImpl) NoResponse(ctx fidl.Context) error {
	defer func() {
	<-impl.sem
	}()

	for {
	select {
	case <-impl.sem:
	case <-ctx.Done():
	return ctx.Err()
	}
	}
	}

	func TestServeConcurrent(t *testing.T) {
	ch, sh, err := zx.NewChannel(0)
	if err != nil {
	t.Fatal(err)
	}
	defer func() {
	if err := ch.Close(); err != nil {
	t.Error(err)
	}
	}()

	impl := hangingImpl{
	sem: make(chan struct{}),
	}
	defer close(impl.sem)

	errChan := make(chan error, 1)

	done := make(chan struct{})
	go func() {
	defer close(done)
	component.Serve(context.Background(), &bindingstest.Test1WithCtxStub{
	Impl: &impl,
	}, sh, component.ServeOptions{
	Concurrent: true,
	OnError: func(err error) {
	errChan <- err
	},
	})
	}()

	client := bindingstest.Test1WithCtxInterface{Channel: ch}
	if err := client.NoResponse(context.Background()); err != nil {
	t.Fatal(err)
	}

	// Ensure the handler is blocked.
	impl.sem <- struct{}{}

	// Closing the channel cancels the handler's context.
	if err := ch.Close(); err != nil {
	t.Fatal(err)
	}

	// Handler should now be blocked on deferred channel read.
	select {
	case <-done:
	t.Error("serving returned while handler running")
	case <-time.After(100 * time.Millisecond):
	}

	impl.sem <- struct{}{}
	<-done

	// Serving should have closed the channel.
	func() {
	err := sh.Close()
	if err, ok := err.(*zx.Error); ok && err.Status == zx.ErrBadHandle {
	return
	}
	t.Errorf("got sh.Close() = %v, want %q", err, zx.ErrBadHandle)
	}()

	close(errChan)
	for err := range errChan {
	if err != nil {
	t.Errorf("Serve(...) = %s", err)
	}
	}
	}

	func TestKeepChannelAlive(t *testing.T) {
	tests := []struct {
	name string
	keepAlive bool
	}{
	{
	name: "keep alive",
	keepAlive: true,
	},
	{
	name: "close",
	keepAlive: false,
	},
	}
	for _, testCase := range tests {
	t.Run(testCase.name, func(t *testing.T) {
	client, server, err := zx.NewChannel(0)
	if err != nil {
	t.Fatal(err)
	}
	defer func() {
	if err := client.Close(); err != nil {
	t.Errorf("client.Close() = %s", err)
	}
	}()

	ctx, cancel := context.WithCancel(context.Background())
	cancel()
	component.Serve(ctx, &bindingstest.Test1WithCtxStub{
	Impl: &test1Impl{},
	}, server, component.ServeOptions{
	KeepChannelAlive: testCase.keepAlive,
	OnError: func(err error) {
	t.Error(err)
	},
	})

	err = server.Close()
	if testCase.keepAlive {
	if err != nil {
	t.Fatalf("server.Close() = %s", err)
	}
	} else {
	var zxErr *zx.Error
	if !errors.As(err, &zxErr) {
	t.Fatalf("expected %s to be %T", err, zxErr)
	}
	if got, want := zxErr.Status, zx.ErrBadHandle; got != want {
	t.Fatalf("zxErr.status = %s, want %s", got, want)
	}
	}
	})
	}

	}