coder · spikecurtis · Jun 27, 2025 · Jun 24, 2025
diff --git a/cli/portforward_test.go b/cli/portforward_test.go
@@ -13,7 +13,6 @@ import (
 	"github.com/pion/udp"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
-	"golang.org/x/xerrors"
 
 	"github.com/coder/coder/v2/agent"
 	"github.com/coder/coder/v2/agent/agenttest"
@@ -161,7 +160,7 @@ func TestPortForward(t *testing.T) {
 			inv.Stdout = pty.Output()
 			inv.Stderr = pty.Output()
 
-			iNet := newInProcNet()
+			iNet := testutil.NewInProcNet()
 			inv.Net = iNet
 			ctx, cancel := context.WithTimeout(context.Background(), testutil.WaitLong)
 			defer cancel()
@@ -177,10 +176,10 @@ func TestPortForward(t *testing.T) {
 			// sync.
 			dialCtx, dialCtxCancel := context.WithTimeout(ctx, testutil.WaitShort)
 			defer dialCtxCancel()
-			c1, err := iNet.dial(dialCtx, addr{c.network, c.localAddress[0]})
+			c1, err := iNet.Dial(dialCtx, testutil.NewAddr(c.network, c.localAddress[0]))
 			require.NoError(t, err, "open connection 1 to 'local' listener")
 			defer c1.Close()
-			c2, err := iNet.dial(dialCtx, addr{c.network, c.localAddress[0]})
+			c2, err := iNet.Dial(dialCtx, testutil.NewAddr(c.network, c.localAddress[0]))
 			require.NoError(t, err, "open connection 2 to 'local' listener")
 			defer c2.Close()
 			testDial(t, c2)
@@ -218,7 +217,7 @@ func TestPortForward(t *testing.T) {
 			inv.Stdout = pty.Output()
 			inv.Stderr = pty.Output()
 
-			iNet := newInProcNet()
+			iNet := testutil.NewInProcNet()
 			inv.Net = iNet
 			ctx, cancel := context.WithTimeout(context.Background(), testutil.WaitLong)
 			defer cancel()
@@ -232,10 +231,10 @@ func TestPortForward(t *testing.T) {
 			// then test them out of order.
 			dialCtx, dialCtxCancel := context.WithTimeout(ctx, testutil.WaitShort)
 			defer dialCtxCancel()
-			c1, err := iNet.dial(dialCtx, addr{c.network, c.localAddress[0]})
+			c1, err := iNet.Dial(dialCtx, testutil.NewAddr(c.network, c.localAddress[0]))
 			require.NoError(t, err, "open connection 1 to 'local' listener 1")
 			defer c1.Close()
-			c2, err := iNet.dial(dialCtx, addr{c.network, c.localAddress[1]})
+			c2, err := iNet.Dial(dialCtx, testutil.NewAddr(c.network, c.localAddress[1]))
 			require.NoError(t, err, "open connection 2 to 'local' listener 2")
 			defer c2.Close()
 			testDial(t, c2)
@@ -257,18 +256,15 @@ func TestPortForward(t *testing.T) {
 	t.Run("All", func(t *testing.T) {
 		t.Parallel()
 		var (
-			dials = []addr{}
+			dials = []testutil.Addr{}
 			flags = []string{}
 		)
 
 		// Start listeners and populate arrays with the cases.
 		for _, c := range cases {
 			p := setupTestListener(t, c.setupRemote(t))
 
-			dials = append(dials, addr{
-				network: c.network,
-				addr:    c.localAddress[0],
-			})
+			dials = append(dials, testutil.NewAddr(c.network, c.localAddress[0]))
 			flags = append(flags, fmt.Sprintf(c.flag[0], p))
 		}
 
@@ -279,7 +275,7 @@ func TestPortForward(t *testing.T) {
 		pty := ptytest.New(t).Attach(inv)
 		inv.Stderr = pty.Output()
 
-		iNet := newInProcNet()
+		iNet := testutil.NewInProcNet()
 		inv.Net = iNet
 		ctx, cancel := context.WithTimeout(context.Background(), testutil.WaitLong)
 		defer cancel()
@@ -296,7 +292,7 @@ func TestPortForward(t *testing.T) {
 		)
 		defer dialCtxCancel()
 		for i, a := range dials {
-			c, err := iNet.dial(dialCtx, a)
+			c, err := iNet.Dial(dialCtx, a)
 			require.NoErrorf(t, err, "open connection %v to 'local' listener %v", i+1, i+1)
 			t.Cleanup(func() {
 				_ = c.Close()
@@ -340,7 +336,7 @@ func TestPortForward(t *testing.T) {
 		inv.Stdout = pty.Output()
 		inv.Stderr = pty.Output()
 
-		iNet := newInProcNet()
+		iNet := testutil.NewInProcNet()
 		inv.Net = iNet
 
 		// listen on port 5555 on IPv6 so it's busy when we try to port forward
@@ -361,7 +357,7 @@ func TestPortForward(t *testing.T) {
 		// Test IPv4 still works
 		dialCtx, dialCtxCancel := context.WithTimeout(ctx, testutil.WaitShort)
 		defer dialCtxCancel()
-		c1, err := iNet.dial(dialCtx, addr{"tcp", "127.0.0.1:5555"})
+		c1, err := iNet.Dial(dialCtx, testutil.NewAddr("tcp", "127.0.0.1:5555"))
 		require.NoError(t, err, "open connection 1 to 'local' listener")
 		defer c1.Close()
 		testDial(t, c1)
@@ -473,95 +469,3 @@ func assertWritePayload(t *testing.T, w io.Writer, payload []byte) {
 	assert.NoError(t, err, "write payload")
 	assert.Equal(t, len(payload), n, "payload length does not match")
 }
-
-type addr struct {
-	network string
-	addr    string
-}
-
-func (a addr) Network() string {
-	return a.network
-}
-
-func (a addr) Address() string {
-	return a.addr
-}
-
-func (a addr) String() string {
-	return a.network + "|" + a.addr
-}
-
-type inProcNet struct {
-	sync.Mutex
-
-	listeners map[addr]*inProcListener
-}
-
-type inProcListener struct {
-	c chan net.Conn
-	n *inProcNet
-	a addr
-	o sync.Once
-}
-
-func newInProcNet() *inProcNet {
-	return &inProcNet{listeners: make(map[addr]*inProcListener)}
-}
-
-func (n *inProcNet) Listen(network, address string) (net.Listener, error) {
-	a := addr{network, address}
-	n.Lock()
-	defer n.Unlock()
-	if _, ok := n.listeners[a]; ok {
-		return nil, xerrors.New("busy")
-	}
-	l := newInProcListener(n, a)
-	n.listeners[a] = l
-	return l, nil
-}
-
-func (n *inProcNet) dial(ctx context.Context, a addr) (net.Conn, error) {
-	n.Lock()
-	defer n.Unlock()
-	l, ok := n.listeners[a]
-	if !ok {
-		return nil, xerrors.Errorf("nothing listening on %s", a)
-	}
-	x, y := net.Pipe()
-	select {
-	case <-ctx.Done():
-		return nil, ctx.Err()
-	case l.c <- x:
-		return y, nil
-	}
-}
-
-func newInProcListener(n *inProcNet, a addr) *inProcListener {
-	return &inProcListener{
-		c: make(chan net.Conn),
-		n: n,
-		a: a,
-	}
-}
-
-func (l *inProcListener) Accept() (net.Conn, error) {
-	c, ok := <-l.c
-	if !ok {
-		return nil, net.ErrClosed
-	}
-	return c, nil
-}
-
-func (l *inProcListener) Close() error {
-	l.o.Do(func() {
-		l.n.Lock()
-		defer l.n.Unlock()
-		delete(l.n.listeners, l.a)
-		close(l.c)
-	})
-	return nil
-}
-
-func (l *inProcListener) Addr() net.Addr {
-	return l.a
-}
diff --git a/testutil/net.go b/testutil/net.go
@@ -0,0 +1,105 @@
+package testutil
+
+import (
+	"context"
+	"net"
+	"sync"
+
+	"golang.org/x/xerrors"
+)
+
+type Addr struct {
+	network string
+	addr    string
+}
+
+func NewAddr(network, addr string) Addr {
+	return Addr{network, addr}
+}
+
+func (a Addr) Network() string {
+	return a.network
+}
+
+func (a Addr) Address() string {
+	return a.addr
+}
+
+func (a Addr) String() string {
+	return a.network + "|" + a.addr
+}
+
+type InProcNet struct {
+	sync.Mutex
+
+	listeners map[Addr]*inProcListener
+}
+
+type inProcListener struct {
+	c chan net.Conn
+	n *InProcNet
+	a Addr
+	o sync.Once
+}
+
+func NewInProcNet() *InProcNet {
+	return &InProcNet{listeners: make(map[Addr]*inProcListener)}
+}
+
+func (n *InProcNet) Listen(network, address string) (net.Listener, error) {
+	a := Addr{network, address}
+	n.Lock()
+	defer n.Unlock()
+	if _, ok := n.listeners[a]; ok {
+		return nil, xerrors.New("busy")
+	}
+	l := newInProcListener(n, a)
+	n.listeners[a] = l
+	return l, nil
+}
+
+func (n *InProcNet) Dial(ctx context.Context, a Addr) (net.Conn, error) {
+	n.Lock()
+	defer n.Unlock()
+	l, ok := n.listeners[a]
+	if !ok {
+		return nil, xerrors.Errorf("nothing listening on %s", a)
+	}
+	x, y := net.Pipe()
+	select {
+	case <-ctx.Done():
+		return nil, ctx.Err()
+	case l.c <- x:
+		return y, nil
+	}
+}
+
+func newInProcListener(n *InProcNet, a Addr) *inProcListener {
+	return &inProcListener{
+		c: make(chan net.Conn),
+		n: n,
+		a: a,
+	}
+}
+
+func (l *inProcListener) Accept() (net.Conn, error) {
+	c, ok := <-l.c
+	if !ok {
+		return nil, net.ErrClosed
+	}
+	return c, nil
+}
+
+func (l *inProcListener) Close() error {
+	l.o.Do(func() {
+		l.n.Lock()
+		defer l.n.Unlock()
+		delete(l.n.listeners, l.a)
+		close(l.c)
+	})
+	return nil
+}
+
+func (l *inProcListener) Addr() net.Addr {
+	return l.a
+}