organize errors in p2p package and add a test

pkg/p2p/error.go

@@ -4,6 +4,15 @@
 
 package p2p
 
+import (
+	"errors"
+	"fmt"
+)
+
+// ErrPeerNotFound should be returned by p2p service methods when the requested
+// peer is not found.
+var ErrPeerNotFound = errors.New("peer not found")
+
 // DisconnectError is an error that is specifically handled inside p2p. If returned by specific protocol
 // handler it causes peer disconnect.
 type DisconnectError struct {
@@ -25,3 +34,24 @@ func (e *DisconnectError) Unwrap() error { return e.err }
 func (e *DisconnectError) Error() string {
 	return e.err.Error()
 }
+
+// IncompatibleStreamError is the error that should be returned by p2p service
+// NewStream method when the stream or its version is not supported.
+type IncompatibleStreamError struct {
+	err error
+}
+
+// NewIncompatibleStreamError wraps the error that is the cause of stream
+// incompatibility with IncompatibleStreamError that it can be detected and
+// returns it.
+func NewIncompatibleStreamError(err error) *IncompatibleStreamError {
+	return &IncompatibleStreamError{err: err}
+}
+
+// Unwrap returns an underlying error.
+func (e *IncompatibleStreamError) Unwrap() error { return e.err }
+
+// Error implements function of the standard go error interface.
+func (e *IncompatibleStreamError) Error() string {
+	return fmt.Sprintf("incompatible stream: %v", e.err)
+}

pkg/p2p/p2p.go

@@ -6,7 +6,6 @@ package p2p
 
 import (
 	"context"
-	"fmt"
 	"io"
 
 	"github.com/ethersphere/bee/pkg/swarm"
@@ -39,23 +38,13 @@ type StreamSpec struct {
 	Handler HandlerFunc
 }
 
-type HandlerFunc func(Peer, Stream) error
-
-type HandlerMiddleware func(HandlerFunc) HandlerFunc
-
-type IncompatibleStreamError struct {
-	err error
+type Peer struct {
+	Address swarm.Address
 }
 
-func NewIncompatibleStreamError(err error) *IncompatibleStreamError {
-	return &IncompatibleStreamError{err: err}
-}
-
-func (e *IncompatibleStreamError) Unwrap() error { return e.err }
+type HandlerFunc func(Peer, Stream) error
 
-func (e *IncompatibleStreamError) Error() string {
-	return fmt.Sprintf("incompatible stream: %v", e.err)
-}
+type HandlerMiddleware func(HandlerFunc) HandlerFunc
 
 func NewSwarmStreamName(protocol, stream, version string) string {
 	return "/swarm/" + protocol + "/" + stream + "/" + version

pkg/p2p/peer.go → pkg/p2p/p2p_test.go

@@ -2,16 +2,19 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-package p2p
+package p2p_test
 
 import (
-	"errors"
+	"testing"
 
-	"github.com/ethersphere/bee/pkg/swarm"
+	"github.com/ethersphere/bee/pkg/p2p"
 )
 
-type Peer struct {
-	Address swarm.Address
-}
+func TestNewSwarmStreamName(t *testing.T) {
+	want := "/swarm/hive/peers/1.2.0"
+	got := p2p.NewSwarmStreamName("hive", "peers", "1.2.0")
 
-var ErrPeerNotFound = errors.New("peer not found")
+	if got != want {
+		t.Errorf("got %s, want %s", got, want)
+	}
+}