Add corrections to comply with govet, golint, etc.

errors.go

@@ -6,19 +6,56 @@ import (
 )
 
 var (
+	// ErrUnknownType indicates an error with Unknown info.
 	ErrUnknownType = errors.New("unknown")
+
+	// ErrConnectionClosed indicates an operation executed after connection
+	// has already been closed.
 	ErrConnectionClosed = errors.New("connection closed")
+
+	// ErrCertificateExpired indicates that an x509 certificate has expired.
 	ErrCertificateExpired = errors.New("x509Cert expired")
+
+	// ErrNoTurnCredencials indicates that a TURN server URL was provided
+	// without required credentials.
 	ErrNoTurnCredencials = errors.New("turn server credentials required")
+
+	// ErrTurnCredencials indicates that provided TURN credentials are partial
+	// or malformed.
 	ErrTurnCredencials = errors.New("invalid turn server credentials")
+
+	// ErrExistingTrack indicates that a track already exists.
 	ErrExistingTrack = errors.New("track aready exists")
+
+	// ErrPrivateKeyType indicates that a particular private key encryption
+	// chosen to generate a certificate is not supported.
 	ErrPrivateKeyType = errors.New("private key type not supported")
+
+	// ErrModifyingPeerIdentity indicates that an attempt to modify
+	// PeerIdentity was made after RTCPeerConnection has been initialized.
 	ErrModifyingPeerIdentity = errors.New("peerIdentity cannot be modified")
+
+	// ErrModifyingCertificates indicates that an attempt to modify
+	// Certificates was made after RTCPeerConnection has been initialized.
 	ErrModifyingCertificates = errors.New("certificates cannot be modified")
+
+	// ErrModifyingBundlePolicy indicates that an attempt to modify
+	// BundlePolicy was made after RTCPeerConnection has been initialized.
 	ErrModifyingBundlePolicy = errors.New("bundle policy cannot be modified")
+
+	// ErrModifyingRtcpMuxPolicy indicates that an attempt to modify
+	// RtcpMuxPolicy was made after RTCPeerConnection has been initialized.
 	ErrModifyingRtcpMuxPolicy = errors.New("rtcp mux policy cannot be modified")
+
+	// ErrModifyingIceCandidatePoolSize indicates that an attempt to modify
+	// IceCandidatePoolSize was made after RTCPeerConnection has been initialized.
 	ErrModifyingIceCandidatePoolSize = errors.New("ice candidate pool size cannot be modified")
+
+	// ErrInvalidValue indicates that an invalid value was provided.
 	ErrInvalidValue = errors.New("invalid value")
+
+	// ErrMaxDataChannels indicates that the maximum number of data channels
+	// was reached.
 	ErrMaxDataChannels = errors.New("maximum number of datachannels reached")
 )
 

media.go

@@ -181,14 +181,14 @@ func (pc *RTCPeerConnection) NewRTCTrack(payloadType uint8, id, label string) (*
 // AddTrack adds a RTCTrack to the RTCPeerConnection
 func (pc *RTCPeerConnection) AddTrack(track *RTCTrack) (*RTCRtpSender, error) {
 	if pc.IsClosed {
-		return nil, &InvalidStateError{ErrConnectionClosed}
+		return nil, &InvalidStateError{Err: ErrConnectionClosed}
 	}
 	for _, transceiver := range pc.rtpTransceivers {
 		if transceiver.Sender.Track == nil {
 			continue
 		}
 		if track.ID == transceiver.Sender.Track.ID {
-			return nil, &InvalidAccessError{ErrExistingTrack}
+			return nil, &InvalidAccessError{Err: ErrExistingTrack}
 		}
 	}
 	var transceiver *RTCRtpTransceiver

pkg/ice/errors.go

@@ -5,27 +5,26 @@ import (
 	"github.com/pkg/errors"
 )
 
-// Types of InvalidStateErrors
 var (
-	// ErrUnknownType indicates a Unknown info
+	// ErrUnknownType indicates an error with Unknown info.
 	ErrUnknownType = errors.New("Unknown")
 
-	// ErrServerType indicates the scheme type could not be parsed
+	// ErrSchemeType indicates the scheme type could not be parsed.
 	ErrSchemeType = errors.New("unknown scheme type")
 
-	// ErrSTUNQuery indicates query arguments are provided in a STUN URL
+	// ErrSTUNQuery indicates query arguments are provided in a STUN URL.
 	ErrSTUNQuery = errors.New("queries not supported in stun address")
 
-	// ErrInvalidQuery indicates an malformed query is provided
+	// ErrInvalidQuery indicates an malformed query is provided.
 	ErrInvalidQuery = errors.New("invalid query")
 
-	// ErrHost indicates malformed hostname is provided
+	// ErrHost indicates malformed hostname is provided.
 	ErrHost = errors.New("invalid hostname")
 
-	// ErrPort indicates malformed port is provided
+	// ErrPort indicates malformed port is provided.
 	ErrPort = errors.New("invalid port")
 
-	// ErrProtoType indicates an unsupported transport type was provided
+	// ErrProtoType indicates an unsupported transport type was provided.
 	ErrProtoType = errors.New("invalid transport protocol type")
 )
 

pkg/ice/url.go

@@ -8,20 +8,26 @@ import (
 
 // TODO: Migrate address parsing to STUN/TURN packages?
 
-// Scheme indicates the type of server used
+// SchemeType indicates the type of server used in the ice.URL structure.
 type SchemeType int
 
 const (
-	// SchemeTypeSTUN indicates the URL represents a STUN server
+	// SchemeTypeSTUN indicates the URL represents a STUN server.
 	SchemeTypeSTUN SchemeType = iota + 1
+
+	// SchemeTypeSTUNS indicates the URL represents a STUNS (secure) server.
 	SchemeTypeSTUNS
 
-	// SchemeTypeTURN indicates the URL represents a TURN server
+	// SchemeTypeTURN indicates the URL represents a TURN server.
 	SchemeTypeTURN
+
+	// SchemeTypeTURNS indicates the URL represents a TURNS (secure) server.
 	SchemeTypeTURNS
 )
 
-func NewSchemeType(raw string) (unknown SchemeType) {
+// NewSchemeType defines a procedure for creating a new SchemeType from a raw
+// string naming the scheme type.
+func NewSchemeType(raw string) (SchemeType) {
 	switch raw {
 	case "stun":
 		return SchemeTypeSTUN
@@ -32,7 +38,7 @@ func NewSchemeType(raw string) (unknown SchemeType) {
 	case "turns":
 		return SchemeTypeTURNS
 	default:
-		return unknown
+		return SchemeType(Unknown)
 	}
 }
 
@@ -51,25 +57,28 @@ func (t SchemeType) String() string {
 	}
 }
 
-// Proto indicates the transport that is used
+// ProtoType indicates the transport protocol type that is used in the ice.URL
+// structure.
 type ProtoType int
 
 const (
-	// ProtoTypeUDP indicates the URL uses a UDP transport
+	// ProtoTypeUDP indicates the URL uses a UDP transport.
 	ProtoTypeUDP ProtoType = iota + 1
 
-	// ProtoTypeTCP indicates the URL uses a TCP transport
+	// ProtoTypeTCP indicates the URL uses a TCP transport.
 	ProtoTypeTCP
 )
 
-func NewProtoType(raw string) (unknown ProtoType) {
+// NewProtoType defines a procedure for creating a new ProtoType from a raw
+// string naming the transport protocol type.
+func NewProtoType(raw string) (ProtoType) {
 	switch raw {
 	case "udp":
 		return ProtoTypeUDP
 	case "tcp":
 		return ProtoTypeTCP
 	default:
-		return unknown
+		return ProtoType(Unknown)
 	}
 }
 
@@ -92,16 +101,19 @@ type URL struct {
 	Proto  ProtoType
 }
 
+// ParseURL parses a STUN or TURN urls following the ABNF syntax described in
+// https://tools.ietf.org/html/rfc7064 and https://tools.ietf.org/html/rfc7065
+// respectively.
 func ParseURL(raw string) (*URL, error) {
 	rawParts, err := url.Parse(raw)
 	if err != nil {
-		return nil, &UnknownError{err}
+		return nil, &UnknownError{Err: err}
 	}
 
 	var u URL
 	u.Scheme = NewSchemeType(rawParts.Scheme)
 	if u.Scheme == SchemeType(Unknown) {
-		return nil, &SyntaxError{ErrSchemeType}
+		return nil, &SyntaxError{Err: ErrSchemeType}
 	}
 
 	var rawPort string
@@ -125,28 +137,28 @@ func ParseURL(raw string) (*URL, error) {
 				}
 			}
 		}
-		return nil, &UnknownError{err}
+		return nil, &UnknownError{Err: err}
 	}
 
 	if u.Host == "" {
-		return nil, &SyntaxError{ErrHost}
+		return nil, &SyntaxError{Err: ErrHost}
 	}
 
 	if u.Port, err = strconv.Atoi(rawPort); err != nil {
-		return nil, &SyntaxError{ErrPort}
+		return nil, &SyntaxError{Err: ErrPort}
 	}
 
 	switch {
 	case u.Scheme == SchemeTypeSTUN:
 		qArgs, err := url.ParseQuery(rawParts.RawQuery)
 		if err != nil || (err == nil && len(qArgs) > 0) {
-			return nil, &SyntaxError{ErrSTUNQuery}
+			return nil, &SyntaxError{Err: ErrSTUNQuery}
 		}
 		u.Proto = ProtoTypeUDP
 	case u.Scheme == SchemeTypeSTUNS:
 		qArgs, err := url.ParseQuery(rawParts.RawQuery)
 		if err != nil || (err == nil && len(qArgs) > 0) {
-			return nil, &SyntaxError{ErrSTUNQuery}
+			return nil, &SyntaxError{Err: ErrSTUNQuery}
 		}
 		u.Proto = ProtoTypeTCP
 	case u.Scheme == SchemeTypeTURN:
@@ -177,19 +189,19 @@ func ParseURL(raw string) (*URL, error) {
 func parseProto(raw string) (ProtoType, error) {
 	qArgs, err := url.ParseQuery(raw)
 	if err != nil || len(qArgs) > 1 {
-		return ProtoType(Unknown), &SyntaxError{ErrInvalidQuery}
+		return ProtoType(Unknown), &SyntaxError{Err: ErrInvalidQuery}
 	}
 
 	var proto ProtoType
 	if rawProto := qArgs.Get("transport"); rawProto != "" {
 		if proto = NewProtoType(rawProto); proto == ProtoType(0) {
-			return ProtoType(Unknown), &NotSupportedError{ErrProtoType}
+			return ProtoType(Unknown), &NotSupportedError{Err: ErrProtoType}
 		}
 		return proto, nil
 	}
 
 	if len(qArgs) > 0 {
-		return ProtoType(Unknown), &SyntaxError{ErrInvalidQuery}
+		return ProtoType(Unknown), &SyntaxError{Err: ErrInvalidQuery}
 	}
 
 	return proto, nil
@@ -203,6 +215,7 @@ func (u URL) String() string {
 	return rawURL
 }
 
+// IsSecure returns whether the this URL's scheme describes secure scheme or not.
 func (u URL) IsSecure() bool {
 	return u.Scheme == SchemeTypeSTUNS || u.Scheme == SchemeTypeTURNS
 }

pkg/ice/url_test.go

@@ -47,19 +47,19 @@ func TestParseURL(t *testing.T) {
 			rawURL      string
 			expectedErr error
 		}{
-			{"", &SyntaxError{ErrSchemeType}},
+			{"", &SyntaxError{Err: ErrSchemeType}},
-			{":::", &UnknownError{errors.New("parse :::: missing protocol scheme")}},
+			{":::", &UnknownError{Err: errors.New("parse :::: missing protocol scheme")}},
-			{"stun:[::1]:123:", &UnknownError{errors.New("address [::1]:123:: too many colons in address")}},
+			{"stun:[::1]:123:", &UnknownError{Err: errors.New("address [::1]:123:: too many colons in address")}},
-			{"stun:[::1]:123a", &SyntaxError{ErrPort}},
+			{"stun:[::1]:123a", &SyntaxError{Err: ErrPort}},
-			{"google.de", &SyntaxError{ErrSchemeType}},
+			{"google.de", &SyntaxError{Err: ErrSchemeType}},
-			{"stun:", &SyntaxError{ErrHost}},
+			{"stun:", &SyntaxError{Err: ErrHost}},
-			{"stun:google.de:abc", &SyntaxError{ErrPort}},
+			{"stun:google.de:abc", &SyntaxError{Err: ErrPort}},
-			{"stun:google.de?transport=udp", &SyntaxError{ErrSTUNQuery}},
+			{"stun:google.de?transport=udp", &SyntaxError{Err: ErrSTUNQuery}},
-			{"stuns:google.de?transport=udp", &SyntaxError{ErrSTUNQuery}},
+			{"stuns:google.de?transport=udp", &SyntaxError{Err: ErrSTUNQuery}},
-			{"turn:google.de?trans=udp", &SyntaxError{ErrInvalidQuery}},
+			{"turn:google.de?trans=udp", &SyntaxError{Err: ErrInvalidQuery}},
-			{"turns:google.de?trans=udp", &SyntaxError{ErrInvalidQuery}},
+			{"turns:google.de?trans=udp", &SyntaxError{Err: ErrInvalidQuery}},
-			{"turns:google.de?transport=udp&another=1", &SyntaxError{ErrInvalidQuery}},
+			{"turns:google.de?transport=udp&another=1", &SyntaxError{Err: ErrInvalidQuery}},
-			{"turn:google.de?transport=ip", &NotSupportedError{ErrProtoType}},
+			{"turn:google.de?transport=ip", &NotSupportedError{Err: ErrProtoType}},
 		}
 
 		for i, testCase := range testCases {

rtcbundlepolicy.go

@@ -24,7 +24,7 @@ const (
 	RTCBundlePolicyMaxBundle
 )
 
-// NewRTCBundlePolicy defines a proceedure for creating a new RTCBundlePolicy
+// NewRTCBundlePolicy defines a procedure for creating a new RTCBundlePolicy
 // from a raw string naming the bundle policy.
 func NewRTCBundlePolicy(raw string) RTCBundlePolicy {
 	switch raw {

rtccertificate.go

@@ -18,6 +18,10 @@ type RTCCertificate struct {
 	x509Cert  *x509.Certificate
 }
 
+// NewRTCCertificate generates a new x509 compliant RTCCertificate to be used
+// by DTLS for encrypting data sent over the wire. This method differs from
+// GenerateCertificate by allowing to specify a template x509.Certificate to
+// be used in order to define certificate parameters.
 func NewRTCCertificate(key crypto.PrivateKey, tpl x509.Certificate) (*RTCCertificate, error) {
 	var err error
 	var certDER []byte
@@ -27,28 +31,29 @@ func NewRTCCertificate(key crypto.PrivateKey, tpl x509.Certificate) (*RTCCertifi
 		tpl.SignatureAlgorithm = x509.SHA256WithRSA
 		certDER, err = x509.CreateCertificate(rand.Reader, &tpl, &tpl, pk, sk)
 		if err != nil {
-			return nil, &UnknownError{err}
+			return nil, &UnknownError{Err: err}
 		}
 	case *ecdsa.PrivateKey:
 		pk := sk.Public()
 		tpl.SignatureAlgorithm = x509.ECDSAWithSHA256
 		certDER, err = x509.CreateCertificate(rand.Reader, &tpl, &tpl, pk, sk)
 		if err != nil {
-			return nil, &UnknownError{err}
+			return nil, &UnknownError{Err: err}
 		}
 	default:
-		return nil, &NotSupportedError{ErrPrivateKeyType}
+		return nil, &NotSupportedError{Err: ErrPrivateKeyType}
 	}
 
 	cert, err := x509.ParseCertificate(certDER)
 	if err != nil {
-		return nil, &UnknownError{err}
+		return nil, &UnknownError{Err: err}
 	}
 
 	return &RTCCertificate{secretKey: key, x509Cert: cert}, nil
 }
 
-// Equals determines if two certificates are identical
+// Equals determines if two certificates are identical by comparing both the
+// secretKeys and x509Certificates.
 func (c RTCCertificate) Equals(o RTCCertificate) bool {
 	switch cSK := c.secretKey.(type) {
 	case *rsa.PrivateKey:
@@ -72,6 +77,7 @@ func (c RTCCertificate) Equals(o RTCCertificate) bool {
 	}
 }
 
+// Expires returns the timestamp after which this certificate is no longer valid.
 func (c RTCCertificate) Expires() time.Time {
 	if c.x509Cert == nil {
 		return time.Time{}
@@ -79,14 +85,18 @@ func (c RTCCertificate) Expires() time.Time {
 	return c.x509Cert.NotAfter
 }
 
+// GetFingerprints returns the list of certificate fingerprints, one of which
+// is computed with the digest algorithm used in the certificate signature.
 func (c RTCCertificate) GetFingerprints() {
-
+	panic("not implemented yet.")
 }
 
+// GenerateCertificate causes the creation of an X.509 certificate and
+// corresponding private key.
 func GenerateCertificate(secretKey crypto.PrivateKey) (*RTCCertificate, error) {
 	origin := make([]byte, 16)
 	if _, err := rand.Read(origin); err != nil {
-		return nil, &UnknownError{err}
+		return nil, &UnknownError{Err: err}
 	}
 
 	// Max random value, a 130-bits integer, i.e 2^130 - 1
@@ -94,7 +104,7 @@ func GenerateCertificate(secretKey crypto.PrivateKey) (*RTCCertificate, error) {
 	maxBigInt.Exp(big.NewInt(2), big.NewInt(130), nil).Sub(maxBigInt, big.NewInt(1))
 	serialNumber, err := rand.Int(rand.Reader, maxBigInt)
 	if err != nil {
-		return nil, &UnknownError{err}
+		return nil, &UnknownError{Err: err}
 	}
 
 	return NewRTCCertificate(secretKey, x509.Certificate{

rtcdatachannel.go

@@ -65,11 +65,11 @@ type RTCDataChannelInit struct {
 // CreateDataChannel creates a new RTCDataChannel object with the given label and optitional options.
 func (pc *RTCPeerConnection) CreateDataChannel(label string, options *RTCDataChannelInit) (*RTCDataChannel, error) {
 	if pc.IsClosed {
-		return nil, &InvalidStateError{ErrConnectionClosed}
+		return nil, &InvalidStateError{Err: ErrConnectionClosed}
 	}
 
 	if len(label) > 65535 {
-		return nil, &TypeError{ErrInvalidValue}
+		return nil, &TypeError{Err: ErrInvalidValue}
 	}
 
 	// Defaults
@@ -95,12 +95,12 @@ func (pc *RTCPeerConnection) CreateDataChannel(label string, options *RTCDataCha
 	}
 
 	if id > 65534 {
-		return nil, &TypeError{ErrInvalidValue}
+		return nil, &TypeError{Err: ErrInvalidValue}
 	}
 
 	if pc.sctp.State == RTCSctpTransportStateConnected &&
 		id >= pc.sctp.MaxChannels {
-		return nil, &OperationError{ErrMaxDataChannels}
+		return nil, &OperationError{Err: ErrMaxDataChannels}
 	}
 
 	_ = ordered  // TODO
@@ -132,13 +132,13 @@ func (pc *RTCPeerConnection) generateDataChannelID(client bool) (uint16, error)
 			return id, nil
 		}
 	}
-	return 0, &OperationError{ErrMaxDataChannels}
+	return 0, &OperationError{Err: ErrMaxDataChannels}
 }
 
 // SendOpenChannelMessage is a test to send OpenChannel manually
 func (d *RTCDataChannel) SendOpenChannelMessage() error {
 	if err := d.rtcPeerConnection.networkManager.SendOpenChannelMessage(d.ID, d.Label); err != nil {
-		return &UnknownError{err}
+		return &UnknownError{Err: err}
 	}
 	return nil
 
@@ -147,7 +147,7 @@ func (d *RTCDataChannel) SendOpenChannelMessage() error {
 // Send sends the passed message to the DataChannel peer
 func (d *RTCDataChannel) Send(p datachannel.Payload) error {
 	if err := d.rtcPeerConnection.networkManager.SendDataChannelMessage(p, d.ID); err != nil {
-		return &UnknownError{err}
+		return &UnknownError{Err: err}
 	}
 	return nil
 }

rtcicecredentialtype.go

@@ -14,7 +14,7 @@ const (
 	RTCIceCredentialTypeOauth
 )
 
-// NewRTCIceCredentialType defines a proceedure for creating a new
+// NewRTCIceCredentialType defines a procedure for creating a new
 // RTCIceCredentialType from a raw string naming the ice credential type.
 func NewRTCIceCredentialType(raw string) RTCIceCredentialType {
 	switch raw {

rtciceserver.go

@@ -27,23 +27,23 @@ func (s RTCIceServer) validate() error {
 		if url.Scheme == ice.SchemeTypeTURN || url.Scheme == ice.SchemeTypeTURNS {
 			// https://www.w3.org/TR/webrtc/#set-the-configuration (step #11.3.2)
 			if s.Username == "" || s.Credential == nil {
-				return &InvalidAccessError{ErrNoTurnCredencials}
+				return &InvalidAccessError{Err: ErrNoTurnCredencials}
 			}
 
 			switch s.CredentialType {
 			case RTCIceCredentialTypePassword:
 				// https://www.w3.org/TR/webrtc/#set-the-configuration (step #11.3.3)
 				if _, ok := s.Credential.(string); !ok {
-					return &InvalidAccessError{ErrTurnCredencials}
+					return &InvalidAccessError{Err: ErrTurnCredencials}
 				}
 			case RTCIceCredentialTypeOauth:
 				// https://www.w3.org/TR/webrtc/#set-the-configuration (step #11.3.4)
 				if _, ok := s.Credential.(RTCOAuthCredential); !ok {
-					return &InvalidAccessError{ErrTurnCredencials}
+					return &InvalidAccessError{Err: ErrTurnCredencials}
 				}
 
 			default:
-				return &InvalidAccessError{ErrTurnCredencials}
+				return &InvalidAccessError{Err: ErrTurnCredencials}
 			}
 		}
 	}

rtciceserver_test.go

@@ -40,25 +40,25 @@ func TestRTCIceServer_validate(t *testing.T) {
 		}{
 			{RTCIceServer{
 				URLs: []string{"turn:192.158.29.39?transport=udp"},
-			}, &InvalidAccessError{ErrNoTurnCredencials}},
+			}, &InvalidAccessError{Err: ErrNoTurnCredencials}},
 			{RTCIceServer{
 				URLs:           []string{"turn:192.158.29.39?transport=udp"},
 				Username:       "unittest",
 				Credential:     false,
 				CredentialType: RTCIceCredentialTypePassword,
-			}, &InvalidAccessError{ErrTurnCredencials}},
+			}, &InvalidAccessError{Err: ErrTurnCredencials}},
 			{RTCIceServer{
 				URLs:           []string{"turn:192.158.29.39?transport=udp"},
 				Username:       "unittest",
 				Credential:     false,
 				CredentialType: RTCIceCredentialTypeOauth,
-			}, &InvalidAccessError{ErrTurnCredencials}},
+			}, &InvalidAccessError{Err: ErrTurnCredencials}},
 			{RTCIceServer{
 				URLs:           []string{"turn:192.158.29.39?transport=udp"},
 				Username:       "unittest",
 				Credential:     false,
 				CredentialType: Unknown,
-			}, &InvalidAccessError{ErrTurnCredencials}},
+			}, &InvalidAccessError{Err: ErrTurnCredencials}},
 			{RTCIceServer{
 				URLs:           []string{"stun:google.de?transport=udp"},
 				Username:       "unittest",

rtcicetransportpolicy.go

@@ -13,7 +13,7 @@ const (
 	RTCIceTransportPolicyAll
 )
 
-// NewRTCIceTransportPolicy defines a proceedure for creating a new
+// NewRTCIceTransportPolicy defines a procedure for creating a new
 // RTCIceTransportPolicy from a raw string naming the ice transport policy.
 func NewRTCIceTransportPolicy(raw string) RTCIceTransportPolicy {
 	switch raw {

rtcpeerconnection.go

@@ -138,14 +138,14 @@ func (pc *RTCPeerConnection) initConfiguration(configuration RTCConfiguration) e
 		now := time.Now()
 		for _, x509Cert := range configuration.Certificates {
 			if !x509Cert.Expires().IsZero() && now.After(x509Cert.Expires()) {
-				return &InvalidAccessError{ErrCertificateExpired}
+				return &InvalidAccessError{Err: ErrCertificateExpired}
 			}
 			pc.configuration.Certificates = append(pc.configuration.Certificates, x509Cert)
 		}
 	} else {
 		sk, err := ecdsa.GenerateKey(elliptic.P256(), rand.Reader)
 		if err != nil {
-			return &UnknownError{err}
+			return &UnknownError{Err: err}
 		}
 		certificate, err := GenerateCertificate(sk)
 		if err != nil {
@@ -185,13 +185,13 @@ func (pc *RTCPeerConnection) initConfiguration(configuration RTCConfiguration) e
 func (pc *RTCPeerConnection) SetConfiguration(configuration RTCConfiguration) error {
 	// https://www.w3.org/TR/webrtc/#dom-rtcpeerconnection-setconfiguration (step #2)
 	if pc.IsClosed {
-		return &InvalidStateError{ErrConnectionClosed}
+		return &InvalidStateError{Err: ErrConnectionClosed}
 	}
 
 	// https://www.w3.org/TR/webrtc/#set-the-configuration (step #3)
 	if configuration.PeerIdentity != "" {
 		if configuration.PeerIdentity != pc.configuration.PeerIdentity {
-			return &InvalidModificationError{ErrModifyingPeerIdentity}
+			return &InvalidModificationError{Err: ErrModifyingPeerIdentity}
 		}
 		pc.configuration.PeerIdentity = configuration.PeerIdentity
 	}
@@ -199,12 +199,12 @@ func (pc *RTCPeerConnection) SetConfiguration(configuration RTCConfiguration) er
 	// https://www.w3.org/TR/webrtc/#set-the-configuration (step #4)
 	if len(configuration.Certificates) > 0 {
 		if len(configuration.Certificates) != len(pc.configuration.Certificates) {
-			return &InvalidModificationError{ErrModifyingCertificates}
+			return &InvalidModificationError{Err: ErrModifyingCertificates}
 		}
 
 		for i, certificate := range configuration.Certificates {
 			if !pc.configuration.Certificates[i].Equals(certificate) {
-				return &InvalidModificationError{ErrModifyingCertificates}
+				return &InvalidModificationError{Err: ErrModifyingCertificates}
 			}
 		}
 		pc.configuration.Certificates = configuration.Certificates
@@ -213,7 +213,7 @@ func (pc *RTCPeerConnection) SetConfiguration(configuration RTCConfiguration) er
 	// https://www.w3.org/TR/webrtc/#set-the-configuration (step #5)
 	if configuration.BundlePolicy != RTCBundlePolicy(Unknown) {
 		if configuration.BundlePolicy != pc.configuration.BundlePolicy {
-			return &InvalidModificationError{ErrModifyingBundlePolicy}
+			return &InvalidModificationError{Err: ErrModifyingBundlePolicy}
 		}
 		pc.configuration.BundlePolicy = configuration.BundlePolicy
 	}
@@ -221,7 +221,7 @@ func (pc *RTCPeerConnection) SetConfiguration(configuration RTCConfiguration) er
 	// https://www.w3.org/TR/webrtc/#set-the-configuration (step #6)
 	if configuration.RtcpMuxPolicy != RTCRtcpMuxPolicy(Unknown) {
 		if configuration.RtcpMuxPolicy != pc.configuration.RtcpMuxPolicy {
-			return &InvalidModificationError{ErrModifyingRtcpMuxPolicy}
+			return &InvalidModificationError{Err: ErrModifyingRtcpMuxPolicy}
 		}
 		pc.configuration.RtcpMuxPolicy = configuration.RtcpMuxPolicy
 	}
@@ -230,7 +230,7 @@ func (pc *RTCPeerConnection) SetConfiguration(configuration RTCConfiguration) er
 	if configuration.IceCandidatePoolSize != 0 {
 		if pc.configuration.IceCandidatePoolSize != configuration.IceCandidatePoolSize &&
 			pc.LocalDescription() != nil {
-			return &InvalidModificationError{ErrModifyingIceCandidatePoolSize}
+			return &InvalidModificationError{Err: ErrModifyingIceCandidatePoolSize}
 		}
 		pc.configuration.IceCandidatePoolSize = configuration.IceCandidatePoolSize
 	}
@@ -256,7 +256,7 @@ func (pc *RTCPeerConnection) SetConfiguration(configuration RTCConfiguration) er
 // GetConfiguration returns an RTCConfiguration object representing the current
 // configuration of this RTCPeerConnection object. The returned object is a
 // copy and direct mutation on it will not take affect until SetConfiguration
-// has been called with RTCConfiguration passed as its only arguement.
+// has been called with RTCConfiguration passed as its only argument.
 // https://www.w3.org/TR/webrtc/#dom-rtcpeerconnection-getconfiguration
 func (pc *RTCPeerConnection) GetConfiguration() RTCConfiguration {
 	return pc.configuration
@@ -452,7 +452,7 @@ func (pc *RTCPeerConnection) CreateOffer(options *RTCOfferOptions) (RTCSessionDe
 	} else if useIdentity {
 		return RTCSessionDescription{}, errors.Errorf("TODO handle identity provider")
 	} else if pc.IsClosed {
-		return RTCSessionDescription{}, &InvalidStateError{ErrConnectionClosed}
+		return RTCSessionDescription{}, &InvalidStateError{Err: ErrConnectionClosed}
 	}
 
 	d := sdp.NewJSEPSessionDescription(pc.networkManager.DTLSFingerprint(), useIdentity)
@@ -491,7 +491,7 @@ func (pc *RTCPeerConnection) CreateAnswer(options *RTCAnswerOptions) (RTCSession
 	} else if useIdentity {
 		return RTCSessionDescription{}, errors.Errorf("TODO handle identity provider")
 	} else if pc.IsClosed {
-		return RTCSessionDescription{}, &InvalidStateError{ErrConnectionClosed}
+		return RTCSessionDescription{}, &InvalidStateError{Err: ErrConnectionClosed}
 	}
 
 	candidates := pc.generateLocalCandidates()

rtcpeerconnection_test.go

@@ -64,7 +64,7 @@ func TestNew(t *testing.T) {
 				return New(RTCConfiguration{
 					Certificates: []RTCCertificate{*certificate},
 				})
-			}, &InvalidAccessError{ErrCertificateExpired}},
+			}, &InvalidAccessError{Err: ErrCertificateExpired}},
 			{func() (*RTCPeerConnection, error) {
 				return New(RTCConfiguration{
 					IceServers: []RTCIceServer{
@@ -77,7 +77,7 @@ func TestNew(t *testing.T) {
 						},
 					},
 				})
-			}, &InvalidAccessError{ErrNoTurnCredencials}},
+			}, &InvalidAccessError{Err: ErrNoTurnCredencials}},
 		}
 
 		for i, testCase := range testCases {
@@ -140,14 +140,14 @@ func TestRTCPeerConnection_SetConfiguration(t *testing.T) {
 				return pc, err
 			}, func() RTCConfiguration {
 				return RTCConfiguration{}
-			}, &InvalidStateError{ErrConnectionClosed}},
+			}, &InvalidStateError{Err: ErrConnectionClosed}},
 			{func() (*RTCPeerConnection, error) {
 				return New(RTCConfiguration{})
 			}, func() RTCConfiguration {
 				return RTCConfiguration{
 					PeerIdentity: "unittest",
 				}
-			}, &InvalidModificationError{ErrModifyingPeerIdentity}},
+			}, &InvalidModificationError{Err: ErrModifyingPeerIdentity}},
 			{func() (*RTCPeerConnection, error) {
 				return New(RTCConfiguration{})
 			}, func() RTCConfiguration {
@@ -166,7 +166,7 @@ func TestRTCPeerConnection_SetConfiguration(t *testing.T) {
 				return RTCConfiguration{
 					Certificates: []RTCCertificate{*certificate1, *certificate2},
 				}
-			}, &InvalidModificationError{ErrModifyingCertificates}},
+			}, &InvalidModificationError{Err: ErrModifyingCertificates}},
 			{func() (*RTCPeerConnection, error) {
 				return New(RTCConfiguration{})
 			}, func() RTCConfiguration {
@@ -179,21 +179,21 @@ func TestRTCPeerConnection_SetConfiguration(t *testing.T) {
 				return RTCConfiguration{
 					Certificates: []RTCCertificate{*certificate},
 				}
-			}, &InvalidModificationError{ErrModifyingCertificates}},
+			}, &InvalidModificationError{Err: ErrModifyingCertificates}},
 			{func() (*RTCPeerConnection, error) {
 				return New(RTCConfiguration{})
 			}, func() RTCConfiguration {
 				return RTCConfiguration{
 					BundlePolicy: RTCBundlePolicyMaxCompat,
 				}
-			}, &InvalidModificationError{ErrModifyingBundlePolicy}},
+			}, &InvalidModificationError{Err: ErrModifyingBundlePolicy}},
 			{func() (*RTCPeerConnection, error) {
 				return New(RTCConfiguration{})
 			}, func() RTCConfiguration {
 				return RTCConfiguration{
 					RtcpMuxPolicy: RTCRtcpMuxPolicyNegotiate,
 				}
-			}, &InvalidModificationError{ErrModifyingRtcpMuxPolicy}},
+			}, &InvalidModificationError{Err: ErrModifyingRtcpMuxPolicy}},
 			// TODO Unittest for IceCandidatePoolSize cannot be done now needs pc.LocalDescription()
 			{func() (*RTCPeerConnection, error) {
 				return New(RTCConfiguration{})
@@ -209,7 +209,7 @@ func TestRTCPeerConnection_SetConfiguration(t *testing.T) {
 						},
 					},
 				}
-			}, &InvalidAccessError{ErrNoTurnCredencials}},
+			}, &InvalidAccessError{Err: ErrNoTurnCredencials}},
 		}
 
 		for i, testCase := range testCases {

rtcpeerconnectionstate.go

@@ -34,7 +34,7 @@ const (
 	RTCPeerConnectionStateClosed
 )
 
-// NewRTCPeerConnectionState defines a proceedure for creating a new
+// NewRTCPeerConnectionState defines a procedure for creating a new
 // RTCPeerConnectionState from a raw string naming the peer connection state.
 func NewRTCPeerConnectionState(raw string) RTCPeerConnectionState {
 	switch raw {

rtcrtcpmuxpolicy.go

@@ -17,7 +17,7 @@ const (
 	RTCRtcpMuxPolicyRequire
 )
 
-// NewRTCRtcpMuxPolicy defines a proceedure for creating a new RTCRtcpMuxPolicy
+// NewRTCRtcpMuxPolicy defines a procedure for creating a new RTCRtcpMuxPolicy
 // from a raw string naming the rtcp multiplexing policy.
 func NewRTCRtcpMuxPolicy(raw string) RTCRtcpMuxPolicy {
 	switch raw {

rtcsdptype.go

@@ -28,7 +28,7 @@ const (
 	RTCSdpTypeRollback
 )
 
-// NewRTCSdpType defines a proceedure for creating a new RTCSdpType from a raw
+// NewRTCSdpType defines a procedure for creating a new RTCSdpType from a raw
 // string naming the session description protocol type.
 func NewRTCSdpType(raw string) RTCSdpType {
 	switch raw {

rtcsignalingstate.go

@@ -31,7 +31,7 @@ const (
 	RTCSignalingStateClosed
 )
 
-// NewRTCSignalingState defines a proceedure for creating a new
+// NewRTCSignalingState defines a procedure for creating a new
 // RTCSignalingState from a raw string naming the signaling state.
 func NewRTCSignalingState(raw string) RTCSignalingState {
 	switch raw {