protofsm: add String() method to ProtocolState

lnwallet/chancloser/rbf_coop_states.go

@@ -361,6 +361,9 @@ type ProtocolState interface {
 	// ProcessEvent takes a protocol event, and implements a state
 	// transition for the state.
 	ProcessEvent(ProtocolEvent, *Environment) (*CloseStateTransition, error)
+
+	// String returns the name of the state.
+	String() string
 }
 
 // AsymmetricPeerState is an extension of the normal ProtocolState interface
@@ -401,6 +404,11 @@ type ProtocolStates interface {
 type ChannelActive struct {
 }
 
+// String returns the name of the state for ChannelActive.
+func (c *ChannelActive) String() string {
+	return "ChannelActive"
+}
+
 // IsTerminal returns true if the target state is a terminal state.
 func (c *ChannelActive) IsTerminal() bool {
 	return false
@@ -443,6 +451,11 @@ type ShutdownPending struct {
 	IdealFeeRate fn.Option[chainfee.SatPerVByte]
 }
 
+// String returns the name of the state for ShutdownPending.
+func (s *ShutdownPending) String() string {
+	return "ShutdownPending"
+}
+
 // IsTerminal returns true if the target state is a terminal state.
 func (s *ShutdownPending) IsTerminal() bool {
 	return false
@@ -478,6 +491,11 @@ type ChannelFlushing struct {
 	IdealFeeRate fn.Option[chainfee.SatPerVByte]
 }
 
+// String returns the name of the state for ChannelFlushing.
+func (c *ChannelFlushing) String() string {
+	return "ChannelFlushing"
+}
+
 // protocolStateSealed indicates that this struct is a ProtocolEvent instance.
 func (c *ChannelFlushing) protocolStateSealed() {}
 
@@ -507,6 +525,15 @@ type ClosingNegotiation struct {
 	PeerState lntypes.Dual[AsymmetricPeerState]
 }
 
+// String returns the name of the state for ClosingNegotiation.
+func (c *ClosingNegotiation) String() string {
+	localState := c.PeerState.GetForParty(lntypes.Local)
+	remoteState := c.PeerState.GetForParty(lntypes.Remote)
+
+	return fmt.Sprintf("ClosingNegotiation(local=%v, remote=%v)",
+		localState, remoteState)
+}
+
 // IsTerminal returns true if the target state is a terminal state.
 func (c *ClosingNegotiation) IsTerminal() bool {
 	return false
@@ -594,6 +621,12 @@ type LocalCloseStart struct {
 	CloseChannelTerms
 }
 
+// String returns the name of the state for LocalCloseStart, including proposed
+// fee details.
+func (l *LocalCloseStart) String() string {
+	return "LocalCloseStart"
+}
+
 // ShouldRouteTo returns true if the target state should process the target
 // event.
 func (l *LocalCloseStart) ShouldRouteTo(event ProtocolEvent) bool {
@@ -634,6 +667,11 @@ type LocalOfferSent struct {
 	LocalSig lnwire.Sig
 }
 
+// String returns the name of the state for LocalOfferSent, including proposed.
+func (l *LocalOfferSent) String() string {
+	return fmt.Sprintf("LocalOfferSent(proposed_fee=%v)", l.ProposedFee)
+}
+
 // ShouldRouteTo returns true if the target state should process the target
 // event.
 func (l *LocalOfferSent) ShouldRouteTo(event ProtocolEvent) bool {
@@ -670,6 +708,11 @@ type ClosePending struct {
 	CloseTx *wire.MsgTx
 }
 
+// String returns the name of the state for ClosePending.
+func (c *ClosePending) String() string {
+	return fmt.Sprintf("ClosePending(txid=%v)", c.CloseTx.TxHash())
+}
+
 // ShouldRouteTo returns true if the target state should process the target
 // event.
 func (c *ClosePending) ShouldRouteTo(event ProtocolEvent) bool {
@@ -696,6 +739,11 @@ type CloseFin struct {
 	ConfirmedTx *wire.MsgTx
 }
 
+// String returns the name of the state for CloseFin.
+func (c *CloseFin) String() string {
+	return "CloseFin"
+}
+
 // protocolStateSealed indicates that this struct is a ProtocolEvent instance.
 func (c *CloseFin) protocolStateSealed() {}
 
@@ -714,6 +762,11 @@ type RemoteCloseStart struct {
 	CloseChannelTerms
 }
 
+// String returns the name of the state for RemoteCloseStart.
+func (r *RemoteCloseStart) String() string {
+	return "RemoteCloseStart"
+}
+
 // ShouldRouteTo returns true if the target state should process the target
 // event.
 func (l *RemoteCloseStart) ShouldRouteTo(event ProtocolEvent) bool {

protofsm/state_machine.go

@@ -77,7 +77,8 @@ type State[Event any, Env Environment] interface {
 	// otherwise.
 	IsTerminal() bool
 
-	// TODO(roasbeef): also add state serialization?
+	// String returns a human readable string that represents the state.
+	String() string
 }
 
 // DaemonAdapters is a set of methods that server as adapters to bridge the
@@ -597,8 +598,8 @@ func (s *StateMachine[Event, Env]) applyEvents(ctx context.Context,
 			}
 
 			s.log.InfoS(ctx, "State transition",
-				btclog.Fmt("from_state", "%T", currentState),
-				btclog.Fmt("to_state", "%T", transition.NextState))
+				btclog.Fmt("from_state", "%v", currentState),
+				btclog.Fmt("to_state", "%v", transition.NextState))
 
 			// With our events processed, we'll now update our
 			// internal state.

protofsm/state_machine_test.go

@@ -51,6 +51,10 @@ type dummyStateStart struct {
 	canSend *atomic.Bool
 }
 
+func (d *dummyStateStart) String() string {
+	return "dummyStateStart"
+}
+
 var (
 	hexDecode = func(keyStr string) []byte {
 		keyBytes, _ := hex.DecodeString(keyStr)
@@ -134,6 +138,10 @@ func (d *dummyStateStart) IsTerminal() bool {
 type dummyStateFin struct {
 }
 
+func (d *dummyStateFin) String() string {
+	return "dummyStateFin"
+}
+
 func (d *dummyStateFin) ProcessEvent(event dummyEvents, env *dummyEnv,
 ) (*StateTransition[dummyEvents, *dummyEnv], error) {