feat: support typed errors over RPC

api/api_errors.go

@@ -0,0 +1,29 @@
+package api
+
+import (
+	"github.com/filecoin-project/go-jsonrpc"
+)
+
+const (
+	EOutOfGas = iota + jsonrpc.FirstUserCode
+	EActorNotFound
+)
+
+type ErrOutOfGas struct{}
+
+func (e ErrOutOfGas) Error() string {
+	return "call ran out of gas"
+}
+
+type ErrActorNotFound struct{}
+
+func (e ErrActorNotFound) Error() string {
+	return "actor not found"
+}
+
+var RPCErrors = jsonrpc.NewErrors()
+
+func init() {
+	RPCErrors.Register(EOutOfGas, new(ErrOutOfGas))
+	RPCErrors.Register(EActorNotFound, new(ErrActorNotFound))
+}