Improve sponsor message

api/error.go

@@ -8,6 +8,9 @@ var ErrNotAvailable = errors.New("not available")
 // ErrMustRetry indicates that a rate-limited operation should be retried
 var ErrMustRetry = errors.New("must retry")
 
+// ErrSponsorRequired indicates that a sponsor token is required
+var ErrSponsorRequired = errors.New("sponsorship required, see https://github.com/andig/evcc#sponsorship")
+
 // ErrTimeout is the error returned when a timeout happened.
 // Modeled after context.DeadlineError
 var ErrTimeout error = errTimeoutError{}

charger/abl.go

@@ -2,7 +2,6 @@ package charger
 
 import (
 	"encoding/binary"
-	"errors"
 	"fmt"
 
 	"github.com/andig/evcc/api"
@@ -59,7 +58,7 @@ func NewABLeMH(uri, device, comset string, baudrate int, slaveID uint8) (api.Cha
 	}
 
 	if !sponsor.IsAuthorized() {
-		return nil, errors.New("abl requires evcc sponsorship, register at https://cloud.evcc.io")
+		return nil, api.ErrSponsorRequired
 	}
 
 	log := util.NewLogger("abl")

charger/easee.go

@@ -1,7 +1,6 @@
 package charger
 
 import (
-	"errors"
 	"fmt"
 	"net/http"
 	"time"
@@ -58,7 +57,7 @@ func NewEasee(user, password, charger string, circuit int, cache time.Duration)
 	log := util.NewLogger("easee")
 
 	if !sponsor.IsAuthorized() {
-		return nil, errors.New("easee requires evcc sponsorship, register at https://cloud.evcc.io")
+		return nil, api.ErrSponsorRequired
 	}
 
 	c := &Easee{

charger/heidelberg-ec.go

@@ -2,7 +2,6 @@ package charger
 
 import (
 	"encoding/binary"
-	"errors"
 	"fmt"
 
 	"github.com/andig/evcc/api"
@@ -58,7 +57,7 @@ func NewHeidelbergEC(uri, device, comset string, baudrate int, slaveID uint8) (a
 	}
 
 	if !sponsor.IsAuthorized() {
-		return nil, errors.New("heidelberg requires evcc sponsorship, register at https://cloud.evcc.io")
+		return nil, api.ErrSponsorRequired
 	}
 
 	log := util.NewLogger("hec")

vehicle/tronity.go

@@ -53,7 +53,7 @@ func NewTronityFromConfig(other map[string]interface{}) (api.Vehicle, error) {
 	}
 
 	if !sponsor.IsAuthorized() {
-		return nil, errors.New("tronity requires evcc sponsorship, register at https://cloud.evcc.io")
+		return nil, api.ErrSponsorRequired
 	}
 
 	// authenticated http client with logging injected to the tronity client