Add TerminalErrorf (#30)

* Add TerminalErrorf

* Use whenever possible TerminalErrorf

error.go

@@ -2,6 +2,7 @@ package restate
 
 import (
 	stderrors "errors"
+	"fmt"
 
 	"github.com/restatedev/sdk-go/internal/errors"
 )
@@ -32,6 +33,11 @@ func TerminalError(err error, code ...errors.Code) error {
 	return errors.NewTerminalError(err, code...)
 }
 
+// TerminalErrorf is a shorthand for combining fmt.Errorf with TerminalError
+func TerminalErrorf(format string, a ...any) error {
+	return TerminalError(fmt.Errorf(format, a...))
+}
+
 // IsTerminalError checks if err is terminal - ie, that returning it in a handler or Run function will finish
 // the invocation with the error as a result.
 func IsTerminalError(err error) bool {

error_test.go

@@ -11,7 +11,7 @@ import (
 func TestTerminal(t *testing.T) {
 	require.False(t, IsTerminalError(fmt.Errorf("not terminal")))
 
-	err := TerminalError(fmt.Errorf("failed terminally"))
+	err := TerminalErrorf("failed terminally")
 	require.True(t, IsTerminalError(err))
 
 	//terminal with code

test-services/counter.go

@@ -1,8 +1,6 @@
 package main
 
 import (
-	"fmt"
-
 	restate "github.com/restatedev/sdk-go"
 )
 
@@ -50,6 +48,6 @@ func init() {
 					newValue := oldValue + addend
 					ctx.Set(COUNTER_KEY, newValue)
 
-					return restate.Void{}, restate.TerminalError(fmt.Errorf("%s", ctx.Key()))
+					return restate.Void{}, restate.TerminalErrorf("%s", ctx.Key())
 				})))
 }

test-services/failing.go

@@ -15,15 +15,15 @@ func init() {
 		restate.NewObject("Failing").
 			Handler("terminallyFailingCall", restate.NewObjectHandler(
 				func(ctx restate.ObjectContext, errorMessage string) (restate.Void, error) {
-					return restate.Void{}, restate.TerminalError(fmt.Errorf(errorMessage))
+					return restate.Void{}, restate.TerminalErrorf(errorMessage)
 				})).
 			Handler("callTerminallyFailingCall", restate.NewObjectHandler(
 				func(ctx restate.ObjectContext, errorMessage string) (string, error) {
 					if err := ctx.Object("Failing", ctx.Rand().UUID().String(), "terminallyFailingCall").Request(errorMessage, restate.Void{}); err != nil {
 						return "", err
 					}
 
-					return "", restate.TerminalError(fmt.Errorf("This should be unreachable"))
+					return "", restate.TerminalErrorf("This should be unreachable")
 				})).
 			Handler("failingCallWithEventualSuccess", restate.NewObjectHandler(
 				func(ctx restate.ObjectContext, _ restate.Void) (int32, error) {
@@ -50,7 +50,7 @@ func init() {
 			Handler("terminallyFailingSideEffect", restate.NewObjectHandler(
 				func(ctx restate.ObjectContext, errorMessage string) (restate.Void, error) {
 					return restate.RunAs(ctx, func(ctx restate.RunContext) (restate.Void, error) {
-						return restate.Void{}, restate.TerminalError(fmt.Errorf(errorMessage))
+						return restate.Void{}, restate.TerminalErrorf(errorMessage)
 					})
 				})))
 }

test-services/testutils.go

@@ -1,7 +1,6 @@
 package main
 
 import (
-	"fmt"
 	"strings"
 	"sync/atomic"
 	"time"
@@ -83,7 +82,7 @@ func init() {
 						i++
 					}
 					if i != len(timers) {
-						return restate.Void{}, restate.TerminalError(fmt.Errorf("unexpected number of timers fired: %d", i))
+						return restate.Void{}, restate.TerminalErrorf("unexpected number of timers fired: %d", i)
 					}
 					return restate.Void{}, nil
 				})).