Test exit directive

coroutine.go

@@ -66,14 +66,23 @@ func (c *GenericCoroutine[I, O]) Run(ctx context.Context, req Request) Response
 	// Run the coroutine until it yields or returns.
 	if coro.Next() {
 		// The coroutine yielded and is now paused.
-		// Serialize the coroutine.
-		state, err := c.serialize(id, coro)
-		if err != nil {
-			return NewResponseError(err)
+		yield := coro.Recv()
+
+		// Serialize the coroutine, unless it's a terminal Exit directive.
+		var state Any
+		if _, terminal := yield.directive.(Exit); !terminal {
+			var err error
+			state, err = c.serialize(id, coro)
+			if err != nil {
+				return NewResponseError(err)
+			}
+		} else {
+			coro.Stop()
+			coro.Next()
 		}
-		// Yield to Dispatch with the directive from the coroutine.
-		result := coro.Recv()
-		return NewResponse(result.status, result.directive, CoroutineState(state))
+
+		// Yield to Dispatch with the directive.
+		return NewResponse(yield.status, yield.directive, CoroutineState(state))
 	}
 
 	// The coroutine returned. Serialize the output / error.

coroutine_test.go

@@ -0,0 +1,99 @@
+package dispatch_test
+
+import (
+	"context"
+	"fmt"
+	"strconv"
+	"testing"
+
+	"github.com/dispatchrun/coroutine"
+	"github.com/dispatchrun/dispatch-go"
+)
+
+func logMode(t *testing.T) {
+	t.Helper()
+
+	if coroutine.Durable {
+		t.Log("running in durable mode")
+	} else {
+		t.Log("running in volatile mode")
+	}
+}
+
+func TestCoroutineReturnOnly(t *testing.T) {
+	logMode(t)
+
+	coro := dispatch.NewCoroutine("stringify", func(ctx context.Context, in int) (string, error) {
+		if in < 0 {
+			return "", fmt.Errorf("%w: %d", dispatch.ErrInvalidArgument, in)
+		}
+		return strconv.Itoa(in), nil
+	})
+	defer coro.Close()
+
+	res := coro.Run(context.Background(), dispatch.NewRequest("stringify", dispatch.Input(dispatch.Int(11))))
+	if res.Status() != dispatch.OKStatus {
+		t.Errorf("unexpected status: %s", res.Status())
+	}
+	output, ok := res.Output()
+	if !ok {
+		t.Errorf("expected output, got: %s", res)
+	}
+	var got string
+	if err := output.Unmarshal(&got); err != nil {
+		t.Fatal(err)
+	} else if got != "11" {
+		t.Errorf("unexpected output: %s", got)
+	}
+
+	res = coro.Run(context.Background(), dispatch.NewRequest("stringify", dispatch.Input(dispatch.Int(-23))))
+	if res.Status() != dispatch.InvalidArgumentStatus {
+		t.Errorf("unexpected status: %s", res.Status())
+	}
+	if err, ok := res.Error(); !ok {
+		t.Errorf("expected error, got: %s", res)
+	} else if got := err.Message(); got != "InvalidArgument: -23" {
+		t.Errorf("unexpected error: %s", got)
+	}
+}
+
+func TestCoroutineExit(t *testing.T) {
+	logMode(t)
+
+	coro := dispatch.NewCoroutine("stringify", func(ctx context.Context, in int) (string, error) {
+		if in < 0 {
+			err := fmt.Errorf("%w: %d", dispatch.ErrInvalidArgument, in)
+			dispatch.Yield[string](dispatch.InvalidArgumentStatus, dispatch.NewExit(dispatch.NewError(err)))
+		} else {
+			output := dispatch.String(strconv.Itoa(in))
+			dispatch.Yield[string](dispatch.OKStatus, dispatch.NewExit(dispatch.Output(output)))
+		}
+		panic("unreachable")
+	})
+	defer coro.Close()
+
+	res := coro.Run(context.Background(), dispatch.NewRequest("stringify", dispatch.Input(dispatch.Int(11))))
+	if res.Status() != dispatch.OKStatus {
+		t.Errorf("unexpected status: %s", res.Status())
+	}
+	output, ok := res.Output()
+	if !ok {
+		t.Errorf("expected output, got: %s", res)
+	}
+	var got string
+	if err := output.Unmarshal(&got); err != nil {
+		t.Fatal(err)
+	} else if got != "11" {
+		t.Errorf("unexpected output: %s", got)
+	}
+
+	res = coro.Run(context.Background(), dispatch.NewRequest("stringify", dispatch.Input(dispatch.Int(-23))))
+	if res.Status() != dispatch.InvalidArgumentStatus {
+		t.Errorf("unexpected status: %s", res.Status())
+	}
+	if err, ok := res.Error(); !ok {
+		t.Errorf("expected error, got: %s", res)
+	} else if got := err.Message(); got != "InvalidArgument: -23" {
+		t.Errorf("unexpected error: %s", got)
+	}
+}