Merge pull request #165 from cschleiden/cschleiden/check-return-type

Check return types when scheduling activities and sub workflows

Author: cschleiden

internal/fn/fn.go

@@ -15,3 +15,17 @@ func Name(i interface{}) string {
 
 	return strings.TrimSuffix(fnName, "-fm")
 }
+
+func ReturnTypeMatch[TResult any](fn interface{}) bool {
+	fnType := reflect.TypeOf(fn)
+	if fnType.Kind() != reflect.Func {
+		return false
+	}
+
+	if fnType.NumOut() == 1 {
+		return true
+	}
+
+	t := *new(TResult)
+	return fnType.Out(0) == reflect.TypeOf(t)
+}

internal/fn/fn_test.go

@@ -52,3 +52,64 @@ func Test_GetFunctionName(t *testing.T) {
 		})
 	}
 }
+
+func intReturn() (int, error) {
+	return 0, nil
+}
+
+func stringReturn() (string, error) {
+	return "", nil
+}
+
+func errorReturn() error {
+	return nil
+}
+
+func TestReturnTypeMatch(t *testing.T) {
+	tests := []struct {
+		name string
+		fn   func() bool
+		want bool
+	}{
+		{
+			name: "int match",
+			fn: func() bool {
+				return ReturnTypeMatch[int](intReturn)
+			},
+			want: true,
+		},
+		{
+			name: "string match",
+			fn: func() bool {
+				return ReturnTypeMatch[string](stringReturn)
+			},
+			want: true,
+		},
+		{
+			name: "int mismatch",
+			fn: func() bool {
+				return ReturnTypeMatch[string](intReturn)
+			},
+		},
+		{
+			name: "no param",
+			fn: func() bool {
+				return ReturnTypeMatch[any](errorReturn)
+			},
+			want: true,
+		},
+		{
+			name: "no param mismatch",
+			fn: func() bool {
+				return ReturnTypeMatch[int](errorReturn)
+			},
+			want: true,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := tt.fn()
+			require.Equal(t, tt.want, got)
+		})
+	}
+}

workflow/activity.go

@@ -38,6 +38,11 @@ func executeActivity[TResult any](ctx Context, options ActivityOptions, attempt
 		return f
 	}
 
+	if !fn.ReturnTypeMatch[TResult](activity) {
+		f.Set(*new(TResult), fmt.Errorf("activity return type does not match expected type"))
+		return f
+	}
+
 	cv := converter.GetConverter(ctx)
 	inputs, err := a.ArgsToInputs(cv, args...)
 	if err != nil {

workflow/activity_test.go

@@ -0,0 +1,40 @@
+package workflow
+
+import (
+	"testing"
+
+	"github.com/benbjohnson/clock"
+	"github.com/cschleiden/go-workflows/internal/converter"
+	"github.com/cschleiden/go-workflows/internal/core"
+	"github.com/cschleiden/go-workflows/internal/logger"
+	"github.com/cschleiden/go-workflows/internal/sync"
+	"github.com/cschleiden/go-workflows/internal/workflowstate"
+	"github.com/cschleiden/go-workflows/internal/workflowtracer"
+	"github.com/stretchr/testify/require"
+	"go.opentelemetry.io/otel/trace"
+)
+
+func Test_executeActivity_ParamMismatch(t *testing.T) {
+	a := func(ctx Context) (int, error) {
+		return 42, nil
+	}
+
+	ctx := sync.Background()
+	ctx = converter.WithConverter(ctx, converter.DefaultConverter)
+	ctx = workflowstate.WithWorkflowState(
+		ctx,
+		workflowstate.NewWorkflowState(core.NewWorkflowInstance("a", ""), logger.NewDefaultLogger(), clock.New()),
+	)
+	ctx = workflowtracer.WithWorkflowTracer(ctx, workflowtracer.New(trace.NewNoopTracerProvider().Tracer("test")))
+
+	c := sync.NewCoroutine(ctx, func(ctx sync.Context) error {
+		f := executeActivity[string](ctx, DefaultActivityOptions, 1, a)
+		_, err := f.Get(ctx)
+		require.Error(t, err)
+
+		return nil
+	})
+
+	c.Execute()
+	require.True(t, c.Finished())
+}

workflow/subworkflow.go

@@ -48,6 +48,11 @@ func createSubWorkflowInstance[TResult any](ctx sync.Context, options SubWorkflo
 		return f
 	}
 
+	if !fn.ReturnTypeMatch[TResult](wf) {
+		f.Set(*new(TResult), fmt.Errorf("subworkflow return type does not match expected type"))
+		return f
+	}
+
 	name := fn.Name(wf)
 
 	cv := converter.GetConverter(ctx)

workflow/subworkflow_test.go

@@ -0,0 +1,40 @@
+package workflow
+
+import (
+	"testing"
+
+	"github.com/benbjohnson/clock"
+	"github.com/cschleiden/go-workflows/internal/converter"
+	"github.com/cschleiden/go-workflows/internal/core"
+	"github.com/cschleiden/go-workflows/internal/logger"
+	"github.com/cschleiden/go-workflows/internal/sync"
+	"github.com/cschleiden/go-workflows/internal/workflowstate"
+	"github.com/cschleiden/go-workflows/internal/workflowtracer"
+	"github.com/stretchr/testify/require"
+	"go.opentelemetry.io/otel/trace"
+)
+
+func Test_createSubWorkflowInstance_ParamMismatch(t *testing.T) {
+	wf := func(ctx Context) (int, error) {
+		return 42, nil
+	}
+
+	ctx := sync.Background()
+	ctx = converter.WithConverter(ctx, converter.DefaultConverter)
+	ctx = workflowstate.WithWorkflowState(
+		ctx,
+		workflowstate.NewWorkflowState(core.NewWorkflowInstance("a", ""), logger.NewDefaultLogger(), clock.New()),
+	)
+	ctx = workflowtracer.WithWorkflowTracer(ctx, workflowtracer.New(trace.NewNoopTracerProvider().Tracer("test")))
+
+	c := sync.NewCoroutine(ctx, func(ctx sync.Context) error {
+		f := createSubWorkflowInstance[string](ctx, DefaultSubWorkflowOptions, 1, wf)
+		_, err := f.Get(ctx)
+		require.Error(t, err)
+
+		return nil
+	})
+
+	c.Execute()
+	require.True(t, c.Finished())
+}