accept a closure in RunAsStep

dbos/dbos.go

@@ -61,7 +61,7 @@ type DBOSContext interface {
 	Cancel()
 
 	// Workflow operations
-	RunAsStep(_ DBOSContext, fn StepFunc, input any) (any, error)
+	RunAsStep(_ DBOSContext, fn StepFunc) (any, error)
 	RunAsWorkflow(_ DBOSContext, fn WorkflowFunc, input any, opts ...WorkflowOption) (WorkflowHandle[any], error)
 	Send(_ DBOSContext, input WorkflowSendInputInternal) error
 	Recv(_ DBOSContext, input WorkflowRecvInput) (any, error)

dbos/queues_test.go

@@ -30,14 +30,16 @@ This suite tests
 */
 
 func queueWorkflow(ctx DBOSContext, input string) (string, error) {
-	step1, err := RunAsStep(ctx, queueStep, input)
+	step1, err := RunAsStep[string](ctx, func(context context.Context) (string, error) {
+		return queueStep(context, input)
+	})
 	if err != nil {
 		return "", fmt.Errorf("failed to run step: %v", err)
 	}
 	return step1, nil
 }
 
-func queueStep(ctx context.Context, input string) (string, error) {
+func queueStep(_ context.Context, input string) (string, error) {
 	return input, nil
 }
 

dbos/serialization_test.go

@@ -23,7 +23,9 @@ func encodingStepBuiltinTypes(_ context.Context, input int) (int, error) {
 }
 
 func encodingWorkflowBuiltinTypes(ctx DBOSContext, input string) (string, error) {
-	stepResult, err := RunAsStep(ctx, encodingStepBuiltinTypes, 123)
+	stepResult, err := RunAsStep[int](ctx, func(context context.Context) (int, error) {
+		return encodingStepBuiltinTypes(context, 123)
+	})
 	return fmt.Sprintf("%d", stepResult), fmt.Errorf("workflow error: %v", err)
 }
 
@@ -49,13 +51,15 @@ type SimpleStruct struct {
 }
 
 func encodingWorkflowStruct(ctx DBOSContext, input WorkflowInputStruct) (StepOutputStruct, error) {
-	return RunAsStep(ctx, encodingStepStruct, StepInputStruct{
-		A: input.A,
-		B: fmt.Sprintf("%d", input.B),
+	return RunAsStep[StepOutputStruct](ctx, func(context context.Context) (StepOutputStruct, error) {
+		return encodingStepStruct(context, StepInputStruct{
+			A: input.A,
+			B: fmt.Sprintf("%d", input.B),
+		})
 	})
 }
 
-func encodingStepStruct(ctx context.Context, input StepInputStruct) (StepOutputStruct, error) {
+func encodingStepStruct(_ context.Context, input StepInputStruct) (StepOutputStruct, error) {
 	return StepOutputStruct{
 		A: input,
 		B: "processed by encodingStepStruct",

dbos/workflow.go

@@ -684,8 +684,8 @@ func (c *dbosContext) RunAsWorkflow(_ DBOSContext, fn WorkflowFunc, input any, o
 /******* STEP FUNCTIONS *******/
 /******************************/
 
-type StepFunc func(ctx context.Context, input any) (any, error)
-type GenericStepFunc[P any, R any] func(ctx context.Context, input P) (R, error)
+type StepFunc func(ctx context.Context) (any, error)
+type GenericStepFunc[R any] func(ctx context.Context) (R, error)
 
 const StepParamsKey DBOSContextKey = "stepParams"
 
@@ -729,7 +729,7 @@ func setStepParamDefaults(params *StepParams, stepName string) *StepParams {
 
 var typeErasedStepNameToStepName = make(map[string]string)
 
-func RunAsStep[P any, R any](ctx DBOSContext, fn GenericStepFunc[P, R], input P) (R, error) {
+func RunAsStep[P any, R any](ctx DBOSContext, fn GenericStepFunc[R]) (R, error) {
 	if ctx == nil {
 		return *new(R), newStepExecutionError("", "", "ctx cannot be nil")
 	}
@@ -738,46 +738,36 @@ func RunAsStep[P any, R any](ctx DBOSContext, fn GenericStepFunc[P, R], input P)
 		return *new(R), newStepExecutionError("", "", "step function cannot be nil")
 	}
 
-	// Type-erase the function based on its actual type
-	typeErasedFn := StepFunc(func(ctx context.Context, input any) (any, error) {
-		typedInput, ok := input.(P)
-		if !ok {
-			return nil, newStepExecutionError("", "", fmt.Sprintf("unexpected input type: expected %T, got %T", *new(P), input))
-		}
-		return fn(ctx, typedInput)
-	})
+	stepName := runtime.FuncForPC(reflect.ValueOf(fn).Pointer()).Name()
 
-	typeErasedStepNameToStepName[runtime.FuncForPC(reflect.ValueOf(typeErasedFn).Pointer()).Name()] = runtime.FuncForPC(reflect.ValueOf(fn).Pointer()).Name()
+	// Type-erase the function
+	typeErasedFn := StepFunc(func(ctx context.Context) (any, error) { return fn(ctx) })
+	typeErasedStepNameToStepName[runtime.FuncForPC(reflect.ValueOf(typeErasedFn).Pointer()).Name()] = stepName
 
-	// Call the executor method
-	result, err := ctx.RunAsStep(ctx, typeErasedFn, input)
-	if err != nil {
-		// In case the errors comes from the DBOS step logic, the result will be nil and we must handle it
-		if result == nil {
-			return *new(R), err
-		}
-		return result.(R), err
+	// Call the executor method and pass through the result/error
+	result, err := ctx.RunAsStep(ctx, typeErasedFn)
+	// Step function could return a nil result
+	if result == nil {
+		return *new(R), err
 	}
-
-	// Type-check and cast the result
+	// Otherwise type-check and cast the result
 	typedResult, ok := result.(R)
 	if !ok {
 		return *new(R), fmt.Errorf("unexpected result type: expected %T, got %T", *new(R), result)
 	}
-
-	return typedResult, nil
+	return typedResult, err
 }
 
-func (c *dbosContext) RunAsStep(_ DBOSContext, fn StepFunc, input any) (any, error) {
+func (c *dbosContext) RunAsStep(_ DBOSContext, fn StepFunc) (any, error) {
 	// Get workflow state from context
 	wfState, ok := c.Value(workflowStateKey).(*workflowState)
 	if !ok || wfState == nil {
 		// TODO: try to print step name
 		return nil, newStepExecutionError("", "", "workflow state not found in context: are you running this step within a workflow?")
 	}
 
+	// This should not happen when called from the package-level RunAsStep
 	if fn == nil {
-		// TODO: try to print step name
 		return nil, newStepExecutionError(wfState.workflowID, "", "step function cannot be nil")
 	}
 
@@ -790,7 +780,7 @@ func (c *dbosContext) RunAsStep(_ DBOSContext, fn StepFunc, input any) (any, err
 
 	// If within a step, just run the function directly
 	if wfState.isWithinStep {
-		return fn(c, input)
+		return fn(c)
 	}
 
 	// Setup step state
@@ -819,7 +809,7 @@ func (c *dbosContext) RunAsStep(_ DBOSContext, fn StepFunc, input any) (any, err
 	// Spawn a child DBOSContext with the step state
 	stepCtx := WithValue(c, workflowStateKey, &stepState)
 
-	stepOutput, stepError := fn(stepCtx, input)
+	stepOutput, stepError := fn(stepCtx)
 
 	// Retry if MaxRetries > 0 and the first execution failed
 	var joinedErrors error
@@ -845,7 +835,7 @@ func (c *dbosContext) RunAsStep(_ DBOSContext, fn StepFunc, input any) (any, err
 			}
 
 			// Execute the retry
-			stepOutput, stepError = fn(stepCtx, input)
+			stepOutput, stepError = fn(stepCtx)
 
 			// If successful, break
 			if stepError == nil {

dbos/workflows_test.go

@@ -35,19 +35,23 @@ func simpleWorkflowError(dbosCtx DBOSContext, input string) (int, error) {
 }
 
 func simpleWorkflowWithStep(dbosCtx DBOSContext, input string) (string, error) {
-	return RunAsStep(dbosCtx, simpleStep, input)
+	return RunAsStep[string](dbosCtx, func(ctx context.Context) (string, error) {
+		return simpleStep(ctx)
+	})
 }
 
-func simpleStep(ctx context.Context, input string) (string, error) {
+func simpleStep(_ context.Context) (string, error) {
 	return "from step", nil
 }
 
-func simpleStepError(ctx context.Context, input string) (string, error) {
+func simpleStepError(_ context.Context) (string, error) {
 	return "", fmt.Errorf("step failure")
 }
 
 func simpleWorkflowWithStepError(dbosCtx DBOSContext, input string) (string, error) {
-	return RunAsStep(dbosCtx, simpleStepError, input)
+	return RunAsStep[string](dbosCtx, func(ctx context.Context) (string, error) {
+		return simpleStepError(ctx)
+	})
 }
 
 // idempotencyWorkflow increments a global counter and returns the input
@@ -292,38 +296,44 @@ func TestWorkflowsRegistration(t *testing.T) {
 	}
 }
 
-func stepWithinAStep(ctx context.Context, input string) (string, error) {
-	return simpleStep(ctx, input)
+func stepWithinAStep(ctx context.Context) (string, error) {
+	return simpleStep(ctx)
 }
 
 func stepWithinAStepWorkflow(dbosCtx DBOSContext, input string) (string, error) {
-	return RunAsStep(dbosCtx, stepWithinAStep, input)
+	return RunAsStep[string](dbosCtx, func(ctx context.Context) (string, error) {
+		return stepWithinAStep(ctx)
+	})
 }
 
 // Global counter for retry testing
 var stepRetryAttemptCount int
 
-func stepRetryAlwaysFailsStep(ctx context.Context, input string) (string, error) {
+func stepRetryAlwaysFailsStep(ctx context.Context) (string, error) {
 	stepRetryAttemptCount++
 	return "", fmt.Errorf("always fails - attempt %d", stepRetryAttemptCount)
 }
 
 var stepIdempotencyCounter int
 
-func stepIdempotencyTest(ctx context.Context, input int) (string, error) {
+func stepIdempotencyTest(ctx context.Context) (string, error) {
 	stepIdempotencyCounter++
 	return "", nil
 }
 
 func stepRetryWorkflow(dbosCtx DBOSContext, input string) (string, error) {
-	RunAsStep(dbosCtx, stepIdempotencyTest, 1)
+	RunAsStep[int](dbosCtx, func(ctx context.Context) (string, error) {
+		return stepIdempotencyTest(ctx)
+	})
 	stepCtx := WithValue(dbosCtx, StepParamsKey, &StepParams{
 		MaxRetries:   5,
 		BaseInterval: 1 * time.Millisecond,
 		MaxInterval:  10 * time.Millisecond,
 	})
 
-	return RunAsStep(stepCtx, stepRetryAlwaysFailsStep, input)
+	return RunAsStep[string](stepCtx, func(ctx context.Context) (string, error) {
+		return stepRetryAlwaysFailsStep(ctx)
+	})
 }
 
 func TestSteps(t *testing.T) {
@@ -335,7 +345,9 @@ func TestSteps(t *testing.T) {
 
 	t.Run("StepsMustRunInsideWorkflows", func(t *testing.T) {
 		// Attempt to run a step outside of a workflow context
-		_, err := RunAsStep(dbosCtx, simpleStep, "test")
+		_, err := RunAsStep[int](dbosCtx, func(ctx context.Context) (string, error) {
+			return simpleStep(ctx)
+		})
 		if err == nil {
 			t.Fatal("expected error when running step outside of workflow context, but got none")
 		}
@@ -411,7 +423,7 @@ func TestSteps(t *testing.T) {
 		}
 
 		// Verify the error contains the step name and max retries
-		expectedErrorMessage := "dbos.stepRetryAlwaysFailsStep has exceeded its maximum of 5 retries"
+		expectedErrorMessage := "has exceeded its maximum of 5 retries"
 		if !strings.Contains(dbosErr.Message, expectedErrorMessage) {
 			t.Fatalf("expected error message to contain '%s', got '%s'", expectedErrorMessage, dbosErr.Message)
 		}
@@ -470,7 +482,9 @@ func TestChildWorkflow(t *testing.T) {
 			return "", fmt.Errorf("expected childWf workflow ID to be %s, got %s", expectedCurrentID, workflowID)
 		}
 		// Steps of a child workflow start with an incremented step ID, because the first step ID is allocated to the child workflow
-		return RunAsStep(dbosCtx, simpleStep, "")
+		return RunAsStep[string](dbosCtx, func(ctx context.Context) (string, error) {
+			return simpleStep(ctx)
+		})
 	}
 	RegisterWorkflow(dbosCtx, childWf)
 
@@ -644,7 +658,9 @@ func TestChildWorkflow(t *testing.T) {
 		customChildID := uuid.NewString()
 
 		simpleChildWf := func(dbosCtx DBOSContext, input string) (string, error) {
-			return RunAsStep(dbosCtx, simpleStep, input)
+			return RunAsStep[string](dbosCtx, func(ctx context.Context) (string, error) {
+				return simpleStep(ctx)
+			})
 		}
 		RegisterWorkflow(dbosCtx, simpleChildWf)
 
@@ -713,23 +729,29 @@ func TestChildWorkflow(t *testing.T) {
 // Idempotency workflows moved to test functions
 
 func idempotencyWorkflow(dbosCtx DBOSContext, input string) (string, error) {
-	RunAsStep(dbosCtx, incrementCounter, int64(1))
+	RunAsStep[int64](dbosCtx, func(ctx context.Context) (int64, error) {
+		return incrementCounter(ctx, int64(1))
+	})
 	return input, nil
 }
 
 var blockingStepStopEvent *Event
 
-func blockingStep(ctx context.Context, input string) (string, error) {
+func blockingStep(_ context.Context) (string, error) {
 	blockingStepStopEvent.Wait()
 	return "", nil
 }
 
 var idempotencyWorkflowWithStepEvent *Event
 
 func idempotencyWorkflowWithStep(dbosCtx DBOSContext, input string) (int64, error) {
-	RunAsStep(dbosCtx, incrementCounter, int64(1))
+	RunAsStep[int64](dbosCtx, func(ctx context.Context) (int64, error) {
+		return incrementCounter(ctx, int64(1))
+	})
 	idempotencyWorkflowWithStepEvent.Set()
-	RunAsStep(dbosCtx, blockingStep, input)
+	RunAsStep[int](dbosCtx, func(ctx context.Context) (string, error) {
+		return blockingStep(ctx)
+	})
 	return idempotencyCounter, nil
 }
 
@@ -1131,9 +1153,9 @@ func TestScheduledWorkflows(t *testing.T) {
 		}
 
 		// Stop the workflowScheduler and check if it stops executing
-		currentCounter := counter
 		dbosCtx.(*dbosContext).getWorkflowScheduler().Stop()
 		time.Sleep(3 * time.Second) // Wait a bit to ensure no more executions
+		currentCounter := counter   // If more scheduled executions happen, this can also trigger a data race. If the scheduler is correct, there should be no race.
 		if counter >= currentCounter+2 {
 			t.Fatalf("Scheduled workflow continued executing after stopping scheduler: %d (expected < %d)", counter, currentCounter+2)
 		}
@@ -1253,7 +1275,9 @@ func stepThatCallsSend(ctx context.Context, input sendWorkflowInput) (string, er
 }
 
 func workflowThatCallsSendInStep(ctx DBOSContext, input sendWorkflowInput) (string, error) {
-	return RunAsStep(ctx, stepThatCallsSend, input)
+	return RunAsStep[sendWorkflowInput](ctx, func(context context.Context) (string, error) {
+		return stepThatCallsSend(context, input)
+	})
 }
 
 type sendRecvType struct {
@@ -2193,7 +2217,7 @@ func TestWorkflowTimeout(t *testing.T) {
 		}
 	})
 
-	waitForCancelStep := func(ctx context.Context, _ string) (string, error) {
+	waitForCancelStep := func(ctx context.Context) (string, error) {
 		// This step will trigger cancellation of the entire workflow context
 		<-ctx.Done()
 		if !errors.Is(ctx.Err(), context.Canceled) && !errors.Is(ctx.Err(), context.DeadlineExceeded) {
@@ -2203,7 +2227,9 @@ func TestWorkflowTimeout(t *testing.T) {
 	}
 
 	waitForCancelWorkflowWithStep := func(ctx DBOSContext, _ string) (string, error) {
-		return RunAsStep(ctx, waitForCancelStep, "trigger-cancellation")
+		return RunAsStep[sendWorkflowInput](ctx, func(context context.Context) (string, error) {
+			return waitForCancelStep(context)
+		})
 	}
 	RegisterWorkflow(dbosCtx, waitForCancelWorkflowWithStep)
 
@@ -2240,7 +2266,9 @@ func TestWorkflowTimeout(t *testing.T) {
 		// The timeout will trigger a step error, the workflow can do whatever it wants with that error
 		stepCtx, stepCancelFunc := WithTimeout(ctx, 1*time.Millisecond)
 		defer stepCancelFunc() // Ensure we clean up the context
-		_, err := RunAsStep(stepCtx, waitForCancelStep, "short-step-timeout")
+		_, err := RunAsStep[string](stepCtx, func(context context.Context) (string, error) {
+			return waitForCancelStep(context)
+		})
 		if !errors.Is(err, context.DeadlineExceeded) {
 			t.Fatalf("expected step to timeout, got: %v", err)
 		}
@@ -2287,7 +2315,9 @@ func TestWorkflowTimeout(t *testing.T) {
 		// This workflow will run a step that is not cancelable.
 		// What this means is the workflow *will* be cancelled, but the step will run normally
 		stepCtx := WithoutCancel(ctx)
-		res, err := RunAsStep(stepCtx, detachedStep, timeout*2)
+		res, err := RunAsStep[time.Duration](stepCtx, func(context context.Context) (string, error) {
+			return detachedStep(context, timeout*2)
+		})
 		if err != nil {
 			t.Fatalf("failed to run detached step: %v", err)
 		}