engine: add LoadAndRun method to reduce needed code to support most typical usage

engine/engine.go

@@ -16,30 +16,36 @@ var (
 	ErrInvalidMemorySize = errors.New("engine: invalid memory size")
 )
 
+// Engine is the main struct for the Mechanoid engine.
 type Engine struct {
 	Interpreter Interpreter
 	FileStore   FileStore
 	Devices     []Device
 }
 
+// NewEngine returns a new Engine.
 func NewEngine() *Engine {
 	return &Engine{
 		Devices: []Device{},
 	}
 }
 
+// UseInterpreter sets the Interpreter for the Engine.
 func (e *Engine) UseInterpreter(interp Interpreter) {
 	e.Interpreter = interp
 }
 
+// UseFileStore sets the FileStore for the Engine.
 func (e *Engine) UseFileStore(fs FileStore) {
 	e.FileStore = fs
 }
 
+// AddDevice adds a Device to the Engine.
 func (e *Engine) AddDevice(d Device) {
 	e.Devices = append(e.Devices, d)
 }
 
+// Init initializes the Engine by initializing the Interpreter and all Devices.
 func (e *Engine) Init() error {
 	if e.Interpreter == nil {
 		return ErrNoInterpreter
@@ -70,3 +76,25 @@ func (e *Engine) Init() error {
 	}
 	return nil
 }
+
+// LoadAndRun loads and runs some WASM code using the current Interpreter.
+// It returns an error if the Engine has no Interpreter, or if the Interpreter
+// fails to load or run the module.
+func (e *Engine) LoadAndRun(code Reader) (Instance, error) {
+	if e.Interpreter == nil {
+		return nil, ErrNoInterpreter
+	}
+
+	mechanoid.Debug("loading WASM code")
+	if err := e.Interpreter.Load(code); err != nil {
+		return nil, err
+	}
+
+	mechanoid.Debug("running WASM code")
+	ins, err := e.Interpreter.Run()
+	if err != nil {
+		return nil, err
+	}
+
+	return ins, nil
+}

engine/engine_test.go

@@ -1,11 +1,17 @@
 package engine
 
 import (
+	"bytes"
 	"testing"
 
+	_ "embed"
+
 	"github.com/orsinium-labs/wypes"
 )
 
+//go:embed tester.wasm
+var wasmCode []byte
+
 func TestEngine(t *testing.T) {
 	t.Run("cannot init without interpreter", func(t *testing.T) {
 		e := NewEngine()
@@ -23,6 +29,19 @@ func TestEngine(t *testing.T) {
 			t.Errorf("Engine.Init() failed: %v", err)
 		}
 	})
+
+	t.Run("can LoadAndRun", func(t *testing.T) {
+		e := NewEngine()
+		e.UseInterpreter(&mockInterpreter{})
+		err := e.Init()
+		if err != nil {
+			t.Errorf("Engine.Init() failed: %v", err)
+		}
+
+		if _, err := e.LoadAndRun(bytes.NewReader(wasmCode)); err != nil {
+			t.Errorf("Engine.LoadAndRun() failed: %v", err)
+		}
+	})
 }
 
 type mockInterpreter struct {