Add error handling for bad directory

generators/static.go

@@ -19,6 +19,10 @@ func (sg *StaticGenerator) Generate(component *core.Component) (manifest string,
 
 	staticPath := path.Join(component.PhysicalPath, component.Path)
 	staticFiles, err := ioutil.ReadDir(staticPath)
+	if err != nil {
+		log.Errorf("error reading from directory %s", staticPath);
+		return "", err
+	}
 
 	manifests := ""
 	for _, staticFile := range staticFiles {

generators/static_test.go

@@ -0,0 +1,20 @@
+package generators
+
+import (
+	"github.com/microsoft/fabrikate/core"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestStaticGenerator_Generate(t *testing.T) {
+	component := core.Component{
+		Name:         "foo",
+		Path:         "",
+		PhysicalPath: "../testdata/invaliddir",
+	}
+
+	generator := &StaticGenerator{}
+	_, err := generator.Generate(&component)
+	assert.NotNil(t, err)
+}