pkg/generator: add stub/handler.go generator

pkg/generator/gen_handler.go

@@ -0,0 +1,27 @@
+package generator
+
+import (
+	"io"
+	"text/template"
+)
+
+// Handler contains all the customized data needed to generate stub/handler.go for a new operator
+// when pairing with handlerTmpl template.
+type Handler struct {
+	// imports
+	OperatorSDKImport string
+}
+
+// renderHandler generates the stub/handler.go file.
+func renderHandler(w io.Writer) error {
+	t := template.New("stub/handler.go")
+	t, err := t.Parse(handlerTmpl)
+	if err != nil {
+		return err
+	}
+
+	h := Handler{
+		OperatorSDKImport: sdkImport,
+	}
+	return t.Execute(w, h)
+}

pkg/generator/handler_tmpl.go

@@ -0,0 +1,17 @@
+package generator
+
+// handlerTmpl is the template for stub/handler.go.
+const handlerTmpl = `package stub
+
+import (
+	"{{.OperatorSDKImport}}/types"
+)
+
+type Handler struct {
+	// Fill me
+}
+
+func (h *Handler) Handle(ctx types.Context, event types.Event) {
+	// Fill me
+}
+`