Addressed comments

container.go

@@ -53,7 +53,7 @@ type Container struct {
 	graph.Graph
 }
 
-// InvokeOnce only allows function invokation once to register the
+// InvokeOnce only allows function invocation once to register the
 // return types. If return types are already registered, specific error
 // is returned to the caller
 func (c *Container) InvokeOnce(t interface{}) error {

internal/graph/graph.go

@@ -138,12 +138,16 @@ func (g *Graph) InsertConstructor(ctor interface{}) error {
 }
 
 // ValidateReturnTypes validates if Invoke func's return type is Provided to the graph
-// checkCachedObjects=true additionally checks if objects are resolved and cached in the graph
+// checkCachedObjects=true ensures to throw an error only when the node is already
+// resolved and cached.
+//
 func (g *Graph) ValidateReturnTypes(ctype reflect.Type, checkCachedObjects bool) error {
 	objMap := make(map[reflect.Type]bool, ctype.NumOut())
 	for i := 0; i < ctype.NumOut(); i++ {
 		objType := ctype.Out(i)
 		if _, ok := g.nodes[objType]; ok {
+			// for Invoke validation, graphNode may not be resolved (still in the form of funcNode).
+			// checkCachedObjects ensures to throw an error only when the node is resolved and cached.
 			if checkCachedObjects {
 				if obj, ok := g.nodes[objType].(*objNode); ok && obj.cached {
 					return errors.Wrapf(errRetNode, "ctor: %v, object type: %v", ctype, objType)

internal/graph/graph_test.go

@@ -128,7 +128,7 @@ func TestCtorConflicts(t *testing.T) {
 	require.Contains(t, err.Error(), "ctor: func() (*graph.Child1, *graph.Child1, error), object type: *graph.Child1: node already exist for the constructor")
 }
 
-func TestValidateReturnTypes(t *testing.T) {
+func TestConstructorOverrideReturnsError(t *testing.T) {
 	t.Parallel()
 	g := NewGraph()