Remove empty sets from managers

Author: jennybuckley

internal/fixture/state.go

@@ -259,5 +259,12 @@ func (tc TestCase) Test(parser *typed.ParseableType) error {
 		}
 	}
 
+	// Fail if any empty sets are present in the managers
+	for manager, set := range state.Managers {
+		if set.Empty() {
+			return fmt.Errorf("expected Managers to have no empty sets, but found one managed by %v", manager)
+		}
+	}
+
 	return nil
 }

merge/leaf_test.go

@@ -221,6 +221,55 @@ func TestUpdateLeaf(t *testing.T) {
 				},
 			},
 		},
+		"update_remove_empty_set": {
+			Ops: []Operation{
+				Apply{
+					Manager:    "default",
+					APIVersion: "v1",
+					Object: `
+						string: "string"
+					`,
+				},
+				Update{
+					Manager:    "controller",
+					APIVersion: "v1",
+					Object: `
+						string: "new string"
+					`,
+				},
+			},
+			Object: `
+				string: "new string"
+			`,
+			Managed: fieldpath.ManagedFields{
+				"controller": &fieldpath.VersionedSet{
+					Set: _NS(
+						_P("string"),
+					),
+					APIVersion: "v1",
+				},
+			},
+		},
+		"apply_remove_empty_set": {
+			Ops: []Operation{
+				Apply{
+					Manager:    "default",
+					APIVersion: "v1",
+					Object: `
+						string: "string"
+					`,
+				},
+				Apply{
+					Manager:    "default",
+					APIVersion: "v1",
+					Object: "",
+				},
+			},
+			Object: `
+				string: "string"
+			`,
+			Managed: fieldpath.ManagedFields{},
+		},
 	}
 
 	for name, test := range tests {

merge/update.go

@@ -85,6 +85,9 @@ func (s *Updater) update(oldObject, newObject typed.TypedValue, version fieldpat
 
 	for manager, conflictSet := range conflicts {
 		managers[manager].Set = managers[manager].Set.Difference(conflictSet.Set)
+		if managers[manager].Set.Empty() {
+			delete(managers, manager)
+		}
 	}
 
 	return managers, nil
@@ -112,6 +115,9 @@ func (s *Updater) Update(liveObject, newObject typed.TypedValue, version fieldpa
 	}
 	managers[manager].Set = managers[manager].Set.Union(compare.Modified).Union(compare.Added).Difference(compare.Removed)
 	managers[manager].APIVersion = version
+	if managers[manager].Set.Empty() {
+		delete(managers, manager)
+	}
 	return managers, nil
 }
 
@@ -138,5 +144,8 @@ func (s *Updater) Apply(liveObject, configObject typed.TypedValue, version field
 		Set:        set,
 		APIVersion: version,
 	}
+	if managers[manager].Set.Empty() {
+		delete(managers, manager)
+	}
 	return newObject, managers, nil
 }