Add garbage collection feature

* Add `todo gc`, which will delete all archived todos.
* `NextId` will now take the first available id, rather than just the MaxId + 1.

1 files changed, 51 insertions, 0 deletions

diff --git a/todolist/todo_list_test.go b/todolist/todo_list_test.go
index 8a40b14..eb0bc84 100644
--- a/todolist/todo_list_test.go
+++ b/todolist/todo_list_test.go
@@ -8,8 +8,42 @@ import (
 
 func TestNextId(t *testing.T) {
 	assert := assert.New(t)
+	todo := &Todo{Subject: "testing", Completed: false, Archived: false}
 	list := &TodoList{}
 	assert.Equal(1, list.NextId())
+	list.Add(todo)
+	assert.Equal(2, list.NextId())
+}
+
+func TestNextIdWhenTodoDeleted(t *testing.T) {
+	assert := assert.New(t)
+	todo := &Todo{Subject: "testing", Completed: false, Archived: false}
+	todo2 := &Todo{Subject: "testing2", Completed: false, Archived: false}
+	todo3 := &Todo{Subject: "testing3", Completed: false, Archived: false}
+	list := &TodoList{}
+
+	list.Add(todo)
+	list.Add(todo2)
+	list.Add(todo3)
+
+	list.Delete(2)
+	assert.Equal(2, list.NextId())
+	list.Add(todo2)
+	assert.Equal(4, list.NextId())
+	list.Delete(1)
+	assert.Equal(1, list.NextId())
+}
+
+func TestMaxId(t *testing.T) {
+	assert := assert.New(t)
+	todo := &Todo{Subject: "testing", Completed: false, Archived: false}
+	todo2 := &Todo{Subject: "testing 2", Completed: false, Archived: false}
+	list := &TodoList{}
+	assert.Equal(0, list.MaxId())
+	list.Add(todo)
+	assert.Equal(1, list.MaxId())
+	list.Add(todo2)
+	assert.Equal(2, list.MaxId())
 }
 
 func TestIndexOf(t *testing.T) {
@@ -77,3 +111,20 @@ func TestUncomplete(t *testing.T) {
 	list.Uncomplete(2)
 	assert.Equal(false, list.FindById(2).Completed)
 }
+
+func TestGarbageCollect(t *testing.T) {
+	assert := assert.New(t)
+	list := &TodoList{}
+	todo := &Todo{Subject: "testing", Completed: false, Archived: true}
+	todo2 := &Todo{Subject: "testing2", Completed: false, Archived: false}
+	todo3 := &Todo{Subject: "testing3", Completed: false, Archived: true}
+	list.Add(todo)
+	list.Add(todo2)
+	list.Add(todo3)
+
+	list.GarbageCollect()
+
+	assert.Equal(len(list.Data), 1)
+	assert.Equal(1, list.NextId())
+	assert.Equal(2, list.MaxId())
+}