示例#1
0
func (stringSetSuite) TestUninitialized(c *gc.C) {
	var uninitialized set.Strings
	c.Assert(uninitialized.Size(), gc.Equals, 0)
	c.Assert(uninitialized.IsEmpty(), gc.Equals, true)
	// You can get values and sorted values from an unitialized set.
	AssertValues(c, uninitialized)
	// All contains checks are false
	c.Assert(uninitialized.Contains("foo"), gc.Equals, false)
	// Remove works on an uninitialized Strings
	uninitialized.Remove("foo")

	var other set.Strings
	// Union returns a new set that is empty but initialized.
	c.Assert(uninitialized.Union(other), gc.DeepEquals, set.NewStrings())
	c.Assert(uninitialized.Intersection(other), gc.DeepEquals, set.NewStrings())
	c.Assert(uninitialized.Difference(other), gc.DeepEquals, set.NewStrings())

	other = set.NewStrings("foo", "bar")
	c.Assert(uninitialized.Union(other), gc.DeepEquals, other)
	c.Assert(uninitialized.Intersection(other), gc.DeepEquals, set.NewStrings())
	c.Assert(uninitialized.Difference(other), gc.DeepEquals, set.NewStrings())
	c.Assert(other.Union(uninitialized), gc.DeepEquals, other)
	c.Assert(other.Intersection(uninitialized), gc.DeepEquals, set.NewStrings())
	c.Assert(other.Difference(uninitialized), gc.DeepEquals, other)

	// Once something is added, the set becomes initialized.
	uninitialized.Add("foo")
	AssertValues(c, uninitialized, "foo")
}