diff --git a/test/unit/plugins/commands/plugin/state_file_test.rb b/test/unit/plugins/commands/plugin/state_file_test.rb
new file mode 100644
index 000000000..0ef0006db
--- /dev/null
+++ b/test/unit/plugins/commands/plugin/state_file_test.rb
@@ -0,0 +1,47 @@
+require "json"
+require "pathname"
+
+require File.expand_path("../../../../base", __FILE__)
+
+describe VagrantPlugins::CommandPlugin::StateFile do
+  let(:path) do
+    f = Tempfile.new("vagrant")
+    p = f.path
+    f.close
+    f.unlink
+    Pathname.new(p)
+  end
+
+  after do
+    path.unlink if path.file?
+  end
+
+  subject { described_class.new(path) }
+
+  it "should have no plugins without saving some" do
+    expect(subject.installed_plugins).to be_empty
+  end
+
+  it "should have plugins when saving" do
+    subject.add_plugin("foo")
+
+    instance = described_class.new(path)
+    expect(instance.installed_plugins).to eql(["foo"])
+  end
+
+  it "should remove plugins" do
+    subject.add_plugin("foo")
+    subject.remove_plugin("foo")
+
+    instance = described_class.new(path)
+    expect(instance.installed_plugins).to be_empty
+  end
+
+  it "should store plugins uniquely" do
+    subject.add_plugin("foo")
+    subject.add_plugin("foo")
+
+    instance = described_class.new(path)
+    expect(instance.installed_plugins).to eql(["foo"])
+  end
+end