Add tests for guest service parents

test/unit/plugins/commands/serve/service/guest_service_test.rb

@@ -0,0 +1,58 @@
+require File.expand_path("../../../../../base", __FILE__)
+
+require Vagrant.source_root.join("plugins/commands/serve/command")
+
+class DummyContext
+  attr_reader :metadata
+  def initialize(plugin_name)
+    @metadata = {"plugin_name" => plugin_name}
+  end
+end
+
+describe VagrantPlugins::CommandServe::Service::GuestService do
+  include_context "unit"
+
+  let(:broker){
+    VagrantPlugins::CommandServe::Broker.new(bind: "bind_addr", ports: ["1234"])
+  }
+
+  let(:machine_arg){ 
+    Hashicorp::Vagrant::Sdk::FuncSpec::Args.new(
+      args: [
+        Hashicorp::Vagrant::Sdk::FuncSpec::Value.new(
+          name: "", 
+          type: "hashicorp.vagrant.sdk.Args.Target", 
+          value: Google::Protobuf::Any.pack(
+            Hashicorp::Vagrant::Sdk::Args::Target.new(
+              stream_id: 1,
+              network: "here:101",
+              target: "unix://here"
+            )
+          )
+        )
+      ]
+    )
+  }
+
+  subject { described_class.new(broker: broker) }
+
+  context "requesting parents" do
+    it "generates a spec" do
+      spec = subject.parents_spec
+      expect(spec).not_to be_nil
+    end
+
+    it "raises an error for unknown plugins" do
+      ctx = DummyContext.new("idontexisthahaha")
+      expect { subject.parents("", ctx) }.to raise_error
+    end
+
+    it "requests parents from plugins" do
+      ctx = DummyContext.new("ubuntu")
+      parents = subject.parents("", ctx)
+      expect(parents).not_to be_nil
+      expect(parents.parents).to include("ubuntu")
+    end
+  end
+
+end