diff --git a/test/unit/plugins/synced_folders/smb/synced_folder_test.rb b/test/unit/plugins/synced_folders/smb/synced_folder_test.rb
new file mode 100644
index 000000000..a1d40d9ef
--- /dev/null
+++ b/test/unit/plugins/synced_folders/smb/synced_folder_test.rb
@@ -0,0 +1,217 @@
+require_relative "../../../base"
+
+require Vagrant.source_root.join("plugins/synced_folders/smb/synced_folder")
+
+describe VagrantPlugins::SyncedFolderSMB::SyncedFolder do
+  include_context "unit"
+
+  let(:iso_env) do
+    env = isolated_environment
+    env.vagrantfile("")
+    env.create_vagrant_env
+  end
+
+  let(:guest){ double("guest") }
+  let(:host){ double("host") }
+  let(:machine) { iso_env.machine(iso_env.machine_names[0], :dummy) }
+  let(:host_caps){ [] }
+  let(:guest_caps){ [] }
+  let(:folders){ {"/first/path" => {}, "/second/path" => {}} }
+  let(:options){ {} }
+
+  before do
+    allow(machine.env).to receive(:host).and_return(host)
+    allow(machine).to receive(:guest).and_return(guest)
+    allow(machine).to receive(:ssh_info).and_return(username: 'sshuser')
+    allow(guest).to receive(:name).and_return("guest_name")
+    allow(host).to receive(:capability?).and_return(false)
+    host_caps.each do |cap|
+      allow(host).to receive(:capability?).with(cap).and_return(true)
+      allow(host).to receive(:capability).with(cap, any_args).and_return(true)
+    end
+    allow(guest).to receive(:capability?).and_return(false)
+    guest_caps.each do |cap|
+      allow(guest).to receive(:capability?).with(cap).and_return(true)
+      allow(guest).to receive(:capability).with(cap, any_args).and_return(true)
+    end
+  end
+
+  describe ".usable?" do
+    context "without supporting capabilities" do
+      it "is not usable" do
+        expect(subject.usable?(machine)).to be(false)
+      end
+
+      it "raises exception when raise_error enabled" do
+        expect{subject.usable?(machine, true)}.to raise_error(
+          VagrantPlugins::SyncedFolderSMB::Errors::SMBNotSupported)
+      end
+    end
+
+    context "with smb not installed" do
+      let(:host_caps){ [:smb_installed] }
+
+      it "is not usable" do
+        expect(host).to receive(:capability).with(:smb_installed).and_return(false)
+        expect(subject.usable?(machine)).to be(false)
+      end
+    end
+
+    context "with smb installed" do
+      let(:host_caps){ [:smb_installed] }
+
+      it "is usable" do
+        expect(subject.usable?(machine)).to be(true)
+      end
+    end
+  end
+
+  describe ".prepare" do
+    let(:host_caps){ [:smb_prepare] }
+
+    context "without credentials provided" do
+      before do
+        expect(machine.env.ui).to receive(:ask).and_return('username')
+        expect(machine.env.ui).to receive(:ask).and_return('password')
+      end
+
+      it "should prompt for credentials" do
+        subject.prepare(machine, folders, options)
+      end
+
+      it "should set credential information into all folder options" do
+        subject.prepare(machine, folders, options)
+        expect(folders['/first/path'][:smb_username]).to eq('username')
+        expect(folders['/first/path'][:smb_password]).to eq('password')
+        expect(folders['/second/path'][:smb_username]).to eq('username')
+        expect(folders['/second/path'][:smb_password]).to eq('password')
+      end
+    end
+
+    context "with credentials provided" do
+      context "in single share entry" do
+        let(:folders){ {'/first/path' => {}, '/second/path' => {smb_username: 'smbuser', smb_password: 'smbpass'}} }
+
+        it "should not prompt for credentials" do
+          expect(machine.env.ui).not_to receive(:ask)
+          subject.prepare(machine, folders, options)
+        end
+
+        it "should add existing credentials to folder options without" do
+          subject.prepare(machine, folders, options)
+          expect(folders['/first/path'][:smb_username]).to eq('smbuser')
+          expect(folders['/first/path'][:smb_password]).to eq('smbpass')
+        end
+      end
+
+      context "in both entries" do
+        let(:folders){ {'/first/path' => {smb_username: 'user', smb_password: 'pass'},
+          '/second/path' => {smb_username: 'smbuser', smb_password: 'smbpass'}} }
+
+        it "should not modify existing credentials" do
+          subject.prepare(machine, folders, options)
+          expect(folders['/first/path'][:smb_username]).to eq('user')
+          expect(folders['/first/path'][:smb_password]).to eq('pass')
+          expect(folders['/second/path'][:smb_username]).to eq('smbuser')
+          expect(folders['/second/path'][:smb_password]).to eq('smbpass')
+        end
+
+        it "should register passwords with scrubber" do
+          expect(Vagrant::Util::CredentialScrubber).to receive(:sensitive).with('pass')
+          expect(Vagrant::Util::CredentialScrubber).to receive(:sensitive).with('smbpass')
+          subject.prepare(machine, folders, options)
+        end
+      end
+    end
+  end
+
+  describe ".enable" do
+    it "fails when guest does not support capability" do
+      expect{
+        subject.enable(machine, folders, options)
+      }.to raise_error(Vagrant::Errors::GuestCapabilityNotFound)
+    end
+
+    context "with guest capability supported" do
+      let(:guest_caps){ [:mount_smb_shared_folder, :choose_addressable_ip_addr] }
+      let(:host_caps){ [:configured_ip_addresses] }
+
+      it "should attempt to install smb on guest" do
+        expect(guest).to receive(:capability?).with(:smb_install).and_return(true)
+        expect(guest).to receive(:capability).with(:smb_install, any_args)
+        subject.enable(machine, folders, options)
+      end
+
+      it "should request host IP addresses" do
+        expect(host).to receive(:capability).with(:configured_ip_addresses)
+        subject.enable(machine, folders, options)
+      end
+
+      it "should determine guest accessible address" do
+        expect(guest).to receive(:capability).with(:choose_addressable_ip_addr, any_args)
+        subject.enable(machine, folders, options)
+      end
+
+      it "should error if no guest accessible address is available" do
+        expect(guest).to receive(:capability).with(:choose_addressable_ip_addr, any_args).and_return(nil)
+        expect{ subject.enable(machine, folders, options) }.to raise_error(
+          VagrantPlugins::SyncedFolderSMB::Errors::NoHostIPAddr)
+      end
+
+      it "should default owner and group to ssh username" do
+        subject.enable(machine, folders, options)
+        expect(folders["/first/path"][:owner]).to eq("sshuser")
+        expect(folders["/first/path"][:group]).to eq("sshuser")
+        expect(folders["/second/path"][:owner]).to eq("sshuser")
+        expect(folders["/second/path"][:group]).to eq("sshuser")
+      end
+
+      it "should set the host address in folder options" do
+        expect(guest).to receive(:capability).with(:choose_addressable_ip_addr, any_args).and_return("ADDR")
+        subject.enable(machine, folders, options)
+        expect(folders["/first/path"][:smb_host]).to eq("ADDR")
+        expect(folders["/second/path"][:smb_host]).to eq("ADDR")
+      end
+
+      context "with smb_host option set" do
+        let(:folders){ {"/first/path" => {smb_host: "ADDR"}, "/second/path" => {}} }
+
+        it "should not update the value" do
+          expect(guest).to receive(:capability).with(:choose_addressable_ip_addr, any_args).and_return("OTHER")
+          subject.enable(machine, folders, options)
+          expect(folders["/first/path"][:smb_host]).to eq("ADDR")
+          expect(folders["/second/path"][:smb_host]).to eq("OTHER")
+        end
+      end
+
+      context "with owner and group set" do
+        let(:folders){ {"/first/path" => {owner: "smbowner"}, "/second/path" => {group: "smbgroup"}} }
+
+        it "should not update set owner or group" do
+          subject.enable(machine, folders, options)
+          expect(folders["/first/path"][:owner]).to eq("smbowner")
+          expect(folders["/first/path"][:group]).to eq("sshuser")
+          expect(folders["/second/path"][:owner]).to eq("sshuser")
+          expect(folders["/second/path"][:group]).to eq("smbgroup")
+        end
+      end
+    end
+  end
+
+  describe ".cleanup" do
+    context "without supporting capability" do
+      it "does nothing" do
+        subject.cleanup(machine, options)
+      end
+    end
+
+    context "with supporting capability" do
+      let(:host_caps){ [:smb_cleanup] }
+
+      it "runs cleanup" do
+        expect(host).to receive(:capability).with(:smb_cleanup, any_args)
+        subject.cleanup(machine, options)
+      end
+    end
+  end
+end