fix issue #21 - run folder test command twice on provision for new Po…

…SH setup

lib/vagrant-dsc/provisioner.rb

@@ -10,7 +10,7 @@ class DSCError < Vagrant::Errors::VagrantError
     end
     class DSCUnsupportedOperation < DSCError
       error_key(:unsupported_operation)
-    end    
+    end
 
     # DSC Provisioner Plugin.
     #
@@ -219,6 +219,10 @@ def run_dsc_apply
       # on the guest machine.
       def verify_shared_folders(folders)
         folders.each do |folder|
+          # Warm up PoSH communicator for new instances - any stderr results
+          # in failure: https://github.com/mefellows/vagrant-dsc/issues/21
+          @machine.communicate.test("test -d #{folder}", sudo: true)
+
           @logger.info("Checking for shared folder: #{folder}")
           if !@machine.communicate.test("test -d #{folder}", sudo: true)
             raise DSCError, :missing_shared_folders

spec/provisioner/provisioner_spec.rb

@@ -89,7 +89,7 @@
     it "should raise error if folders not shared" do
       root_config.synced_folder_type = "nfs"
 
-      expect(communicator).to receive(:test).with("test -d foo/modules", {:sudo=>true}).and_return(false)
+      expect(communicator).to receive(:test).twice.with("test -d foo/modules", {:sudo=>true}).and_return(false)
 
       subject.configure(root_config)
 
@@ -100,9 +100,9 @@
     it "should ensure shared folders are properly shared" do
       root_config.synced_folder_type = "nfs"
 
-      expect(communicator).to receive(:test).with("test -d foo/modules", {:sudo=>true}).and_return(true)
-      expect(communicator).to receive(:test).with("test -d foo/modules2", {:sudo=>true}).and_return(true)
-      expect(communicator).to receive(:test).with("test -d manifests", {:sudo=>true}).and_return(true)
+      expect(communicator).to receive(:test).twice.with("test -d foo/modules", {:sudo=>true}).and_return(true)
+      expect(communicator).to receive(:test).twice.with("test -d foo/modules2", {:sudo=>true}).and_return(true)
+      expect(communicator).to receive(:test).twice.with("test -d manifests", {:sudo=>true}).and_return(true)
 
       subject.configure(root_config)
 
@@ -183,12 +183,12 @@
       expect(subject).to receive(:run_dsc_apply)
 
       subject.provision
-    end    
+    end
 
     it "should ensure shared folders are properly configured" do
       allow(communicator).to receive(:test)
       allow(communicator).to receive(:sudo)
-      allow(communicator).to receive(:upload)      
+      allow(communicator).to receive(:upload)
       allow(subject).to receive(:verify_dsc).and_return(true)
       allow(subject).to receive(:run_dsc_apply).and_return(true)
       allow(guest).to receive(:capability?)
@@ -225,7 +225,7 @@
 
     it "should raise an error if Powershell version is invalid" do
 
-    end    
+    end
   end
 
   describe "DSC runner script" do
@@ -288,7 +288,7 @@ def get_and_update_counter(name=nil) 1 end
       it "should generate a valid powershell command" do
         root_config.manifests_path = "../manifests"
         root_config.configuration_file = configuration_file
-        
+
         script = subject.generate_dsc_runner_script
         expect_script = "#
 # DSC Runner.