Increase code coverage of BCS service app resource tests

Tests/xSharePoint/xSharePoint.xSPBCSServiceApp.Tests.ps1

@@ -34,7 +34,7 @@ Describe "xSPBCSServiceApp" {
 
         Import-Module $Global:CurrentSharePointStubModule -WarningAction SilentlyContinue
 
-        Context "When no service application exists in the current farm" {
+        Context "When no service applications exist in the current farm" {
 
             Mock Get-SPServiceApplication { return $null }
             Mock New-SPBusinessDataCatalogServiceApplication { }
@@ -54,6 +54,19 @@ Describe "xSPBCSServiceApp" {
             }
         }
 
+        Context "When service applications exist in the current farm but the specific BCS app does not" {
+
+            Mock Get-SPServiceApplication { return @(@{
+                TypeName = "Some other service app type"
+            }) }
+
+            It "returns null from the Get method" {
+                Get-TargetResource @testParams | Should BeNullOrEmpty
+                Assert-MockCalled Get-SPServiceApplication -ParameterFilter { $Name -eq $testParams.Name } 
+            }
+
+        }
+
         Context "When a service application exists and is configured correctly" {
             Mock Get-SPServiceApplication { 
                 return @(@{