Add better error handling for -Path in Publish-PSResource

Author: alerickson

src/code/PublishPSResource.cs

@@ -167,8 +167,8 @@ protected override void BeginProcessing()
                 ThrowTerminatingError(
                     new ErrorRecord(
                         new ArgumentException(
-                            "The path to the resource to publish is not in the correct format, point to a path or file of the module or script to publish."),
-                            "InvalidSourcePath",
+                            "The path to the resource to publish is not in the correct format or does not exist. Please provide the path of the root module or the path to the .psd1."),
+                            "InvalidPublishPath",
                             ErrorCategory.InvalidArgument,
                             this));
             }
@@ -187,6 +187,15 @@ protected override void BeginProcessing()
                 pathToScriptFileToPublish = resolvedPath;
                 resourceType = ResourceType.Script;
             }
+            else {
+                ThrowTerminatingError(
+                    new ErrorRecord(
+                        new ArgumentException(
+                            $"The publish path provided, '{resolvedPath}', is not a valid. Please provide a path to the root module or path to the .psd1."),
+                            "InvalidPublishPath",
+                            ErrorCategory.InvalidArgument,
+                            this));
+            }
 
             if (!String.IsNullOrEmpty(DestinationPath))
             {

test/PublishPSResourceTests/PublishPSResource.Tests.ps1

@@ -534,4 +534,12 @@ Describe "Test Publish-PSResource" -tags 'CI' {
 
         {Publish-PSResource -Path $incorrectdepmoduleversion -ErrorAction Stop} | Should -Throw -ErrorId "InvalidModuleManifest,Microsoft.PowerShell.PSResourceGet.Cmdlets.PublishPSResource"
     }
+
+    It "Publish a module with using an invalid file path (path to .psm1), should throw" {
+        $fileName = "$script:PublishModuleName.psm1"
+        $psm1Path = Join-Path -Path $script:PublishModuleBase -ChildPath $fileName
+        $null = New-Item -Path $psm1Path -ItemType File -Force
+
+        {Publish-PSResource -Path $psm1Path -Repository $testRepository2 -ErrorAction Stop} | Should -Throw -ErrorId "InvalidPublishPath,Microsoft.PowerShell.PSResourceGet.Cmdlets.PublishPSResource"
+    }
 }