New parameter -CodeCoveragePath, and adds Modules folder (#270)

- Add a new parameter `-CodeCoveragePath` in the function
  `Invoke-AppveyorTestScriptTask` to be able to add one or more relative
  paths which will be searched for PowerShell modules files (.psm1) to be used
  for evaluating code coverage (issue #114).
- The Modules folder, in the resource module root path, was added as a
  default path to be searched for PowerShell modules files (.psm1) to be
  used for evaluating code coverage.

AppVeyor.psm1

@@ -132,6 +132,14 @@ function Invoke-AppveyorInstallTask
         integration test with a specific order has run.
         This will also enable running unit tests and integration tests in a
         Docker Windows container.
+
+    .PARAMETER CodeCoveragePath
+        One or more relative paths to PowerShell modules, from the root module
+        folder. For each relative folder it will recursively search the first
+        level subfolders for PowerShell module files (.psm1).
+        Default to 'DSCResources', 'DSCClassResources', and 'Modules'.
+        This parameter is ignored when testing the DscResource.Tests repository
+        since that repository is treated differently, and has hard-coded paths.
 #>
 function Invoke-AppveyorTestScriptTask
 {
@@ -176,7 +184,15 @@ function Invoke-AppveyorTestScriptTask
 
         [Parameter(ParameterSetName = 'Default')]
         [Switch]
-        $RunTestInOrder
+        $RunTestInOrder,
+
+        [Parameter(ParameterSetName = 'Default')]
+        [String[]]
+        $CodeCoveragePath = @(
+            'DSCResources',
+            'DSCClassResources',
+            'Modules'
+        )
     )
 
     # Convert the Main Module path into an absolute path if it is relative
@@ -275,10 +291,7 @@ function Invoke-AppveyorTestScriptTask
                         Define the folders to check, if found add the path for
                         code coverage.
                     #>
-                    $possibleModulePaths = @(
-                        'DSCResources',
-                        'DSCClassResources'
-                    )
+                    $possibleModulePaths = $CodeCoveragePath
 
                     foreach ($possibleModulePath in $possibleModulePaths)
                     {

README.md

@@ -377,6 +377,14 @@ Pester code coverage, which the first two sections cover.
 1. On the call to `Invoke-AppveyorTestScriptTask`, make sure you have
    `-CodeCoverage` specified.  This will enable Pester code coverage.
 
+It is possible to control which relative paths, from the root module folder, are
+evaluated for code coverage.
+By specifying one or more relative paths in the parameter `-CodeCoveragePath`
+each path is searched for PowerShell modules files (.psm1). For each relative
+folder it will look in the root of the relative path, and also recursively
+search the first level subfolders, for PowerShell module files (.psm1).
+Defaults to the relative paths 'DSCResources', 'DSCClassResources', and 'Modules'.
+
 #### Repository using `-Type 'Harness'` for `Invoke-AppveyorTestScriptTask`
 
 1. Make sure you are properly generating pester code coverage in the repository
@@ -974,6 +982,11 @@ Contributors that add or change an example to be published must make sure that
 - Added Rule Name to PS Script Analyzer custom rules
 - Added PsScript Analyzer Rule Name to Write-Warning output in meta.tests
 - Removed sections 'Goals' and 'Git and Unicode' as they have become redundant.
+- Add a new parameter `-CodeCoveragePath` in the function
+  `Invoke-AppveyorTestScriptTask` to be able to add one or more relative
+  paths which will be searched for PowerShell modules files (.psm1) to be used
+  for evaluating code coverage
+  ([issue #114](https://github.com/PowerShell/DscResource.Tests/issues/114)).
 
 ### 0.2.0.0