From 509c05b6ccd3d5ee90b2e15218345c92cbbce44b Mon Sep 17 00:00:00 2001
From: Frederic Gagnon <frederic.gagnon@cae.com>
Date: Thu, 11 Apr 2024 08:28:07 -0400
Subject: [PATCH] Allow using 'RootModule/NestedModule' as ModuleName

---
 src/functions/InModuleScope.ps1       |  7 ++++-
 tst/functions/InModuleScope.Tests.ps1 | 45 ++++++++++++++++++++++++++-
 2 files changed, 50 insertions(+), 2 deletions(-)

diff --git a/src/functions/InModuleScope.ps1 b/src/functions/InModuleScope.ps1
index 9b9066b43..e26ae9b41 100644
--- a/src/functions/InModuleScope.ps1
+++ b/src/functions/InModuleScope.ps1
@@ -176,7 +176,12 @@ function Get-CompatibleModule {
         if ($PesterPreference.Debug.WriteDebugMessages.Value) {
             Write-PesterDebugMessage -Scope Runtime "Searching for a module $ModuleName."
         }
-        $modules = @(& $SafeCommands['Get-Module'] -Name $ModuleName -All -ErrorAction Stop)
+        if ($ModuleName -match '(?<RootModule>\w+)[/\\](?<NestedModule>\w+)') {
+            $modules = @(& $SafeCommands['Get-Module'] -Name $Matches['RootModule'] -All -ErrorAction Stop | & $SafeCommands['Select-Object'] -ExpandProperty NestedModules | & $SafeCommands['Where-Object'] { $_.Name -eq $Matches['NestedModule'] })
+        }
+        else {
+            $modules = @(& $SafeCommands['Get-Module'] -Name $ModuleName -All -ErrorAction Stop)
+        }
     }
     catch {
         throw "No modules named '$ModuleName' are currently loaded."
diff --git a/tst/functions/InModuleScope.Tests.ps1 b/tst/functions/InModuleScope.Tests.ps1
index 9f3f74fd1..6e144487c 100644
--- a/tst/functions/InModuleScope.Tests.ps1
+++ b/tst/functions/InModuleScope.Tests.ps1
@@ -125,6 +125,49 @@ Describe 'Get-CompatibleModule' {
         }
     }
 
+    Context 'when module name matches a root and a nested module' {
+        BeforeAll {
+            $nestedModuleName = 'NestedModule'
+            $moduleName = 'RootWithNestedModule'
+            $moduleManifestPath = "TestDrive:/$moduleName.psd1"
+            New-Item -Path "TestDrive:/$nestedModuleName.psm1" -ItemType File -Force -ErrorAction Stop | Out-Null
+            '[string]$Script:ModuleVar = "Foo"' | Out-File -FilePath "TestDrive:/$nestedModuleName.psm1" -Encoding ascii
+            New-ModuleManifest -Path $moduleManifestPath -NestedModules ".\$nestedModuleName.psm1"
+            Import-Module $moduleManifestPath -Force
+        }
+
+        AfterAll {
+            Get-Module $moduleName -ErrorAction SilentlyContinue | Remove-Module -Force
+        }
+
+        It 'should return a single ModuleInfo object when using a slash as delimiter' {
+            $moduleInfo = InPesterModuleScope { Get-CompatibleModule -ModuleName 'RootWithNestedModule/NestedModule' }
+            $moduleInfo | Should -Not -BeNullOrEmpty
+            @($moduleInfo).Count | Should -Be 1
+            $moduleInfo.Name | Should -Be 'NestedModule'
+            $moduleInfo.ModuleType | Should -Be 'Script'
+        }
+
+        It 'should return a single ModuleInfo object when using a backslash as delimiter' {
+            $moduleInfo = InPesterModuleScope { Get-CompatibleModule -ModuleName 'RootWithNestedModule\NestedModule' }
+            $moduleInfo | Should -Not -BeNullOrEmpty
+            @($moduleInfo).Count | Should -Be 1
+            $moduleInfo.Name | Should -Be 'NestedModule'
+            $moduleInfo.ModuleType | Should -Be 'Script'
+        }
+
+        It 'should return the module session state name' {
+            $name = InModuleScope -ModuleName 'RootWithNestedModule\NestedModule' -ScriptBlock { $ExecutionContext.SessionState.Module.Name }
+            $name | Should -Be 'NestedModule'
+        }
+
+        It 'should return a nested module variable value' {
+            InModuleScope -ModuleName 'RootWithNestedModule\NestedModule' -ScriptBlock {
+                $Script:ModuleVar | Should -Be 'Foo'
+            }
+        }
+    }
+
 }
 
 Describe 'InModuleScope arguments and parameter binding' {
@@ -340,4 +383,4 @@ Describe 'Working with manifest modules' {
         $res = InModuleScope -ModuleName $moduleName -ScriptBlock { myPrivateFunction }
         $res | Should -Be 'real'
     }
-}
\ No newline at end of file
+}