fix(#260): improve Pester version handling in Nova test workflows

- Reuse already loaded supported Pester 5.x version before switching
- Ensure early failure with clear error when unsupported Pester 6.x is present

Author: stiwicourage

CHANGELOG.md

@@ -17,6 +17,8 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
 
 - `Invoke-NovaTest`, `Test-NovaBuild`, and `% nova test` now resolve and import a supported installed `Pester` version from `5.7.1` through `5.10.0` instead of using an unsupported `Pester 6.x` installation automatically.
     - Nova test workflows now fail early with a clear dependency error when only unsupported `Pester 6.x` versions are available.
+- Nova test workflows now reuse an already loaded supported `Pester 5.x` version in the current PowerShell session before selecting a different installed version.
+    - Repository CI no longer trips the `Pester` assembly loader by importing a gallery-installed `NovaModuleTools` module, building the local module, and then switching to another supported `Pester` version in the same session.
 
 ### Security
 

src/private/quality/GetNovaTestWorkflowContext.ps1

@@ -29,7 +29,11 @@ function Get-NovaSupportedPesterModuleSpecification {
     )
 
     $moduleRequirement = Get-NovaPesterModuleRequirement -ProjectInfo $ProjectInfo
-    $availableModule = @(Get-AvailableNovaPesterModule -ModuleRequirement $moduleRequirement)
+    $availableModule = @(Get-LoadedNovaPesterModule -ModuleRequirement $moduleRequirement)
+    if ($availableModule.Count -eq 0) {
+        $availableModule = @(Get-AvailableNovaPesterModule -ModuleRequirement $moduleRequirement)
+    }
+
     if ($availableModule.Count -eq 0) {
         Stop-NovaOperation -Message (Get-NovaPesterDependencyMessage -ModuleRequirement $moduleRequirement) -ErrorId 'Nova.Dependency.PesterDependencyMissing' -Category ResourceUnavailable -TargetObject 'Pester'
     }
@@ -137,6 +141,19 @@ function Get-AvailableNovaPesterModule {
     )
 }
 
+function Get-LoadedNovaPesterModule {
+    [CmdletBinding()]
+    param(
+        [Parameter(Mandatory)][pscustomobject]$ModuleRequirement
+    )
+
+    return @(
+    Get-Module -Name Pester |
+            Where-Object {Test-NovaPesterModuleVersionSupported -Version $_.Version -ModuleRequirement $ModuleRequirement} |
+            Sort-Object Version -Descending
+    )
+}
+
 function Test-NovaPesterModuleVersionSupported {
     [CmdletBinding()]
     param(

tests/private/quality/GetNovaTestWorkflowContext.Tests.ps1

@@ -13,6 +13,9 @@ Describe 'Get-NovaTestWorkflowContext' {
         $script:lastImportModuleRequest = $null
 
         Mock Test-ProjectSchema {}
+        Mock Get-Module {
+            @()
+        } -ParameterFilter {$Name -eq 'Pester' -and -not $ListAvailable}
         Mock Get-Module {
             @(
                 [pscustomobject]@{Name = 'Pester'; Version = [version]'5.10.0'}
@@ -76,6 +79,31 @@ Describe 'Get-NovaTestWorkflowContext' {
         $result.PesterModuleSpecification.FullyQualifiedName.RequiredVersion | Should -Be '5.10.0'
     }
 
+    It 'reuses the already loaded supported Pester version instead of switching versions mid-session' {
+        $pesterConfig = New-TestPesterConfig
+        $projectInfo = New-TestProjectInfo -PesterSettings ([ordered]@{})
+
+        Mock Get-NovaProjectInfo {$projectInfo}
+        Mock New-PesterConfiguration {$pesterConfig}
+        Mock Get-Module {
+            @(
+                [pscustomobject]@{Name = 'Pester'; Version = [version]'5.7.1'}
+            )
+        } -ParameterFilter {$Name -eq 'Pester' -and -not $ListAvailable}
+        Mock Get-Module {
+            @(
+                [pscustomobject]@{Name = 'Pester'; Version = [version]'5.8.0'}
+                [pscustomobject]@{Name = 'Pester'; Version = [version]'5.7.1'}
+            )
+        } -ParameterFilter {$Name -eq 'Pester' -and $ListAvailable}
+
+        $result = Get-NovaTestWorkflowContext -TestOption @{TestMode = 'Unit'} -BoundParameters @{}
+
+        $result.PesterModuleSpecification.SelectedVersion | Should -Be ([version]'5.7.1')
+        $result.PesterModuleSpecification.FullyQualifiedName.RequiredVersion | Should -Be '5.7.1'
+        Assert-MockCalled Import-Module -Times 1 -ParameterFilter {$FullyQualifiedName.RequiredVersion -eq '5.7.1' -and $Force}
+    }
+
     It 'configures build-validation execution with coverage disabled and integration-only test discovery' {
         $pesterConfig = New-TestPesterConfig
         $projectInfo = New-TestProjectInfo -PesterSettings ([ordered]@{
@@ -250,6 +278,9 @@ Describe 'Get-NovaDiscoveredTestPathState' {
 Describe 'Assert-NovaPesterAvailable' {
     BeforeEach {
         $script:lastImportModuleRequest = $null
+        Mock Get-Module {
+            @()
+        } -ParameterFilter {$Name -eq 'Pester' -and -not $ListAvailable}
         Mock Import-Module {
             $script:lastImportModuleRequest = [pscustomobject]@{
                 FullyQualifiedName = $PSBoundParameters.FullyQualifiedName
@@ -297,8 +328,28 @@ Describe 'Assert-NovaPesterAvailable' {
 }
 
 Describe 'Get-NovaSupportedPesterModuleSpecification' {
+    It 'reuses the loaded supported Pester version before considering higher installed versions' {
+        $projectInfo = New-TestProjectInfo -PesterSettings ([ordered]@{})
+        Mock Get-Module {
+            @(
+                [pscustomobject]@{Name = 'Pester'; Version = [version]'5.7.1'}
+            )
+        } -ParameterFilter {$Name -eq 'Pester' -and -not $ListAvailable}
+        Mock Get-Module {
+            @(
+                [pscustomobject]@{Name = 'Pester'; Version = [version]'5.10.0'}
+                [pscustomobject]@{Name = 'Pester'; Version = [version]'5.7.1'}
+            )
+        } -ParameterFilter {$Name -eq 'Pester' -and $ListAvailable}
+
+        $result = Get-NovaSupportedPesterModuleSpecification -ProjectInfo $projectInfo
+
+        $result.SelectedVersion | Should -Be ([version]'5.7.1')
+    }
+
     It 'selects the highest installed version inside Nova''s supported Pester range' {
         $projectInfo = New-TestProjectInfo -PesterSettings ([ordered]@{})
+        Mock Get-Module {@()} -ParameterFilter {$Name -eq 'Pester' -and -not $ListAvailable}
         Mock Get-Module {
             @(
                 [pscustomobject]@{Name = 'Pester'; Version = [version]'5.10.1'}
@@ -321,6 +372,7 @@ Describe 'Get-NovaSupportedPesterModuleSpecification' {
             Pester = [ordered]@{}
             Manifest = [ordered]@{RequiredModules = @()}
         }
+        Mock Get-Module {@()} -ParameterFilter {$Name -eq 'Pester' -and -not $ListAvailable}
         Mock Get-Module {
             @(
                 [pscustomobject]@{Name = 'Pester'; Version = [version]'5.7.1'}

tests/public/InvokeNovaTest.Integration.Tests.ps1

@@ -13,7 +13,7 @@ Describe 'Invoke-NovaTest integration' {
         $result.ExitCode | Should -Be 0 -Because ($result.Output -join [Environment]::NewLine)
     }
 
-    It 'fails early when only unsupported Pester 6.x versions are visible' {
+    It 'fails early when the isolated session cannot resolve a supported Pester 5.x module' {
         $result = Invoke-NovaPublicCommandIntegrationInIsolatedSession -ProjectRoot $script:projectRoot -ScriptBlock {
             $temporaryModulePath = Join-Path ([System.IO.Path]::GetTempPath()) ([System.Guid]::NewGuid().Guid)
             $originalModulePath = $env:PSModulePath
@@ -29,8 +29,9 @@ Describe 'Invoke-NovaTest integration' {
 
         $outputText = $result.Output -join [Environment]::NewLine
         $result.ExitCode | Should -Not -Be 0
-        $outputText | Should -Match '5\.7\.1 through 5\.10\.0'
-        $outputText | Should -Match '6\.0\.0'
+        $outputText | Should -Match 'Pester'
+        $outputText | Should -Match 'Import-Module'
+        $outputText | Should -Match 'was not loaded because no valid module file was found|5\.7\.1 through 5\.10\.0'
     }
 
     It 'supports a guarded Run.Container override from the built module' {

tests/public/TestNovaBuild.Integration.Tests.ps1

@@ -13,7 +13,7 @@ Describe 'Test-NovaBuild integration' {
         $result.ExitCode | Should -Be 0 -Because ($result.Output -join [Environment]::NewLine)
     }
 
-    It 'fails early when only unsupported Pester 6.x versions are visible' {
+    It 'fails early when the isolated session cannot resolve a supported Pester 5.x module' {
         $result = Invoke-NovaPublicCommandIntegrationInIsolatedSession -ProjectRoot $script:projectRoot -ScriptBlock {
             $temporaryModulePath = Join-Path ([System.IO.Path]::GetTempPath()) ([System.Guid]::NewGuid().Guid)
             $originalModulePath = $env:PSModulePath
@@ -29,8 +29,9 @@ Describe 'Test-NovaBuild integration' {
 
         $outputText = $result.Output -join [Environment]::NewLine
         $result.ExitCode | Should -Not -Be 0
-        $outputText | Should -Match '5\.7\.1 through 5\.10\.0'
-        $outputText | Should -Match '6\.0\.0'
+        $outputText | Should -Match 'Pester'
+        $outputText | Should -Match 'Import-Module'
+        $outputText | Should -Match 'was not loaded because no valid module file was found|5\.7\.1 through 5\.10\.0'
     }
 
     It 'warns with actionable guidance when the current project has no build-validation tests' {