Require verified prerelease enumeration metadata before choosing a counter

Author: MariusStorhaug

.github/actions/Resolve-PSModuleVersion/src/Resolve-PSModuleVersion.Helpers.psm1

@@ -597,6 +597,18 @@ function Get-NextPrereleaseNumber {
     }
     try {
         $galleryVersions = @(Find-PSResource @params)
+        if ($galleryVersions.Count -eq 0) {
+            throw 'The successful prerelease enumeration returned no verifiable package metadata.'
+        }
+        $galleryVersions = @($galleryVersions | ForEach-Object {
+                if ($_.Name -ine $ModuleName -or [string]$_.Version -notmatch '^\d+\.\d+\.\d+$') {
+                    throw "The Gallery prerelease enumeration returned unverifiable version metadata for [$ModuleName]."
+                }
+                [pscustomobject]@{
+                    Version    = [version]([string]$_.Version)
+                    Prerelease = $_.Prerelease
+                }
+            })
     } catch {
         $failure = $_
         if ($failure.FullyQualifiedErrorId -notlike 'PackageNotFound,*') {

.github/actions/Resolve-PSModuleVersion/tests/Resolve-PSModuleVersion.Helpers.Tests.ps1

@@ -8,6 +8,15 @@ param()
 BeforeAll {
     Import-Module -Name 'PSModule' -Force
     Import-Module -Name (Join-Path -Path $PSScriptRoot -ChildPath '../src/Resolve-PSModuleVersion.Helpers.psm1') -Force
+    Mock -CommandName Find-PSResource -ModuleName Resolve-PSModuleVersion.Helpers -MockWith {
+        $errorRecord = [Management.Automation.ErrorRecord]::new(
+            [Exception]::new('The isolated fixture module is absent.'),
+            'PackageNotFound,Find-PSResource',
+            [Management.Automation.ErrorCategory]::ObjectNotFound,
+            'PSModuleNonExistentModuleForTesting'
+        )
+        throw $errorRecord
+    }
 
     function Get-TestConfiguration {
         <#

.github/actions/Resolve-PSModuleVersion/tests/Resolve-PSModuleVersion.ReadErrors.Tests.ps1

@@ -89,4 +89,17 @@ Describe 'Version lookup errors are not version baselines' {
 
         { Get-NextPrereleaseNumber @parameters } | Should -Throw
     }
+
+    It 'rejects prerelease missing version metadata before filtering' {
+        $script:state.Package = [pscustomobject]@{ Name = 'TestModule'; Version = $null; Prerelease = 'preview001' }
+        $parameters = @{ ModuleName = 'TestModule'; BaseVersion = '1.2.4'; PrereleaseName = 'preview'; Releases = @() }
+
+        { Get-NextPrereleaseNumber @parameters } | Should -Throw '*metadata*'
+    }
+
+    It 'rejects prerelease empty successful enumeration instead of treating it as verified absence' {
+        $parameters = @{ ModuleName = 'TestModule'; BaseVersion = '1.2.4'; PrereleaseName = 'preview'; Releases = @() }
+
+        { Get-NextPrereleaseNumber @parameters } | Should -Throw '*metadata*'
+    }
 }