Treat an empty GitHub release list as a valid starting state

A repository that has never released returns '[]' from 'gh release
list', which deserializes to nothing and reached the version helpers
as $null. Return an array instead and let the helpers bind an empty
one.

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>

Author: MariusStorhaug

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

@@ -298,7 +298,9 @@ function Get-GitHubRelease {
             Write-Error 'Failed to list releases for the repo.'
             exit $LASTEXITCODE
         }
-        $releases = $releasesJson | ConvertFrom-Json
+        # A repository that has never released returns '[]', which deserializes to nothing. Wrap the
+        # result so callers always receive an array, even for a module being bootstrapped.
+        $releases = @($releasesJson | ConvertFrom-Json)
 
         Write-Host '-------------------------------------------------'
         Write-Host ($releases | Select-Object -Property name, isPrerelease, isLatest, publishedAt |
@@ -327,6 +329,7 @@ function Get-LatestGitHubVersion {
     param(
         # The GitHub releases array to search.
         [Parameter(Mandatory)]
+        [AllowEmptyCollection()]
         [array] $Releases
     )
 
@@ -474,6 +477,7 @@ function Get-NextPrereleaseNumber {
 
         # The GitHub releases list.
         [Parameter(Mandatory)]
+        [AllowEmptyCollection()]
         [array] $Releases
     )
 
@@ -551,6 +555,7 @@ function Get-NextModuleVersion {
 
         # The GitHub releases list, used for incremental prerelease calculation.
         [Parameter(Mandatory)]
+        [AllowEmptyCollection()]
         [array] $Releases
     )
 

.github/actions/Resolve-PSModuleVersion/src/main.ps1

@@ -28,7 +28,7 @@ $decision = if ($null -eq $pullRequest) {
     Resolve-ReleaseDecision -Configuration $config -PullRequest $pullRequest
 }
 
-$releases = Get-GitHubRelease
+$releases = @(Get-GitHubRelease)
 $ghVersion = Get-LatestGitHubVersion -Releases $releases
 $psGalleryVersion = Get-LatestPSGalleryVersion -ModuleName $actionInput.Name
 $latestVersion = Get-LatestPublishedVersion -GitHubVersion $ghVersion -PSGalleryVersion $psGalleryVersion