diff --git a/.github/actions/Resolve-PSModuleVersion/src/Resolve-PSModuleVersion.Helpers.psm1 b/.github/actions/Resolve-PSModuleVersion/src/Resolve-PSModuleVersion.Helpers.psm1
index d4f2f450..cd48d4dc 100644
--- a/.github/actions/Resolve-PSModuleVersion/src/Resolve-PSModuleVersion.Helpers.psm1
+++ b/.github/actions/Resolve-PSModuleVersion/src/Resolve-PSModuleVersion.Helpers.psm1
@@ -277,16 +277,52 @@ function Resolve-ReleaseDecision {
     }
 }
 
+function ConvertFrom-GitHubReleaseJson {
+    <#
+        .SYNOPSIS
+        Converts the JSON output of 'gh release list' into a flat array of release objects.
+
+        .DESCRIPTION
+        Normalizes the release listing so a repository with no releases, or a command that
+        produced no output at all, yields an empty array instead of $null.
+
+        .OUTPUTS
+        Array of release objects. Empty when there are no releases.
+
+        .EXAMPLE
+        $releases = ConvertFrom-GitHubReleaseJson -Json '[{"tagName":"v1.0.0"}]'
+    #>
+    [CmdletBinding()]
+    [OutputType([object[]], [array])]
+    param(
+        # The raw JSON returned by 'gh release list'. Empty or null when the command produced no output.
+        [Parameter()]
+        [AllowNull()]
+        [AllowEmptyString()]
+        [string] $Json
+    )
+
+    if ([string]::IsNullOrWhiteSpace($Json)) {
+        return @()
+    }
+
+    @($Json | ConvertFrom-Json)
+}
+
 function Get-GitHubRelease {
     <#
         .SYNOPSIS
         Retrieves all releases from the current GitHub repository.
 
+        .DESCRIPTION
+        Lists the releases of the current repository. A repository that has no releases yet
+        produces no output, so callers normalize the result with @() before using it.
+
         .OUTPUTS
-        Array of release objects.
+        Array of release objects. Nothing when the repository has no releases.
 
         .EXAMPLE
-        $releases = Get-GitHubRelease
+        $releases = @(Get-GitHubRelease)
     #>
     [CmdletBinding()]
     [OutputType([array])]
@@ -298,9 +334,10 @@ function Get-GitHubRelease {
             Write-Error 'Failed to list releases for the repo.'
             exit $LASTEXITCODE
         }
-        $releases = $releasesJson | ConvertFrom-Json
+        $releases = ConvertFrom-GitHubReleaseJson -Json $releasesJson
 
         Write-Host '-------------------------------------------------'
+        Write-Host "Found [$($releases.Count)] releases."
         Write-Host ($releases | Select-Object -Property name, isPrerelease, isLatest, publishedAt |
                 Format-Table | Out-String)
         Write-Host '-------------------------------------------------'
@@ -314,6 +351,11 @@ function Get-LatestGitHubVersion {
         .SYNOPSIS
         Extracts the latest stable version from a GitHub releases list.
 
+        .DESCRIPTION
+        Returns the version of the release marked as latest. A repository that has no releases
+        yet - or that has releases but none marked as latest - resolves to '0.0.0' so a brand-new
+        module can still be versioned before its first release exists.
+
         .OUTPUTS
         PSSemVer representing the latest GitHub release version.
 
@@ -325,9 +367,11 @@ function Get-LatestGitHubVersion {
     [CmdletBinding()]
     [OutputType([object])]
     param(
-        # The GitHub releases array to search.
-        [Parameter(Mandatory)]
-        [array] $Releases
+        # The GitHub releases array to search. Empty or null when the repository has no releases.
+        [Parameter()]
+        [AllowNull()]
+        [AllowEmptyCollection()]
+        [array] $Releases = @()
     )
 
     LogGroup 'Get latest version - GitHub' {
@@ -409,6 +453,11 @@ function Get-LatestPublishedVersion {
         .SYNOPSIS
         Returns the highest version between GitHub and the PowerShell Gallery.
 
+        .DESCRIPTION
+        Compares the two known published versions and returns the highest one. A missing
+        (null) version is treated as '0.0.0', so a module that has never been released to
+        GitHub or published to the PowerShell Gallery resolves to a '0.0.0' baseline.
+
         .OUTPUTS
         PSSemVer representing the highest known published version.
 
@@ -420,19 +469,27 @@ function Get-LatestPublishedVersion {
     [CmdletBinding()]
     [OutputType([object])]
     param(
-        # The latest version found in GitHub releases.
-        [Parameter(Mandatory)]
+        # The latest version found in GitHub releases. Null when the repository has no releases.
+        [Parameter()]
+        [AllowNull()]
         [object] $GitHubVersion,
 
-        # The latest version found in the PowerShell Gallery.
-        [Parameter(Mandatory)]
+        # The latest version found in the PowerShell Gallery. Null when the module is unpublished.
+        [Parameter()]
+        [AllowNull()]
         [object] $PSGalleryVersion
     )
 
     LogGroup 'Latest version' {
-        $latestVersion = New-PSSemVer -Version (
-            $PSGalleryVersion, $GitHubVersion | Sort-Object -Descending | Select-Object -First 1
-        )
+        $candidates = @($PSGalleryVersion, $GitHubVersion) |
+            Where-Object { $null -ne $_ -and -not [string]::IsNullOrWhiteSpace([string]$_) }
+
+        $latestVersion = if ($candidates.Count -gt 0) {
+            New-PSSemVer -Version ($candidates | Sort-Object -Descending | Select-Object -First 1)
+        } else {
+            Write-Warning "No published version found in GitHub or the PowerShell Gallery. Using '0.0.0'."
+            New-PSSemVer -Version '0.0.0'
+        }
         Write-Host "Latest version: [$($latestVersion.ToString())]"
         $latestVersion
     }
@@ -472,9 +529,11 @@ function Get-NextPrereleaseNumber {
         [ValidateNotNullOrEmpty()]
         [string] $PrereleaseName,
 
-        # The GitHub releases list.
-        [Parameter(Mandatory)]
-        [array] $Releases
+        # The GitHub releases list. Empty or null when the repository has no releases.
+        [Parameter()]
+        [AllowNull()]
+        [AllowEmptyCollection()]
+        [array] $Releases = @()
     )
 
     $params = @{
@@ -532,8 +591,9 @@ function Get-NextModuleVersion {
     [CmdletBinding()]
     [OutputType([object])]
     param(
-        # The current latest published version.
-        [Parameter(Mandatory)]
+        # The current latest published version. Null resolves to a '0.0.0' baseline.
+        [Parameter()]
+        [AllowNull()]
         [object] $LatestVersion,
 
         # The release decision object.
@@ -550,12 +610,21 @@ function Get-NextModuleVersion {
         [string] $ModuleName,
 
         # The GitHub releases list, used for incremental prerelease calculation.
-        [Parameter(Mandatory)]
-        [array] $Releases
+        # Empty or null when the repository has no releases.
+        [Parameter()]
+        [AllowNull()]
+        [AllowEmptyCollection()]
+        [array] $Releases = @()
     )
 
     LogGroup 'Calculate new version' {
-        $newVersion = New-PSSemVer -Version $LatestVersion
+        $baseVersion = if ($null -eq $LatestVersion -or [string]::IsNullOrWhiteSpace([string]$LatestVersion)) {
+            Write-Warning "No latest version was resolved. Using '0.0.0' as the baseline."
+            '0.0.0'
+        } else {
+            $LatestVersion
+        }
+        $newVersion = New-PSSemVer -Version $baseVersion
         $newVersion.Prefix = $Configuration.VersionPrefix
 
         if ($Decision.MajorRelease) {
diff --git a/.github/actions/Resolve-PSModuleVersion/src/main.ps1 b/.github/actions/Resolve-PSModuleVersion/src/main.ps1
index da6d70e6..9d143fba 100644
--- a/.github/actions/Resolve-PSModuleVersion/src/main.ps1
+++ b/.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
diff --git a/.github/actions/Resolve-PSModuleVersion/tests/Resolve-PSModuleVersion.Helpers.Tests.ps1 b/.github/actions/Resolve-PSModuleVersion/tests/Resolve-PSModuleVersion.Helpers.Tests.ps1
new file mode 100644
index 00000000..5c212c9a
--- /dev/null
+++ b/.github/actions/Resolve-PSModuleVersion/tests/Resolve-PSModuleVersion.Helpers.Tests.ps1
@@ -0,0 +1,454 @@
+[Diagnostics.CodeAnalysis.SuppressMessageAttribute(
+    'PSUseDeclaredVarsMoreThanAssignments', '',
+    Justification = 'Variables are assigned in BeforeAll and used inside It blocks.'
+)]
+[CmdletBinding()]
+param()
+
+BeforeAll {
+    Import-Module -Name 'PSModule' -Force
+    Import-Module -Name (Join-Path -Path $PSScriptRoot -ChildPath '../src/Resolve-PSModuleVersion.Helpers.psm1') -Force
+
+    function Get-TestConfiguration {
+        <#
+            .SYNOPSIS
+            Builds a publish configuration object equivalent to what Get-PublishConfiguration returns.
+        #>
+        [CmdletBinding()]
+        [OutputType([PSCustomObject])]
+        param(
+            # Whether an unlabeled pull request is treated as a patch.
+            [Parameter()]
+            [bool] $AutoPatching = $true,
+
+            # Whether prereleases get an incrementing number suffix.
+            [Parameter()]
+            [bool] $IncrementalPrerelease,
+
+            # The date format appended to the prerelease tag.
+            [Parameter()]
+            [string] $DatePrereleaseFormat = '',
+
+            # The prefix put in front of the version, for example 'v'.
+            [Parameter()]
+            [string] $VersionPrefix = 'v',
+
+            # The release type resolved from the pull request labels.
+            [Parameter()]
+            [string] $ReleaseType = 'Release'
+        )
+
+        [PSCustomObject]@{
+            AutoPatching          = $AutoPatching
+            IncrementalPrerelease = $IncrementalPrerelease
+            DatePrereleaseFormat  = $DatePrereleaseFormat
+            VersionPrefix         = $VersionPrefix
+            ReleaseType           = $ReleaseType
+            IgnoreLabels          = @('NoRelease')
+            MajorLabels           = @('major')
+            MinorLabels           = @('minor')
+            PatchLabels           = @('patch')
+        }
+    }
+
+    function Get-TestDecision {
+        <#
+            .SYNOPSIS
+            Builds a release decision object equivalent to what Resolve-ReleaseDecision returns.
+        #>
+        [CmdletBinding()]
+        [OutputType([PSCustomObject])]
+        param(
+            # The version bump to apply - Major, Minor, Patch, or None.
+            [Parameter()]
+            [ValidateSet('Major', 'Minor', 'Patch', 'None')]
+            [string] $Bump = 'Patch',
+
+            # Whether a prerelease tag is added to the resolved version.
+            [Parameter()]
+            [bool] $CreatePrerelease,
+
+            # The sanitized prerelease name derived from the branch name.
+            [Parameter()]
+            [string] $PrereleaseName = '',
+
+            # Whether the run publishes the resolved version.
+            [Parameter()]
+            [bool] $ShouldPublish = $true
+        )
+
+        [PSCustomObject]@{
+            ShouldPublish    = $ShouldPublish
+            CreateRelease    = $ShouldPublish -and -not $CreatePrerelease
+            CreatePrerelease = $CreatePrerelease
+            MajorRelease     = $Bump -eq 'Major'
+            MinorRelease     = $Bump -eq 'Minor'
+            PatchRelease     = $Bump -eq 'Patch'
+            HasVersionBump   = $Bump -ne 'None'
+            PrereleaseName   = $PrereleaseName
+        }
+    }
+}
+
+Describe 'Resolve-PSModuleVersion' {
+    Describe 'ConvertFrom-GitHubReleaseJson' {
+        Context 'ConvertFrom-GitHubReleaseJson - repository without releases' {
+            It 'ConvertFrom-GitHubReleaseJson - returns an empty array for an empty JSON array' {
+                $result = ConvertFrom-GitHubReleaseJson -Json '[]'
+                @($result).Count | Should -Be 0
+            }
+
+            It 'ConvertFrom-GitHubReleaseJson - returns an empty array when the command produced no output' {
+                $result = ConvertFrom-GitHubReleaseJson -Json ''
+                @($result).Count | Should -Be 0
+            }
+
+            It 'ConvertFrom-GitHubReleaseJson - returns an empty array for null input' {
+                $result = ConvertFrom-GitHubReleaseJson -Json $null
+                @($result).Count | Should -Be 0
+            }
+        }
+
+        Context 'ConvertFrom-GitHubReleaseJson - releases present' {
+            It 'ConvertFrom-GitHubReleaseJson - returns a flat array of release objects' {
+                $json = '[{"tagName":"v1.2.3","isLatest":true},{"tagName":"v1.2.2","isLatest":false}]'
+                $result = @(ConvertFrom-GitHubReleaseJson -Json $json)
+                $result.Count | Should -Be 2
+                $result[0].tagName | Should -Be 'v1.2.3'
+            }
+
+            It 'ConvertFrom-GitHubReleaseJson - returns a single release without nesting it in an inner array' {
+                $result = @(ConvertFrom-GitHubReleaseJson -Json '[{"tagName":"v0.0.1","isLatest":true}]')
+                $result.Count | Should -Be 1
+                $result[0].tagName | Should -Be 'v0.0.1'
+            }
+
+            It 'ConvertFrom-GitHubReleaseJson - output binds to the Releases parameter without nesting' {
+                $json = '[{"tagName":"v1.2.3","isLatest":true},{"tagName":"v1.2.2","isLatest":false}]'
+                $releases = @(ConvertFrom-GitHubReleaseJson -Json $json)
+                $result = Get-LatestGitHubVersion -Releases $releases
+                $result.ToString() | Should -Be 'v1.2.3'
+            }
+
+            It 'ConvertFrom-GitHubReleaseJson - survives the log group wrapper without nesting' {
+                $json = '[{"tagName":"v1.2.3","isLatest":true},{"tagName":"v1.2.2","isLatest":false}]'
+                $releases = @(LogGroup 'Get releases - GitHub' { ConvertFrom-GitHubReleaseJson -Json $json })
+                $releases.Count | Should -Be 2
+                $releases[0].tagName | Should -Be 'v1.2.3'
+            }
+        }
+    }
+
+    Describe 'Get-LatestGitHubVersion' {
+        Context 'Get-LatestGitHubVersion - repository without releases' {
+            It 'Get-LatestGitHubVersion - returns 0.0.0 when the releases list is null' {
+                $result = Get-LatestGitHubVersion -Releases $null
+                $result.ToString() | Should -Be '0.0.0'
+            }
+
+            It 'Get-LatestGitHubVersion - returns 0.0.0 when the releases list is an empty array' {
+                $result = Get-LatestGitHubVersion -Releases @()
+                $result.ToString() | Should -Be '0.0.0'
+            }
+
+            It 'Get-LatestGitHubVersion - returns 0.0.0 when no releases list is passed at all' {
+                $result = Get-LatestGitHubVersion
+                $result.ToString() | Should -Be '0.0.0'
+            }
+
+            It 'Get-LatestGitHubVersion - does not fail parameter binding on a null releases list' {
+                { Get-LatestGitHubVersion -Releases $null } | Should -Not -Throw
+            }
+        }
+
+        Context 'Get-LatestGitHubVersion - releases present but none marked as latest' {
+            It 'Get-LatestGitHubVersion - returns 0.0.0 when no release is marked as latest' {
+                $releases = @(
+                    [PSCustomObject]@{ tagName = 'v1.2.3'; isLatest = $false; isPrerelease = $false }
+                    [PSCustomObject]@{ tagName = 'v1.2.2'; isLatest = $false; isPrerelease = $false }
+                )
+                $result = Get-LatestGitHubVersion -Releases $releases
+                $result.ToString() | Should -Be '0.0.0'
+            }
+
+            It 'Get-LatestGitHubVersion - returns 0.0.0 when the repository only has prereleases' {
+                $releases = @(
+                    [PSCustomObject]@{ tagName = 'v0.0.1-mybranch001'; isLatest = $false; isPrerelease = $true }
+                )
+                $result = Get-LatestGitHubVersion -Releases $releases
+                $result.ToString() | Should -Be '0.0.0'
+            }
+        }
+
+        Context 'Get-LatestGitHubVersion - releases present' {
+            It 'Get-LatestGitHubVersion - returns the version of the release marked as latest' {
+                $releases = @(
+                    [PSCustomObject]@{ tagName = 'v1.2.2'; isLatest = $false; isPrerelease = $false }
+                    [PSCustomObject]@{ tagName = 'v1.2.3'; isLatest = $true; isPrerelease = $false }
+                    [PSCustomObject]@{ tagName = 'v1.3.0-mybranch001'; isLatest = $false; isPrerelease = $true }
+                )
+                $result = Get-LatestGitHubVersion -Releases $releases
+                $result.Major | Should -Be 1
+                $result.Minor | Should -Be 2
+                $result.Patch | Should -Be 3
+            }
+
+            It 'Get-LatestGitHubVersion - returns the version when the repository has a single release' {
+                $releases = @(
+                    [PSCustomObject]@{ tagName = 'v0.0.1'; isLatest = $true; isPrerelease = $false }
+                )
+                $result = Get-LatestGitHubVersion -Releases $releases
+                $result.Patch | Should -Be 1
+            }
+        }
+    }
+
+    Describe 'Get-LatestPublishedVersion' {
+        Context 'Get-LatestPublishedVersion - brand-new module' {
+            It 'Get-LatestPublishedVersion - returns 0.0.0 when neither source has a version' {
+                $result = Get-LatestPublishedVersion -GitHubVersion $null -PSGalleryVersion $null
+                $result.ToString() | Should -Be '0.0.0'
+            }
+
+            It 'Get-LatestPublishedVersion - returns 0.0.0 when both sources report the 0.0.0 baseline' {
+                $params = @{
+                    GitHubVersion    = New-PSSemVer -Version '0.0.0'
+                    PSGalleryVersion = New-PSSemVer -Version '0.0.0'
+                }
+                $result = Get-LatestPublishedVersion @params
+                $result.ToString() | Should -Be '0.0.0'
+            }
+
+            It 'Get-LatestPublishedVersion - returns 0.0.0 when no versions are passed at all' {
+                $result = Get-LatestPublishedVersion
+                $result.ToString() | Should -Be '0.0.0'
+            }
+        }
+
+        Context 'Get-LatestPublishedVersion - one source has a version' {
+            It 'Get-LatestPublishedVersion - returns the GitHub version when the gallery has none' {
+                $result = Get-LatestPublishedVersion -GitHubVersion (New-PSSemVer -Version '1.2.3') -PSGalleryVersion $null
+                $result.ToString() | Should -Be '1.2.3'
+            }
+
+            It 'Get-LatestPublishedVersion - returns the gallery version when GitHub has none' {
+                $result = Get-LatestPublishedVersion -GitHubVersion $null -PSGalleryVersion (New-PSSemVer -Version '2.0.0')
+                $result.ToString() | Should -Be '2.0.0'
+            }
+        }
+
+        Context 'Get-LatestPublishedVersion - both sources have a version' {
+            It 'Get-LatestPublishedVersion - returns the highest of the two versions' {
+                $params = @{
+                    GitHubVersion    = New-PSSemVer -Version '1.4.2'
+                    PSGalleryVersion = New-PSSemVer -Version '1.5.0'
+                }
+                $result = Get-LatestPublishedVersion @params
+                $result.ToString() | Should -Be '1.5.0'
+            }
+        }
+    }
+
+    Describe 'Get-NextPrereleaseNumber' {
+        Context 'Get-NextPrereleaseNumber - repository without releases' {
+            It 'Get-NextPrereleaseNumber - returns 001 when the releases list is null' {
+                $params = @{
+                    ModuleName     = 'PSModuleNonExistentModuleForTesting'
+                    BaseVersion    = '0.0.1'
+                    PrereleaseName = 'mybranch'
+                    Releases       = $null
+                }
+                Get-NextPrereleaseNumber @params | Should -Be '001'
+            }
+
+            It 'Get-NextPrereleaseNumber - returns 001 when the releases list is an empty array' {
+                $params = @{
+                    ModuleName     = 'PSModuleNonExistentModuleForTesting'
+                    BaseVersion    = '0.0.1'
+                    PrereleaseName = 'mybranch'
+                    Releases       = @()
+                }
+                Get-NextPrereleaseNumber @params | Should -Be '001'
+            }
+
+            It 'Get-NextPrereleaseNumber - returns 001 when no releases list is passed at all' {
+                $params = @{
+                    ModuleName     = 'PSModuleNonExistentModuleForTesting'
+                    BaseVersion    = '0.0.1'
+                    PrereleaseName = 'mybranch'
+                }
+                Get-NextPrereleaseNumber @params | Should -Be '001'
+            }
+        }
+
+        Context 'Get-NextPrereleaseNumber - matching prereleases exist on GitHub' {
+            It 'Get-NextPrereleaseNumber - returns the number after the highest matching GitHub prerelease' {
+                $params = @{
+                    ModuleName     = 'PSModuleNonExistentModuleForTesting'
+                    BaseVersion    = '1.2.3'
+                    PrereleaseName = 'mybranch'
+                    Releases       = @(
+                        [PSCustomObject]@{ tagName = 'v1.2.3-mybranch001'; isLatest = $false; isPrerelease = $true }
+                        [PSCustomObject]@{ tagName = 'v1.2.3-mybranch005'; isLatest = $false; isPrerelease = $true }
+                    )
+                }
+                Get-NextPrereleaseNumber @params | Should -Be '006'
+            }
+        }
+    }
+
+    Describe 'Get-NextModuleVersion' {
+        Context 'Get-NextModuleVersion - brand-new module without releases' {
+            It 'Get-NextModuleVersion - resolves the first patch release to 0.0.1' {
+                $params = @{
+                    LatestVersion = New-PSSemVer -Version '0.0.0'
+                    Decision      = Get-TestDecision -Bump 'Patch'
+                    Configuration = Get-TestConfiguration
+                    ModuleName    = 'MyBrandNewModule'
+                    Releases      = @()
+                }
+                $result = Get-NextModuleVersion @params
+                $result.ToString() | Should -Be 'v0.0.1'
+            }
+
+            It 'Get-NextModuleVersion - resolves the first minor release to 0.1.0' {
+                $params = @{
+                    LatestVersion = New-PSSemVer -Version '0.0.0'
+                    Decision      = Get-TestDecision -Bump 'Minor'
+                    Configuration = Get-TestConfiguration
+                    ModuleName    = 'MyBrandNewModule'
+                    Releases      = @()
+                }
+                $result = Get-NextModuleVersion @params
+                $result.ToString() | Should -Be 'v0.1.0'
+            }
+
+            It 'Get-NextModuleVersion - resolves the first major release to 1.0.0' {
+                $params = @{
+                    LatestVersion = New-PSSemVer -Version '0.0.0'
+                    Decision      = Get-TestDecision -Bump 'Major'
+                    Configuration = Get-TestConfiguration
+                    ModuleName    = 'MyBrandNewModule'
+                    Releases      = @()
+                }
+                $result = Get-NextModuleVersion @params
+                $result.ToString() | Should -Be 'v1.0.0'
+            }
+
+            It 'Get-NextModuleVersion - resolves a version when the releases list is null' {
+                $params = @{
+                    LatestVersion = New-PSSemVer -Version '0.0.0'
+                    Decision      = Get-TestDecision -Bump 'Patch'
+                    Configuration = Get-TestConfiguration
+                    ModuleName    = 'MyBrandNewModule'
+                    Releases      = $null
+                }
+                $result = Get-NextModuleVersion @params
+                $result.ToString() | Should -Be 'v0.0.1'
+            }
+
+            It 'Get-NextModuleVersion - resolves a version when no releases list is passed at all' {
+                $params = @{
+                    LatestVersion = New-PSSemVer -Version '0.0.0'
+                    Decision      = Get-TestDecision -Bump 'Patch'
+                    Configuration = Get-TestConfiguration
+                    ModuleName    = 'MyBrandNewModule'
+                }
+                $result = Get-NextModuleVersion @params
+                $result.ToString() | Should -Be 'v0.0.1'
+            }
+
+            It 'Get-NextModuleVersion - falls back to the 0.0.0 baseline when no latest version was resolved' {
+                $params = @{
+                    LatestVersion = $null
+                    Decision      = Get-TestDecision -Bump 'Patch'
+                    Configuration = Get-TestConfiguration
+                    ModuleName    = 'MyBrandNewModule'
+                    Releases      = @()
+                }
+                $result = Get-NextModuleVersion @params
+                $result.ToString() | Should -Be 'v0.0.1'
+            }
+
+            It 'Get-NextModuleVersion - resolves the first prerelease from an empty releases list' {
+                $params = @{
+                    LatestVersion = New-PSSemVer -Version '0.0.0'
+                    Decision      = Get-TestDecision -Bump 'Patch' -CreatePrerelease $true -PrereleaseName 'mybranch'
+                    Configuration = Get-TestConfiguration -ReleaseType 'Prerelease'
+                    ModuleName    = 'MyBrandNewModule'
+                    Releases      = @()
+                }
+                $result = Get-NextModuleVersion @params
+                $result.ToString() | Should -Be 'v0.0.1-mybranch'
+            }
+        }
+
+        Context 'Get-NextModuleVersion - existing module with releases' {
+            It 'Get-NextModuleVersion - bumps the patch version of the latest release' {
+                $params = @{
+                    LatestVersion = New-PSSemVer -Version '1.2.3'
+                    Decision      = Get-TestDecision -Bump 'Patch'
+                    Configuration = Get-TestConfiguration
+                    ModuleName    = 'MyModule'
+                    Releases      = @(
+                        [PSCustomObject]@{ tagName = 'v1.2.3'; isLatest = $true; isPrerelease = $false }
+                    )
+                }
+                $result = Get-NextModuleVersion @params
+                $result.ToString() | Should -Be 'v1.2.4'
+            }
+        }
+    }
+
+    Describe 'Resolve-PSModuleVersion' {
+        Context 'Resolve-PSModuleVersion - brand-new module with no GitHub release and no gallery version' {
+            It 'Resolve-PSModuleVersion - resolves the full chain to the first patch version' {
+                $githubVersion = Get-LatestGitHubVersion -Releases @()
+                $latestVersion = Get-LatestPublishedVersion -GitHubVersion $githubVersion -PSGalleryVersion $null
+                $params = @{
+                    LatestVersion = $latestVersion
+                    Decision      = Get-TestDecision -Bump 'Patch'
+                    Configuration = Get-TestConfiguration
+                    ModuleName    = 'MyBrandNewModule'
+                    Releases      = @()
+                }
+                $result = Get-NextModuleVersion @params
+
+                $latestVersion.ToString() | Should -Be '0.0.0'
+                $result.ToString() | Should -Be 'v0.0.1'
+            }
+
+            It 'Resolve-PSModuleVersion - resolves the full chain to the first minor version' {
+                $githubVersion = Get-LatestGitHubVersion -Releases $null
+                $psGalleryVersion = New-PSSemVer -Version '0.0.0'
+                $latestVersion = Get-LatestPublishedVersion -GitHubVersion $githubVersion -PSGalleryVersion $psGalleryVersion
+                $params = @{
+                    LatestVersion = $latestVersion
+                    Decision      = Get-TestDecision -Bump 'Minor'
+                    Configuration = Get-TestConfiguration
+                    ModuleName    = 'MyBrandNewModule'
+                    Releases      = $null
+                }
+                $result = Get-NextModuleVersion @params
+
+                $result.ToString() | Should -Be 'v0.1.0'
+            }
+
+            It 'Resolve-PSModuleVersion - resolves the full chain to the first major version' {
+                $githubVersion = Get-LatestGitHubVersion -Releases @()
+                $psGalleryVersion = New-PSSemVer -Version '0.0.0'
+                $latestVersion = Get-LatestPublishedVersion -GitHubVersion $githubVersion -PSGalleryVersion $psGalleryVersion
+                $params = @{
+                    LatestVersion = $latestVersion
+                    Decision      = Get-TestDecision -Bump 'Major'
+                    Configuration = Get-TestConfiguration
+                    ModuleName    = 'MyBrandNewModule'
+                    Releases      = @()
+                }
+                $result = Get-NextModuleVersion @params
+
+                $result.ToString() | Should -Be 'v1.0.0'
+            }
+        }
+    }
+}
diff --git a/.github/workflows/Test-Actions.yml b/.github/workflows/Test-Actions.yml
new file mode 100644
index 00000000..1960cf35
--- /dev/null
+++ b/.github/workflows/Test-Actions.yml
@@ -0,0 +1,54 @@
+name: Test-Actions
+
+run-name: "Test-Actions - [${{ github.event.pull_request.title }} #${{ github.event.pull_request.number }}] by @${{ github.actor }}"
+
+on:
+  workflow_dispatch:
+  pull_request:
+    paths:
+      - '.github/actions/**'
+      - '.github/workflows/Test-Actions.yml'
+  schedule:
+    - cron: '0 0 * * *'
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+permissions:
+  contents: read
+
+jobs:
+  TestActions:
+    name: Test actions
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout repo
+        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
+        with:
+          persist-credentials: false
+
+      - name: Install-PSModule
+        uses: ./.github/actions/Install-PSModule
+
+      - name: Install test dependencies
+        shell: pwsh
+        run: |
+          Install-PSResource -Name Pester -Version '[5.7.1,6.0.0)' -Repository PSGallery -TrustRepository
+          Install-PSResource -Name PSSemVer -Repository PSGallery -TrustRepository
+
+      - name: Run action unit tests
+        shell: pwsh
+        run: |
+          $testPaths = Get-ChildItem -Path '.github/actions' -Directory |
+              ForEach-Object { Join-Path -Path $_.FullName -ChildPath 'tests' } |
+              Where-Object { Test-Path -Path $_ }
+          if (-not $testPaths) {
+              throw 'No action test folders were found under .github/actions.'
+          }
+
+          $configuration = New-PesterConfiguration
+          $configuration.Run.Path = $testPaths
+          $configuration.Run.Throw = $true
+          $configuration.Output.Verbosity = 'Detailed'
+          Invoke-Pester -Configuration $configuration