ConvertTo-SemVersion

ConvertTo-SemVersion.ps1

function ConvertTo-SemVersion {
    <#
.SYNOPSIS
    Converts a Version to to semantic versioning v2
.DESCRIPTION
    Converts a Version to to semantic versioning v2. The function accepts a version as a string and will try to convert it.
    It will return a string representing at least major.minor.patch. If revision is 0 it will be dropped, unless is has a prerelease or buildmetadata.
    1           -> 1.0.0
    1.1         -> 1.1.0
    1.1.1.0     -> 1.1.1
    1.1.1.1     -> 1.1.1.1
    1.01        -> 1.1.0
    1-Alpha     -> 1.0.0-Alpha
    1.1.0.0-RC  -> 1.1.0-RC
    1.1.0.0-RC+2019 -> 1.1.0-RC+2019

.EXAMPLE
    PS C:\> ConvertTo-SemVersion -Version 1.0
    1.0.0
.INPUTS
    [String]
.OUTPUTS
    [String]
#>
    [CmdletBinding()]
    param (
        [Parameter(Mandatory = $true,
            ValueFromPipeline = $true,
            Position = 0,
            HelpMessage = "Specifies the version to convert.")]
        [String]$Version
    )

    begin {}

    process {
        $normVersion = $null
        $regexPattern = '^(?<major>\d*)?(?:\.(?<minor>\d*))?(?:\.(?<patch>\d*))?(?:\.(?<build>\d*))?(?:-(?<prerelease>[0-9a-zA-Z-]+(?:\.[0-9a-zA-Z-]+)*))?(?:\+(?<buildmetadata>[0-9a-zA-Z-]+(?:\.[0-9a-zA-Z-]+)*))?$'
        $result = [Regex]::Match($Version, $regexPattern)
        
        # throw error if version not valid
        if (! $result.Success) {
            Throw "$Version is not a valid semantic version"
        }

        # convert the major minor and patch
        Write-Verbose "Converting version"
        $normVersion = [version]::new($result.groups["major"].Value, $result.groups["minor"].Value, $result.groups["patch"].Value)
        $rev = $result.groups[4].Value
        if ($rev -gt 0) {
            Write-Verbose "Revision ($rev) is not 0 and will be preserved"
            $normVersion = [System.Version]::Parse("$($normVersion).$($result.groups["build"].Value)")
        }
        elseif ($rev -eq 0) {
            Write-Verbose "Revision is 0 and will be removed from the converted version"
        }
        $versionString = $normVersion.ToString()

        # if version is a prerelease or has build metadata then return converted version with metadata

        if ($result.Groups["prerelease"].Success -or $result.Groups["buildmetadata"].Success) {
            Write-Verbose "Version has prerelease or buildmetadata and will be returned as is"
            if ($result.groups["prerelease"].Value) {
                Write-Verbose "Version has prerelease tag"
                $versionString += "-" + $result.groups["prerelease"].Value
            }
            if ($result.groups["buildmetadata"].Value) {
                Write-Verbose "Version has buildmetadata tag"
                $versionString += "+" + $result.groups["buildmetadata"].Value
            }

        }

        return $versionString
    }

    end {}
}

ConvertTo-SemVersion.Tests.ps1

[Diagnostics.CodeAnalysis.SuppressMessageAttribute('PSUseDeclaredVarsMoreThanAssignments', '', Scope='Function')]
Param()

BeforeAll {
    . $PSCommandPath.Replace('.Tests.ps1','.ps1')
}
Describe "ConvertTo-SemVersion Tests" {
    Context "When providing a valid version" {
        It "Should normalize version 1 to 1.0.0" {
            $version = "1"
            $expected = "1.0.0"
            $result = ConvertTo-SemVersion -Version $version
            $result | Should -Be $expected
        }

        It "Should normalize version 1.1 to 1.1.0" {
            $version = "1.1"
            $expected = "1.1.0"
            $result = ConvertTo-SemVersion -Version $version
            $result | Should -Be $expected
        }

        It "Should normalize version 1.1.1.0 to 1.1.1" {
            $version = "1.1.1.0"
            $expected = "1.1.1"
            $result = ConvertTo-SemVersion -Version $version
            $result | Should -Be $expected
        }

        It "Should preserve version 1.1.1.1" {
            $version = "1.1.1.1"
            $expected = "1.1.1.1"
            $result = ConvertTo-SemVersion -Version $version
            $result | Should -Be $expected
        }

        It "Should normalize version 1.01 to 1.1.0" {
            $version = "1.01"
            $expected = "1.1.0"
            $result = ConvertTo-SemVersion -Version $version
            $result | Should -Be $expected
        }

        It "Should normalize version 1-Alpha to 1.0.0-Alpha" {
            $version = "1-Alpha"
            $expected = "1.0.0-Alpha"
            $result = ConvertTo-SemVersion -Version $version
            $result | Should -Be $expected
        }
        
        It "Should normalize version 1-Alpha-1 to 1.0.0-Alpha-1" {
            $version = "1-Alpha-1"
            $expected = "1.0.0-Alpha-1"
            $result = ConvertTo-SemVersion -Version $version
            $result | Should -Be $expected
        }

        It "Should normalize version 1.1.0.0-RC to 1.1.0-RC" {
            $version = "1.1.0.0-RC"
            $expected = "1.1.0-RC"
            $result = ConvertTo-SemVersion -Version $version
            $result | Should -Be $expected
        }

        It "Should normalize version 1.1.0.0-RC+2019 to 1.1.0-RC+2019" {
            $version = "1.1.0.0-RC+2019"
            $expected = "1.1.0-RC+2019"
            $result = ConvertTo-SemVersion -Version $version
            $result | Should -Be $expected
        }
    }

    Context "When providing an invalid version" {
        It "Should throw an error for an invalid version" {
            $version = "invalid"
            { ConvertTo-SemVersion -Version $version } | Should -Throw
        }
    }
}