diff --git a/bin/checkver.ps1 b/bin/checkver.ps1
index 660971ab8f..ea4a92cac6 100644
--- a/bin/checkver.ps1
+++ b/bin/checkver.ps1
@@ -292,7 +292,7 @@ while ($in_progress -gt 0) {
 
     Write-Host $ver -ForegroundColor DarkRed -NoNewline
     Write-Host " (scoop version is $expected_ver)" -NoNewline
-    $update_available = (compare_versions $expected_ver $ver) -eq -1
+    $update_available = (Compare-Version -ReferenceVersion $ver -DifferenceVersion $expected_ver) -ne 0
 
     if ($json.autoupdate -and $update_available) {
         Write-Host ' autoupdate available' -ForegroundColor Cyan
diff --git a/bin/uninstall.ps1 b/bin/uninstall.ps1
index 59bd9718b1..c97762724d 100644
--- a/bin/uninstall.ps1
+++ b/bin/uninstall.ps1
@@ -34,7 +34,7 @@ $errors = $false
 
 # Uninstall given app
 function do_uninstall($app, $global) {
-    $version = current_version $app $global
+    $version = Select-CurrentVersion -AppName $app -Global:$global
     $dir = versiondir $app $version $global
     $manifest = installed_manifest $app $version $global
     $install = install_info $app $version $global
diff --git a/lib/core.ps1 b/lib/core.ps1
index 182144a2d5..c67970258f 100644
--- a/lib/core.ps1
+++ b/lib/core.ps1
@@ -290,7 +290,7 @@ function Test-Aria2Enabled {
 function app_status($app, $global) {
     $status = @{}
     $status.installed = (installed $app $global)
-    $status.version = current_version $app $global
+    $status.version = Select-CurrentVersion -AppName $app -Global:$global
     $status.latest_version = $status.version
 
     $install_info = install_info $app $status.version $global
@@ -300,13 +300,17 @@ function app_status($app, $global) {
 
     $manifest = manifest $app $install_info.bucket $install_info.url
     $status.removed = (!$manifest)
-    if($manifest.version) {
+    if ($manifest.version) {
         $status.latest_version = $manifest.version
     }
 
     $status.outdated = $false
-    if($status.version -and $status.latest_version) {
-        $status.outdated = ((compare_versions $status.latest_version $status.version) -gt 0)
+    if ($status.version -and $status.latest_version) {
+        if (get_config 'force-update' $false) {
+            $status.outdated = ((Compare-Version -ReferenceVersion $status.version -DifferenceVersion $status.latest_version) -ne 0)
+        } else {
+            $status.outdated = ((Compare-Version -ReferenceVersion $status.version -DifferenceVersion $status.latest_version) -gt 0)
+        }
     }
 
     $status.missing_deps = @()
@@ -314,8 +318,8 @@ function app_status($app, $global) {
         $app, $bucket, $null = parse_app $_
         return !(installed $app)
     }
-    if($deps) {
-        $status.missing_deps += ,$deps
+    if ($deps) {
+        $status.missing_deps += , $deps
     }
 
     return $status
diff --git a/lib/versions.ps1 b/lib/versions.ps1
index 4f55e653e7..a3a1309ca1 100644
--- a/lib/versions.ps1
+++ b/lib/versions.ps1
@@ -1,53 +1,274 @@
 # versions
-function latest_version($app, $bucket, $url) {
-    (manifest $app $bucket $url).version
-}
-function current_version($app, $global) {
-    @(versions $app $global)[-1]
+function Get-LatestVersion {
+    <#
+    .SYNOPSIS
+        Get latest version of app from manifest
+    .PARAMETER AppName
+        App's name
+    .PARAMETER Bucket
+        Bucket which the app belongs to
+    .PARAMETER Uri
+        Remote app manifest's URI
+    #>
+    [OutputType([String])]
+    [CmdletBinding()]
+    param (
+        [Parameter(Mandatory = $true, Position = 0, ValueFromPipeline = $true)]
+        [Alias('App')]
+        [String]
+        $AppName,
+        [Parameter(Position = 1)]
+        [String]
+        $Bucket,
+        [Parameter(Position = 2)]
+        [String]
+        $Uri
+    )
+    process {
+        return (manifest $AppName $Bucket $Uri).version
+    }
 }
-function versions($app, $global) {
-    $appdir = appdir $app $global
-    if(!(test-path $appdir)) { return @() }
 
-    sort_versions (Get-ChildItem $appdir -dir -attr !reparsePoint | Where-Object { $null -ne $(Get-ChildItem $_.fullname) } | ForEach-Object { $_.name })
+function Select-CurrentVersion {
+    <#
+    .SYNOPSIS
+        Select current version of installed app, from 'current\manifest.json' or modified time of version directory
+    .PARAMETER AppName
+        App's name
+    .PARAMETER Global
+        Globally installed application
+    #>
+    [OutputType([String])]
+    [CmdletBinding()]
+    param (
+        [Parameter(Mandatory = $true, Position = 0, ValueFromPipeline = $true)]
+        [Alias('App')]
+        [String]
+        $AppName,
+        [Parameter(Position = 1)]
+        [Switch]
+        $Global
+    )
+    process {
+        $appPath = appdir $AppName $Global
+        if (Test-Path "$appPath\current" -PathType Container) {
+            $currentVersion = (installed_manifest $AppName 'current' $Global).version
+            if ($currentVersion -eq 'nightly') {
+                $currentVersion = (Get-Item "$appPath\current").Target | Split-Path -Leaf
+            }
+        } else {
+            $installedVersion = Get-InstalledVersion -AppName $AppName -Global:$Global
+            if ($installedVersion) {
+                $currentVersion = $installedVersion[-1]
+            } else {
+                $currentVersion = $null
+            }
+        }
+        return $currentVersion
+    }
 }
 
-function version($ver) {
-    $ver -split '[\.-]' | ForEach-Object {
-        $num = $_ -as [int]
-        if($num) { $num } else { $_ }
+function Get-InstalledVersion {
+    <#
+    .SYNOPSIS
+        Get all installed version of app, by checking version directories' 'install.json'
+    .PARAMETER AppName
+        App's name
+    .PARAMETER Global
+        Globally installed application
+    .NOTES
+        Versions are sorted from oldest to newest, i.e., latest installed version is the last one in the output array.
+        If no installed version found, empty array will be returned.
+    #>
+    [OutputType([Object[]])]
+    [CmdletBinding()]
+    param (
+        [Parameter(Mandatory = $true, Position = 0, ValueFromPipeline = $true)]
+        [Alias('App')]
+        [String]
+        $AppName,
+        [Parameter(Position = 1)]
+        [Switch]
+        $Global
+    )
+    process {
+        $appPath = appdir $AppName $Global
+        if (Test-Path $appPath) {
+            $versions = @((Get-ChildItem "$appPath\*\install.json" | Sort-Object -Property LastWriteTimeUtc).Directory.Name)
+            return $versions | Where-Object { ($_ -ne 'current') -and ($_ -notlike '_*.old*') }
+        } else {
+            return @()
+        }
     }
+    # Deprecated
+    # sort_versions (Get-ChildItem $appPath -dir -attr !reparsePoint | Where-Object { $null -ne $(Get-ChildItem $_.FullName) } | ForEach-Object { $_.Name })
 }
-function compare_versions($a, $b) {
-    $ver_a = @(version $a)
-    $ver_b = @(version $b)
 
-    for($i=0;$i -lt $ver_a.length;$i++) {
-        if($i -gt $ver_b.length) { return 1; }
+function Compare-Version {
+    <#
+    .SYNOPSIS
+        Compare versions, mainly according to SemVer's rules
+    .PARAMETER ReferenceVersion
+        Specifies a version used as a reference for comparison
+    .PARAMETER DifferenceVersion
+        Specifies the version that are compared to the reference version
+    .PARAMETER Delimiter
+        Specifies the delimiter of versions
+    .OUTPUTS
+        System.Int32
+            '0' if DifferenceVersion is equal to ReferenceVersion,
+            '1' if DifferenceVersion is greater then ReferenceVersion,
+            '-1' if DifferenceVersion is less then ReferenceVersion
+    #>
+    [OutputType([Int32])]
+    [CmdletBinding()]
+    param (
+        [Parameter(Mandatory = $true, Position = 0)]
+        [AllowEmptyString()]
+        [String]
+        $ReferenceVersion,
+        [Parameter(Mandatory = $true, Position = 1, ValueFromPipeline = $true)]
+        [AllowEmptyString()]
+        [String]
+        $DifferenceVersion,
+        [String]
+        $Delimiter = '-'
+    )
+    process {
+        # Use '+' sign as post-release, see https://github.com/lukesampson/scoop/pull/3721#issuecomment-553718093
+        $ReferenceVersion, $DifferenceVersion = @($ReferenceVersion, $DifferenceVersion) -replace '\+', '-'
 
-        # don't try to compare int to string
-        if($ver_b[$i] -is [string] -and $ver_a[$i] -isnot [string]) {
-            $ver_a[$i] = "$($ver_a[$i])"
+        # Return 0 if versions are equal
+        if ($DifferenceVersion -eq $ReferenceVersion) {
+            return 0
         }
 
-        if($ver_a[$i] -gt $ver_b[$i]) { return 1; }
-        if($ver_a[$i] -lt $ver_b[$i]) { return -1; }
+        # Preprocess versions (split, convert and separate)
+        $splitReferenceVersion = @(SplitVersion -Version $ReferenceVersion -Delimiter $Delimiter)
+        $splitDifferenceVersion = @(SplitVersion -Version $DifferenceVersion -Delimiter $Delimiter)
+
+        # Nightly versions are always equal
+        if ($splitReferenceVersion[0] -eq 'nightly' -and $splitDifferenceVersion[0] -eq 'nightly') {
+            return 0
+        }
+
+        for ($i = 0; $i -lt [Math]::Max($splitReferenceVersion.Length, $splitDifferenceVersion.Length); $i++) {
+            # '1.1-alpha' is less then '1.1'
+            if ($i -ge $splitReferenceVersion.Length) {
+                if ($splitDifferenceVersion[$i] -match 'alpha|beta|rc|pre') {
+                    return -1
+                } else {
+                    return 1
+                }
+            }
+            # '1.1' is greater then '1.1-beta'
+            if ($i -ge $splitDifferenceVersion.Length) {
+                if ($splitReferenceVersion[$i] -match 'alpha|beta|rc|pre') {
+                    return 1
+                } else {
+                    return -1
+                }
+            }
+
+            # If some parts of versions have '.', compare them with delimiter '.'
+            if (($splitReferenceVersion[$i] -match '\.') -or ($splitDifferenceVersion[$i] -match '\.')) {
+                $Result = Compare-Version -ReferenceVersion $splitReferenceVersion[$i] -DifferenceVersion $splitDifferenceVersion[$i] -Delimiter '.'
+                # If the parts are equal, continue to next part, otherwise return
+                if ($Result -ne 0) {
+                    return $Result
+                } else {
+                    continue
+                }
+            }
+
+            # Don't try to compare [Long] to [String]
+            if ($null -ne $splitReferenceVersion[$i] -and $null -ne $splitDifferenceVersion[$i]) {
+                if ($splitReferenceVersion[$i] -is [String] -and $splitDifferenceVersion[$i] -isnot [String]) {
+                    $splitDifferenceVersion[$i] = "$($splitDifferenceVersion[$i])"
+                }
+                if ($splitDifferenceVersion[$i] -is [String] -and $splitReferenceVersion[$i] -isnot [String]) {
+                    $splitReferenceVersion[$i] = "$($splitReferenceVersion[$i])"
+                }
+            }
+
+            # Compare [String] or [Long]
+            if ($splitDifferenceVersion[$i] -gt $splitReferenceVersion[$i]) {
+                return 1
+            }
+            if ($splitDifferenceVersion[$i] -lt $splitReferenceVersion[$i]) {
+                return -1
+            }
+        }
     }
-    if($ver_b.length -gt $ver_a.length) { return -1 }
-    return 0
 }
 
+# Helper function
+function SplitVersion {
+    <#
+    .SYNOPSIS
+        Split version by Delimiter, convert number string to number, and separate letters from numbers
+    .PARAMETER Version
+        Specifies a version
+    .PARAMETER Delimiter
+        Specifies the delimiter of version (Literal)
+    #>
+    [OutputType([Object[]])]
+    [CmdletBinding()]
+    param (
+        [Parameter(Mandatory = $true, Position = 0, ValueFromPipeline = $true)]
+        [AllowEmptyString()]
+        [String]
+        $Version,
+        [String]
+        $Delimiter = '-'
+    )
+    process {
+        $Version = $Version -replace '[a-zA-Z]+', "$Delimiter$&$Delimiter"
+        return ($Version -split [Regex]::Escape($Delimiter) -ne '' | ForEach-Object { if ($_ -match '^\d+$') { [Long]$_ } else { $_ } })
+    }
+}
+
+# Deprecated
+# Not used anymore in scoop core
 function qsort($ary, $fn) {
-    if($null -eq $ary) { return @() }
-    if(!($ary -is [array])) { return @($ary) }
+    warn '"qsort" is deprecated. Please avoid using it anymore.'
+    if ($null -eq $ary) { return @() }
+    if (!($ary -is [array])) { return @($ary) }
 
     $pivot = $ary[0]
-    $rem = $ary[1..($ary.length-1)]
+    $rem = $ary[1..($ary.length - 1)]
 
-    $lesser = qsort ($rem | Where-Object { (& $fn $_ $pivot) -lt 0 }) $fn
+    $lesser = qsort ($rem | Where-Object { (& $fn $pivot $_) -lt 0 }) $fn
 
-    $greater = qsort ($rem | Where-Object { (& $fn $_ $pivot) -ge 0 }) $fn
+    $greater = qsort ($rem | Where-Object { (& $fn $pivot $_) -ge 0 }) $fn
 
     return @() + $lesser + @($pivot) + $greater
 }
-function sort_versions($versions) { qsort $versions compare_versions }
+
+# Deprecated
+# Not used anymore in scoop core
+function sort_versions($versions) {
+    warn '"sort_versions" is deprecated. Please avoid using it anymore.'
+    qsort $versions Compare-Version
+}
+
+function compare_versions($a, $b) {
+    Show-DeprecatedWarning $MyInvocation 'Compare-Version'
+    # Please note the parameters' sequence
+    return Compare-Version -ReferenceVersion $b -DifferenceVersion $a
+}
+
+function latest_version($app, $bucket, $url) {
+    Show-DeprecatedWarning $MyInvocation 'Get-LatestVersion'
+    return Get-LatestVersion -AppName $app -Bucket $bucket -Uri $url
+}
+
+function current_version($app, $global) {
+    Show-DeprecatedWarning $MyInvocation 'Select-CurrentVersion'
+    return Select-CurrentVersion -AppName $app -Global:$global
+}
+
+function versions($app, $global) {
+    Show-DeprecatedWarning $MyInvocation 'Get-InstalledVersion'
+    return Get-InstalledVersion -AppName $app -Global:$global
+}
diff --git a/libexec/scoop-cleanup.ps1 b/libexec/scoop-cleanup.ps1
index 482fbc1ac0..4b9c735b7d 100644
--- a/libexec/scoop-cleanup.ps1
+++ b/libexec/scoop-cleanup.ps1
@@ -31,11 +31,11 @@ if ($global -and !(is_admin)) {
 }
 
 function cleanup($app, $global, $verbose, $cache) {
-    $current_version = current_version $app $global
+    $current_version = Select-CurrentVersion -AppName $app -Global:$global
     if ($cache) {
         Remove-Item "$cachedir\$app#*" -Exclude "$app#$current_version#*"
     }
-    $versions = versions $app $global | Where-Object { $_ -ne $current_version -and $_ -ne 'current' }
+    $versions = Get-InstalledVersion -AppName $app -Global:$global | Where-Object { $_ -ne $current_version -and $_ -ne 'current' }
     if (!$versions) {
         if ($verbose) { success "$app is already clean" }
         return
diff --git a/libexec/scoop-export.ps1 b/libexec/scoop-export.ps1
index e2cce6d7b7..e4a9d81f5c 100644
--- a/libexec/scoop-export.ps1
+++ b/libexec/scoop-export.ps1
@@ -23,7 +23,7 @@ if($apps) {
     $apps | Sort-Object { $_.name } | Where-Object { !$query -or ($_.name -match $query) } | ForEach-Object {
         $app = $_.name
         $global = $_.global
-        $ver = current_version $app $global
+        $ver = Select-CurrentVersion -AppName $app -Global:$global
         $global_display = $null; if($global) { $global_display = ' *global*'}
 
         $install_info = install_info $app $ver $global
diff --git a/libexec/scoop-info.ps1 b/libexec/scoop-info.ps1
index e13119a945..b54720a4cc 100644
--- a/libexec/scoop-info.ps1
+++ b/libexec/scoop-info.ps1
@@ -85,7 +85,7 @@ Write-Output "Manifest:`n  $manifest_file"
 if($status.installed) {
     # Show installed versions
     Write-Output "Installed:"
-    $versions = versions $app $global
+    $versions = Get-InstalledVersion -AppName $app -Global:$global
     $versions | ForEach-Object {
         $dir = versiondir $app $_ $global
         if($global) { $dir += " *global*" }
diff --git a/libexec/scoop-install.ps1 b/libexec/scoop-install.ps1
index 379784d5b5..8a759463ea 100644
--- a/libexec/scoop-install.ps1
+++ b/libexec/scoop-install.ps1
@@ -37,7 +37,7 @@ function is_installed($app, $global) {
     if (installed $app $global) {
         function gf($g) { if ($g) { ' --global' } }
 
-        $version = @(versions $app $global)[-1]
+        $version = Select-CurrentVersion -AppName $app -Global:$global
         if (!(install_info $app $version $global)) {
             warn "Purging previous failed installation of $app."
             & "$PSScriptRoot\scoop-uninstall.ps1" $app$(gf $global)
@@ -117,7 +117,7 @@ $apps, $skip = prune_installed $apps $global
 
 $skip | Where-Object { $explicit_apps -contains $_ } | ForEach-Object {
     $app, $null, $null = parse_app $_
-    $version = @(versions $app $global)[-1]
+    $version = Select-CurrentVersion -AppName $app -Global:$global
     warn "'$app' ($version) is already installed. Skipping."
 }
 
diff --git a/libexec/scoop-list.ps1 b/libexec/scoop-list.ps1
index 44c45a7415..438d56ab9b 100644
--- a/libexec/scoop-list.ps1
+++ b/libexec/scoop-list.ps1
@@ -21,7 +21,7 @@ if($apps) {
     $apps | Sort-Object { $_.name } | Where-Object { !$query -or ($_.name -match $query) } | ForEach-Object {
         $app = $_.name
         $global = $_.global
-        $ver = current_version $app $global
+        $ver = Select-CurrentVersion -AppName $app -Global:$global
 
         $install_info = install_info $app $ver $global
         write-host "  $app " -NoNewline
diff --git a/libexec/scoop-reset.ps1 b/libexec/scoop-reset.ps1
index 1c89fb1c2f..b2ce410734 100644
--- a/libexec/scoop-reset.ps1
+++ b/libexec/scoop-reset.ps1
@@ -45,7 +45,7 @@ $apps | ForEach-Object {
     }
 
     if ($null -eq $version) {
-        $version = current_version $app $global
+        $version = Select-CurrentVersion -AppName $app -Global:$global
     }
 
     $manifest = installed_manifest $app $version $global
diff --git a/libexec/scoop-search.ps1 b/libexec/scoop-search.ps1
index 7758fa53c8..e60cddeea9 100644
--- a/libexec/scoop-search.ps1
+++ b/libexec/scoop-search.ps1
@@ -44,7 +44,7 @@ function search_bucket($bucket, $query) {
             }
         }
     }
-    $apps | ForEach-Object { $_.version = (latest_version $_.name $bucket); $_ }
+    $apps | ForEach-Object { $_.version = (Get-LatestVersion -AppName $_.name -Bucket $bucket); $_ }
 }
 
 function download_json($url) {
diff --git a/libexec/scoop-uninstall.ps1 b/libexec/scoop-uninstall.ps1
index e9797e6cbf..500d6c4bc5 100644
--- a/libexec/scoop-uninstall.ps1
+++ b/libexec/scoop-uninstall.ps1
@@ -50,7 +50,7 @@ if (!$apps) { exit 0 }
 :app_loop foreach ($_ in $apps) {
     ($app, $global) = $_
 
-    $version = current_version $app $global
+    $version = Select-CurrentVersion -AppName $app -Global:$global
     Write-Host "Uninstalling '$app' ($version)."
 
     $dir = versiondir $app $version $global
@@ -101,7 +101,7 @@ if (!$apps) { exit 0 }
     }
 
     # remove older versions
-    $old = @(versions $app $global)
+    $old = Get-InstalledVersion -AppName $app -Global:$global
     foreach ($oldver in $old) {
         Write-Host "Removing older version ($oldver)."
         $dir = versiondir $app $oldver $global
@@ -115,7 +115,7 @@ if (!$apps) { exit 0 }
         }
     }
 
-    if (@(versions $app $global).length -eq 0) {
+    if ((Get-InstalledVersion -AppName $app -Global:$global).length -eq 0) {
         $appdir = appdir $app $global
         try {
             # if last install failed, the directory seems to be locked and this
diff --git a/libexec/scoop-update.ps1 b/libexec/scoop-update.ps1
index de071d1a56..100e3c0a91 100644
--- a/libexec/scoop-update.ps1
+++ b/libexec/scoop-update.ps1
@@ -154,7 +154,7 @@ function update_scoop() {
 }
 
 function update($app, $global, $quiet = $false, $independent, $suggested, $use_cache = $true, $check_hash = $true) {
-    $old_version = current_version $app $global
+    $old_version = Select-CurrentVersion -AppName $app -Global:$global
     $old_manifest = installed_manifest $app $old_version $global
     $install = install_info $app $old_version $global
 
@@ -173,7 +173,7 @@ function update($app, $global, $quiet = $false, $independent, $suggested, $use_c
         $deps | ForEach-Object { install_app $_ $architecture $global $suggested $use_cache $check_hash }
     }
 
-    $version = latest_version $app $bucket $url
+    $version = Get-LatestVersion -AppName $app -Bucket $bucket -Uri $url
     $is_nightly = $version -eq 'nightly'
     if ($is_nightly) {
         $version = nightly_version $(get-date) $quiet
diff --git a/test/Scoop-Versions.Tests.ps1 b/test/Scoop-Versions.Tests.ps1
index a02e968213..8fee628604 100644
--- a/test/Scoop-Versions.Tests.ps1
+++ b/test/Scoop-Versions.Tests.ps1
@@ -1,37 +1,96 @@
 . "$psscriptroot\Scoop-TestLib.ps1"
 . "$psscriptroot\..\lib\versions.ps1"
 
-describe "versions" -Tag 'Scoop' {
-    it 'compares versions with integer-string mismatch' {
-        $a = '1.8.9'
-        $b = '1.8.5-1'
-        $res = compare_versions $a $b
+Describe 'versions comparison' -Tag 'Scoop' {
+    Context 'semver compliant versions' {
+        It 'handles major.minor.patch progressing' {
+            Compare-Version '0.1.0' '0.1.1' | Should -Be 1
+            Compare-Version '0.1.1' '0.2.0' | Should -Be 1
+            Compare-Version '0.2.0' '1.0.0' | Should -Be 1
+        }
 
-        $res | should -be 1
-    }
-
-    it 'handles plain string version comparison to int version' {
-        $a = 'latest'
-        $b = '20150405'
-        $res = compare_versions $a $b
+        It 'handles pre-release versioning progression' {
+            Compare-Version '0.4.0' '0.5.0-alpha.1' | Should -Be 1
+            Compare-Version '0.5.0-alpha.1' '0.5.0-alpha.2' | Should -Be 1
+            Compare-Version '0.5.0-alpha.2' '0.5.0-alpha.10' | Should -Be 1
+            Compare-Version '0.5.0-alpha.10' '0.5.0-beta' | Should -Be 1
+            Compare-Version '0.5.0-beta' '0.5.0-alpha.10' | Should -Be -1
+            Compare-Version '0.5.0-beta' '0.5.0-beta.0' | Should -Be 1
+        }
 
-        $res | should -be 1
+        It 'handles the pre-release tags in an alphabetic order' {
+            Compare-Version '0.5.0-rc.1' '0.5.0-z' | Should -Be 1
+            Compare-Version '0.5.0-rc.1' '0.5.0-howdy' | Should -Be -1
+            Compare-Version '0.5.0-howdy' '0.5.0-rc.1' | Should -Be 1
+        }
     }
 
-    it 'handles dashed version components' {
-        $a = '7.0.4-9'
-        $b = '7.0.4-10'
+    Context 'semver semi-compliant versions' {
+        It 'handles Windows-styled major.minor.patch.build progression' {
+            Compare-Version '0.0.0.0' '0.0.0.1' | Should -Be 1
+            Compare-Version '0.0.0.1' '0.0.0.2' | Should -Be 1
+            Compare-Version '0.0.0.2' '0.0.1.0' | Should -Be 1
+            Compare-Version '0.0.1.0' '0.0.1.1' | Should -Be 1
+            Compare-Version '0.0.1.1' '0.0.1.2' | Should -Be 1
+            Compare-Version '0.0.1.2' '0.0.2.0' | Should -Be 1
+            Compare-Version '0.0.2.0' '0.1.0.0' | Should -Be 1
+            Compare-Version '0.1.0.0' '0.1.0.1' | Should -Be 1
+            Compare-Version '0.1.0.1' '0.1.0.2' | Should -Be 1
+            Compare-Version '0.1.0.2' '0.1.1.0' | Should -Be 1
+            Compare-Version '0.1.1.0' '0.1.1.1' | Should -Be 1
+            Compare-Version '0.1.1.1' '0.1.1.2' | Should -Be 1
+            Compare-Version '0.1.1.2' '0.2.0.0' | Should -Be 1
+            Compare-Version '0.2.0.0' '1.0.0.0' | Should -Be 1
+        }
 
-        $res = compare_versions $a $b
+        It 'handles partial semver version differences' {
+            Compare-Version '1' '1.1' | Should -Be 1
+            Compare-Version '1' '1.0' | Should -Be 1
+            Compare-Version '1.1.0.0' '1.1' | Should -Be -1
+            Compare-Version '1.4' '1.3.0' | Should -Be -1
+            Compare-Version '1.4' '1.3.255.255' | Should -Be -1
+            Compare-Version '1.4' '1.4.4' | Should -Be 1
+            Compare-Version '1.1.1_8' '1.1.1' | Should -Be -1
+            Compare-Version '1.1.1b' '1.1.1a' | Should -Be -1
+            Compare-Version '1.1.1a' '1.1.1b' | Should -Be 1
+            Compare-Version '1.1a2' '1.1a3' | Should -Be 1
+            Compare-Version '1.1.1a10' '1.1.1b1' | Should -Be 1
+        }
 
-        $res | should -be -1
+        It 'handles dash-style versions' {
+            Compare-Version '1.8.9' '1.8.5-1' | Should -Be -1
+            Compare-Version '7.0.4-9' '7.0.4-10' | Should -Be 1
+            Compare-Version '7.0.4-9' '7.0.4-8' | Should -Be -1
+            Compare-Version '2019-01-01' '2019-01-02' | Should -Be 1
+            Compare-Version '2019-01-02' '2019-01-01' | Should -Be -1
+            Compare-Version '2018-01-01' '2019-01-01' | Should -Be 1
+            Compare-Version '2019-01-01' '2018-01-01' | Should -Be -1
+        }
+        It 'handles post-release tagging ("+")' {
+            Compare-Version '1' '1+hotfix.0' | Should -Be 1
+            Compare-Version '1.0.0' '1.0.0+hotfix.0' | Should -Be 1
+            Compare-Version '1.0.0+hotfix.0' '1.0.0+hotfix.1' | Should -Be 1
+            Compare-Version '1.0.0+hotfix.1' '1.0.1' | Should -Be 1
+            Compare-Version '1.0.0+1.1' '1.0.0+1' | Should -Be -1
+        }
     }
 
-    it 'handles comparsion against en empty string' {
-        compare_versions '7.0.4-9' '' | should -be 1
-    }
+    Context 'other misc versions' {
+        It 'handles plain text string' {
+            Compare-Version 'latest' '20150405' | Should -Be -1
+            Compare-Version '0.5alpha' '0.5' | Should -Be 1
+            Compare-Version '0.5' '0.5Beta' | Should -Be -1
+            Compare-Version '0.4' '0.5Beta' | Should -Be 1
+        }
+
+        It 'handles empty string' {
+            Compare-Version '7.0.4-9' '' | Should -Be -1
+        }
 
-    it 'handles equal versions' {
-        compare_versions '12.0' '12.0' | should -be 0
+        It 'handles equal versions' {
+            Compare-Version '12.0' '12.0' | Should -Be 0
+            Compare-Version '7.0.4-9' '7.0.4-9' | Should -Be 0
+            Compare-Version 'nightly-20190801' 'nightly' | Should -Be 0
+        }
     }
 }