initial update vendors script

scripts/update.ps1

@@ -0,0 +1,266 @@
+<#
+.Synopsis
+    Update Cmder vendored dependencies
+.DESCRIPTION
+    This script updates dependencies to the latest version in vendor/sources.json file.
+
+    You will need to make this script executable by setting your Powershell Execution Policy to Remote signed
+    Then unblock the script for execution with UnblockFile .\build.ps1
+.EXAMPLE
+    .\build.ps1
+
+    Updates the dependency sources in the default location, the vendor/sources.json file.
+.EXAMPLE
+    .\build -verbose
+
+    Updates the dependency sources and see what's going on.
+.EXAMPLE
+    .\build.ps1 -SourcesPath '~/custom/vendors.json'
+
+    Specify the path to update dependency sources file at.
+.NOTES
+    AUTHORS
+    David Refoua <David@Refoua.me>
+    Part of the Cmder project.
+.LINK
+    http://cmder.app/ - Project Home
+#>
+[CmdletBinding(SupportsShouldProcess=$true)]
+Param(
+    # CmdletBinding will give us;
+    # -verbose switch to turn on logging and
+    # -whatif switch to not actually make changes
+
+    # Path to the vendor configuration source file
+    [string]$sourcesPath = "$PSScriptRoot\..\vendor\sources.json"
+)
+
+# Get the root directory of the cmder project.
+$cmder_root = Resolve-Path "$PSScriptRoot\.."
+
+# Dot source util functions into this scope
+. "$PSScriptRoot\utils.ps1"
+$ErrorActionPreference = "Stop"
+
+# Attempts to match the current link with the new link, returning the count of matching characters.
+function Match-Filenames {
+    param (
+        $url,
+        $downloadUrl,
+        $fromEnd
+    )
+
+    $filename = [System.IO.Path]::GetFileName($url)
+    $filenameDownload = [System.IO.Path]::GetFileName($downloadUrl)
+
+    $position = 0
+
+    if ([String]::IsNullOrEmpty($filename) -Or [String]::IsNullOrEmpty($filenameDownload)) {
+        throw "Either one or both filenames are empty!"
+    }
+
+    if ($fromEnd) {
+        $arr = $filename -split ""
+        [array]::Reverse($arr)
+        $filename = $arr -join ''
+        $arr = $filenameDownload -split ""
+        [array]::Reverse($arr)
+        $filenameDownload = $arr -join ''
+    }
+
+    while ($filename.Substring($position, 1) -eq $filenameDownload.Substring($position, 1)) {
+        $position++
+
+        if ( ($position -ge $filename.Length) -or ($position -ge $filenameDownload.Length) ) {
+            break
+        }
+    }
+
+    return $position
+}
+
+# Uses the GitHub api in order to fetch the current download links for the latest releases of the repo.
+function Fetch-DownloadUrl {
+    param (
+        [Parameter(Mandatory = $true)]
+        $urlStr
+    )
+
+    $url = [uri] $urlStr
+
+    if ((-Not $url) -Or ($null -eq $url) -Or ($url -eq '')) {
+        throw "Failed to parse url: $urlStr"
+    }
+
+    if (-Not ("http", "https" -Contains $url.Scheme)) {
+        throw "unknown source scheme: $($url.Scheme)"
+    }
+
+    if (-Not ($url.Host -ilike "*github.com")) {
+        throw "unknown source domain: $($url.Host)"
+    }
+
+    $p = $url.Segments.Split([Environment]::NewLine)
+
+    # Api server for GitHub
+    $urlHost = "api.github.com"
+
+    # Path for releases end-point
+    $urlPath = [IO.Path]::Combine('repos', $p[1], $p[2], 'releases').Trim('/')
+
+    $apiUrl = [uri] (New-Object System.UriBuilder -ArgumentList $url.Scheme, $urlHost, -1, $urlPath).Uri
+
+    $info = Invoke-RestMethod -Uri $apiUrl
+
+    $downloadLinks = (New-Object System.Collections.Generic.List[System.Object])
+
+    $charCount = 0
+
+    if (-Not ($info -Is [array])) {
+        throw "The response received from API server is invalid"
+    }
+
+    :loop foreach ($i in $info) {
+        if (-Not ($i.assets -Is [array])) {
+            continue
+        }
+
+        foreach ($a in $i.assets) {
+            if ([String]::IsNullOrEmpty($a.browser_download_url)) {
+                continue
+            }
+
+			# Skip some download links as we're not interested in them
+            if ( $a.browser_download_url -ilike "*_symbols*" ) {
+                continue
+            }
+
+            $score = Match-Filenames $url $a.browser_download_url
+
+			# Skip links that don't match or are less similar
+            if ( ($score -eq 0) -or ($score -lt $charCount) ) {
+                continue
+            }
+
+			# If we reach the same download link as we have
+            if ( $score -eq [System.IO.Path]::GetFileName($url).Length ) {
+            }
+
+            $charCount = $score
+            $downloadLinks.Add($a.browser_download_url)
+        }
+
+		# If at least one download link was found, don't continue with older releases
+        if ( $downloadLinks.Length -gt 0 ) {
+            break :loop
+        }
+    }
+
+	# Special case for archive downloads of repository
+    if (($null -eq $downloadLinks) -Or (-Not $downloadLinks)) {
+        if ((($p | % {$_.Trim('/')}) -Contains "archive") -And $info[0].tag_name) {
+            for ($i = 0; $i -lt $p.Length; $i++) {
+                if ($p[$i].Trim('/') -eq "archive") {
+                    $p[$i+1] = $info[0].tag_name + ".zip"
+                    $downloadLinks = $url.Scheme + "://" + $url.Host + ($p -Join '')
+                    return $downloadLinks
+                }
+            }
+        }
+        return ''
+    }
+
+    $temp = $downloadLinks | Where-Object { (Match-Filenames $url $_) -eq $charCount }
+
+    $downloadLinks = (New-Object System.Collections.Generic.List[System.Object])
+
+    $charCount = 0
+
+    foreach ($l in $temp) {
+        $score = Match-Filenames $url $l true
+
+        if ( ($score -eq 0) -or ($score -lt $charCount) ) {
+            continue
+        }
+
+        $charCount = $score
+    }
+
+    $downloadLinks = $temp | Where-Object { (Match-Filenames $url $_ true) -eq $charCount }
+
+    if (($null -eq $downloadLinks) -Or (-Not $downloadLinks)) {
+        throw "No suitable download links matched for the url!"
+    }
+
+    if (-Not($downloadLinks -is [String])) {
+        throw "Found multiple matches for the same url:`n" + $downloadLinks
+    }
+
+    return $downloadLinks
+}
+
+$count = 0
+
+# Read the current sources content
+$sources = Get-Content $sourcesPath | Out-String | ConvertFrom-Json
+
+foreach ($s in $sources) {
+    Write-Verbose "Updating sources link for $($s.name)..."
+
+	Write-Verbose "Old Link: $($s.url)"
+
+    $downloadUrl = Fetch-DownloadUrl $s.url
+
+    if (($null -eq $downloadUrl) -Or ($downloadUrl -eq '')) {
+        Write-Verbose "No new links were found"
+        continue
+    }
+
+    Write-Verbose "Link: $downloadUrl"
+
+    $url = [uri] $downloadUrl
+
+    $version = ''
+
+    if ( ($url.Segments[-3] -eq "download/") -And ($url.Segments[-2].StartsWith("v")) ) {
+        $version = $url.Segments[-2].TrimStart('v').TrimEnd('/')
+    }
+
+    if ( ($url.Segments[-2] -eq "archive/") ) {
+        $version = [System.IO.Path]::GetFileNameWithoutExtension($url.Segments[-1].TrimStart('v').TrimEnd('/'))
+    }
+
+    if ( $version -eq '' ) {
+        throw "Unable to extract version from url string"
+    }
+
+    Write-Verbose "Version: $version"
+
+	if ( $s.version -ne $version ) {
+		if ( ([System.Version] $s.version) -gt ([System.Version] $version) ) {
+			throw "The current version $($s.version) is already newer than the found version $version!"
+		}
+
+		$count++
+	}
+
+    $s.url = $downloadUrl
+    $s.version = $version
+}
+
+$sources | ConvertTo-Json | Set-Content $sourcesPath
+
+if ($count -eq 0) {
+	Write-Host -ForegroundColor yellow "No new releases were found."
+	return
+}
+
+if ( $Env:APPVEYOR -eq 'True' ) {
+    Add-AppveyorMessage -Message "Successfully updated $count dependencies." -Category Information
+}
+
+if ( $Env:GITHUB_ACTIONS -eq 'true' ) {
+    Write-Output "::notice title=Build Complete::Successfully updated $count dependencies."
+}
+
+Write-Host -ForegroundColor green "Successfully updated $count dependencies."