Opens html in private github repos from browser

download_open_browser.ps1

<#
.SYNOPSIS
  Open an .html file that lives in a (possibly private) GitHub repository.

.DESCRIPTION
  GitHub serves .html as source, and public preview services cannot reach a
  private repository. This downloads the repository archive through your
  signed-in browser -- which supplies the GitHub session cookie, so no token or
  CLI is needed -- unpacks it, and opens the requested file. Taking the whole
  archive rather than a single raw file means relative assets (images, css)
  still resolve.

.EXAMPLE
  .\Open-RepoHtml.ps1 -Repo eyalk11/fei_conjecture
  .\Open-RepoHtml.ps1 -Repo eyalk11/fei_conjecture -Path docs/fei_program_map.html
  .\Open-RepoHtml.ps1 -Repo twbs/bootstrap -Ref main -Path index.html -Browser msedge
#>
[CmdletBinding()]
param(
    [Parameter(Mandatory)][ValidatePattern('^[^/\s]+/[^/\s]+$')]
    [string]  $Repo,                              # owner/name
    [string]  $Ref         = 'master',            # branch name
    [string]  $Path        = 'README.html',       # file inside the repo
    [string]  $Browser     = 'chrome',            # must be signed in to GitHub
    [string]  $DownloadDir = "$HOME\Downloads",   # where the browser
    [int]     $TimeoutSec  = 180,
    [switch]  $KeepArchive                        # leave the .zip in
)

$ErrorActionPreference = 'Stop'

$name    = $Repo.Split('/')[-1]
$refSlug = $Ref -replace '/', '-'                 # GitHub flattens f
$pattern = "$name-$refSlug*.zip"
$url     = "https://github.com/$Repo/archive/refs/heads/$Ref.zip"
$out     = Join-Path $env:TEMP "$name-$refSlug"

# Clear the previous archive and extraction: the browser will not overwrite a
# download (it would save as "...(1).zip" and we would keep finding t
# one), and Expand-Archive -Force overwrites files but leaves behind any that
# have since been deleted upstream.
Remove-Item (Join-Path $DownloadDir $pattern), $out -Recurse -Force -ErrorAction SilentlyContinue

$t = Get-Date
Write-Verbose "fetching $url via $Browser"
try   { Start-Process $Browser $url }
catch { throw "could not launch '$Browser': $($_.Exception.Message)"

do {
    Start-Sleep 1
    $zip = Get-ChildItem $DownloadDir -Filter $pattern -ErrorAction S
           Sort-Object LastWriteTime -Descending | Select-Object -First 1
} until ($zip -or ((Get-Date) - $t).TotalSeconds -gt $TimeoutSec)

if (-not $zip) {
    throw "no archive matching '$pattern' appeared in $DownloadDir within ${TimeoutSec}s. " +
          "Is $Browser signed in to GitHub, does the branch '$Ref' ex
          "browser save downloads there without prompting?"
}

Expand-Archive $zip.FullName $out -Force
if (-not $KeepArchive) { Remove-Item $zip.FullName -Force -ErrorAction SilentlyContinue }

$root   = (Get-ChildItem $out -Directory | Select-Object -First 1).FullName
$target = Join-Path $root ($Path -replace '/', '\')
if (-not (Test-Path $target)) {
    throw "'$Path' is not in the archive. Top level holds: " +
          ((Get-ChildItem $root | Select-Object -First 12 -ExpandProperty Name) -join ', ')
}

Invoke-Item $target
$target      # so the caller can reuse the extracted path

Opens html in private github repos from browser.