github-actions-download-latest-release.yaml

# Probably ~90% correct
# Be sure to update the line that sets MatchingAssets to whatever requirement you need
# Only downloads the first asset in MatchingAssets
  
  jobname:
    steps:
    - name: Download latest
      id: download
      shell: pwsh
      run: |
        # Requires a GitHub personal access token with `repo` scope
        [char[]]$Token = "${{ secrets.BUILD_GITHUB_TOKEN }}"
        $Base64Token = [System.Convert]::ToBase64String($Token);
        $Repository = "user/repo"
        $OutputPath = "${{ github.workspace }}/output.zip"

        $Headers = @{
          Authorization = "Basic $Base64Token"
        }

        # Get latest release
        Write-Host "Checking for latest release"
        $LatestRelease = Invoke-RestMethod -Headers $Headers -Uri "https://api.github.com/repos/$Repository/releases/latest" -Method GET
        Write-Host "Latest release is $($LatestRelease.tag_name)"

        # Get all assets for the release
        $Assets = Invoke-RestMethod -Headers $Headers -Uri $LatestRelease.assets_url -Method GET
        Write-Host "Release assets:"
        $Assets | Select-Object -ExpandProperty "browser_download_url"

        # Find assets matching pattern
        $MatchingAssets = $Assets | Where-Object { $_.browser_download_url.Contains("-win-")}

        # Download the first asset
        $DownloadUrl = $MatchingAssets[0].url
        Write-Host "Downloading $DownloadUrl"
        $DownloadHeaders = @{
          Accept = "application/octet-stream"
          Authorization = "Basic $Base64Token"
        }

        Write-Host "Downloading $DownloadUrl to $OutputPath"
        Invoke-RestMethod -Headers $DownloadHeaders -Uri $DownloadUrl -Method GET -OutFile $OutputPath