Script to create a new github pull request and add and update a file.

upload-or-update-file-and-create-pull-request.ps1

$ErrorActionPreference = "Stop"
#https://github.com/settings/tokens/new?scopes=repo
$githubAuth = "use your own"
$headers = @{
    Accept = "application/vnd.github.v3+json"
    Authorization = "bearer $githubAuth"
}
$baseUrl = "https://api.github.com"

function Get-GitResource($url) {
    try {
        return Invoke-RestMethod -Method GET -Uri $url -Headers $headers
    } catch {
         if($_.Exception.Response.StatusCode -eq "NotFound") {
            return $null
         }

         throw $_.Exception
    }
}

function Upsert-GitBranch($organization, $repoName, $fromRef, $featureName) {
    $refs = Get-GitResource "$baseUrl/repos/$organization/$repoName/git/refs/heads"
    $branch = $refs | ? { $_.ref -eq "refs/heads/$featureName" }
    if (!$branch) {
        $from = $refs | ? { $_.ref -eq $fromRef }
        if (!$from) {
            throw "fromRef not found"
        }
        $body = ConvertTo-Json @{
            ref = "refs/heads/$featureName"
            sha = $from.object.sha
        }
        $branch = Invoke-RestMethod -Method POST -Uri "$baseUrl/repos/$organization/$repoName/git/refs" -Headers $headers -Body $body
    }

    return $branch
}

function Upsert-GitContent($organization, $repoName, $branchName, $path, $text, $comment) {
    $content = Get-GitResource "$baseUrl/repos/$organization/$repoName/contents/$($path)?ref=$branchName" 
    $bytes = [System.Text.Encoding]::Unicode.GetBytes($text)
    $data = @{
        message = $comment
        content = [Convert]::ToBase64String($bytes)
        branch = $branchName
    }
    if ($content) {
        $data.Add("sha", $content.sha)
    }    

    $body = ConvertTo-Json $data
    Invoke-RestMethod -Method PUT -Uri "$baseUrl/repos/$organization/$repoName/contents/$($path)" -Headers $headers -Body $body
}

function Get-GitPr($organization, $repoName, $title, $head, $base) {
    $pr = Get-GitResource "$baseUrl/repos/$organization/$repoName/pulls" | ? { $_.title -eq $title }

    if (!$pr) {
        $body = ConvertTo-Json @{
            title = $title
            head = $head
            base = $base
        }
        $pr = Invoke-RestMethod -Method POST -Uri "$baseUrl/repos/$organization/$repoName/pulls"  -Headers $headers -Body $body
    }

    return $pr
}


$branch = Upsert-GitBranch "your org" "your repo" "refs/heads/main" "your new feature branch"
Upsert-GitContent "your org" "your repo" "your new feature branch" "file path" "file content" "commit comments"
Get-GitPr "your org" "your repo" "your pr name" "your new feature branch" "refs/heads/main"