Sync-GithubFork.ps1

Sync-GithubFork.ps1

function Sync-GithubFork {
    [CmdletBinding()]
    Param(
        [Parameter(ValueFromPipeline = $true)]
        [System.String[]]
        $Path = (Get-Location)
        ,
        [System.String[]]
        $Branch = $null
    )


    begin {
        function Get-GitBranch {
            Param(
                [Switch]
                $Current = $false
            )
            # Get all branches
            $Branch = (git.exe branch)

            # If Current switch get only branch with asterisk
            if ($Current) {
                $Branch = $Branch | Where-Object { $_ -match '^\*' }
            }

            # Remove asterisk and whitespace to return only names
            $Branch = $Branch | ForEach-Object { $_.Replace('*', '').Trim() }

            return $Branch
        }
    }


    process {

        foreach ($p in $Path) {

            Write-Verbose -Message "Checking for Git repository in path: $p"
            $IsGitRepo = Test-Path -Path (Join-Path -Path $p -ChildPath '.git') -PathType Container

            if ($IsGitRepo) {

                Write-Verbose -Message 'Git repository found'

                Write-Verbose -Message 'Getting Remote Origin URL for repository'
                $RemoteOriginUrl = (git.exe config --get remote.origin.url).Trim()
                Write-Verbose -Message "Remote Origin URL: $RemoteOriginUrl"

                Write-Verbose -Message 'Checking if it is a GitHub repository'
                $IsGitHub = ($RemoteOriginUrl -match 'github.com')

                if ($IsGitHub) {

                    Write-Verbose -Message 'It appear to be a GitHub repository'

                    Write-Verbose -Message 'Getting User and Repository parts from the Remote Origin URL'
                    $UserAndRepo = [regex]::Match($RemoteOriginUrl, '([^\/.]+\/[^\/.]+)\.git$').Groups[1].Value
                    Write-Verbose -Message "Github User/Repository: $UserAndRepo"

                    Write-Verbose 'Getting GitHub Repository REST data'
                    $RestData = Invoke-RestMethod -Uri "https://api.github.com/repos/$UserAndRepo"

                    Write-Verbose -Message 'Checking if GitHub Repository is a fork'
                    if ($RestData.fork) {

                        Write-Verbose 'Repository is a fork'

                        Write-Verbose 'Getting parent repository owner'
                        $ParentOwner = $RestData.parent.owner.login
                        Write-Verbose "Parent repository owner: $ParentOwner"

                        Write-Verbose 'Getting parent repository clone URL'
                        $ParentCloneUrl = $RestData.parent.clone_url
                        Write-Verbose "Parent repository clone URL: $ParentCloneUrl"

                        Write-Verbose 'Getting configured remotes'
                        $Remotes = (git.exe remote -v)

                        Write-Verbose 'Building HashTable of configured remotes'
                        $RemotesHash = @{}
                        foreach ($Remote in $Remotes) {
                            $RegEx = [regex]::Match($Remote, '^(.+)\s(.+)\s\((.+)\)$')
                            $RemotesHash[$RegEx.Groups[1].Value] = $RegEx.Groups[2].Value
                        }

                        Write-Verbose "Checking if $ParentOwner is already configured as remote"
                        if (-not ($ParentOwner -in $RemotesHash.GetEnumerator().Name)) {

                            Write-Verbose "Adding $ParentOwner as a remote"
                            git.exe remote add $ParentOwner $ParentCloneUrl

                        }
                        else {

                            Write-Verbose "$ParentOwner is already configured as a remote"

                        }

                        Write-Verbose -Message 'Getting local branches'
                        $LocalBranches = Get-GitBranch
                        Write-Verbose -Message "Local branches found: [$($LocalBranches -join ', ')]"

                        Write-Verbose -Message 'Getting current branch'
                        $CurrentBranch = Get-GitBranch -Current
                        Write-Verbose -Message "Current branch: $CurrentBranch"

                        Write-Verbose -Message 'Checking if branches where specified'
                        if (-not $Branch) {

                            Write-Verbose -Message "No branch specified defaulting to current branch: $CurrentBranch"
                            $Branch = $CurrentBranch

                        }

                        Write-Verbose -Message "Performing action: git.exe fetch $ParentOwner"
                        git.exe fetch $ParentOwner

                        Write-Verbose -Message 'Loop through branches'
                        foreach ($b in $Branch) {

                            Write-Verbose -Message "Processing branch: $b"

                            Write-Verbose -Message "Verify that branch [$b] match a local branch [$($LocalBranches -join ', ')]"
                            if ($b -in $LocalBranches) {

                                Write-Verbose -Message "Verify if branch [$b] is the current branch"
                                if (-not ($b -eq (Get-GitBranch -Current))) {

                                    Write-Verbose -Message "Branch [$b] is not the current branch"
                                    Write-Verbose -Message "Performing action: git.exe checkout $b"
                                    git.exe checkout $b

                                }

                                Write-Verbose -Message "Performing action: git.exe merge $ParentOwner/$b"
                                git.exe merge $ParentOwner/$b

                                Write-Verbose -Message "Performing action: git.exe push origin $b"
                                git.exe push origin $b


                            } else {
                                Write-Warning -Message "Specified branch [$b] is not available in local repository"
                            }
                        }
                    } else {
                        Write-Warning -Message "Remote Origin does not appear to be a fork: $RemoteOriginUrl"
                    }

                } else {
                    Write-Warning -Message "This does not appear to be a GitHub repository: $p"
                }
            } else {
                Write-Warning -Message "This does not appear to be a Git repository: $p"
            }
        }
    }
}