New-GitHubRelease

1.0.0

New-GitHubRelease.psm1

#Requires -Version 2.0

function New-GitHubRelease
{
<#
    .SYNOPSIS
    Creates a new Release for the given GitHub repository.
 
    .DESCRIPTION
    Uses the GitHub API to create a new Release for a given repository.
    Allows you to specify all of the Release properties, such as the Tag, Name, Assets, and if it's a Draft or Prerelease or not.
 
    .PARAMETER GitHubUsername
    The username that the GitHub repository exists under.
    e.g. For the repository https://github.com/deadlydog/New-GitHubRelease, the username is 'deadlydog'.
 
    .PARAMETER GitHubRepositoryName
    The name of the repository to create the Release for.
    e.g. For the repository https://github.com/deadlydog/New-GitHubRelease, the repository name is 'New-GitHubRelease'.
 
    .PARAMETER GitHubAccessToken
    The Access Token to use as credentials for GitHub.
    Access tokens can be generated at https://github.com/settings/tokens.
    The access token will need to have the repo/public_repo permission on it for it to be allowed to create a new Release.
 
    .PARAMETER TagName
    The name of the tag to create at the Commitish.
 
    .PARAMETER ReleaseName
    The name to use for the new release.
    If blank, the TagName will be used.
 
    .PARAMETER ReleaseNotes
    The text describing the contents of the release.
 
    .PARAMETER AssetFilePaths
    The full paths of the files to include in the release.
 
    .PARAMETER Commitish
    Specifies the commitish value that determines where the Git tag is created from.
    Can be any branch or commit SHA. Unused if the Git tag already exists.
    Default: the repository's default branch (usually master).
 
    .PARAMETER IsDraft
    True to create a draft (unpublished) release, false to create a published one.
    Default: false
 
    .PARAMETER IsPreRelease
    True to identify the release as a prerelease. false to identify the release as a full release.
    Default: false
 
    .OUTPUTS
    A hash table with the following properties is returned:
 
    Succeeded = $true if the Release was created successfully and all assets were uploaded to it, $false if some part of the process failed.
    ReleaseCreationSucceeded = $true if the Release was created successfully (does not include asset uploads), $false if the Release was not created.
    AllAssetUploadsSucceeded = $true if all assets were uploaded to the Release successfully, $false if one of them failed, $null if there were no assets to upload.
    ReleaseUrl = The URL of the new Release that was created.
    ErrorMessage = A message describing what went wrong in the case that Succeeded is $false.
 
    .EXAMPLE
    $gitHubReleaseParameters =
    @{
        GitHubUsername = 'deadlydog'
        GitHubRepositoryName = 'New-GitHubRelease'
        GitHubAccessToken = 'SomeLongHexidecimalString'
        ReleaseName = "New-GitHubRelease v1.0.0"
        TagName = "v1.0.0"
        ReleaseNotes = "This release contains the following changes: ..."
        AssetFilePaths = @('C:\MyProject\Installer.exe','C:\MyProject\Documentation.md')
        IsPreRelease = $false
        IsDraft = $true # Set to true when testing so we don't publish a real release (visible to everyone) by accident.
    }
    $result = New-GitHubRelease @gitHubReleaseParameters
 
    if ($result.Succeeded -eq $true)
    {
        Write-Output "Release published successfully! View it at $($result.ReleaseUrl)"
    }
    elseif ($result.ReleaseCreationSucceeded -eq $false)
    {
        Write-Error "The release was not created. Error message is: $($result.ErrorMessage)"
    }
    elseif ($result.AllAssetUploadsSucceeded -eq $null)
    {
        Write-Error "The release was created, but not all of the assets were uploaded to it. View it at $($result.ReleaseUrl). Error message is: $($result.ErrorMessage)"
    }
 
    Attempts to create a new Release, and returns a hash table containing the results.
    The PowerShell script will halt execution until the Release creation succeeds or fails.
 
    .LINK
    Project home: https://github.com/deadlydog/New-GitHubRelease
 
    .NOTES
    Name: New-GitHubRelease
    Author: Daniel Schroeder (originally based on the script at https://github.com/majkinetor/au/blob/master/scripts/Github-CreateRelease.ps1)
    GitHub Release API Documentation: https://developer.github.com/v3/repos/releases/#create-a-release
    Version: 1.0.0
#>
    [CmdletBinding()]
    param
    (
        [Parameter(Mandatory=$true,HelpMessage="The username the repository is under (e.g. deadlydog).")]
        [string] $GitHubUsername,

        [Parameter(Mandatory=$true,HelpMessage="The repository name to create the release in (e.g. Invoke-MsBuild).")]
        [string] $GitHubRepositoryName,

        [Parameter(Mandatory=$true,HelpMessage="The Acess Token to use as credentials for GitHub.")]
        [string] $GitHubAccessToken,

        [Parameter(Mandatory=$true,HelpMessage="The name of the tag to create at the the Commitish.")]
        [string] $TagName,

        [Parameter(Mandatory=$false,HelpMessage="The name of the release. If blank, the TagName will be used.")]
        [string] $ReleaseName,

        [Parameter(Mandatory=$false,HelpMessage="Text describing the contents of the tag.")]
        [string] $ReleaseNotes,

        [Parameter(Mandatory=$false,HelpMessage="The full paths of the files to include in the release.")]
        [string[]] $AssetFilePaths,

        [Parameter(Mandatory=$false, HelpMessage="Specifies the commitish value that determines where the Git tag is created from. Can be any branch or commit SHA. Unused if the Git tag already exists. Default: the repository's default branch (usually master).")]
        [string] $Commitish,

        [Parameter(Mandatory=$false,HelpMessage="True to create a draft (unpublished) release, false to create a published one. Default: false")]
        [bool] $IsDraft = $false,

        [Parameter(Mandatory=$false,HelpMessage="True to identify the release as a prerelease. false to identify the release as a full release. Default: false")]
        [bool] $IsPreRelease = $false
    )

    BEGIN
    {
        # Turn on Strict Mode to help catch syntax-related errors.
        # This must come after a script's/function's param section.
        # Forces a function to be the first non-comment code to appear in a PowerShell Script/Module.
        Set-StrictMode -Version Latest

        $NewLine = [Environment]::NewLine

        if ([string]::IsNullOrEmpty($ReleaseName))
        {
            $ReleaseName = $TagName
        }

        # Ensure that all of the given asset file paths to upload are valid.
        Test-AllFilePathsAndThrowErrorIfOneIsNotValid $AssetFilePaths
    }

    END { }

    PROCESS
    {
        # Create the hash table to return, with default values.
        $result = @{}
        $result.Succeeded = $false
        $result.ReleaseCreationSucceeded = $false
        $result.AllAssetUploadsSucceeded = $false
        $result.ReleaseUrl = $null
        $result.ErrorMessage = $null

        [bool] $thereAreNoAssetsToIncludeInTheRelease = ($AssetFilePaths -eq $null) -or ($AssetFilePaths.Count -le 0)
        if ($thereAreNoAssetsToIncludeInTheRelease)
        {
            $result.AllAssetUploadsSucceeded = $null
        }

        $authHeader =
        @{
            Authorization = 'Basic ' + [Convert]::ToBase64String([Text.Encoding]::ASCII.GetBytes($GitHubAccessToken + ":x-oauth-basic"))
        }

        $releaseData =
        @{
            tag_name         = $TagName
            target_commitish = $Commitish
            name             = $ReleaseName
            body             = $ReleaseNotes
            draft            = $IsDraft
            prerelease       = $IsPreRelease
        }

        $createReleaseWebRequestParameters =
        @{
            Uri         = "https://api.github.com/repos/$GitHubUsername/$GitHubRepositoryName/releases"
            Method      = 'POST'
            Headers     = $authHeader
            ContentType = 'application/json'
            Body        = (ConvertTo-Json $releaseData -Compress)
        }

        try
        {
            Write-Verbose "Sending web request to create the new Release..."
            $createReleaseWebRequestResults = Invoke-RestMethodAndThrowDescriptiveErrorOnFailure $createReleaseWebRequestParameters
        }
        catch
        {
            $result.ReleaseCreationSucceeded = $false
            $result.ErrorMessage = $_.Exception.Message
            return $result
        }

        $result.ReleaseCreationSucceeded = $true
        $result.ReleaseUrl = $createReleaseWebRequestResults.html_url

        if ($thereAreNoAssetsToIncludeInTheRelease)
        {
            $result.Succeeded = $true
            return $result
        }

        # Upload Url has template parameters on the end (e.g. ".../assets{?name,label}"), so remove them.
        [string] $urlToUploadFilesTo = $createReleaseWebRequestResults.upload_url -replace '{.+}'

        try
        {
            Write-Verbose "Uploading asset files to the new release..."
            Send-FilesToGitHubRelease -filePathsToUpload $AssetFilePaths -urlToUploadFilesTo $urlToUploadFilesTo -authHeader $authHeader
        }
        catch
        {
            $result.AllAssetUploadsSucceeded = $false
            $result.ErrorMessage = $_.Exception.Message
            return $result
        }

        $result.AllAssetUploadsSucceeded = $true
        $result.Succeeded = $true
        return $result
    }
}

function Send-FilesToGitHubRelease([string[]] $filePathsToUpload, [string] $urlToUploadFilesTo, $authHeader)
{
    [int] $numberOfFilesToUpload = $filePathsToUpload.Count
    [int] $numberOfFilesUploaded = 0
    $filePathsToUpload | ForEach-Object `
    {
        $filePath = $_
        $fileName = Get-Item $filePath | Select-Object -ExpandProperty Name

        $uploadAssetWebRequestParameters =
        @{
            # Append the name of the file to the upload url.
            Uri         = $urlToUploadFilesTo + "?name=$fileName"
            Method      = 'POST'
            Headers     = $authHeader
            ContentType = 'application/zip'
            InFile      = $filePath
        }

        $numberOfFilesUploaded = $numberOfFilesUploaded + 1
        Write-Verbose "Uploading asset $numberOfFilesUploaded of $numberOfFilesToUpload, '$filePath'."
        Invoke-RestMethodAndThrowDescriptiveErrorOnFailure $uploadAssetWebRequestParameters > $null
    }
}

function Test-AllFilePathsAndThrowErrorIfOneIsNotValid([string[]] $filePaths)
{
    foreach ($filePath in $filePaths)
    {
        [bool] $fileWasNotFoundAtPath = [string]::IsNullOrEmpty($filePath) -or !(Test-Path -Path $filePath -PathType Leaf)
        if ($fileWasNotFoundAtPath)
        {
            throw "There is no file at the specified path, '$filePath'."
        }
    }
}

function Invoke-RestMethodAndThrowDescriptiveErrorOnFailure($requestParametersHashTable)
{
    $requestDetailsAsNicelyFormattedString = Convert-HashTableToNicelyFormattedString $requestParametersHashTable
    Write-Verbose "Making web request with the following parameters:$NewLine$requestDetailsAsNicelyFormattedString"

    try
    {
        $webRequestResult = Invoke-RestMethod @requestParametersHashTable
    }
    catch
    {
        $exception = $_.Exception

        $responseDetails = @{
            ResponseUri = $exception.Response.ResponseUri
            StatusCode = $exception.Response.StatusCode
            StatusDescription = $exception.Response.StatusDescription
            ErrorMessage = $exception.Message
        }
        $responseDetailsAsNicelyFormattedString = Convert-HashTableToNicelyFormattedString $responseDetails

        $errorInfo = "Request Details:" + $NewLine + $requestDetailsAsNicelyFormattedString
        $errorInfo += $NewLine
        $errorInfo += "Response Details:" + $NewLine + $responseDetailsAsNicelyFormattedString
        throw "An unexpected error occurred while making web request: $NewLine$errorInfo"
    }

    Write-Verbose "Web request returned the following result:$NewLine$webRequestResult"
    return $webRequestResult
}

function Convert-HashTableToNicelyFormattedString($hashTable)
{
    [string] $nicelyFormattedString = $hashTable.Keys | ForEach-Object `
    {
        $key = $_
        $value = $hashTable.$key
        " $key = $value$NewLine"
    }
    return $nicelyFormattedString
}

Export-ModuleMember -Function New-GitHubRelease