Get changelog of an app in scoop.

get-changelog-scoop.md

This is a simple script to get changelog of an app in scoop. It fetches changelog from GitHub releases or CHANGELOG.md.

Add the following to your PowerShell $PROFILE, and try Get-Changelog <App>.

<#
.SYNOPSIS
    Get changelog of an app in scoop
.NOTES
    Prerequisites:
    - [scoop](https://scoop.sh).
    - [gh](https://cli.github.com) to interact with GitHub API.
    - [glow](https://github.com/charmbracelet/glow) to render markdown.
.EXAMPLE
    Get-Changelog gh

    Get changelog of gh.
.EXAMPLE
    Get-Changelog gh -Verbose

    Get changelog of gh and show the specific source.
.EXAMPLE
    Get-Changelog just -From File

    Get changelog of just from the `CHANGELOG.md` file in its repo.
.EXAMPLE
    Get-Changelog main/glow

    Get changelog of glow in the main bucket.
.LINK
    https://github.com/ScoopInstaller/Scoop/issues/2067
.LINK
    https://gist.github.com/YDX-2147483647/f8c11c3355f0e9d2aaa8c63926edde08
#>
function Get-Changelog {
    param (
        # An app in scoop. It will be passed to `scoop cat` directly.
        [Parameter(Mandatory = $true)]
        [string] $App,
        # Where to fetch the changelog.
        # - Release: From the GitHub release. (default)
        # - File: From the `CHANGELOG.md` in its repo.
        [ValidateSet("Release", "File")]
        [string] $From = "Release"
    )

    $manifest = scoop cat $App | ConvertFrom-Json

    $github_url = if ($manifest.checkver -eq 'github') {
        [string]$manifest.homepage
    }
    elseif ($null -ne $manifest.checkver.github) {
        [string]$manifest.checkver.github
    }
    else {
        throw "Cannot find GitHub URL for `“$App`”. You can ``scoop home $App`` to open its homepage for changelog, or ``scoop cat $App`` to debug."
    }

    switch ($From) {
        "Release" {
            Write-Verbose "Fetching changelog of $App v$($manifest.version) from the release of ${github_url}."
            gh release view --repo $github_url
        }
        "File" {
            Write-Verbose "Fetching changelog of $App v$($manifest.version) from CHANGELOG.md in ${github_url}."

            $owner_repo = $github_url.Replace('https://github.com/', '')

            $changelog = gh api -H "Accept: application/vnd.github.raw" -H "X-GitHub-Api-Version: 2022-11-28" /repos/${owner_repo}/contents/CHANGELOG.md
            $changelog | glow -
        }
        Default {
            throw "Fetching changelog from `“$From`” is not supported."
        }
    }
}

You can integrate Get-Changelog into scoop as an alias:

scoop alias add c '"Get-Changelog $args" | Invoke-Expression'

However, PowerShell won't auto complete for you then.

Known issue

Only simple manifests are supported

> Get-Changelog pnpm
Exception: Cannot find GitHub URL for “pnpm”. You can `scoop home pnpm` to open its homepage for changelog, or `scoop cat pnpm` to debug.

Because pnpm.json uses a script to checkver, which is too complicated for this simple script… I will appreciate it if someone can detect the repo from autoupdate or something.