[Feature Request] Add command to generate only recent changelog changes

Description

So a normal workflow would be to automatically release to GitHub after a new version tag is created. That part works, but there is no good way to include the recent changelog additions as the body paragraph of the GitHub release.

To release with github actions, you do something like

name: Release

on:
  push:
    tags:
      - "v*"

jobs:
  github_release:
    runs-on: ubuntu-latest
    steps:
    - uses: actions/checkout@v2

    - name: Release to GitHub
      uses: actions/create-release@v1
      env:
        GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
      with:
        tag_name: ${{ github.ref }}
        release_name: Release ${{ github.ref }}
        body: |
        "my new changes here"
        draft: false
        prerelease: false

Currently, and please correct me if I’m wrong, there is no way to automatically fill “body” with the recent additions to the changelog

Possible Solution

Introduce an option to cz changelog that would allow to to generate the most recent version so you could say something like this:

    # so we can use it as the github release body
    - name: Store recent changelog changes
      run: |
        echo ::set-env name=CHANGELOG::$(cz changelog --dry-run --recent)

    - name: Release to GitHub
      uses: actions/create-release@v1
      env:
        GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
      with:
        tag_name: ${{ github.ref }}
        release_name: Release ${{ github.ref }}
        body: ${{ env.CHANGELOG }}
        draft: false
        prerelease: false

[jtpavlock]

cz changelog --incremental --dry-run

This will generate the changelog for the next version. I’m trying to get the changelog for the most recent version.

cz changelog --dry-run --start-rev 0.1.0

I don’t think there’s any way to programatically know the previous version. This would work, if --start-rev included the version passed, but I don’t think that’s the current behavior.

[jtpavlock]

Would something like #399 be useful?

Yes, that looks like it would solve my issue.