Question: extract only current release notes from `body_path`

[mu88]

Question: Is there a way to extract only the current release notes from CHANGELOG.md using body_path?

Background:
I generate release notes for my apps using the .NET tool versionize, which updates the CHANGELOG.md file by appending the release notes for the current release to the notes of all previous releases. This means CHANGELOG.md always contains the full history of release notes.

Problem:
When creating a GitHub release with softprops/action-gh-release, I want to use the body_path parameter to provide release notes. However, since CHANGELOG.md contains notes for all releases, this would add the entire file as release notes for the current release, which is not what I want.

Question:
Is there any way for softprops/action-gh-release to automatically extract only the release notes for the current release from CHANGELOG.md? For example, can the action "diff" the changelog against the previous release, or is there a built-in way to specify which section to use as the release notes?

Use Case:
I would like to avoid manually editing the changelog or maintaining separate files for each release. Is there a recommended approach or existing feature in the action to handle this scenario?

Thank you for your help!

[orgua]

Would also love to see a solution to that problem!
Filtering for the tag in the headings of the sub-sections of changelog.md would be my preferred mode of operation.

[zzshiro]

You could use a script. If your CHANGELOG.md follows a structured format (each release under a ## [version] heading), you can extract the current release section with something like:

# Extract content between the first and second ## heading sed -n '/^## /,/^## /p' CHANGELOG.md | sed '$d' > current_release.md

Then, use body_path: current_release.md in your workflow.

[lexcibien]

For those who's using semantic versioning like me, i managed with these lines on a action:

- name: Extract Changelog for Firmware Version
        id: extract_changelog
        run: |
          LATEST_VERSION=$(grep -m 1 -oE '\[([0-9]+\.[0-9]+\.[0-9]+)\]' CHANGELOG.md | tr -d '[]')
          
          CHANGELOG_SECTION=$(sed -n "/^## \[${LATEST_VERSION}\]/,/^## \[/p" CHANGELOG.md | sed '$d' | tail -n +3)
          
          echo "changelog<<EOF" >> $GITHUB_OUTPUT
          echo "$CHANGELOG_SECTION" >> $GITHUB_OUTPUT
          echo "EOF" >> $GITHUB_OUTPUT

If you use another job to create a release, you will need to transfer this changelog section to this job

- name: Create current_release.md
        run: |
          echo "${{ needs.compile_sketch.outputs.changelog }}" > current_release.md