I am trying to create a migration notes section for the next generated semantic-release with the help of semantic-release based on the merge-request description of the last commits.

it works with my inline-plugin to read the merge request since the last release and successfully read the migration notes.

I would now like to write these collected migration notes to the semantic-release context in order to attach them to the release created here during the ‘publish’ step of @semantic-release/gitlab.

my configuration is as follows:

/**
 * @type {import('semantic-release').GlobalConfig}
 */
module.exports = {
  branches: ["main", "master", "+([0-9])?(.{+([0-9]),x}).x"],
  ci: false,
  plugins: [
    [
      "@semantic-release/commit-analyzer",
      {
        preset: "conventionalcommits",
      },
    ],
    [
      "@semantic-release/release-notes-generator",
      {
        preset: "conventionalcommits",
      },
    ],
    [
      "@semantic-release/changelog",
      {
        changelogFile: "CHANGELOG.md",
        changelogTitle:
          "# ChangelognnAll notable changes to this project will be documented in this file.",
      },
    ],
    [
      "@semantic-release/git",
      {
        assets: ["CHANGELOG.md"],
        message:
          "chore(release): version ${nextRelease.version}nn${nextRelease.notes}",
      },
    ],
    {
      analyzeCommits: async (pluginConfig, context) => {
        const { commits, logger } = context;

        const migrationNotes = [];

        logger.log(
          `Analyzing ${commits.length} commits for migration notes...`
        );

        for (const commit of commits) {
          const subjectPattern = /Merge branch .* into 'main'/;
          const bodyPattern = /See merge request ([w/-]+![0-9]+)/;

          // check if the commit is a merge commit
          if (subjectPattern.test(commit.subject)) {
            const bodyMatch = commit.body.match(bodyPattern);

            // check if the merge commit is a merge request
            if (bodyMatch) {
              const mergeRequest = bodyMatch[1];

              // fetch the merge request description
              const response = await fetchMergeRequest(mergeRequest, logger);

              const migrationSection = extractMigrationNotes(response);

              if (migrationNotes) {
                migrationNotes.push(migrationSection);
              }
            }
          }
        }

        // save migration notes to context
        if (migrationNotes.length > 0) {
          const joinedNotes = migrationNotes.join("nn");
          logger.log("Joining migration notes: ", joinedNotes);

          context.migrationNotes = joinedNotes;
          logger.log("Context 1:", context);
        }

        // return null to indicate no special release type
        return null;
      },
    },
    [
      "@semantic-release/gitlab",
      {
        successComment:
          "This ${issue.pull_request ? 'PR is included' : 'issue has been resolved'} in version ${nextRelease.version} :tada:",
        labels: false,
        releasedLabels: false,
        assets: [{ path: "dist/*", label: "Distribution" }],
        publish: async (pluginConfig, context) => {
          const { nextRelease, logger } = context;
          const { migrationNotes } = context;

          logger.log("Context 2: ", context);

          if (migrationNotes) {
            logger.log("Appending migration notes to GitLab release notes...");
            nextRelease.notes += `nn### Migration Notesnn${migrationNotes}`;
          }

          // Call the default publish function
          const { publish } = require("@semantic-release/gitlab/lib/publish");
          return publish(pluginConfig, context);
        },
      },
    ],
  ],
};

// helper function to fetch merge request description from GitLab API
async function fetchMergeRequest(input, logger) {
  // extract the project and merge request number
  const [project, mergeRequestId] = input.split("!");
  const urlEncodedProject = encodeURIComponent(project);

  try {
    const response = await fetch(
      `${process.env.CI_API_V4_URL}/projects/${urlEncodedProject}/merge_requests/${mergeRequestId}`,
      {
        headers: {
          "PRIVATE-TOKEN": process.env.GITLAB_TOKEN,
        },
      }
    );
    const data = await response.json();
    return data;
  } catch (error) {
    logger.log("Error fetching merge request description: ", error);
    return null;
  }
}

// helper function to extract migration notes from the MR description
function extractMigrationNotes(mergeRequest) {
  const migrationNotesRegex = /## Migration Notes([sS]*?)(?=###|$)/;

  const match = mergeRequest.description.match(migrationNotesRegex);

  if (match) {
    return `Migration Notes ${mergeRequest.source_branch}` + match[1];
  }

  return null;
}

however, nothing is attached. it looks like my extension of the publish function is not executed