@semantic-release/github/lib/add-channel.js

const debug = require('debug')('semantic-release:github');
const {RELEASE_NAME} = require('./definitions/constants');
const parseGithubUrl = require('./parse-github-url');
const resolveConfig = require('./resolve-config');
const getClient = require('./get-client');
const isPrerelease = require('./is-prerelease');

module.exports = async (pluginConfig, context) => {
  const {
    options: {repositoryUrl},
    branch,
    nextRelease: {name, gitTag, notes},
    logger,
  } = context;
  const {githubToken, githubUrl, githubApiPathPrefix, proxy} = resolveConfig(pluginConfig, context);
  const {owner, repo} = parseGithubUrl(repositoryUrl);
  const github = getClient({githubToken, githubUrl, githubApiPathPrefix, proxy});
  let releaseId;

  const release = {owner, repo, name, prerelease: isPrerelease(branch), tag_name: gitTag};

  debug('release object: %O', release);

  try {
    ({
      data: {id: releaseId},
    } = await github.repos.getReleaseByTag({owner, repo, tag: gitTag}));
  } catch (error) {
    if (error.status === 404) {
      logger.log('There is no release for tag %s, creating a new one', gitTag);

      const {
        data: {html_url: url},
      } = await github.repos.createRelease({...release, body: notes});

      logger.log('Published GitHub release: %s', url);
      return {url, name: RELEASE_NAME};
    }

    throw error;
  }

  debug('release release_id: %o', releaseId);

  const {
    data: {html_url: url},
  } = await github.repos.updateRelease({...release, release_id: releaseId});

  logger.log('Updated GitHub release: %s', url);

  return {url, name: RELEASE_NAME};
};