react-native-changelog-generator.js

'use strict';

const base = '0.38-stable';
const compare = '0.39-stable';

function fetchJSON(host, path) {
  return new Promise((resolve, reject) => {
    let data = '';

    require('https').get({
      host,
      path,
      headers: { 'User-Agent': 'Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.0)' },
    }).on('response', response => {
      response.on('data', chunk => {
        data += chunk;
      });

      response.on('end', () => {
        try {
          const json = JSON.parse(data);
          resolve(json);
        } catch (e) {
          reject(e);
        }
      });

      response.on('error', error => {
        reject(error);
      });
    });
  });
}

function filterCICommits(commits) {
  return commits.filter(item => {
    const text = item.commit.message.toLowerCase();
    return !(text.includes('travis') || text.includes('circleci') || text.includes('circle ci'));
  });
}

function isBreaking(change) {
  return /\b(breaking)\b/i.test(change);
}

function isAndroidCommit(change) {
  return /\b(android|java)\b/i.test(change) || /android/i.test(change);
}

function isIOSCommit(change) {
  return /\b(ios|xcode|swift|objective-c|iphone|ipad)\b/i.test(change) || /ios\b/i.test(change) || /\brct/i.test(change);
}

function isBugFix(change) {
  return /\b(fix|fixes|crash|exception)\b/i.test(change);
}

function isNewFeature(change) {
  return /\b(feature|add)\b/i.test(change);
}

function getChangeMessage(item) {
  return `  - ${item.commit.message.split('\n')[0]} (${item.sha.slice(0, 7)}) ${item.author ? '- @' + item.author.login : ''}`;
}

function getChangelogDesc(commits) {
  const acc = {
    breaking: { android: [], ios: [], unknown: [] },
    android: { fix: [], feat: [], others: [] },
    ios: { fix: [], feat: [], others: [] },
    unknown: { fix: [], feat: [], others: [] },
  };

  commits.forEach(item => {
    const change = item.commit.message.split('\n')[0];
    const message = getChangeMessage(item);

    if (isBreaking(change)) {
      if (isAndroidCommit(change)) {
        acc.breaking.android.push(message);
      } else if (isIOSCommit(change)) {
        acc.breaking.ios.push(message);
      } else {
        acc.breaking.unknown.push(message);
      }
    } else if (isBugFix(change)) {
      if (isAndroidCommit(change)) {
        acc.android.fix.push(message);
      } else if (isIOSCommit(change)) {
        acc.ios.fix.push(message);
      } else {
        acc.unknown.fix.push(message);
      }
    } else if (isNewFeature(change)) {
      if (isAndroidCommit(change)) {
        acc.android.feat.push(message);
      } else if (isIOSCommit(change)) {
        acc.ios.feat.push(message);
      } else {
        acc.unknown.feat.push(message);
      }
    } else {
      if (isAndroidCommit(change)) {
        acc.android.others.push(message);
      } else if (isIOSCommit(change)) {
        acc.ios.others.push(message);
      } else {
        acc.unknown.others.push(message);
      }
    }
  });

  return acc;
}

function buildMarkDown(data) {
  return `
## Breaking changes

### Android

${data.breaking.android.join('\n')}

### iOS

${data.breaking.ios.join('\n')}

### Unknown

${data.breaking.unknown.join('\n')}


## Android

### Bugfixes

${data.android.fix.join('\n')}

### New features and enhancements

${data.android.feat.join('\n')}

### Others

${data.android.others.join('\n')}


## iOS

### Bugfixes

${data.ios.fix.join('\n')}

### New features and enhancements

${data.ios.feat.join('\n')}

### Others

${data.ios.others.join('\n')}


## Unknown

### Bugfixes

${data.unknown.fix.join('\n')}

### New features and enhancements

${data.unknown.feat.join('\n')}

### Others

${data.unknown.others.join('\n')}
`;
}

fetchJSON('api.github.com', '/repos/facebook/react-native/compare/' + base + '...' + compare)
  .then(data => data.commits)
  .then(filterCICommits)
  .then(getChangelogDesc)
  .then(buildMarkDown)
  .then(data => console.log(data))
  .catch(e => console.error(e));