Add script to generate changelog

resources/gen-changelog.js

@@ -0,0 +1,253 @@
+/* @noflow */
+
+'use strict';
+
+const util = require('util');
+const https = require('https');
+const { exec } = require('./utils');
+const packageJSON = require('../package.json');
+
+const graphqlRequest = util.promisify(graphqlRequestImpl);
+const labelsConfig = {
+  'PR: breaking change 💥': {
+    section: 'Breaking Change 💥',
+  },
+  'PR: feature 🚀': {
+    section: 'New Feature 🚀',
+  },
+  'PR: bug fix 🐞': {
+    section: 'Bug Fix 🐞',
+  },
+  'PR: docs 📝': {
+    section: 'Docs 📝',
+    fold: true,
+  },
+  'PR: polish 💅': {
+    section: 'Polish 💅',
+    fold: true,
+  },
+  'PR: internal 🏠': {
+    section: 'Internal 🏠',
+    fold: true,
+  },
+  'PR: dependency 📦': {
+    section: 'Dependency 📦',
+    fold: true,
+  },
+};
+const lastTag = `v${packageJSON.version}`;
+const GH_TOKEN = process.env['GH_TOKEN'];
+
+if (!GH_TOKEN) {
+  console.error('Must provide GH_TOKEN as enviroment variable!');
+  process.exit(1);
+}
+
+getCommitsInfo(lastTag)
+  .then(genChangeLog)
+  .then(changelog => process.stdout.write(changelog))
+  .catch(error => console.error(error));
+
+function genChangeLog(commitsInfo) {
+  const allPRs = commitsInfoToPRs(commitsInfo);
+  const byLabel = {};
+  const commitersByLogin = {};
+
+  for (const pr of allPRs) {
+    if (!labelsConfig[pr.label]) {
+      throw new Error('Unknown label: ' + pr.label + pr.number);
+    }
+    byLabel[pr.label] = byLabel[pr.label] || [];
+    byLabel[pr.label].push(pr);
+    commitersByLogin[pr.author.login] = pr.author;
+  }
+
+  let changelog = '';
+  for (const [label, config] of Object.entries(labelsConfig)) {
+    const prs = byLabel[label];
+    if (prs) {
+      const shouldFold = config.fold && prs.length > 1;
+
+      changelog += `\n#### ${config.section}\n`;
+      if (shouldFold) {
+        changelog += '<details>\n';
+        changelog += `<summary> ${prs.length} PRs were merged </summary>\n\n`;
+      }
+
+      for (const pr of prs) {
+        const { number, url, author } = pr;
+        changelog += `* [#${number}](${url}) ${pr.title} ([@${author.login}](${author.url}))\n`;
+      }
+
+      if (shouldFold) {
+        changelog += '</details>\n';
+      }
+    }
+  }
+
+  const commiters = Object.values(commitersByLogin).sort((a, b) =>
+    (a.name || a.login).localeCompare(b.name || b.login),
+  );
+  changelog += `\n#### Committers: ${commiters.length}\n`;
+  for (const commiter of commiters) {
+    changelog += `* ${commiter.name}([@${commiter.login}](${commiter.url}))\n`;
+  }
+
+  return changelog;
+}
+
+function graphqlRequestImpl(query, variables, cb) {
+  const resultCB = typeof variables === 'function' ? variables : cb;
+
+  const req = https.request('https://api.github.com/graphql', {
+    method: 'POST',
+    headers: {
+      Authorization: 'bearer ' + GH_TOKEN,
+      'Content-Type': 'application/json',
+      'User-Agent': 'graphql-js-changelog',
+    },
+  });
+
+  req.on('response', res => {
+    let responseBody = '';
+
+    res.setEncoding('utf8');
+    res.on('data', d => (responseBody += d));
+    res.on('error', error => resultCB(error));
+
+    res.on('end', () => {
+      if (res.statusCode !== 200) {
+        return resultCB(
+          new Error(
+            `GitHub responded with ${res.statusCode}: ${res.statusMessage}\n` +
+              responseBody,
+          ),
+        );
+      }
+
+      let json;
+      try {
+        json = JSON.parse(responseBody);
+      } catch (error) {
+        return resultCB(error);
+      }
+
+      if (json.errors) {
+        return resultCB(
+          new Error('Errors: ' + JSON.stringify(json.errors, null, 2)),
+        );
+      }
+
+      resultCB(undefined, json.data);
+    });
+  });
+
+  req.on('error', error => cb(error));
+  req.write(JSON.stringify({ query, variables }));
+  req.end();
+}
+
+async function batchCommitInfo(commits) {
+  let commitsSubQuery = '';
+  for (const oid of commits) {
+    commitsSubQuery += `
+        commit_${oid}: object(oid: "${oid}") {
+          ... on Commit {
+            oid
+            message
+            associatedPullRequests(first: 10) {
+              nodes {
+                number
+                title
+                url
+                author {
+                  login
+                  url
+                  ... on User {
+                    name
+                  }
+                }
+                repository {
+                  nameWithOwner
+                }
+                labels(first: 10) {
+                  nodes {
+                    name
+                  }
+                }
+              }
+            }
+          }
+        }
+    `;
+  }
+
+  const response = await graphqlRequest(`
+    {
+      repository(owner: "graphql", name: "graphql-js") {
+        ${commitsSubQuery}
+      }
+    }
+  `);
+
+  const commitsInfo = [];
+  for (const oid of commits) {
+    commitsInfo.push(response.repository['commit_' + oid]);
+  }
+  return commitsInfo;
+}
+
+function commitsInfoToPRs(commits) {
+  const prs = [];
+  for (const commit of commits) {
+    const associatedPRs = commit.associatedPullRequests.nodes.filter(
+      pr => pr.repository.nameWithOwner === 'graphql/graphql-js',
+    );
+    if (associatedPRs.length === 0) {
+      throw new Error(
+        `Commit ${commit.oid} has no associated PR: ${commit.message}`,
+      );
+    }
+    if (associatedPRs.length > 1) {
+      throw new Error(
+        `Commit ${commit.oid} is associated with multiple PRs: ${commit.message}`,
+      );
+    }
+
+    const pr = associatedPRs[0];
+    const labels = pr.labels.nodes
+      .map(label => label.name)
+      .filter(label => label.startsWith('PR: '));
+
+    if (labels.length === 0) {
+      throw new Error(`PR #${pr.number} missing label`);
+    }
+    if (labels.length > 1) {
+      throw new Error(
+        `PR #${pr.number} has conflicting labels: ` + labels.join('\n'),
+      );
+    }
+    prs.push({
+      number: pr.number,
+      title: pr.title,
+      url: pr.url,
+      author: pr.author,
+      label: labels[0],
+    });
+  }
+
+  return prs;
+}
+
+async function getCommitsInfo(tag) {
+  const commits = exec(`git rev-list --reverse ${tag}..`).split('\n');
+
+  // Split commits into batches of 50 to prevent timeouts
+  const commitInfoPromises = [];
+  for (let i = 0; i < commits.length; i += 50) {
+    const batch = commits.slice(i, i + 50);
+    commitInfoPromises.push(batchCommitInfo(batch));
+  }
+
+  return (await Promise.all(commitInfoPromises)).flat();
+}