1 files changed, 45 insertions, 0 deletions
diff --git a/tools/doc/versions.js b/tools/doc/versions.js
new file mode 100644
index 0000000000..854329bd9a
--- /dev/null
+++ b/tools/doc/versions.js
@@ -0,0 +1,45 @@
+'use strict';
+
+let _versions;
+
+const getUrl = (url) => {
+  return new Promise((resolve, reject) => {
+    const https = require('https');
+    const request = https.get(url, (response) => {
+      if (response.statusCode !== 200) {
+        reject(new Error(
+          `Failed to get ${url}, status code ${response.statusCode}`));
+      }
+      response.setEncoding('utf8');
+      let body = '';
+      response.on('data', (data) => body += data);
+      response.on('end', () => resolve(body));
+    });
+    request.on('error', (err) => reject(err));
+  });
+};
+
+module.exports = {
+  async versions() {
+    if (_versions) {
+      return _versions;
+    }
+
+    // The CHANGELOG.md on release branches may not reference newer semver
+    // majors of Node.js so fetch and parse the version from the master branch.
+    const githubContentUrl = 'https://raw.githubusercontent.com/nodejs/node/';
+    const changelog = await getUrl(`${githubContentUrl}/master/CHANGELOG.md`);
+    const ltsRE = /Long Term Support/i;
+    const versionRE = /\* \[Node\.js ([0-9.]+)\][^-—]+[-—]\s*(.*)\n/g;
+    _versions = [];
+    let match;
+    while ((match = versionRE.exec(changelog)) != null) {
+      const entry = { num: `${match[1]}.x` };
+      if (ltsRE.test(match[2])) {
+        entry.lts = true;
+      }
+      _versions.push(entry);
+    }
+    return _versions;
+  }
+};