chore: add check-node-versions script

.github/scripts/check-node-versions.js

@@ -0,0 +1,96 @@
+/**
+ * Copyright (c) HashiCorp, Inc.
+ * SPDX-License-Identifier: MPL-2.0
+ */
+const fetch = require("node-fetch"); // @TODO this can be removed once we upgrade to Node 18 and use native fetch
+
+const today = new Date();
+const oneMonthFromToday = new Date();
+oneMonthFromToday.setDate(today.getDate() + 30);
+// console.debug("oneMonthFromToday", oneMonthFromToday.toDateString());
+
+// Code below adapted from https://stackoverflow.com/a/71520193
+const versionRegex = /v(\d+)\.(\d+)\.(\d+)/; // 'v16.14.3'
+
+// convert version string to a number for easier sorting
+function calcVersion(x) {
+  const match = x.match(versionRegex);
+  if (!match) {
+    throw new Error(`version regex failed to match version string '${x}'`);
+  }
+  return +match[1] * 1000000 + +match[2] * 1000 + +match[3];
+}
+
+async function getLTSVersions() {
+  const response = await fetch(
+    "https://nodejs.org/download/release/index.json",
+  );
+  const data = await response.json();
+  const allLTSVersions = data.filter((item) => item.lts);
+
+  // for performance reasons when sorting,
+  // precalculate an actual version number from the version string
+  allLTSVersions.forEach(
+    (item) => (item.numVersion = calcVersion(item.version)),
+  );
+  allLTSVersions.sort((a, b) => a.numVersion - b.numVersion);
+
+  // console.debug("All LTS versions - sorted oldest first");
+  // console.debug(allLTSVersions.map(item => item.version));
+
+  const firstLTSVersions = {};
+  allLTSVersions.forEach((item) => {
+    const majorVersion = `v${item.version.match(versionRegex)[1]}`;
+    if (!firstLTSVersions[majorVersion]) {
+      firstLTSVersions[majorVersion] = item.version;
+    }
+  });
+
+  console.debug("First LTS versions");
+  console.debug(firstLTSVersions);
+
+  return firstLTSVersions;
+}
+
+/** Return the earliest supported version whose EOL date is at least a month away */
+async function getEarliestSupportedVersion() {
+  // https://github.com/nodejs/Release/blob/main/schedule.json
+  const response = await fetch(
+    "https://raw.githubusercontent.com/nodejs/Release/main/schedule.json",
+  );
+  const data = await response.json();
+  const activelySupportedVersions = Object.entries(data)
+    .filter(([version, metadata]) => {
+      return (
+        new Date(metadata.lts) <= today &&
+        new Date(metadata.end) > oneMonthFromToday
+      );
+    })
+    .sort((a, b) => new Date(a[1].start) - new Date(b[1].start));
+
+  console.debug(
+    "Actively supported versions with an EOL date at least 1 month away",
+  );
+  console.debug(Object.fromEntries(activelySupportedVersions));
+
+  return activelySupportedVersions[0][0];
+}
+
+async function getDesiredVersion() {
+  const ltsVersions = await getLTSVersions();
+  const earliestSupportedVersion = await getEarliestSupportedVersion();
+  const version = ltsVersions[earliestSupportedVersion];
+
+  // console.debug("earliestSupportedVersion", earliestSupportedVersion);
+  console.log("desired version", version);
+
+  return version;
+}
+
+module.exports = async ({ github, context, core }) => {
+  const version = await getDesiredVersion();
+  const short = version.match(versionRegex)[1];
+
+  core.exportVariable("NEW_NODEJS_VERSION", version.slice(1)); // strip the 'v' from the start of the string
+  core.exportVariable("NEW_NODEJS_VERSION_SHORT", short);
+};