Add additional warning for semver major updates

Author: mrbbot

src/cli.ts

@@ -15,6 +15,7 @@ import {
 } from "./index";
 
 const defaultPort = 8787;
+const numericCompare = new Intl.Collator(undefined, { numeric: true }).compare;
 
 function stripUndefinedOptions(options: Options): Options {
   return Object.entries(options)
@@ -278,7 +279,7 @@ export async function updateCheck({
   const res = await fetch(`${registry}${pkg.name}/latest`, {
     headers: { Accept: "application/json" },
   });
-  const registryVersion = (await res.json()).version;
+  const registryVersion: string = (await res.json()).version;
   if (!registryVersion) return;
 
   // Record new last check time
@@ -287,12 +288,18 @@ export async function updateCheck({
   // Log version if latest version is greater than the currently installed
   if (semiver(registryVersion, pkg.version) > 0) {
     log.warn(
-      [
-        `Miniflare ${registryVersion} is available,`,
-        `but you're using ${pkg.version}.`,
-        "Update for improved compatibility with Cloudflare Workers.",
-      ].join(" ")
+      `Miniflare ${registryVersion} is available, ` +
+        `but you're using ${pkg.version}. ` +
+        "Update for improved compatibility with Cloudflare Workers."
     );
+    const registryMajor = registryVersion.split(".")[0];
+    const pkgMajor = pkg.version.split(".")[0];
+    if (numericCompare(registryMajor, pkgMajor) > 0) {
+      log.warn(
+        `${registryVersion} includes breaking changes.` +
+          "Make sure you check the changelog before upgrading."
+      );
+    }
   }
 }
 

test/cli.spec.ts

@@ -266,7 +266,7 @@ test("updateCheck: logs if updated version available", async (t) => {
   const now = 172800000; // 2 days since unix epoch (must be > 1 day)
   const registry = await useServer(t, (req, res) => {
     t.is(req.url, "/miniflare/latest");
-    res.end('{"version": "2.0.0"}');
+    res.end('{"version": "1.1.0"}');
   });
   const log = new TestLog();
   await updateCheck({
@@ -281,12 +281,35 @@ test("updateCheck: logs if updated version available", async (t) => {
   t.is(log.warns.length, 1);
   t.regex(
     log.warns[0],
-    /^Miniflare 2\.0\.0 is available, but you're using 1\.0\.0/
+    /^Miniflare 1\.1\.0 is available, but you're using 1\.0\.0/
   );
   // Check last update check file written
   const lastCheck = await fs.readFile(path.join(tmp, "update-check"), "utf8");
   t.is(lastCheck, now.toString());
 });
+test("updateCheck: logs additional warning on semver major change", async (t) => {
+  const tmp = await useTmp(t);
+  const now = 172800000; // 2 days since unix epoch (must be > 1 day)
+  const registry = await useServer(t, (req, res) => {
+    res.end('{"version": "2.0.0"}');
+  });
+  const log = new TestLog();
+  await updateCheck({
+    pkg: { name: "miniflare", version: "1.0.0" },
+    cachePath: tmp,
+    now,
+    registry: registry.http.toString(),
+    log,
+  });
+
+  // Check update messages logged
+  t.is(log.warns.length, 2);
+  t.regex(
+    log.warns[0],
+    /^Miniflare 2\.0\.0 is available, but you're using 1\.0\.0/
+  );
+  t.regex(log.warns[1], /^2\.0\.0 includes breaking changes/);
+});
 test("updateCheck: doesn't log if no updated version available", async (t) => {
   const tmp = await useTmp(t);
   const now = 172800000; // 2 days since unix epoch (must be > 1 day)