New logic for checking last updated

Also adds scripts to update the date the package was last updated to be
executed alongside version bumps with `npm run prepare`.

Author: tonypconway

index.js

@@ -1,2 +1,5 @@
 const getBaselineVersions = require('./scripts/get-baseline-versions')
 module.exports = getBaselineVersions();
+
+const compareVersions = require('./scripts/compare-versions-warning');
+compareVersions();

lastUpdated.json

@@ -0,0 +1 @@
+{"lastUpdated":"2025-03-28"}

package.json

@@ -16,7 +16,8 @@
     "url": "https://github.com/web-platform-dx/browserslist-config-baseline/issues"
   },
   "scripts": {
-    "test": "node test.mjs"
+    "test": "node test.mjs",
+    "prepare": "node scripts/update-last-updated.js"
   },
   "keywords": [
     "browserslist",

scripts/compare-versions-warning.js

@@ -1,30 +1,33 @@
-module.exports = function (last_updated) {
+module.exports = function () {
 
-  var cv = require('compare-versions');
+  const cv = require('compare-versions');
+  const lastUpdated = require('../lastUpdated.json').lastUpdated;
 
-  var date_one_month_ago = new Date().setMonth(new Date().getMonth() - 1);
+  let dateOneMonthAgo = new Date();
+  dateOneMonthAgo.setMonth(new Date().getMonth() - 1);
 
-  if (new Date(last_updated) < date_one_month_ago) {
-
-    const package_json = require('../package.json');
+  if (new Date(lastUpdated) < dateOneMonthAgo) {
 
     fetch('https://registry.npmjs.org/browserslist-config-baseline')
       .then((response) => response.json())
       .then(data => {
-        var local_version = package_json.version;
-        var remote_version = data['dist-tags'].latest;
-        if (cv.compare(local_version, remote_version, '<')) {
+        const packageJson = require('../package.json')
+        var localVersion = packageJson.version;
+        var remoteVersion = data['dist-tags'].latest;
+        if (cv.compare(localVersion, remoteVersion, '<')) {
           console.warn(
-            'Browserslist: browserslist-config-baseline \n' +
-            'has not been updated in over a month and \n' +
-            'you are using an out of date definition of \n' +
-            'Baseline Widely Available. \n\n' +
+            `You are using browserlist-config-baseline version: \t${localVersion} \n` +
+            `The latest available version is: \t\t\t${remoteVersion} \n` +
+            'You may be using stale data.  Please update browserslist-config-baseline \n' +
+            'to ensure your config is accurate. \n\n' +
             '  # If using npm, please run: \n' +
             '  npm i browserslist-config-baseline@latest \n\n' +
             '  # If using yarn, please run: \n' +
             '  yarn upgrade --latest browserslist-config-baseline \n\n' +
             '  # If using bun, please run: \n' +
-            '  bun update browserslist-config-baseline@latest \n\n'
+            '  bun update browserslist-config-baseline@latest \n\n' +
+            'Consider adding whichever command is appropriate to your ' +
+            'build scripts to avoid seeing this message in future.'
           )
         }
       })

scripts/update-last-updated.js

@@ -0,0 +1,13 @@
+const fs = require('node:fs');
+const output = JSON.stringify({
+  lastUpdated: new Date().toISOString().slice(0, 10)
+});
+try {
+  fs.writeFileSync(
+    './lastUpdated.json',
+    output,
+    { encoding: 'utf-8' }
+  );
+} catch (e) {
+  console.error(e);
+}

with-downstream/index.js

@@ -1,3 +1,5 @@
 const getBaselineVersions = require('../scripts/get-baseline-versions')
-
 module.exports = getBaselineVersions({ includeDownstreamBrowsers: true });
+
+const compareVersions = require('../scripts/compare-versions-warning');
+compareVersions();