Remove unneeded req params related to the URL

modules/middleware/validatePackageVersion.js

@@ -0,0 +1,77 @@
+import semver from 'semver';
+
+import asyncHandler from '../utils/asyncHandler.js';
+import createPackageURL from '../utils/createPackageURL.js';
+import { getPackageConfig, getVersionsAndTags } from '../utils/npm.js';
+
+function semverRedirect(req, res, newVersion) {
+  res
+    .set({
+      'Cache-Control': 'public, s-maxage=600, max-age=60', // 10 mins on CDN, 1 min on clients
+      'Cache-Tag': 'redirect, semver-redirect'
+    })
+    .redirect(
+      302,
+      req.baseUrl +
+        createPackageURL(req.packageName, newVersion, req.filename, req.query)
+    );
+}
+
+async function resolveVersion(packageName, range, log) {
+  const versionsAndTags = await getVersionsAndTags(packageName, log);
+
+  if (versionsAndTags) {
+    const { versions, tags } = versionsAndTags;
+
+    if (range in tags) {
+      range = tags[range];
+    }
+
+    return versions.includes(range)
+      ? range
+      : semver.maxSatisfying(versions, range);
+  }
+
+  return null;
+}
+
+/**
+ * Check the package version/tag in the URL and make sure it's good. Also
+ * fetch the package config and add it to req.packageConfig. Redirect to
+ * the resolved version number if necessary.
+ */
+async function validateVersion(req, res, next) {
+  const version = await resolveVersion(
+    req.packageName,
+    req.packageVersion,
+    req.log
+  );
+
+  if (!version) {
+    return res
+      .status(404)
+      .type('text')
+      .send(`Cannot find package ${req.packageSpec}`);
+  }
+
+  if (version !== req.packageVersion) {
+    return semverRedirect(req, res, version);
+  }
+
+  req.packageConfig = await getPackageConfig(
+    req.packageName,
+    req.packageVersion,
+    req.log
+  );
+
+  if (!req.packageConfig) {
+    return res
+      .status(500)
+      .type('text')
+      .send(`Cannot get config for package ${req.packageSpec}`);
+  }
+
+  next();
+}
+
+export default asyncHandler(validateVersion);