s3: make sure Expires always is a Date.

https://github.com/sitespeedio/sitespeed.io/issues/4501

lib/plugins/s3/index.js

@@ -12,19 +12,35 @@ import { runWithConcurrencyLimit } from './limit.js';
 
 const log = getLogger('sitespeedio.plugin.s3');
 
+const normalizeExpires = maybeSeconds => {
+  if (typeof maybeSeconds === 'number' && Number.isFinite(maybeSeconds)) {
+    const seconds = Number.parseInt(maybeSeconds, 10);
+    const expires = new Date(Date.now() + seconds * 1000);
+    log.info('Setting s3.expires to ' + expires);
+    return expires;
+  }
+  return maybeSeconds;
+};
+
 async function uploadFile(file, s3Client, s3Options, prefix, baseDir) {
   const stream = await fsPromises.readFile(file);
   const contentType = getContentType(file);
   const subPath = path.relative(baseDir, file);
-  const parameters = {
+  const baseParams = {
     Bucket: s3Options.bucketname,
     Key: path.join(s3Options.path || prefix, subPath),
     Body: stream,
     ContentType: contentType,
-    ACL: s3Options.acl,
-    ...s3Options.params
+    ACL: s3Options.acl
   };
 
+  const userParams = { ...s3Options.params };
+  if ('Expires' in userParams) {
+    userParams.Expires = normalizeExpires(userParams.Expires);
+  }
+
+  const parameters = { ...baseParams, ...userParams };
+
   try {
     await s3Client.send(new PutObjectCommand(parameters));
     log.debug(`Uploaded ${file} to S3 bucket ${s3Options.bucketname}`);