tests/perf: add cross-origin isolation for more precise measurement

See: https://developer.mozilla.org/en-US/docs/Web/API/Performance/now#security_requirements

This requires a change of dependencies from http-server to serve as http-server does not currently support setting the required headers.  See:

* http-party/http-server#759
* http-party/http-server#806

bin/dev-server.js

@@ -2,8 +2,9 @@
 
 'use strict';
 
+const http = require('http');
 var watch = require('watch-glob');
-var http_server = require('http-server');
+const serveHandler = require('serve-handler');
 var debounce = require('lodash.debounce');
 var browserify = require('browserify');
 var fs = require('fs');
@@ -92,7 +93,15 @@ var readyCallback;
 
 function startServers(callback) {
   readyCallback = callback;
-  http_server.createServer().listen(HTTP_PORT, function () {
+  const server = http.createServer((req, res) => {
+    // Add cross-origin isolation headers to allow for more precise performance measurements.
+    // See: https://developer.mozilla.org/en-US/docs/Web/API/Performance/now#security_requirements
+    res.setHeader('Cross-Origin-Opener-Policy', 'same-origin');
+    res.setHeader('Cross-Origin-Embedder-Policy', 'require-corp');
+
+    return serveHandler(req, res, { trailingSlash:true });
+  });
+  server.listen(HTTP_PORT, () => {
     var testRoot = 'http://127.0.0.1:' + HTTP_PORT;
     const query = new URLSearchParams(queryParams);
     console.log(`Integration  tests: ${testRoot}/tests/integration/?${query}`);

package.json

@@ -76,7 +76,6 @@
     "express-pouchdb": "4.2.0",
     "find-requires": "1.0.0",
     "glob": "7.1.5",
-    "http-server": "0.12.3",
     "istanbul": "0.4.5",
     "istanbul-coveralls": "1.0.3",
     "less": "3.9.0",
@@ -99,6 +98,7 @@
     "rollup-plugin-node-resolve": "4.2.4",
     "rollup-plugin-replace": "1.2.1",
     "seedrandom": "3.0.5",
+    "serve-handler": "6.1.5",
     "source-map": "0.7.4",
     "stacktrace-parser": "0.1.10",
     "stream-to-promise": "1.1.1",