feat: HTTP add TLS fingerprint fallback (#1444)

pkg/download/engine/testdata/wpt/fetch/api/request/request-keepalive.any.js

@@ -0,0 +1,17 @@
+// META: global=window,worker
+// META: title=Request keepalive
+// META: script=/common/utils.js
+// META: script=/common/get-host-info.sub.js
+
+test(() => {
+  assert_false(new Request('/').keepalive, 'default');
+  assert_true(new Request('/', {keepalive: true}).keepalive, 'true');
+  assert_false(new Request('/', {keepalive: false}).keepalive, 'false');
+  assert_true(new Request('/', {keepalive: 1}).keepalive, 'truish');
+  assert_false(new Request('/', {keepalive: 0}).keepalive, 'falsy');
+}, 'keepalive flag');
+
+test(() => {
+  const init = {method: 'POST', keepalive: true, body: new ReadableStream()};
+  assert_throws_js(TypeError, () => {new Request('/', init)});
+}, 'keepalive flag with stream body');