new file mode 100644
--- /dev/null
+++ b/js_async.t
@@ -0,0 +1,183 @@
+#!/usr/bin/perl
+
+# (C) Dmitry Volyntsev
+# (C) Nginx, Inc.
+
+# Async tests for http JavaScript module.
+
+###############################################################################
+
+use warnings;
+use strict;
+
+use Test::More;
+
+BEGIN { use FindBin; chdir($FindBin::Bin); }
+
+use lib 'lib';
+use Test::Nginx;
+
+###############################################################################
+
+select STDERR; $| = 1;
+select STDOUT; $| = 1;
+
+my $t = Test::Nginx->new()->has(qw/http rewrite/)
+	->write_file_expand('nginx.conf', <<'EOF');
+
+%%TEST_GLOBALS%%
+
+daemon off;
+
+events {
+}
+
+http {
+    %%TEST_GLOBALS_HTTP%%
+
+    js_set $test_async      set_timeout;
+    js_set $context_var     context_var;
+
+    js_include test.js;
+
+    server {
+        listen       127.0.0.1:8080;
+        server_name  localhost;
+
+        location /async_var {
+            return 200 $test_async;
+        }
+
+        location /shared_ctx {
+            add_header H $context_var;
+            js_content shared_ctx;
+        }
+
+        location /set_timeout {
+            js_content set_timeout;
+        }
+
+        location /set_timeout_many {
+            js_content set_timeout_many;
+        }
+
+        location /set_timeout_data {
+            postpone_output 0;
+            js_content set_timeout_data;
+        }
+
+        location /limit_rate {
+            postpone_output 0;
+            sendfile_max_chunk 5;
+            js_content limit_rate;
+        }
+    }
+}
+
+EOF
+
+$t->write_file('test.js', <<EOF);
+    function set_timeout(req, res) {
+        var timerId = setTimeout(timeout_cb_r, 5, req, res, 0);
+        clearTimeout(timerId);
+        setTimeout(timeout_cb_r, 5, req, res, 0)
+    }
+
+    function set_timeout_data(req, res) {
+        setTimeout(timeout_cb_data, 5, req, res, 0);
+    }
+
+    function set_timeout_many(req, res) {
+        for (var i = 0; i < 5; i++) {
+            setTimeout(timeout_cb_empty, 5, req, i);
+        }
+
+        setTimeout(timeout_cb_reply, 10, res);
+    }
+
+    function timeout_cb_r(req, res, cnt) {
+        if (cnt == 10) {
+            res.status = 200;
+            res.contentType = 'foo';
+            res.sendHeader();
+            res.finish();
+
+        } else {
+            setTimeout(timeout_cb_r, 5, req, res, ++cnt);
+        }
+    }
+
+    function timeout_cb_empty(req, arg) {
+        req.log("timeout_cb_empty" + arg);
+    }
+
+    function timeout_cb_reply(res) {
+        res.status = 200;
+        res.contentType = 'reply';
+        res.sendHeader();
+        res.finish();
+    }
+
+    function timeout_cb_data(req, res, counter) {
+        if (counter == 0) {
+            req.log("timeout_cb_data: init");
+            res.status = 200;
+            res.sendHeader();
+            setTimeout(timeout_cb_data, 5, req, res, ++counter);
+
+        } else if (counter == 10) {
+            req.log("timeout_cb_data: finish");
+            res.finish();
+
+        } else {
+            res.send("" + counter);
+            setTimeout(timeout_cb_data, 5, req, res, ++counter);
+        }
+    }
+
+    var js_;
+    function context_var() {
+        return js_;
+    }
+
+    function shared_ctx(req, res) {
+        js_ = req.variables.arg_a;
+
+        res.status = 200;
+        res.sendHeader();
+        res.finish();
+    }
+
+    function limit_rate_cb(res) {
+        res.finish();
+    }
+
+    function limit_rate(req, res) {
+        res.status = 200;
+        res.sendHeader();
+        res.send("AAAAA".repeat(10))
+        setTimeout(limit_rate_cb, 1000, res);
+    }
+
+EOF
+
+$t->try_run('no njs available')->plan(7);
+
+###############################################################################
+
+like(http_get('/set_timeout'), qr/Content-Type: foo/, 'setTimeout');
+like(http_get('/set_timeout_many'), qr/Content-Type: reply/, 'setTimeout many');
+like(http_get('/set_timeout_data'), qr/123456789/, 'setTimeout data');
+like(http_get('/shared_ctx?a=xxx'), qr/H: xxx/, 'shared context');
+like(http_get('/limit_rate'), qr/A{50}/, 'limit_rate');
+
+http_get('/async_var');
+
+$t->stop();
+
+ok(index($t->read_file('error.log'), 'pending events') > 0,
+   'pending js events');
+ok(index($t->read_file('error.log'), 'async operation inside') > 0,
+   'async op in var handler');
+
+###############################################################################