new file mode 100644
--- /dev/null
+++ b/js_buffer.t
@@ -0,0 +1,171 @@
+#!/usr/bin/perl
+
+# (C) Dmitry Volyntsev
+# (C) Nginx, Inc.
+
+# Tests for http njs module, buffer properties.
+
+###############################################################################
+
+use warnings;
+use strict;
+
+use Test::More;
+
+use Socket qw/ CRLF /;
+
+BEGIN { use FindBin; chdir($FindBin::Bin); }
+
+use lib 'lib';
+use Test::Nginx;
+
+###############################################################################
+
+select STDERR; $| = 1;
+select STDOUT; $| = 1;
+
+eval { require JSON::PP; };
+plan(skip_all => "JSON::PP not installed") if $@;
+
+my $t = Test::Nginx->new()->has(qw/http rewrite proxy/)
+	->write_file_expand('nginx.conf', <<'EOF');
+
+%%TEST_GLOBALS%%
+
+daemon off;
+
+events {
+}
+
+http {
+    %%TEST_GLOBALS_HTTP%%
+
+    js_import test.js;
+
+    server {
+        listen       127.0.0.1:8080;
+        server_name  localhost;
+
+        location /njs {
+            js_content test.njs;
+        }
+
+        location /return {
+            js_content test.return;
+        }
+
+        location /req_body {
+            js_content test.req_body;
+        }
+
+        location /res_body {
+            js_content test.res_body;
+        }
+
+        location /binary_var {
+            js_content test.binary_var;
+        }
+
+        location /p/ {
+            proxy_pass http://127.0.0.1:8081/;
+        }
+    }
+
+    server {
+        listen       127.0.0.1:8081;
+        server_name  localhost;
+
+        location /sub1 {
+            return 200 '{"a": {"b": 1}}';
+        }
+    }
+}
+
+EOF
+
+$t->write_file('test.js', <<EOF);
+    function test_njs(r) {
+        r.return(200, njs.version);
+    }
+
+    function test_return(r) {
+        var body = Buffer.from("body: ");
+        body = Buffer.concat([body, Buffer.from(r.args.text)]);
+        r.return(200, body);
+    }
+
+    function req_body(r) {
+        var body = r.reqBody;
+        var view = new DataView(body.buffer);
+        view.setInt8(2, 'c'.charCodeAt(0));
+        r.return(200, JSON.parse(body).c.b);
+    }
+
+    function res_body(r) {
+        r.subrequest('/p/sub1')
+        .then(reply => {
+            var body = reply.resBody;
+            var view = new DataView(body.buffer);
+            view.setInt8(2, 'c'.charCodeAt(0));
+            r.return(200, JSON.stringify(JSON.parse(body)));
+        })
+    }
+
+    function binary_var(r) {
+        var test = r.vars.binary_remote_addr.equals(Buffer.from([127,0,0,1]));
+        r.return(200, test);
+    }
+
+    export default {njs: test_njs, return: test_return, req_body, res_body,
+	                binary_var};
+
+EOF
+
+$t->try_run('no njs buffer')->plan(4);
+
+###############################################################################
+
+TODO: {
+local $TODO = 'not yet'
+	unless http_get('/njs') =~ /^([.0-9]+)$/m && $1 ge '0.5.0';
+
+like(http_get('/return?text=FOO'), qr/200 OK.*body: FOO$/s,
+	'return buffer');
+like(http_post('/req_body'), qr/200 OK.*BAR$/s, 'req body');
+is(get_json('/res_body'), '{"c":{"b":1}}', 'res body');
+like(http_get('/binary_var'), qr/200 OK.*true$/s,
+	'binary var');
+
+}
+
+###############################################################################
+
+sub recode {
+	my $json;
+	eval { $json = JSON::PP::decode_json(shift) };
+
+	if ($@) {
+		return "<failed to parse JSON>";
+	}
+
+	JSON::PP->new()->canonical()->encode($json);
+}
+
+sub get_json {
+	http_get(shift) =~ /\x0d\x0a?\x0d\x0a?(.*)/ms;
+	recode($1);
+}
+
+sub http_post {
+	my ($url, %extra) = @_;
+
+	my $p = "POST $url HTTP/1.0" . CRLF .
+		"Host: localhost" . CRLF .
+		"Content-Length: 17" . CRLF .
+		CRLF .
+		"{\"a\":{\"b\":\"BAR\"}}";
+
+	return http($p, %extra);
+}
+
+###############################################################################