Tests: added tests for js_header_filter directive.
diff --git a/js_header_filter.t b/js_header_filter.t
new file mode 100644
index 0000000..aecac34
--- /dev/null
+++ b/js_header_filter.t
@@ -0,0 +1,93 @@
+#!/usr/bin/perl
+
+# (C) Dmitry Volyntsev
+# (C) Nginx, Inc.
+
+# Tests for http njs module, header filter.
+
+###############################################################################
+
+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 $t = Test::Nginx->new()->has(qw/http proxy rewrite/)
+ ->write_file_expand('nginx.conf', <<'EOF');
+
+%%TEST_GLOBALS%%
+
+daemon off;
+
+events {
+}
+
+http {
+ %%TEST_GLOBALS_HTTP%%
+
+ js_import test.js;
+
+ server {
+ listen 127.0.0.1:8080;
+ server_name localhost;
+
+ location /njs {
+ js_content test.njs;
+ }
+
+ location /filter/ {
+ js_header_filter test.filter;
+ proxy_pass http://127.0.0.1:8081/;
+ }
+ }
+
+ server {
+ listen 127.0.0.1:8081;
+ server_name localhost;
+
+ location / {
+ add_header Set-Cookie "BB";
+ add_header Set-Cookie "CCCC";
+
+ return 200;
+ }
+ }
+}
+
+EOF
+
+$t->write_file('test.js', <<EOF);
+ function test_njs(r) {
+ r.return(200, njs.version);
+ }
+
+ function filter(r) {
+ var cookies = r.headersOut['Set-Cookie'];
+ var len = r.args.len ? Number(r.args.len) : 0;
+ r.headersOut['Set-Cookie'] = cookies.filter(v=>v.length > len);
+ }
+
+ export default {njs: test_njs, filter};
+
+EOF
+
+$t->try_run('no njs header filter')->plan(2);
+
+###############################################################################
+
+like(http_get('/filter/?len=1'), qr/Set-Cookie: BB.*Set-Cookie: CCCC.*/ms,
+ 'all');;
+unlike(http_get('/filter/?len=3'), qr/Set-Cookie: BB/,
+ 'filter');
+
+###############################################################################
