new file mode 100644
--- /dev/null
+++ b/addition.t
@@ -0,0 +1,117 @@
+#!/usr/bin/perl
+
+# (C) Sergey Kandaurov
+# (C) Nginx, Inc.
+
+# Tests for addition 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 $t = Test::Nginx->new()->has(qw/http rewrite addition/)->plan(9);
+
+$t->write_file_expand('nginx.conf', <<'EOF');
+
+%%TEST_GLOBALS%%
+
+daemon off;
+
+events {
+}
+
+http {
+    %%TEST_GLOBALS_HTTP%%
+
+    server {
+        listen       127.0.0.1:8080;
+        server_name  localhost;
+
+        location /regular {
+            return 200 "body";
+        }
+
+        location /b.html {
+            add_before_body /add_before;
+            return 200 "body";
+        }
+
+        location /a.html {
+            add_after_body /add_after;
+            return 200 "body";
+        }
+
+        location /ba.html {
+            add_before_body /add_before;
+            add_after_body /add_after;
+            return 200 "body";
+        }
+
+        location /notype {
+            add_before_body /add_before;
+            add_after_body /add_after;
+            return 200 "body";
+        }
+
+        location /notype2 {
+            addition_types text/plain;
+            add_after_body /add_after;
+            return 200 "body";
+        }
+
+        location /notype.html {
+            types {}
+            add_before_body /add_before;
+            return 200 "body";
+        }
+
+        location /add_before {
+            return 200 "before";
+        }
+
+        location /add_after {
+            return 200 "after";
+        }
+
+        location /self.html {
+            add_after_body /self.html;
+            return 200 "self";
+        }
+
+        location /return202.html {
+            add_after_body /add_after;
+            return 202 "body";
+        }
+    }
+}
+
+EOF
+
+$t->run();
+
+###############################################################################
+
+like(http_get('/regular'), qr/^body$/ms, 'no addition');
+like(http_get('/b.html'), qr/^beforebody$/ms, 'add_before');
+like(http_get('/a.html'), qr/^bodyafter$/ms, 'add_after');
+like(http_get('/ba.html'), qr/^beforebodyafter$/ms, 'both');
+like(http_get('/notype'), qr/^body$/ms, 'no content type');
+like(http_get('/notype2'), qr/^bodyafter$/ms, 'addition_types');
+like(http_get('/notype.html'), qr/^body$/ms, 'empty content type');
+like(http_get('/self.html'), qr/^selfself$/ms, 'self');
+like(http_get('/return202.html'), qr/HTTP\/1.. 202.*^body$/ms, 'not 200');
+
+###############################################################################