From cb518dca8867f6b3c051558aabc1500c3abe0104 Mon Sep 17 00:00:00 2001
From: Tomas Cohen Arazi <tomascohen@theke.io>
Date: Thu, 9 Jan 2020 11:13:47 -0300
Subject: [PATCH] Bug 24369: Add CORS support to the API

This patch adds CORS support for API requests. It uses the
AccessControlAllowOrigin syspref. To test:

1. Apply this patch
2. Run:
   $ kshell
  k$ prove t/db_dependent/api/v1/auth.t
=> SUCCESS: Tests pass!
3. Set the AccessControlAllowOrigin to any string (for example, *)
4. Use any API testing tool (Postman?) to place a request on the API
=> SUCCESS: The response headers include Access-Control-Allow-Origin,
    containing what you set on the syspref
5. Sign off :-D
---
 Koha/REST/V1.pm              | 17 +++++++++++++----
 t/db_dependent/api/v1/auth.t | 21 ++++++++++++++++++++-
 2 files changed, 33 insertions(+), 5 deletions(-)

diff --git a/Koha/REST/V1.pm b/Koha/REST/V1.pm
index b1f4657d4a..610d75d38f 100644
--- a/Koha/REST/V1.pm
+++ b/Koha/REST/V1.pm
@@ -39,10 +39,19 @@ Overloaded Mojolicious->startup method. It is called at application startup.
 sub startup {
     my $self = shift;
 
-    # Remove /api/v1/app.pl/ from the path
-    $self->hook( before_dispatch => sub {
-        shift->req->url->base->path('/');
-    });
+    $self->hook(
+        before_dispatch => sub {
+            my $c = shift;
+
+            # Remove /api/v1/app.pl/ from the path
+            $c->req->url->base->path('/');
+
+            # Handle CORS
+            $c->res->headers->header( 'Access-Control-Allow-Origin' =>
+                  C4::Context->preference('AccessControlAllowOrigin') )
+              if C4::Context->preference('AccessControlAllowOrigin');
+        }
+    );
 
     # Force charset=utf8 in Content-Type header for JSON responses
     $self->types->type( json    => 'application/json; charset=utf8' );
diff --git a/t/db_dependent/api/v1/auth.t b/t/db_dependent/api/v1/auth.t
index 4f47227886..74c3162538 100644
--- a/t/db_dependent/api/v1/auth.t
+++ b/t/db_dependent/api/v1/auth.t
@@ -17,7 +17,7 @@
 
 use Modern::Perl;
 
-use Test::More tests => 1;
+use Test::More tests => 2;
 use Test::Mojo;
 use Test::Warn;
 
@@ -107,6 +107,25 @@ subtest 'under() tests' => sub {
     $schema->storage->txn_rollback;
 };
 
+subtest 'CORS support' => sub {
+
+    plan tests => 6;
+
+    t::lib::Mocks::mock_preference('AccessControlAllowOrigin','');
+    $t->get_ok("/api/v1/patrons")
+      ->header_is( 'Access-control-allow-origin', undef, 'Header not returned' );
+      # FIXME: newer Test::Mojo has header_exists_not
+
+    t::lib::Mocks::mock_preference('AccessControlAllowOrigin',undef);
+    $t->get_ok("/api/v1/patrons")
+      ->header_is( 'Access-control-allow-origin', undef, 'Header not returned' );
+    # FIXME: newer Test::Mojo has header_exists_not
+
+    t::lib::Mocks::mock_preference('AccessControlAllowOrigin','*');
+    $t->get_ok("/api/v1/patrons")
+      ->header_is( 'Access-control-allow-origin', '*', 'Header set' );
+};
+
 sub create_user_and_session {
     my $user = $builder->build(
         {
-- 
2.24.1