Implement OPTIONS requests for NCNv1; fixes #107

lib/REST/NextCloudNews/V1_2.php

@@ -76,6 +76,10 @@ class V1_2 extends \JKingWeb\Arsse\REST\AbstractHandler {
         if (!Arsse::$user->authHTTP()) {
             return new Response(401, "", "", ['WWW-Authenticate: Basic realm="'.self::REALM.'"']);
         }
+        // handle HTTP OPTIONS requests
+        if ($req->method=="OPTIONS") {
+            return $this->handleHTTPOptions($req->paths);
+        }
         // normalize the input
         if ($req->body) {
             // if the entity body is not JSON according to content type, return "415 Unsupported Media Type"
@@ -144,7 +148,7 @@ class V1_2 extends \JKingWeb\Arsse\REST\AbstractHandler {
                 throw new Exception405(implode(", ", array_keys($this->paths[$url])));
             } 
         } else {
-            // if the path is not supported, return 501
+            // if the path is not supported, return 404
             throw new Exception404();  
         }
     }
@@ -202,6 +206,26 @@ class V1_2 extends \JKingWeb\Arsse\REST\AbstractHandler {
         ], $this->dateFormat);
         return $article;
     }
+
+    protected function handleHTTPOptions(array $url): Response {
+        // normalize the URL path
+        $url = $this->normalizePath($url);
+        if (isset($this->paths[$url])) {
+            // if the path is supported, respond with the allowed methods and other metadata
+            $allowed = array_keys($this->paths[$url]);
+            // if GET is allowed, so is HEAD
+            if (in_array("GET", $allowed)) {
+                array_unshift($allowed, "HEAD");
+            }
+            return new Response(204, "", "", [
+                "Allow: ".implode(",", $allowed),
+                "Accept: application/json",
+            ]);
+        } else {
+            // if the path is not supported, return 404
+            return new Response(404);  
+        }
+    }
     
     // list folders
     protected function folderList(array $url, array $data): Response {

lib/REST/NextCloudNews/Versions.php

@@ -13,21 +13,23 @@ class Versions implements \JKingWeb\Arsse\REST\Handler {
     }
 
     public function dispatch(\JKingWeb\Arsse\REST\Request $req): Response {
-        // if a method other than GET was used, this is an error
-        if ($req->method != "GET") {
-            return new Response(405, "", "", ["Allow: GET"]);
-        }
-        if (preg_match("<^/?$>", $req->path)) {
-            // if the request path is an empty string or just a slash, return the supported versions
+        if (!preg_match("<^/?$>", $req->path)) {
+            // if the request path is an empty string or just a slash, the client is probably trying a version we don't support
+            return new Response(404);
+        } elseif ($req->method=="OPTIONS") {
+            // if the request method is OPTIONS, respond accordingly
+            return new Response(204, "", "", ["Allow: HEAD,GET"]);
+        } elseif ($req->method != "GET") {
+            // if a method other than GET was used, this is an error
+            return new Response(405, "", "", ["Allow: HEAD,GET"]);
+        } else {
+            // otherwise return the supported versions
             $out = [
                 'apiLevels' => [
                     'v1-2',
                 ]
             ];
             return new Response(200, $out);
-        } else {
-            // if the URL path was anything else, the client is probably trying a version we don't support
-            return new Response(404);
         }
     }
 }

tests/REST/NextCloudNews/TestNCNV1_2.php

@@ -311,6 +311,12 @@ class TestNCNV1_2 extends Test\AbstractTest {
         $this->clearData();
     }
 
+    public function testSendAuthenticationChallenge() {
+        Phake::when(Arsse::$user)->authHTTP->thenReturn(false);
+        $exp = new Response(401, "", "", ['WWW-Authenticate: Basic realm="'.REST\NextCloudNews\V1_2::REALM.'"']);
+        $this->assertEquals($exp, $this->h->dispatch(new Request("GET", "/")));
+    }
+
     public function testRespondToInvalidPaths() {
         $errs = [
             404 => [
@@ -364,10 +370,24 @@ class TestNCNV1_2 extends Test\AbstractTest {
         $this->assertEquals($exp, $this->h->dispatch(new Request("PUT", "/folders/1", '<data/>', 'application/json')));
     }
 
-    public function testSendAuthenticationChallenge() {
-        Phake::when(Arsse::$user)->authHTTP->thenReturn(false);
-        $exp = new Response(401, "", "", ['WWW-Authenticate: Basic realm="'.REST\NextCloudNews\V1_2::REALM.'"']);
-        $this->assertEquals($exp, $this->h->dispatch(new Request("GET", "/")));
+    public function testRespondToOptionsRequests() {
+        $exp = new Response(204, "", "", [
+            "Allow: HEAD,GET,POST",
+            "Accept: application/json",
+        ]);
+        $this->assertEquals($exp, $this->h->dispatch(new Request("OPTIONS", "/feeds")));
+        $exp = new Response(204, "", "", [
+            "Allow: DELETE",
+            "Accept: application/json",
+        ]);
+        $this->assertEquals($exp, $this->h->dispatch(new Request("OPTIONS", "/feeds/2112")));
+        $exp = new Response(204, "", "", [
+            "Allow: HEAD,GET",
+            "Accept: application/json",
+        ]);
+        $this->assertEquals($exp, $this->h->dispatch(new Request("OPTIONS", "/user")));
+        $exp = new Response(404);
+        $this->assertEquals($exp, $this->h->dispatch(new Request("OPTIONS", "/invalid/path")));
     }
 
     public function testListFolders() {

tests/REST/NextCloudNews/TestNCNVersionDiscovery.php

@@ -29,8 +29,16 @@ class TestNCNVersionDiscovery extends Test\AbstractTest {
         $this->assertEquals($exp, $res);
     }
 
+    public function testRespondToOptionsRequest() {
+        $exp = new Response(204, "", "", ["Allow: HEAD,GET"]);
+        $h = new REST\NextCloudNews\Versions();
+        $req = new Request("OPTIONS", "/");
+        $res = $h->dispatch($req);
+        $this->assertEquals($exp, $res);
+    }
+
     public function testUseIncorrectMethod() {
-        $exp = new Response(405, "", "", ["Allow: GET"]);
+        $exp = new Response(405, "", "", ["Allow: HEAD,GET"]);
         $h = new REST\NextCloudNews\Versions();
         $req = new Request("POST", "/");
         $res = $h->dispatch($req);
@@ -43,5 +51,8 @@ class TestNCNVersionDiscovery extends Test\AbstractTest {
         $req = new Request("GET", "/ook");
         $res = $h->dispatch($req);
         $this->assertEquals($exp, $res);
+        $req = new Request("OPTIONS", "/ook");
+        $res = $h->dispatch($req);
+        $this->assertEquals($exp, $res);
     }
 }