Throw exceptions in API Client responses

Currently, the API client middleware includes an error handler instance in its middleware stack, so any exceptions thrown have to be manually checked for in API client callers. This is generally forgotten or omited, and leads to issues when call sites try to read data from the response but fail with a confusing error.

In this PR, we no longer handle those errors, so they will be propogated in their original form to the original request's error handler. This is more appropriate behavior, and will make debugging errors significantly easier. This is not a breaking change, since broken requests would have failed anyway due to other, more confusing errors. Additionally, all error checking code that I've found just throws a new error if an API client request fails, so that case won't be broken either.

src/Api/ApiServiceProvider.php

@@ -106,6 +106,7 @@ class ApiServiceProvider extends AbstractServiceProvider
         $this->container->singleton('flarum.api_client.exclude_middleware', function () {
             return [
                 HttpMiddleware\InjectActorReference::class,
+                'flarum.api.error_handler',
                 HttpMiddleware\ParseJsonBody::class,
                 Middleware\FakeHttpMethods::class,
                 HttpMiddleware\StartSession::class,

src/Forum/Content/Discussion.php

@@ -116,11 +116,6 @@ class Discussion
             ->withParentRequest($request)
             ->withQueryParams($params)
             ->get("/discussions/$id");
-        $statusCode = $response->getStatusCode();
-
-        if ($statusCode === 404) {
-            throw new RouteNotFoundException;
-        }
 
         return json_decode($response->getBody());
     }

src/Forum/Content/User.php

@@ -61,11 +61,6 @@ class User
     protected function getApiDocument(Request $request, string $username)
     {
         $response = $this->api->withParentRequest($request)->withQueryParams(['bySlug' => true])->get("/users/$username");
-        $statusCode = $response->getStatusCode();
-
-        if ($statusCode === 404) {
-            throw new ModelNotFoundException;
-        }
 
         return json_decode($response->getBody());
     }

src/Forum/Controller/LogInController.php

@@ -74,19 +74,17 @@ class LogInController implements RequestHandlerInterface
 
         $response = $this->apiClient->withParentRequest($request)->withBody($params)->post('/token');
 
-        if ($response->getStatusCode() === 200) {
+        $data = json_decode($response->getBody());
-            $data = json_decode($response->getBody());
 
-            $token = AccessToken::findValid($data->token);
+        $token = AccessToken::findValid($data->token);
 
-            $session = $request->getAttribute('session');
+        $session = $request->getAttribute('session');
-            $this->authenticator->logIn($session, $token);
+        $this->authenticator->logIn($session, $token);
 
-            $this->events->dispatch(new LoggedIn($this->users->findOrFail($data->userId), $token));
+        $this->events->dispatch(new LoggedIn($this->users->findOrFail($data->userId), $token));
 
-            if ($token instanceof RememberAccessToken) {
+        if ($token instanceof RememberAccessToken) {
-                $response = $this->rememberer->remember($response, $token);
+            $response = $this->rememberer->remember($response, $token);
-            }
         }
 
         return $response;