refactor: Upload extractor, 429 refusal test, stricter contract test

crates/adapters/http-axum/src/tests/api_handlers.rs

@@ -529,3 +529,28 @@ async fn a_json_body_of_the_wrong_shape_is_refused_as_unprocessable() {
     assert_eq!(resp.status(), StatusCode::UNPROCESSABLE_ENTITY);
     assert_eq!(refusal_body(resp).await["code"], "INVALID_INPUT");
 }
+
+#[tokio::test]
+async fn a_non_multipart_upload_is_refused_with_invalid_input_code() {
+    let app = Router::new()
+        .route(
+            "/api/v1/webhooks/plex",
+            axum::routing::post(crate::api::webhook::post_plex_webhook),
+        )
+        .with_state(test_app_state());
+
+    let resp = app
+        .oneshot(
+            Request::builder()
+                .method("POST")
+                .uri("/api/v1/webhooks/plex?token=t")
+                .header("content-type", "text/plain")
+                .body(Body::from("hello"))
+                .unwrap(),
+        )
+        .await
+        .unwrap();
+
+    assert!(resp.status().is_client_error());
+    assert_eq!(refusal_body(resp).await["code"], "INVALID_INPUT");
+}