fix: overwrite existing query if conflict in pagination

src/client.rs

@@ -154,14 +154,26 @@ impl Client {
                 if let Some(page) = page.as_ref() {
                     match page {
                         PaginationType::Query(queries) => {
-                            let mut existing = base_request.url_mut().query_pairs_mut();
+                            // There's no easy way to just overwrite specific queries, so we need
+                            // to do some extra manipulating.
+                            let keys: Vec<_> = queries.iter().map(|(k, _)| k).collect();
+                            let unchanged_queries: Vec<(_, _)> = base_request
+                                .url()
+                                .query_pairs()
+                                .filter(|(k, _)| !keys.contains(&&k.to_string()))
+                                .collect();
+                            let mut temp_url = base_request.url().clone();
+                            temp_url.set_query(None);
+                            for (key, val) in unchanged_queries {
+                                temp_url.query_pairs_mut().append_pair(&key, &val);
+                            }
                             for (key, val) in queries.iter() {
-                                existing.append_pair(key, val);
+                                temp_url.query_pairs_mut().append_pair(key, val);
                             }
+                            base_request.url_mut().set_query(temp_url.query());
                         }
                     };
                 }
-
                 let response = self.send_raw(base_request).await?;
                 let state = paginator.next(&state, &response);
                 Ok(Some((response, (paginator, state))))

tests/integration/pagination.rs

@@ -101,3 +101,46 @@ async fn query() {
     );
     assert!(response.next().await.is_none());
 }
+
+#[tokio::test]
+async fn can_overwrite_existing_query() {
+    let server = MockServer::start().await;
+    let uri = server.uri();
+    let client = Client::new(&uri);
+
+    Mock::given(method("GET"))
+        .and(path("/page"))
+        .and(query_param("page", "0"))
+        .respond_with(|_: &MockRequest| {
+            let body = PaginationResponse {
+                next_page: Some(1),
+                data: "First!".into(),
+            };
+            ResponseTemplate::new(200).set_body_json(body)
+        })
+        .mount(&server)
+        .await;
+
+    Mock::given(method("GET"))
+        .and(path("/page"))
+        .and(query_param("page", "1"))
+        .respond_with(|_: &MockRequest| {
+            let body = PaginationResponse {
+                next_page: Some(2),
+                data: "Second!".into(),
+            };
+            ResponseTemplate::new(200).set_body_json(body)
+        })
+        .mount(&server)
+        .await;
+
+    let mut response = client.send_paginated(&PaginationRequest { page: Some(0) });
+    assert_eq!(
+        response.next().await.unwrap().unwrap().data,
+        "First!".to_string()
+    );
+    assert_eq!(
+        response.next().await.unwrap().unwrap().data,
+        "Second!".to_string()
+    );
+}