From f8fc9947982f6dfbb4823d75cd202876077fae3c Mon Sep 17 00:00:00 2001
From: Piyush <piyush41y08h@gmail.com>
Date: Sat, 16 Nov 2024 18:30:04 +0530
Subject: [PATCH] fix bug in query cache and fix todos page

---
 example/lib/pages/todos_page.dart |  8 +++-----
 lib/src/query_cache.dart          | 19 ++++++++++++++-----
 lib/src/query_client.dart         |  8 ++++++--
 3 files changed, 23 insertions(+), 12 deletions(-)

diff --git a/example/lib/pages/todos_page.dart b/example/lib/pages/todos_page.dart
index 7929cf7..b60c965 100644
--- a/example/lib/pages/todos_page.dart
+++ b/example/lib/pages/todos_page.dart
@@ -1,7 +1,6 @@
 // ignore_for_file: public_member_api_docs, sort_constructors_first
 
 import 'dart:math';
-import 'package:basic/main.dart';
 import 'package:basic/widgets/todo_list_tile.dart';
 import 'package:basic/models/todos.dart';
 import 'package:flutter/cupertino.dart';
@@ -26,11 +25,10 @@ class TodosPage extends HookWidget {
     final todoInputController = useTextEditingController();
     final addTodoMutation = useMutation<Todo, Exception, String, List<Todo>>(
         todosAPI.add, onMutate: (text) async {
-      final previousTodos =
-          queryClient.getQueryData<List<Todo>>(['todos']) ?? [];
+      final previousTodos = client.getQueryData<List<Todo>>(['todos']) ?? [];
 
       // Optimistically update the todo list
-      queryClient.setQueryData<List<Todo>>(['todos'], (previous) {
+      client.setQueryData<List<Todo>>(['todos'], (previous) {
         final id = Random().nextInt(pow(10, 6).toInt());
         final newTodo = Todo(id: id, text: text);
         return [...(previous ?? []), newTodo];
@@ -40,7 +38,7 @@ class TodosPage extends HookWidget {
       return previousTodos;
     }, onError: (err, text, previousTodos) {
       // On failure, revert back to original data
-      queryClient.setQueryData<List<Todo>>(
+      client.setQueryData<List<Todo>>(
         ['todos'],
         (_) => previousTodos as List<Todo>,
       );
diff --git a/lib/src/query_cache.dart b/lib/src/query_cache.dart
index c9f8438..a12e061 100644
--- a/lib/src/query_cache.dart
+++ b/lib/src/query_cache.dart
@@ -9,8 +9,12 @@ class QueryCache extends ChangeNotifier {
   final QueriesMap _queries = {};
   QueriesMap get queries => _queries;
 
-  Query<TData, TError>? get<TData, TError>(QueryKey queryKey) {
-    return _queries[queryKey.lock] as Query<TData, TError>?;
+  Query<TData, TError> get<TData, TError>(QueryKey queryKey) {
+    final query = _queries[queryKey.lock];
+    if (query == null) {
+      throw ArgumentError("Query with given key doesn't exist.");
+    }
+    return query as Query<TData, TError>;
   }
 
   void add(QueryKey queryKey, Query query) {
@@ -30,9 +34,14 @@ class QueryCache extends ChangeNotifier {
     required QueryKey queryKey,
     required QueryClient client,
   }) {
-    var query =
-        get<TData, TError>(queryKey) ?? Query(client: client, key: queryKey);
-    add(queryKey, query);
+    late final Query<TData, TError> query;
+    try {
+      query = get<TData, TError>(queryKey);
+      add(queryKey, query);
+    } catch (e) {
+      query = Query(client: client, key: queryKey);
+      add(queryKey, query);
+    }
     return query;
   }
 
diff --git a/lib/src/query_client.dart b/lib/src/query_client.dart
index 3855031..7a7f595 100644
--- a/lib/src/query_client.dart
+++ b/lib/src/query_client.dart
@@ -56,8 +56,12 @@ class QueryClient {
   }
 
   TData? getQueryData<TData>(QueryKey queryKey) {
-    final query = queryCache.get<TData, dynamic>(queryKey);
-    return query?.state.data;
+    try {
+      final query = queryCache.get<TData, dynamic>(queryKey);
+      return query.state.data;
+    } catch (e) {
+      return null as TData?;
+    }
   }
 
   /// Marks the query as stale.