Remove Zustand and replace with React Context + useReducer #5
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- Remove zustand dependency from package.json - Replace Zustand store with React Context API and useReducer - Create TodoProvider component to wrap the app - Update useTodoStore hook to use React Context - Maintain same API for backward compatibility - Add comprehensive tests for the new context-based state management - Update README to reflect the change from Zustand to React Context - Remove old todo-store.ts and related test files - Add @testing-library/react for component testing
WalkthroughThe codebase transitions from using Zustand to React Context with useReducer for state management in the todo app. All relevant logic, tests, and documentation are updated to reflect this shift. The Zustand store and its tests are removed, replaced by a new context-based implementation and corresponding tests. Dependency changes align with this migration. Changes
Sequence Diagram(s)sequenceDiagram
participant AppRoot as App Root
participant TodoProvider as TodoProvider (Context)
participant Home as Home Route Component
participant useTodoStore as useTodoStore Hook
AppRoot->>TodoProvider: Wrap children with TodoProvider
TodoProvider->>Home: Provide context value
Home->>useTodoStore: Call useTodoStore()
useTodoStore-->>Home: Return state and actions from context
Home->>TodoProvider: Dispatch actions (add, toggle, delete, etc.)
TodoProvider-->>Home: State updates via useReducer
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Actionable comments posted: 1
🧹 Nitpick comments (2)
apps/todo-app/app/lib/todo-context.tsx (2)
19-45: Consider varying the timestamps for more realistic initial data.The initial todos all have identical
createdAtandupdatedAttimestamps since they're created in the same execution cycle. For more realistic sample data and better testing scenarios, consider adding some time variation.- { - id: '1', - text: 'Learn React Router 7', - completed: false, - createdAt: new Date(), - updatedAt: new Date() - }, - { - id: '2', - text: 'Set up Tailwind CSS', - completed: true, - createdAt: new Date(), - updatedAt: new Date() - }, - { - id: '3', - text: 'Build a todo app', - completed: false, - createdAt: new Date(), - updatedAt: new Date() - } + { + id: '1', + text: 'Learn React Router 7', + completed: false, + createdAt: new Date(Date.now() - 24 * 60 * 60 * 1000), // 1 day ago + updatedAt: new Date(Date.now() - 24 * 60 * 60 * 1000) + }, + { + id: '2', + text: 'Set up Tailwind CSS', + completed: true, + createdAt: new Date(Date.now() - 2 * 60 * 60 * 1000), // 2 hours ago + updatedAt: new Date(Date.now() - 30 * 60 * 1000) // 30 minutes ago + }, + { + id: '3', + text: 'Build a todo app', + completed: false, + createdAt: new Date(), + updatedAt: new Date() + }
114-134: Consider memoizing the context value to prevent unnecessary re-renders.The
contextValueobject is recreated on every render, which will cause all consuming components to re-render even when the state hasn't changed. Consider usinguseMemoto optimize performance.+import { createContext, useContext, useReducer, useMemo, type ReactNode } from 'react'; export function TodoProvider({ children }: { children: ReactNode }) { const [state, dispatch] = useReducer(todoReducer, initialState); - const contextValue: TodoContextType = { - ...state, - addTodo: (text: string) => dispatch({ type: 'ADD_TODO', payload: text }), - toggleTodo: (id: string) => dispatch({ type: 'TOGGLE_TODO', payload: id }), - deleteTodo: (id: string) => dispatch({ type: 'DELETE_TODO', payload: id }), - updateTodo: (id: string, text: string) => - dispatch({ type: 'UPDATE_TODO', payload: { id, text } }), - setFilter: (filter: TodoFilter) => dispatch({ type: 'SET_FILTER', payload: filter }), - clearCompleted: () => dispatch({ type: 'CLEAR_COMPLETED' }) - }; + const contextValue: TodoContextType = useMemo(() => ({ + ...state, + addTodo: (text: string) => dispatch({ type: 'ADD_TODO', payload: text }), + toggleTodo: (id: string) => dispatch({ type: 'TOGGLE_TODO', payload: id }), + deleteTodo: (id: string) => dispatch({ type: 'DELETE_TODO', payload: id }), + updateTodo: (id: string, text: string) => + dispatch({ type: 'UPDATE_TODO', payload: { id, text } }), + setFilter: (filter: TodoFilter) => dispatch({ type: 'SET_FILTER', payload: filter }), + clearCompleted: () => dispatch({ type: 'CLEAR_COMPLETED' }) + }), [state]);
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📒 Files selected for processing (8)
README.md(3 hunks)apps/todo-app/app/lib/__tests__/todo-context.test.tsx(1 hunks)apps/todo-app/app/lib/__tests__/todo-store.test.ts(0 hunks)apps/todo-app/app/lib/todo-context.tsx(1 hunks)apps/todo-app/app/lib/todo-store.ts(0 hunks)apps/todo-app/app/root.tsx(2 hunks)apps/todo-app/app/routes/home.tsx(1 hunks)apps/todo-app/package.json(2 hunks)
💤 Files with no reviewable changes (2)
- apps/todo-app/app/lib/tests/todo-store.test.ts
- apps/todo-app/app/lib/todo-store.ts
🧰 Additional context used
🧬 Code Graph Analysis (3)
apps/todo-app/app/root.tsx (1)
apps/todo-app/app/lib/todo-context.tsx (1)
TodoProvider(115-134)
apps/todo-app/app/lib/__tests__/todo-context.test.tsx (2)
apps/todo-app/app/lib/todo-context.tsx (3)
useTodoStore(137-143)TodoProvider(115-134)getFilteredTodos(146-155)packages/utils/src/types.ts (1)
Todo(1-7)
apps/todo-app/app/lib/todo-context.tsx (2)
packages/utils/src/types.ts (2)
TodoFilter(9-9)Todo(1-7)apps/todo-app/app/routes/create-todo.tsx (1)
action(32-71)
🔇 Additional comments (19)
apps/todo-app/app/routes/home.tsx (1)
8-8: LGTM! Clean import migration.The import path update correctly points to the new React Context implementation while maintaining the same API interface, ensuring seamless transition from Zustand.
apps/todo-app/app/root.tsx (2)
4-4: LGTM! Proper context import.The import correctly brings in the TodoProvider for React Context integration.
24-26: LGTM! Correct provider placement.The TodoProvider is properly positioned at the root level, wrapping the Outlet to ensure all child routes have access to the todo context. This follows React Context best practices.
apps/todo-app/package.json (2)
26-26: LGTM! Appropriate testing library addition.Adding @testing-library/react as a dev dependency is correct for testing the new React Context implementation. Version ^16.1.0 is compatible with React 19.
51-51: LGTM! Correct dependency retention.Keeping the zod dependency is appropriate as it's used for form validation, not state management, and is unrelated to the Zustand migration.
README.md (3)
12-12: LGTM! Accurate feature description.The feature list correctly reflects the migration from Zustand to React's built-in state management solution.
85-90: LGTM! Comprehensive state management documentation.The state management section accurately describes the React Context + useReducer implementation, maintaining the same level of detail while reflecting the architectural change. The emphasis on "type-safe actions and state updates" is particularly valuable.
185-185: LGTM! Appropriate documentation link update.The external link correctly points to React Context documentation, replacing the previous Zustand link to align with the new implementation.
apps/todo-app/app/lib/__tests__/todo-context.test.tsx (6)
6-11: LGTM! Appropriate test setup.The crypto.randomUUID mock ensures consistent test behavior and predictable ID generation across test runs.
14-64: LGTM! Well-designed test component.The TestComponent provides excellent coverage of all context functionality through a clean, testable interface. The conditional checks (e.g.,
todos.length > 0) prevent runtime errors during testing.
76-81: LGTM! Proper initial state verification.The test correctly verifies the initial state with 3 todos and 'all' filter, establishing a baseline for subsequent operations.
83-92: LGTM! Comprehensive add todo test.The test properly uses
act()for state updates and verifies both the count increment and the specific todo creation with mocked UUID.
161-171: LGTM! Proper error boundary testing.The test correctly verifies that the hook throws an error when used outside the provider, with appropriate console.error suppression to keep test output clean.
174-209: LGTM! Comprehensive utility function testing.The getFilteredTodos tests cover all filter cases ('all', 'active', 'completed') with proper mock data and meaningful assertions. The test structure is clean and thorough.
apps/todo-app/app/lib/todo-context.tsx (5)
4-17: LGTM! Well-designed action types and state interface.The action types comprehensively cover all todo operations with appropriate payload typing. The state interface is clean and minimal.
47-99: LGTM! Excellent reducer implementation.The reducer correctly handles all action types with proper immutability, input validation (trimming), and timestamp management. The use of
crypto.randomUUID()for ID generation is appropriate for modern browsers.
101-112: LGTM! Clean context type definition.The context type effectively combines state and actions into a cohesive interface that maintains API compatibility with the previous Zustand implementation.
136-143: LGTM! Excellent custom hook implementation.The hook provides proper error handling and maintains API compatibility with the previous Zustand implementation. The error message clearly guides developers to use the hook within the provider.
145-155: LGTM! Helper function maintains perfect API compatibility.The filtering logic correctly handles all todo filter types and maintains the same API as the previous Zustand implementation.
| import { createContext, useContext, useReducer, type ReactNode } from 'react'; | ||
| import type { Todo, TodoFilter, TodoStore } from '@todo-starter/utils'; |
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💡 Verification agent
🧩 Analysis chain
Verify TodoStore import usage.
The import includes TodoStore type from the utils package, but this type doesn't appear to be used anywhere in the context implementation. Since this PR migrates away from Zustand, this import might be unnecessary.
🏁 Script executed:
#!/bin/bash
# Check if TodoStore type is used in this file
rg -n "TodoStore" apps/todo-app/app/lib/todo-context.tsxLength of output: 260
Remove unused TodoStore import
The TodoStore type imported from @todo-starter/utils on line 2 of apps/todo-app/app/lib/todo-context.tsx isn’t used and can be removed.
• apps/todo-app/app/lib/todo-context.tsx
-import type { Todo, TodoFilter, TodoStore } from '@todo-starter/utils';
+import type { Todo, TodoFilter } from '@todo-starter/utils';📝 Committable suggestion
‼️ IMPORTANT
Carefully review the code before committing. Ensure that it accurately replaces the highlighted code, contains no missing lines, and has no issues with indentation. Thoroughly test & benchmark the code to ensure it meets the requirements.
| import { createContext, useContext, useReducer, type ReactNode } from 'react'; | |
| import type { Todo, TodoFilter, TodoStore } from '@todo-starter/utils'; | |
| import { createContext, useContext, useReducer, type ReactNode } from 'react'; | |
| import type { Todo, TodoFilter } from '@todo-starter/utils'; |
🤖 Prompt for AI Agents
In apps/todo-app/app/lib/todo-context.tsx at line 2, the imported type TodoStore
from '@todo-starter/utils' is not used anywhere in the file. Remove TodoStore
from the import statement to clean up unused imports.
This PR removes Zustand from the react-router-starter and replaces it with React's built-in state management using Context API and useReducer.
Changes Made
🗑️ Removed
zustanddependency from package.jsontodo-store.tsfile✨ Added
todo-context.tsxwith React Context + useReducer implementationTodoProvidercomponent to wrap the application@testing-library/reactfor component testing🔄 Updated
root.tsxto wrap the app withTodoProviderhome.tsxto import from the new contextBenefits
Testing
The new implementation includes comprehensive tests that cover:
Requested by: Jake Ruesink
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Summary by CodeRabbit
New Features
Bug Fixes
Documentation
Tests
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