monaco-editor-lsp-next/README.md

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# monaco-editor-lsp-next

✨ A seamless Next.js integration of the Monaco Editor with robust LSP support – all without SSR hassles.

![demo](demo.png)

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## ⚠️ LSP Configuration and Environment Variable Limitations

**Warning: Pre-built Image LSP Configuration Limitations**

The pre-built Docker image `cfngc4594/monaco-editor-lsp-next` is configured to connect exclusively to `ws://localhost:4594/clangd` and `ws://localhost:4595/clangd`. This is due to the LSP configuration being set via `NEXT_PUBLIC` environment variables during the image build process.

* **Build-Time Freezing:** As per the Next.js [official documentation](https://nextjs.org/docs/pages/building-your-application/configuring/environment-variables#bundling-environment-variables-for-the-browser), `NEXT_PUBLIC` variables are frozen at build time, and subsequent changes are ineffective.
* **Local LSP Server Dependency:** Therefore, the pre-built image can only connect to the specified local LSP servers.
* **Custom Configuration Requirement:** If you wish to define your own LSP configuration via environment variables, you **cannot** use the pre-built image. Instead, you must:
    * Clone the source code.
    * Set your desired environment variables.
    * Manually build the Docker image.

**Upcoming Improvements (v0.0.1):**

To address these limitations, v0.0.1 will implement the officially recommended API approach for retrieving LSP configurations, enabling runtime dynamic LSP server configuration without image rebuilding.

## ⚠️ WSL Users: Critical Configuration

### 🐧 Network Mode Requirement

When using Windows Subsystem for Linux (WSL), you **must** configure your network mode as **Mirrored** to ensure proper LSP server connectivity. Standard WSL network configurations may create IPv6 conflicts that block Monaco-LSP communication.

#### 🔧 Mirror Mode Setup:

1.  Open WSL settings ⚙️
2.  Navigate to **Network** section 🌐
3.  Select **Mirrored** mode 🔄
4.  Restart WSL instance 💻

Complete these steps before launching the editor for seamless LSP integration! 🎉

## 🚀 Getting Started

### 🐳 Docker Deployment (Recommended)

Deploy the project quickly using Docker. Follow the steps below:

#### Step 1: Clone the Repository

```shell
git clone https://github.com/cfngc4594/monaco-editor-lsp-next
cd monaco-editor-lsp-next
```

#### Step 2: Install Dependencies

This project uses `bun` as the default package manager, but you can also use other package managers like `npm`, `yarn`, or `pnpm` if you prefer.

If you choose to use a package manager other than `bun`, you should delete the `bun.lock` file from your project directory.

The `Dockerfile` is designed to dynamically detect and adapt to the package manager you are using, ensuring compatibility with your preferred tool.

```shell
bun install
```

#### Step 3: Configure Environment Variables

1. Copy the example environment file:

   ```sh
   cp .env.example .env
   ```

2. Open the `.env` file and set the following variables:

   - **PostgreSQL Credentials**:
     ```sh
     POSTGRES_USER="your_postgres_user"
     POSTGRES_PASSWORD="your_postgres_password"
     POSTGRES_DB="your_postgres_db"
     ```

   - **Authentication Secret**:
     Generate a secure secret key using:
     ```sh
     bunx auth secret
     ```
     Then, set the `AUTH_SECRET` variable:
     ```sh
     AUTH_SECRET="your_auth_secret"
     ```

   - **GitHub OAuth** (Optional):
     If you need GitHub OAuth, replace the following variables with your GitHub OAuth credentials:
     ```sh
     AUTH_GITHUB_ID="your_github_client_id"
     AUTH_GITHUB_SECRET="your_github_client_secret"
     ```

#### Step 4: Start the Application

Once the environment variables are configured, start the application using Docker Compose:

```sh
docker compose up -d --build
```

#### Step 5: Access the Application

The application should now be running. You can access it at:

- **Web Interface**: `http://localhost:3000`
- **LSP Service (C Language)**: `ws://localhost:4594/clangd`
- **LSP Service (C++ Language)**: `ws://localhost:4595/clangd`

#### 📁 `.env.example` File

For reference, you can see the content of the `.env.example` file.

## ⚙️ Technical Configuration

### LSP Server Mapping

| **Language** | **LSP Server** | **Port** |
|--------------|----------------|----------|
| `C`          | `clangd`       | `4594`   |
| `C++`        | `clangd`       | `4595`   |

## 📦 Dependency Management

### 🔒 Version Lock Requirements

**Critical Pairing**:  
| Package                 | Max Version | Reference |  
|-------------------------|-------------|-----------|  
| `monaco-editor`         | ≤0.36.1     | [Compatibility Matrix](https://github.com/TypeFox/monaco-languageclient/blob/main/docs/versions-and-history.md#monaco-editor--codingamemonaco-vscode-api-compatibility-table) |  
| `monaco-languageclient` | ≤5.0.1      |           |  

**Version Lock Rationale**:  
1. **API Stability**  
   - Newer `monaco-editor` (≥0.40.0) breaks `monaco-languageclient` integration  
   - v0.36.1 matches `@codingame/monaco-vscode-api@1.76.9` requirements  

2. **LSP Feature Breakdown**  
   - Version mismatches disable:  
     - Auto `textDocument/didOpen` events  
     - `textDocument/inlayHint` resolution  
     - `textDocument/documentLink` functionality  

3. **Version Conflict**  
   - `@codingame` package versioning (e.g., `11.1.2`) ≠ `monaco-editor` versions (e.g., `0.36.1`)  
   - `@monaco-editor/react` depends on `monaco-editor` versioning scheme  

**Failure Indicators**:  
- ✔️ WebSocket connection established  
- ❌ Missing syntax highlighting  
- ❌ No autocomplete suggestions  
- ❌ Silent LSP initialization failures  

### 🎨 Shiki Compatibility Notice

Syntax highlighting depends on `rehype-pretty-code`'s deprecated `getHighlighter` API from `shiki@legacy`.

**Key Points**:

- **Affected File:** `src/components/mdx-preview.tsx`
- **Dependency Chain:** `rehype-pretty-code` → `shiki@legacy`
- **Version Constraints**:

  ```sh
  "shiki": "<=2.5.0"
  "@shikijs/monaco": "<=2.5.0"
  ```

**Maintenance Note**:  
While `shiki@3.0.0+` introduces modern APIs (`createHighlighter`/`getSingletonHighlighter`), upgrading requires `rehype-pretty-code` updates. Track progress [here](https://github.com/atomiks/rehype-pretty-code).