## For All Settings

1. Add the setting to ExtensionMessage.ts:
   - Add the setting to the ExtensionState interface
   - Make it required if it has a default value, optional if it can be undefined
   - Example: `preferredLanguage: string`

2. Add test coverage:
   - Add the setting to mockState in ClineProvider.test.ts
   - Add test cases for setting persistence and state updates
   - Ensure all tests pass before submitting changes

## For Checkbox Settings

1. Add the message type to WebviewMessage.ts:
   - Add the setting name to the WebviewMessage type's type union
   - Example: `| "multisearchDiffEnabled"`

2. Add the setting to ExtensionStateContext.tsx:
   - Add the setting to the ExtensionStateContextType interface
   - Add the setter function to the interface
   - Add the setting to the initial state in useState
   - Add the setting to the contextValue object
   - Example:
     ```typescript
     interface ExtensionStateContextType {
       multisearchDiffEnabled: boolean;
       setMultisearchDiffEnabled: (value: boolean) => void;
     }
     ```

3. Add the setting to ClineProvider.ts:
   - Add the setting name to the GlobalStateKey type union
   - Add the setting to the Promise.all array in getState
   - Add the setting to the return value in getState with a default value
   - Add the setting to the destructured variables in getStateToPostToWebview
   - Add the setting to the return value in getStateToPostToWebview
   - Add a case in setWebviewMessageListener to handle the setting's message type
   - Example:
     ```typescript
     case "multisearchDiffEnabled":
       await this.updateGlobalState("multisearchDiffEnabled", message.bool)
       await this.postStateToWebview()
       break
     ```

4. Add the checkbox UI to SettingsView.tsx:
   - Import the setting and its setter from ExtensionStateContext
   - Add the VSCodeCheckbox component with the setting's state and onChange handler
   - Add appropriate labels and description text
   - Example:
     ```typescript
     <VSCodeCheckbox 
       checked={multisearchDiffEnabled} 
       onChange={(e: any) => setMultisearchDiffEnabled(e.target.checked)}
     >
       <span style={{ fontWeight: "500" }}>Enable multi-search diff matching</span>
     </VSCodeCheckbox>
     ```

5. Add the setting to handleSubmit in SettingsView.tsx:
   - Add a vscode.postMessage call to send the setting's value when clicking Done
   - Example:
     ```typescript
     vscode.postMessage({ type: "multisearchDiffEnabled", bool: multisearchDiffEnabled })
     ```

## For Select/Dropdown Settings

1. Add the message type to WebviewMessage.ts:
   - Add the setting name to the WebviewMessage type's type union
   - Example: `| "preferredLanguage"`

2. Add the setting to ExtensionStateContext.tsx:
   - Add the setting to the ExtensionStateContextType interface
   - Add the setter function to the interface
   - Add the setting to the initial state in useState with a default value
   - Add the setting to the contextValue object
   - Example:
     ```typescript
     interface ExtensionStateContextType {
       preferredLanguage: string;
       setPreferredLanguage: (value: string) => void;
     }
     ```

3. Add the setting to ClineProvider.ts:
   - Add the setting name to the GlobalStateKey type union
   - Add the setting to the Promise.all array in getState
   - Add the setting to the return value in getState with a default value
   - Add the setting to the destructured variables in getStateToPostToWebview
   - Add the setting to the return value in getStateToPostToWebview
   - Add a case in setWebviewMessageListener to handle the setting's message type
   - Example:
     ```typescript
     case "preferredLanguage":
       await this.updateGlobalState("preferredLanguage", message.text)
       await this.postStateToWebview()
       break
     ```

4. Add the select UI to SettingsView.tsx:
   - Import the setting and its setter from ExtensionStateContext
   - Add the select element with appropriate styling to match VSCode's theme
   - Add options for the dropdown
   - Add appropriate labels and description text
   - Example:
     ```typescript
     <select
       value={preferredLanguage}
       onChange={(e) => setPreferredLanguage(e.target.value)}
       style={{
         width: "100%",
         padding: "4px 8px",
         backgroundColor: "var(--vscode-input-background)",
         color: "var(--vscode-input-foreground)",
         border: "1px solid var(--vscode-input-border)",
         borderRadius: "2px"
       }}>
       <option value="English">English</option>
       <option value="Spanish">Spanish</option>
       ...
     </select>
     ```

5. Add the setting to handleSubmit in SettingsView.tsx:
   - Add a vscode.postMessage call to send the setting's value when clicking Done
   - Example:
     ```typescript
     vscode.postMessage({ type: "preferredLanguage", text: preferredLanguage })
     ```

These steps ensure that:
- The setting's state is properly typed throughout the application
- The setting persists between sessions
- The setting's value is properly synchronized between the webview and extension
- The setting has a proper UI representation in the settings view
- Test coverage is maintained for the new setting