# Spark Runtime Type Errors - Resolution Complete

## Problem
The codebase had 54 TypeScript errors where `window.spark` was not recognized as a valid property. This occurred because the global type definitions for the Spark runtime weren't being properly recognized by TypeScript.

## Root Cause
The Spark runtime was implemented in `src/lib/spark-runtime.ts` and properly assigned to `window.spark` at runtime, but TypeScript didn't have the type definitions available during compilation.

## Solution Implemented

### 1. Created Global Type Definitions
Created `/workspaces/spark-template/src/global.d.ts` with complete type definitions for the Spark runtime:

```typescript
declare global {
  interface Window {
    spark: {
      llmPrompt: (strings: TemplateStringsArray, ...values: any[]) => string
      llm: (prompt: string, modelName?: string, jsonMode?: boolean) => Promise<string>
      user: () => Promise<{
        avatarUrl: string
        email: string
        id: string
        isOwner: boolean
        login: string
      }>
      kv: {
        keys: () => Promise<string[]>
        get: <T>(key: string) => Promise<T | undefined>
        set: <T>(key: string, value: T) => Promise<void>
        delete: (key: string) => Promise<void>
      }
    }
  }
  var spark: Window['spark']
}
```

### 2. Updated TypeScript Configuration
Modified `tsconfig.json` to explicitly include the global type definitions file.

### 3. Added Type References to All Files Using Spark
Added `/// <reference path="../global.d.ts" />` directives to all files that use `window.spark`:

**Components:**
- `FeatureIdeaCloud.tsx`
- `PlaywrightDesigner.tsx`
- `StorybookDesigner.tsx`
- `TemplateExplorer.tsx`
- `UnitTestDesigner.tsx`

**Hooks:**
- `hooks/data/use-seed-data.ts`
- `hooks/data/use-seed-templates.ts`
- `hooks/json-ui/use-data-sources.ts`
- `hooks/orchestration/use-actions.ts`
- `hooks/use-component-tree-loader.ts`

**Library Files:**
- `lib/ai-service.ts`
- `lib/error-repair-service.ts`
- `lib/project-service.ts`
- `lib/protected-llm-service.ts`
- `lib/spark-runtime.ts`
- `lib/unified-storage.ts`

### 4. Removed Unnecessary @ts-expect-error Comments
Removed all `@ts-expect-error` comments that were previously needed to suppress the missing property errors (8 from `ai-service.ts` and 2 from `error-repair-service.ts`).

### 5. Updated Spark Runtime Implementation
Enhanced `src/lib/spark-runtime.ts` to fully implement the expected interface:
- Added `llmPrompt` template literal function
- Updated `llm` function to match expected signature
- Updated `user` function to return a Promise with correct shape
- Ensured `kv` methods have proper type signatures

## Verification
All TypeScript errors have been resolved. Running `npx tsc --noEmit` now produces zero errors related to `window.spark`.

## Benefits
1. **Type Safety**: Full TypeScript support for Spark runtime API
2. **IntelliSense**: Developers get autocomplete and type hints when using `window.spark`
3. **Error Prevention**: Compile-time checking prevents runtime errors from incorrect API usage
4. **Maintainability**: Clear, documented interface for the Spark runtime

## Related Systems
The Spark runtime provides:
- **KV Storage**: IndexedDB-backed persistent storage (with optional Flask API backend)
- **LLM Service**: Mock LLM service for AI features
- **User Service**: Mock user authentication and profile data

The implementation correctly defaults to IndexedDB storage, with Flask API as an optional backend that can be enabled via environment variables or UI settings.
