Feature Request: Support MockAppSheetClient injection in SchemaManager

[wagnert]

Problem

SchemaManager cannot be used with MockAppSheetClient for testing because:

1. SchemaManager constructor only accepts SchemaConfig, not a pre-configured ConnectionManager
2. ConnectionManager.register() only accepts ConnectionConfig and always creates a new AppSheetClient internally

This makes it impossible to inject a MockAppSheetClient for unit/integration testing while using the SchemaManager API with its automatic validation features.

Current API (v2.1.0)

// SchemaManager creates its own ConnectionManager internally
const schemaManager = new SchemaManager(schema);

// ConnectionManager only accepts config, not a ready client
connectionManager.register(config: ConnectionConfig);  // Always creates new AppSheetClient

Proposed API

Option 1: SchemaManager accepts optional ConnectionManager

export class SchemaManager {
  constructor(schema: SchemaConfig, connectionManager?: ConnectionManager) {
    this.schema = schema;
    this.connectionManager = connectionManager || new ConnectionManager();
    if (!connectionManager) {
      this.initialize(); // Only auto-initialize if no ConnectionManager provided
    }
  }
}

Option 2: ConnectionManager.registerClient() method

export class ConnectionManager {
  // Existing method - creates new client from config
  register(config: ConnectionConfig): void;
  
  // NEW method - accepts pre-created client
  registerClient(name: string, client: AppSheetClientInterface): void {
    if (this.connections.has(name)) {
      throw new Error(`Connection "${name}" is already registered`);
    }
    this.connections.set(name, client);
  }
}

Use Case: TSyringe DI with Mock Support

// container.base.ts
export function registerSchemaManager(c: DependencyContainer): void {
  c.register(TOKENS.SchemaManager, {
    useFactory: (container) => {
      const client = container.resolve(TOKENS.AppSheetClient); // Real or Mock
      const schema = SchemaLoader.fromJson('config/appsheet-schema.json');
      const connectionManager = new ConnectionManager();
      connectionManager.registerClient('default', client); // ← NEW API
      return new SchemaManager(schema, connectionManager); // ← NEW API
    }
  });
}

// container.development.ts - Uses MockAppSheetClient
registerMockAppSheetClient(container);
registerSchemaManager(container); // SchemaManager uses MockAppSheetClient

// container.production.ts - Uses real AppSheetClient
registerRealAppSheetClient(container);
registerSchemaManager(container); // SchemaManager uses real AppSheetClient

Benefits

• Testability: Unit/integration tests can use MockAppSheetClient with full SchemaManager features
• DI Support: Works with TSyringe, InversifyJS, and other DI containers
• Validation: DynamicTable runtime validation still works (the core value of SchemaManager)
• Backward Compatible: Existing code using new SchemaManager(schema) continues to work

Related

• This is a follow-up to Issue Feature Request: Add per-request email support to DynamicTable API #3 (Per-request user context)
• Enables full adoption of SchemaManager API in projects using DI patterns

[wagnert]

Implemented in v3.0.0 via Factory Injection Pattern. See PR #8.