tsconfig.json

// TypeScript configuration for this Office Scripts project and its tests.
//
// - We set "strictNullChecks" to false because Office Scripts APIs return 'undefined' in many cases
//   where TypeScript would expect 'null', and enabling strict null checks would cause excessive
//   type errors or force verbose code without practical benefit in this context.
//
// - "mocks" and "wrappers" directories are included for testability and local development:
//     * "mocks" provides stand-ins for Office Scripts APIs, enabling unit testing outside Excel online.
//     * "wrappers" adapt Office Scripts APIs to be more test-friendly and to allow dependency injection.
//
// - All strict type checks except strictNullChecks are enabled for code quality.
// - Side comments explain individual settings inline.
// - This config includes all code folders for full IntelliSense in VS Code. For a production-only build, use a separate config if needed.
//
// - "typeRoots" specifies directories where TypeScript should look for type definition files (*.d.ts).
//     * "./types" is included to provide Office Scripts and custom global type definitions for this project.
//     * "./node_modules/@types" is included for compatibility with community and built-in type packages (e.g., for Node.js or testing frameworks).
//     * Only .d.ts files in these folders will be included for global types, so make sure all necessary type definitions are placed accordingly.
//
{
  "compilerOptions": {
    "emitDeclarationOnly": true, // Only output .d.ts files, not .js
    "declaration": true, // Generate type declaration files
    "outDir": "dist", // Output directory for build artifacts
    "rootDir": ".", // Project root as rootDir to capture all code
    "module": "commonjs", // Module system for output
    "target": "es2019", // Set JS target (irrelevant here, but required)
    "strict": true, // Enable all strict type-checking options
    "strictNullChecks": false, // Disable strict null/undefined checks (see note above)
    "esModuleInterop": true, // Enable compatibility for ES modules/CommonJS imports
    "typeRoots": [
      "./types",                // Look for custom and Office Scripts type definitions here
      "./node_modules/@types"   // Standard location for community-provided type definitions
    ]
  },
  "include": [
    "src/**/*",
    "test/**/*",
    "mocks/**/*",
    "wrappers/**/*",
    "types/**/*.d.ts"
  ],
  "exclude": [
    "dist",
    "node_modules"
  ]
}