tsconfig.json

{
	// CHANGE: Complete rewrite of TypeScript configuration for maximum type safety and Effect compatibility
	// WHY: Remove redundancy (strict flag includes many explicit options), add missing strict checks,
	//      modernize module system for Effect (NodeNext vs CommonJS), enable full verification
	// QUOTE(ТЗ): "Давать проверяемые решения через формализацию и строгую типизацию в функциональной парадигме"
	// REF: REQ-TS-MAX-VERIFICATION
	// SOURCE: TypeScript 5.x documentation - Compiler Options Reference
	//         https://www.typescriptlang.org/tsconfig
	// RATIONALE: strict:true already includes noImplicitAny, strictNullChecks, strictFunctionTypes,
	//            strictBindCallApply, strictPropertyInitialization, noImplicitThis, alwaysStrict,
	//            useUnknownInCatchVariables - explicit duplication removed for clarity

	"compilerOptions": {
		// ═══════════════════════════════════════════════════════════════════════════
		// STRICTNESS CORE (single flag enables 8 checks)
		// ═══════════════════════════════════════════════════════════════════════════
		"strict": true,
		"alwaysStrict": true,
		// Automatically enables:
		//   - noImplicitAny: reject implicit any types
		//   - strictNullChecks: null/undefined not assignable to other types
		//   - strictFunctionTypes: contravariant function parameter checking
		//   - strictBindCallApply: strict checking of bind/call/apply
		//   - strictPropertyInitialization: class properties must be initialized
		//   - noImplicitThis: this must have explicit type
		//   - alwaysStrict: emit "use strict" in JS output
		//   - useUnknownInCatchVariables: catch clause variables are unknown not any

		// ═══════════════════════════════════════════════════════════════════════════
		// ADDITIONAL STRICT CHECKS (not included in strict)
		// ═══════════════════════════════════════════════════════════════════════════
		"noUnusedLocals": true,
		"noUnusedParameters": true,
		"noImplicitReturns": true,
		"noFallthroughCasesInSwitch": true,
		"exactOptionalPropertyTypes": true,
		"noUncheckedIndexedAccess": true,
		"noImplicitOverride": true,
		"noPropertyAccessFromIndexSignature": true,
		"allowUnusedLabels": false,
		"allowUnreachableCode": false,

		// CHANGE: Add verbatimModuleSyntax for explicit import control
		// WHY: Require explicit type keyword for type-only imports, better bundler compatibility
		"verbatimModuleSyntax": true,

		// ═══════════════════════════════════════════════════════════════════════════
		// MODULE SYSTEM (modernized for Effect and ESM)
		// ═══════════════════════════════════════════════════════════════════════════
		// CHANGE: Switch from CommonJS to NodeNext
		// WHY: Effect library designed for modern ESM, NodeNext provides best compatibility
		//      with both ESM and CJS, enables package.json "exports" field support
		"target": "ES2022",
		"module": "NodeNext",
		"moduleResolution": "NodeNext",
		"lib": ["ES2022"],

		"esModuleInterop": true,
		"allowSyntheticDefaultImports": true,
		"resolveJsonModule": true,

		// CHANGE: Keep isolatedModules for esbuild/swc compatibility
		// WHY: Each file must be compilable independently, critical for fast build tools
		"isolatedModules": true,

		// ═══════════════════════════════════════════════════════════════════════════
		// TYPE CHECKING CONTROL
		// ═══════════════════════════════════════════════════════════════════════════
		// CHANGE: Set skipLibCheck to false for maximum verification
		// WHY: Full type checking of declaration files ensures library type correctness
		// TRADEOFF: Increases compilation time 2-3x, but ensures complete type safety
		// NOTE: For development speed, can temporarily set to true, but CI must use false
		"skipLibCheck": false,

		"forceConsistentCasingInFileNames": true,

		// ═══════════════════════════════════════════════════════════════════════════
		// OUTPUT CONFIGURATION
		// ═══════════════════════════════════════════════════════════════════════════
		// NOTE: Moved emission-related options to project configs (tsconfig.src.json, tsconfig.test.json)
		// WHY: Root (solution) tsconfig must not define outDir/tsBuildInfoFile to avoid TS6377 collisions

		// ═══════════════════════════════════════════════════════════════════════════
		// PATH RESOLUTION
		// ═══════════════════════════════════════════════════════════════════════════
		"baseUrl": ".",
		"paths": {
			"@/*": ["src/*"]
		}
	},

	// ═══════════════════════════════════════════════════════════════════════════
	// PROJECT STRUCTURE
	// ═══════════════════════════════════════════════════════════════════════════
	"include": ["src/**/*", "test/**/*"],
	"exclude": ["node_modules", "dist"]
}