typescript-expert

Strict type safety in TypeScript is enforced through strict mode configuration and type guards that prevent null/undefined errors and catch type mismatches at compile time. Enable `strict: true` in tsconfig.json, implement discriminated unions for exhaustive type checking, and use type guard patterns to safely narrow types before runtime operations.

Configure ESLint for TypeScript by pairing it with typescript-eslint parser and plugins, then enable rules that enforce strict type checking across .ts and .tsx files. This catches type-related violations during linting and maintains consistency with your strict TypeScript configuration for robust, maintainable code.

Null handling in TypeScript uses strict null checks combined with type guards—conditional checks that verify a value exists before use. Patterns include optional chaining, nullish coalescing, and explicit type narrowing with if statements or discriminated unions to prevent null reference errors.

Yes, ESLint and type-checking patterns apply to .js, .jsx, .ts, and .tsx files. While TypeScript provides compile-time checks in .ts files, ESLint can enforce type-safety conventions in JavaScript files using JSDoc annotations and linting rules for consistent code quality across your mixed project.

Discriminated unions are TypeScript types that combine a literal field with variant types, enabling exhaustive type checking. Use them when handling multiple related object shapes—like API responses or state machines—to ensure all cases are handled and catch missing branches at compile time.

Strict TypeScript configuration catches type errors early, reducing bugs in production and maintenance burden. For scalable projects, it enforces uniform type discipline across teams, prevents unsafe patterns, and makes refactoring safer by ensuring type contracts are upheld throughout the codebase.