Strict null checks active

With strictNullChecks disabled, null and undefined are subtypes of every type — string implicitly includes null. This means the compiler cannot warn when you call .trim() on a value that could be null, or access .user.name on a possibly-undefined response. ISO 25010:2011 §6.5.4 classifies null-safety gaps as reliability defects. Null pointer exceptions are one of the most common runtime crashes in production JavaScript: nearly always preventable, never fun to debug from a Sentry alert.

Enable strictNullChecks via strict: true in tsconfig.json. During migration, the compiler will surface every place where null or undefined could flow into a non-nullable type — fix each with optional chaining, null guards, or explicit non-null assertions with a comment.

// Errors with strictNullChecks: user might be null
const name = user.name;

// Fixed: optional chaining
const name = user?.name ?? 'Anonymous';

// Fixed: explicit guard
if (user === null) throw new Error('User not authenticated');
const name = user.name;