TypeScript 6. 0 Strict Function Types: Why Contravariance Breaks Your Existing Callbacks This article was written with the assistance of AI, under human supervision and review. Most TypeScript migration failures stem from a single misunderstood compiler flag: strictFunctionTypes .
Source: [Dev.to](https://dev.to/jsmanifest/typescript-60-strict-function-types-why-contravariance-breaks-your-existing-callbacks-5enk)