Posts tagged “strict-mode”
6 posts found
TypeScript 6.0 Strict Function Types: Why Contravariance Breaks Your Existing Callbacks
August 18, 2026
TypeScript 6.0 makes strictFunctionTypes the default, breaking callbacks that relied on bivariant parameter checking. Learn why contravariance matters and how to migrate production code without sacrificing type safety.
TypeScript 6.0 `--noPropertyAccessFromIndexSignature`: The Flag That Forces Honest API Contracts
August 11, 2026
Most runtime property access errors stem from index signatures pretending to guarantee properties they don't. This flag exposes the lie and forces honest API contracts.
TypeScript exactOptionalPropertyTypes: The Strict Flag That Catches the Bugs strict Misses
July 27, 2026
Most production TypeScript bugs stem from a single assumption: that strict mode catches every type safety hole. It doesn't. The exactOptionalPropertyTypes flag exposes runtime crashes that strict mode silently permits—here's why teams overlook it and how to fix it.
Strict Mode Isn't Enough: Using TypeScript's New Variance Annotations to Catch Subtle Generic Bugs
June 26, 2026
Most generic type bugs stem from variance issues that strict mode doesn't catch. TypeScript's new 'in' and 'out' annotations finally give developers explicit control over covariance and contravariance in generic parameters.
TypeScript Strict Migration in 2026: Upgrading a Real Codebase to TS 6.0 Defaults Step by Step
June 16, 2026
The engineering playbook for migrating production TypeScript codebases to TS 6.0 strict defaults—without breaking your build or losing velocity.
TypeScript 6.0 Released: Strict Mode by Default, ES5 Dropped, and Why This Is a Breaking Migration
June 15, 2026
TypeScript 6.0 ships with strict mode enabled by default, drops ES5 support, and changes module resolution. Here's how to migrate production codebases without breaking CI pipelines.