ESLint 9 vs TypeScript 5.7 Strict Mode: Bug Detection Rate Comparison Modern JavaScript and TypeScript development relies heavily on static analysis tools to catch bugs before runtime. Two of the most widely used tools are ESLint (the industry-standard linter) and TypeScript’s strict mode (type-checking system). With ESLint 9 rolling out performance improvements and new rules, and TypeScript 5.7 introducing stricter type checks and bug fixes, developers are asking: which catches more bugs? This article breaks down real-world test results to compare their bug detection rates. Testing Methodology To ensure fair, reproducible results, we designed a test suite across three categories of codebases: 10 open-source TypeScript projects (1k–50k lines of code) from GitHub, spanning React, Node.js, and utility libraries. 50 synthetic test cases designed to trigger common bug patterns: null/undefined access, type mismatches, unreachable code, unused variables, and race conditions.…