code-gen-independent
Understand That Code Generation Is Independent of Types
Overview
TypeScript compilation and type checking are separate processes.
The TypeScript compiler does two things: (1) transpile TypeScript to JavaScript, and (2) check types. These are independent - type errors don't prevent code generation, and types don't exist at runtime.
When to Use This Skill
- Confused why code runs despite type errors
- Trying to check types at runtime
- Using instanceof with interfaces
- Expecting types to affect runtime behavior
The Iron Rule
NEVER expect TypeScript types to exist at runtime. They are erased.
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