Instruction file imported from PaulJPhilp/wetware-software (.cursor/rules/strict-typing-and-type-safety.mdc). Copyright stays with the author.

Strict Typing & Type Safety

Rule: Avoid any, enable strict mode in tsconfig.json, use readonly, explicit return types, and precise types where possible.

Why

• Catches bugs at compile time
• Improves developer confidence
• Enables more robust tooling support

Bad Example

function process(input: any): any {
  return JSON.parse(input)
}

Using any loses type safety.

Good Example

interface Input { a: number; b: string }
function process(input: string): Input {
  const obj = JSON.parse(input) as Input
  return { a: obj.a, b: obj.b }
}

Or even better:

function process(input: string): Input {
  return JSON.parse(input)
}

with correct type annotations and checks.

Tips

•In tsconfig.json, set "strict": true and related flags (noImplicitAny, strictNullChecks, etc.). •Use readonly for properties that should not change. •Explicitly annotate function return types, especially public APIs. •Prefer union / literal types / discriminated unions over any or unknown when possible.