TypeScript24 min readTypeScript Error Handling Patterns
Model errors using types instead of throwing blindly, building safer and more predictable flows.
Errors should also be typed. ## Result pattern ```ts type Ok<T> = { ok: true; value: T }; type Err = { ok: false; error: string }; type Result<T> = Ok<T> | Err; ``` ## Function returning Result ```ts function parseNum(s: string): Result<number> { const n = Number(s); return isNaN(n) ? { ok: false, error: "Not a number" } : { ok: true, value: n }; } ``` ## Use it ```ts const r = parseNum("10"); if (r.ok) { console.log(r.value); } else { console.error(r.error); } ``` ## Graph ```mermaid flowchart TD A[Function] --> B{ok?} B -->|Yes| C[Value] B -->|No| D[Error] ``` ## Remember - Types can model success and failure - Reduces runtime surprises