ts-r
  • Error
  • Reported by the type checker

TS2531

Object is possibly 'null'.

An object that may be null is accessed or called. Check for null first, or use optional chaining.

What it means

With strictNullChecks, a value whose type includes null can't be used as an object until the null case is handled. This form of the message is used when the expression has no simple name to show; with a name, the message is the newer 'x' is possibly 'null'.

Example

index.ts
declare function find(): { name: string } | null;
export const n = find().name;
ts-r-check -p tsconfig.json --pretty false ts-r output
index.ts(2,18): error TS2531: Object is possibly 'null'.

Recorded by node scripts/verify-examples.mjs with ts-r built from commit 6deaf01. The example uses the default tsconfig: strict, target: es2022, module: esnext, moduleResolution: bundler.

How to fix

  • Check first: const r = find(); if (r) { r.name }.
  • Use optional chaining and a default: find()?.name ?? "".
  • Change the function so it can't return null, if that's never meant to happen.