TS2564: Property has no initializer - in CI

By Kaveh Alemi·Latchkey

With strictPropertyInitialization on, a class property is neither initialized nor definitely assigned in the constructor.

What this error means

Type-checking fails with TS2564 naming the uninitialized property on a class.

src/user.ts(2,3): error TS2564: Property 'name' has no initializer and is not definitely assigned in the constructor.

Common causes

How to fix it

Initialize or assign in the constructor

1. Give the property a default, or assign it in the constructor

class User {
  name = ""
}

Use the definite assignment assertion

1. When a framework guarantees assignment, mark it with ! to opt out

class User {
  name!: string
}

How to prevent it

• Initialize class fields or use the definite-assignment ! only where a framework truly sets them.

Frequently asked questions

Related guides

References

• Node.js documentation
• npm CLI documentation
• GitHub Actions documentation