---
title: "Expectation"
source: "https://github.com/remix-run/remix/blob/8905f3943706e1f53696ab83e70a84873cabfc90/packages/assert/src/lib/expect.ts#L177"
---

# Expectation

## Summary

Object returned by [`expect`](/assert/variable/expect/). Exposes the synchronous matcher set
directly on the object, plus the negation and async-resolution gateways
needed for full jest/vitest-style assertions.

## Signature

```ts
interface Expectation {
  not: Matchers
  rejects: AsyncMatchers
  resolves: AsyncMatchers
  toBe(expected: unknown): void
  toBeCloseTo(n: number, precision: number): void
  toBeDefined(): void
  toBeGreaterThan(n: number): void
  toBeGreaterThanOrEqual(n: number): void
  toBeInstanceOf(ctor: Function): void
  toBeLessThan(n: number): void
  toBeLessThanOrEqual(n: number): void
  toBeNull(): void
  toBeTruthy(): void
  toBeUndefined(): void
  toContain(item: unknown): void
  toEqual(expected: unknown): void
  toHaveBeenCalled(): void
  toHaveBeenCalledTimes(n: number): void
  toHaveBeenCalledWith(args: unknown[]): void
  toHaveBeenNthCalledWith(nth: number, args: unknown[]): void
  toHaveLength(n: number): void
  toHaveProperty(key: string, value: unknown): void
  toMatch(re: string | RegExp): void
  toMatchObject(expected: object): void
  toThrow(expected: unknown): void
}

```

## Properties

### `not`

Negates the next matcher — `expect(x).not.toBe(1)` passes when `x !== 1`.

### `rejects`

Awaits the received promise expecting it to reject, then runs the next
matcher against the rejection value. Use with `await`.

### `resolves`

Awaits the received promise expecting it to resolve, then runs the next
matcher against the resolved value. Use with `await`.