#prefer-expect-resolves

#Configuration

import { defineConfig, rstestPlugin } from '@rslint/core';

export default defineConfig([
  rstestPlugin.configs.recommended,
  {
    rules: {
      'rstest/prefer-expect-resolves': 'error',
    },
  },
]);

#Rule Details

Prefer await expect(promise).resolves.toBe(value) over placing await inside expect(). The resolves modifier describes an unexpected rejection as an assertion failure.

The rule recognizes globals, named and renamed imports, namespace imports, and CommonJS bindings from @rstest/core, rstack/test, and @rstest/playwright. It also recognizes direct import.meta.rstest.expect calls, destructured imports from import.meta.rstest, and test-context expect, including renamed destructuring and the second callback parameter of test.for. Reassigned or locally shadowed bindings are excluded. Copying import.meta.rstest.expect to a variable is not currently recognized.

Single method assertions, including Chai method assertions, are checked. Chai property assertions, chains containing multiple assertions, expect.soft, expect.poll, expect.element, browser locator/page matchers, and chains already using resolves or rejects are excluded. Without type information, the rule checks syntax. With type information, known non-promise values and unions with non-promise alternatives are excluded.

#Incorrect

import { expect, test } from "@rstest/core";

test("loads the account status", async () => {
  expect(await loadAccountStatus()).toBe("active");
});

#Correct

import { expect, test } from "@rstest/core";

test("loads the account status", async () => {
  await expect(loadAccountStatus()).resolves.toBe("active");
});

#Autofix

The fix removes the inner await, adds .resolves after expect(...), and awaits the complete assertion. An existing outer await is retained. Comments and parentheses are preserved.

Automatic fixes require a known thenable type and a built-in value matcher: toBe, toEqual, toStrictEqual, toBeDefined, toBeUndefined, toBeNull, toBeTruthy, toBeFalsy, toBeNaN, the four numeric comparison matchers, toBeCloseTo, toContain, toContainEqual, toHaveLength, toMatch, toMatchObject, toHaveProperty, or toBeInstanceOf. The optional expect message and every matcher argument must be string, number, bigint, boolean, null, or non-interpolated template literals. Expressions such as variables and calls may observe different values when evaluated before the promise settles.

Optional chains, explicit type arguments on expect, custom or locally overridden matchers, and assertions whose result is assigned or passed to another expression are reported without edits. The assertion must be an expression statement, a return value, or directly awaited; parentheses are allowed. Throw, snapshot, and Chai method assertions are reported without edits.

When the promise type is unknown, the rule offers the same rewrite as a suggestion under the edit conditions above. Check that the awaited value is always a promise before applying it: JavaScript await also accepts plain values, while .resolves requires a thenable.