oxc-project/oxc · error · OxcDiagnostic

`expect.{member_name}` must be awaited or returned

Error message

`expect.{member_name}` must be awaited or returned

What it means

Emitted by the vitest/require-awaited-expect-poll rule at an `expect.poll(...)` / `expect.element`-style call that is neither awaited nor returned from the test. Un-awaited poll assertions resolve asynchronously, so the test can finish before the assertion ever runs, silently passing without checking anything.

Source

Thrown at crates/oxc_linter/src/rules/vitest/require_awaited_expect_poll.rs:16

use oxc_allocator::GetAddress;
use oxc_ast::AstKind;
use oxc_diagnostics::OxcDiagnostic;
use oxc_macros::declare_oxc_lint;
use oxc_span::Span;

use crate::{
    AstNode,
    context::LintContext,
    rule::Rule,
    rules::PossibleJestNode,
    utils::{KnownMemberExpressionProperty, parse_expect_and_typeof_vitest_fn_call},
};

fn require_awaited_expect_poll_diagnostic(span: Span, member_name: &str) -> OxcDiagnostic {
    OxcDiagnostic::warn(format!("`expect.{member_name}` must be awaited or returned"))
        .with_help(format!("Add `await` to the `expect.{member_name}` call."))
        .with_label(span)
}

fn require_awaited_expect_poll_return_diagnostic(span: Span, member_name: &str) -> OxcDiagnostic {
    OxcDiagnostic::warn(format!("`expect.{member_name}` must be awaited or returned as the last expression"))
          .with_help(format!("Add `await` to the `expect.{member_name}` call or move it to the last position in the sequence."))
          .with_label(span)
}

#[derive(Debug, Default, Clone)]
pub struct RequireAwaitedExpectPoll;

declare_oxc_lint!(
    /// ### What it does
    ///
    /// This rule ensures that promises returned by `expect.poll` and `expect.element` calls are handled properly.
    ///

View on GitHub (pinned to e1e7af627c)

Solutions

1. Add `await` to the `expect.poll(...)` call
2. Or return the assertion from the test callback so it is awaited by the runner

When it happens

Trigger: Thrown at crates/oxc_linter/src/rules/vitest/require_awaited_expect_poll.rs:16 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of oxc-project/oxc@e1e7af627c (2026-08-20). Data as JSON: /api/errors/2ec95ea930389374. Report an issue: GitHub.