oxc-project/oxc · error · OxcDiagnostic

`Promise.{prop_name}()` requires 1 or 2 arguments, but recei

Error message

`Promise.{prop_name}()` requires 1 or 2 arguments, but received {args_len}.

What it means

Diagnostic from the oxlint rule `promise/valid-params` (plugin `promise`, category `correctness`). It fires when `.then(...)` is called with an argument count other than 1 or 2 (0 callbacks, or 3+). `then` takes an optional fulfillment handler and an optional rejection handler - a third argument does nothing, and zero arguments means the call is a pure no-op that still allocates a new promise.

Source

Thrown at crates/oxc_linter/src/rules/promise/valid_params.rs:24

use crate::{AstNode, context::LintContext, rule::Rule, utils::is_promise_with_context};

fn zero_or_one_argument_required_diagnostic(
    span: Span,
    prop_name: &str,
    args_len: usize,
) -> OxcDiagnostic {
    OxcDiagnostic::warn(format!(
        "`Promise.{prop_name}()` requires 0 or 1 arguments, but received {args_len}."
    ))
    .with_label(span)
}

fn one_or_two_argument_required_diagnostic(
    span: Span,
    prop_name: &str,
    args_len: usize,
) -> OxcDiagnostic {
    OxcDiagnostic::warn(format!(
        "`Promise.{prop_name}()` requires 1 or 2 arguments, but received {args_len}."
    ))
    .with_label(span)
}

fn one_argument_required_diagnostic(span: Span, prop_name: &str, args_len: usize) -> OxcDiagnostic {
    OxcDiagnostic::warn(format!(
        "`Promise.{prop_name}()` requires 1 argument, but received {args_len}."
    ))
    .with_label(span)
}

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

declare_oxc_lint!(
    /// ### What it does
    ///

View on GitHub (pinned to e1e7af627c)

Solutions

1. Pass exactly one or two handler functions to `then`
2. Move cleanup logic to `.finally(fn)` instead of a third `then` argument
3. Delete empty `.then()` links from the chain
4. Add `tsc --noEmit` to CI so arity errors surface at compile time

Example fix

// before
p.then(onSuccess, onFailure, onFinally)

// after
p.then(onSuccess, onFailure).finally(onFinally)

npx oxlint --promise/valid-params src/
tsc --noEmit  # flags then() with 0 or 3+ args via ts(2554)

// lib signature: then<TResult1, TResult2>(
//   onfulfilled?: ((value: T) => TResult1 | PromiseLike<TResult1>) | null,
//   onrejected?: ((reason: any) => TResult2 | PromiseLike<TResult2>) | null
// ): PromiseLike<TResult1 | TResult2>;  // exactly 2 optional params - a 3rd arg fails tsc

When it happens

Trigger: `somePromise().then()` (0 args); `somePromise().then(a, b, c)` (3+ args); `promiseReference.then(() => {}, () => {}, () => {})`.

Common situations: Passing a third callback intended as a finally-style handler; refactoring that deleted the callback but left `.then()`; spreading arrays of handlers into `then`.

Related errors

• `Promise.{prop_name}()` requires 0 or 1 arguments, but recei
• `Promise.{prop_name}()` requires 1 argument, but received {a
• Promise executor functions should not be `async`.
• Unexpected `await` inside a loop.
• Avoid nesting promises.

AI-assisted analysis of oxc-project/oxc@e1e7af627c (2026-08-20). Data as JSON: /api/errors/e5ea916bf53b689e. Report an issue: GitHub.