oxc-project/oxc · error · OxcDiagnostic

Do not use `new` on `Promise.{static_name}`

Error message

Do not use `new` on `Promise.{static_name}`

What it means

Diagnostic from the oxlint rule `promise/no-new-statics` (plugin `promise`). It fires on any `new` expression whose callee is a static member of `Promise` (from the PROMISE_STATIC_METHODS surface, e.g. `new Promise.resolve()`, `new Promise.all()`, `new Promise.reject()`). These statics are plain functions, not constructors, so `new` throws `TypeError: Promise.resolve is not a constructor` at runtime when the line executes.

Source

Thrown at crates/oxc_linter/src/rules/promise/no_new_statics.rs:9

use oxc_ast::{AstKind, ast::Expression};
use oxc_diagnostics::OxcDiagnostic;
use oxc_macros::declare_oxc_lint;
use oxc_span::Span;

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

fn static_promise_diagnostic(static_name: &str, span: Span) -> OxcDiagnostic {
    OxcDiagnostic::warn(format!("Do not use `new` on `Promise.{static_name}`"))
        .with_help(format!(
            "`Promise.{static_name}` is not a constructor. Call it as a function instead."
        ))
        .with_label(span)
}

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

declare_oxc_lint!(
    /// ### What it does
    ///
    /// Disallows calling new on static `Promise` methods.
    ///
    /// ### Why is this bad?
    ///
    /// Calling a static `Promise` method with `new` is invalid and will result
    /// in a `TypeError` at runtime.

View on GitHub (pinned to e1e7af627c)

Solutions

1. Drop `new` and call the static directly: `Promise.resolve(value)`
2. If you truly need a fresh `Promise` instance object, wrap: `Promise.resolve(Promise.all(iterable))`
3. Run `tsc --noEmit` alongside oxlint - TypeScript also rejects this with ts(2350) 'This expression is not constructable'

Example fix

// before
const p = new Promise.all([fetchA(), fetchB()])

// after
const p = Promise.all([fetchA(), fetchB()])

npx oxlint --promise/no-new-statics src/
# and at compile time:
tsc --noEmit  # ts(2350): This expression is not constructable.

// TypeScript's lib.es2015.promise.d.ts declares statics without construct signatures,
// so `new Promise.resolve(x)` fails type-check with ts(2350).
// Guard = keep files inside a tsconfig project and run `tsc --noEmit` in CI.

// last-resort runtime containment while fixing the code:
try {
  const p = new Promise.all(xs)
} catch (e) {
  if (e instanceof TypeError && /not a constructor/.test(e.message)) {
    // statics are plain functions - drop `new`
  }
  throw e
}

When it happens

Trigger: `const p = new Promise.resolve(value)`; `new Promise.all([a, b])`; any `new Promise.<static>()` where `<static>` is resolve/reject/all/allSettled/any/race/withResolvers/try.

Common situations: Muscle memory from `new Promise(executor)` applied to the shorter static forms; autocomplete inserting `new`; porting snippets between promise construction styles.

Related errors

• Promise executor functions should not be `async`.
• Unexpected `await` inside a loop.
• Avoid nesting promises.
• Avoid using promises inside of callbacks.
• Don't return in a finally callback

AI-assisted analysis of oxc-project/oxc@e1e7af627c (2026-08-20). Data as JSON: /api/errors/902d1c56c5b2c6a8. Report an issue: GitHub.