import/unambiguous Restriction

What it does

Warn if a module could be mistakenly parsed as a script and not pure ESM module

Why is this bad?

For ESM-only environments helps to determine files that not pure ESM modules

Examples

Examples of incorrect code for this rule:

function x() {}

(function x() {
  return 42;
})();

Examples of correct code for this rule:

import "foo";
function x() {
  return 42;
}

export function x() {
  return 42;
}

(function x() {
  return 42;
})();
export {}; // simple way to mark side-effects-only file as 'module' without any imports/exports

References

• Rule Source