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unused-internal-properties

Disallow object properties that are defined but never read.

Targeted pattern scope​

This rule targets object literal properties.

What this rule reports​

This rule reports properties that are declared but never consumed.

Why this rule exists​

Dead properties make object shapes noisy and increase long-term maintenance cost.

❌ Incorrect​

const data = {
 used: 1,
 unused: 2,
};

console.log(data.used);

✅ Correct​

const data = {
 used: 1,
 alsoUsed: 2,
};

console.log(data.used + data.alsoUsed);

Behavior and migration notes​

This rule forwards options and behavior to unicorn/no-unused-properties.

Additional examples​

const result = {
 id: 1,
 debug: true,
};
console.log(result.id);
// ❌ `debug` is never read

const resultFixed = {
 id: 1,
 debug: true,
};
console.log(resultFixed.id, resultFixed.debug);
// ✅ valid

ESLint flat config example​

import etcMisc from "eslint-plugin-etc-misc";

export default [
 {
  plugins: { "etc-misc": etcMisc },
  rules: {
   "etc-misc/unused-internal-properties": "error",
  },
 },
];

When not to use it​

Disable this rule when object literals intentionally include reserved fields for external contracts.

Package documentation​

Rule catalog ID: R077

Further reading​

Adoption resources​

  • Start at warning level in CI, then move to error after cleanup.
  • Use focused codemods/autofix batches per package or directory.