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typescript/no-inferrable-types

Disallow explicit primitive type annotations when the type is inferrable.

Targeted pattern scope​

This rule targets type annotations on:

  • class property definitions initialized with literal values, and
  • variable declarators initialized with literal values.

What this rule reports​

This rule reports explicit annotations where a literal initializer already provides obvious type information.

Why this rule exists​

Removing redundant literal-based annotations can reduce noise and keep declarations concise.

❌ Incorrect​

const value: number = 1;

✅ Correct​

const value = 1;

Deprecated​

Behavior and migration notes​

This rule is deprecated in favor of @typescript-eslint/no-inferrable-types.

It reports only and does not provide an autofix.

Options​

This rule has no options.

Status​

Use the Deprecated section above for lifecycle details.

Additional examples​

class Counter {
 count: number = 0;
 // ❌ reported
}

class CounterFixed {
 count = 0;
 // ✅ valid
}

ESLint flat config example​

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

export default [
 {
  plugins: { "etc-misc": etcMisc },
  rules: {
   "etc-misc/typescript/no-inferrable-types": "error",
  },
 },
];

When not to use it​

Disable this rule if explicit primitive annotations are required for readability.

Package documentation​

Rule catalog ID: R089

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.