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no-location-mutation

Disallow in-place mutation of browser location state.

Targeted pattern scope​

This rule targets global location objects (location, window.location, self.location, globalThis.location) and aliases when mutation APIs are used or location properties are assigned/deleted/updated.

What this rule reports​

  • location.assign(...)
  • location.reload(...)
  • location.replace(...)
  • Property assignments/deletes/updates on location and tracked aliases (for example location.href = ...)

Why this rule exists​

location represents process-wide browser navigation state. Mutating it in place triggers implicit global effects and makes control flow harder to reason about in immutable architectures.

This rule enforces immutable navigation intent by preventing direct location mutations.

❌ Incorrect​

location.href = "https://example.com";

✅ Correct​

const currentPath = location.pathname;

Additional examples​

// ❌ Mutates global navigation state
const navLocation = location;
navLocation.replace("/account");

// ✅ Read-only location usage
const navLocation = location;
navLocation.pathname;

ESLint flat config example​

import immutable from "eslint-plugin-immutable-2";

export default [
    {
        files: ["**/*.{js,mjs,cjs,ts,mts,cts,tsx}"],
        plugins: { immutable },
        rules: {
            "immutable/no-location-mutation": "error",
        },
    },
];

When not to use it​

If your runtime intentionally performs direct browser redirects in a narrow infrastructure layer, this rule may be too strict for those files.

Rule catalog ID: R930

Further reading​