unicorn/prefer-node-protocol

import fs from "fs" looks like it imports an npm package. node:fs makes it obvious that the module is built in.

The rule checks import, export { ... } from, import(), require() and TypeScript's import fs = require("fs").

--fix adds the prefix.

Configure

Off by default. To turn it on:

[lint.rules]
"unicorn/prefer-node-protocol" = "error" # or "warn"

Examples

Reported:

import fs from "fs";
import { readFile } from "fs/promises";
export { EventEmitter } from "events";

const os = await import("os");

Not reported:

import fs from "node:fs";
import { readFile } from "node:fs/promises";
export { EventEmitter } from "node:events";

const os = await import("node:os");

Packages and your own files aren't reported:

import express from "express";
import fs from "./fs.js";