What is the output of this require cache example?

Direct answer

Output: module run, 1, 2, true — the module body runs once; both requires share the same exports object; increment mutates shared state (Q36).

This tests require.cache singleton behavior — a frequent follow-up to module caching and exports questions.

require-cache

// counter.cjs
console.log("module run");
let count = 0;
module.exports = {
  inc() { return ++count; },
};

// main.cjs
const a = require("./counter.cjs");
const b = require("./counter.cjs");

console.log(a.inc());
console.log(b.inc());
console.log(a === b);

Output

module run
1
2
true

module run once — second require hits cache; body does not re-execute.
1 then 2 — shared count variable across both references.
true — a and b reference identical exports object.