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What is the purpose of the assert module in Node.js?

Q: What is the purpose of the assert module in Node.js?

**TL;DR.** node:assert provides **assertion** functions that throw an AssertionError when a condition is false. It's the foundation for **tests** (used by node:test ) and for enforcing **invariants** in code. Prefer the **strict** mode ( node:assert/strict ) so comparisons use === semantics. assert(condition) check invariant true → pass <

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This assesses the candidate's understanding of native testing and assertion mechanisms within Node.js.

testingmodulesassert

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Strict assertions in a test

import assert from 'node:assert/strict';

assert.equal(2 + 2, 4);
assert.deepStrictEqual({ a: [1, 2] }, { a: [1, 2] });   // structural
assert.throws(() => JSON.parse('{bad}'), SyntaxError);

// guarding an invariant in code:
function area({ w, h }) { assert(w > 0 && h > 0, 'dims must be positive'); return w * h; }

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