javascript / intermediate
Snippet
Internal State Validation with Node.js Assert
The 'node:assert' module provides functions for verifying internal invariants. While not a replacement for user input validation, it is essential for defensive programming to ensure that logic assumptions remain true during execution.
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import assert from 'node:assert';function processOrder(price, quantity) {assert(typeof price === 'number', 'Price must be a number');assert(quantity > 0, 'Quantity must be at least 1');const total = price * quantity;assert.strictEqual(total, price * quantity, 'Calculation integrity failure');return total;}try {processOrder(19.99, -1);} catch (err) {console.log('Validation failed:', err.message);}
nodejs
Breakdown
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import assert from 'node:assert';
Imports the built-in assertion module for Node.js.
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assert(condition, message);
Throws an AssertionError if the condition evaluates to false.
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assert.strictEqual(a, b, msg);
Ensures that two values are identical using strict equality (===).