typeforce

var typeforce = require('typeforce'); var typeforceNoThrow = require('typeforce/nothrow'); // Define some data var user = { id: 123, name: 'Alice' }; var product = { id: 456, price: 10.99 }; var inventory = [user, product]; var configTuple = ['development', 8080]; // Basic type checking for primitives typeforce('Array', inventory); // OK typeforce('Number', 123); // OK // Array of a specific type (e.g., objects with an ID and a string name) typeforce(typeforce.arrayOf({ id: 'Number', name: 'String' }), [user]); // Recursive type templating for objects with optional properties typeforce({ id: 'Number', name: '?String', price: '?Number' }, product); // Sum types (anyOf) and intersection types (allOf) typeforce(typeforce.anyOf('String', 'Number'), 'foobar'); // 'foobar' is String typeforce(typeforce.allOf({ x: typeforce.Number }, { y: typeforce.String }), { x: 1, y: '2' }); // Both properties must match // Custom type definition (e.g., a specific length string) function HexString32(value) { return typeforce.String(value) && /^[0-9a-fA-F]{32}$/.test(value); } typeforce(HexString32, 'a0b1c2d3e4f5a0b1c2d3e4f5a0b1c2d3'); // OK! // Using the non-throwing version for graceful error handling var potentiallyBadValue = 'this is not a number'; if (!typeforceNoThrow(typeforceNoThrow.Number, potentiallyBadValue)) { console.log(`Error caught by no-throw: ${typeforceNoThrow.error.message}`); } // Protip: use precompiled types for performance on repeated checks var compiledSchema = typeforce.compile({ id: typeforce.Number, timestamp: typeforce.Number }); compiledSchema({ id: 1, timestamp: Date.now() }); // Fast check! // Protip: enforce strictness to disallow extra properties typeforce({ a: 'Number' }, { a: 1 }, true); // OK try { typeforce({ a: 'Number' }, { a: 1, b: 2 }, true); // This will throw an error } catch (e) { console.log(`Strict check error: ${e.message}`); }