curiouser / gist:d61c2d421e064cff8aa10c524e46ac5e

#!/usr/bin/env node const currentYear = new Date().getFullYear(); const adjustments = { exteriorColor: { black: 1000, blue: -500, burgundy: 500, charcoal: 500, deepBlue: 250, silver: 0, white: 250, }, interiorColor: { dark: 0, light: 500, mixed: -250, }, miles: [ 5000, 150 ], year: [ 1, 750 ], }; const benchmark = { exteriorColor: 'silver', interiorColor: 'dark', miles: 100000, price: 10357, year: 2016, }; const [ price, year, miles, exteriorColor, interiorColor ] = process.argv.slice(2); // args list length if (process.argv.slice(2).length !== 5) { throw new Error(`Expected exactly 5 args, found ${process.argv.slice(2).length}`); } // 1st 3 args should be numbers [ price, year, miles ].forEach((number, i) => { if (isNaN(number)) { throw new Error(`arg #${number + 1} should be number`); } }); // 4th arg should be enumerated if (!Object.keys(adjustments.exteriorColor).includes(exteriorColor)) { throw new Error(`4th arg (exteriorColor) must be in list ${Object.keys(adjustments.exteriorColor).join(', ')}`); } // 5th arg should be enumerated if (!Object.keys(adjustments.interiorColor).includes(interiorColor)) { throw new Error(`5th arg (interiorColor) must be in list ${Object.keys(adjustments.interiorColor).join(', ')}`); } const benchYearsOld = currentYear - benchmark.year; const yearsOld = currentYear - Number(year); function calcAdjustment (benchValue, value, [ quantifier, valueAdjustment ] = [ 1, 1 ]) { return (Number(value) - benchValue) / quantifier * valueAdjustment; } let adjustedPrice = Number(price); adjustedPrice += calcAdjustment(benchmark.miles, miles, adjustments.miles); adjustedPrice += calcAdjustment(benchYearsOld, yearsOld, adjustments.year); adjustedPrice += calcAdjustment(0, adjustments.exteriorColor[exteriorColor]); adjustedPrice += calcAdjustment(0, adjustments.interiorColor[interiorColor]); console.log(adjustedPrice);