advent of code 2023 day 8: replace forEach and {} with reduce

2023/08/impl.js

@@ -2,12 +2,11 @@
 module.exports.solve = function(input) {
 	const [instructionLine, nodeLines] = input.split('\n\n')
 	const instructions = instructionLine.split('').map(s => s === 'R' ? 1 : 0)
-	const map = {} // this could be a reduce()?
-	const nodes = nodeLines.split('\n').forEach(line => {
+	const map = nodeLines.split('\n').reduce((acc, line) => {
 		// e.g. AAA = (BBB, CCC)
 		const [pos, _, left, right] = line.replace(/[\(]?[\)]?[=]?[,]?/g, "").split(' ')
-		map[pos] = [left, right]
-	})
+		return acc[pos] = [left, right], acc
+	}, {})
 
 	let curr = 'AAA'
 	let i = 0

2023/08/test.js

@@ -15,8 +15,7 @@ EEE = (EEE, EEE)
 GGG = (GGG, GGG)
 ZZZ = (ZZZ, ZZZ)`
 
-	const out = solve(input)
-	assert.equal(out, 2)
+	assert.equal(solve(input), 2)
 })
 
 
@@ -27,6 +26,5 @@ AAA = (BBB, BBB)
 BBB = (AAA, ZZZ)
 ZZZ = (ZZZ, ZZZ)`
 
-	const out = solve(input)
-	assert.equal(out, 6)
+	assert.equal(solve(input), 6)
 })