feat(2022-day-02): score rochambeau games

2022/day-02/index.js

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+// eslint-disable-next-line no-unused-vars
+const console = require('../helpers')
+require('./solution')

2022/day-02/rochambeau.js

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+
+// Lookup tables for possible rock / paper / scissor values
+const selfCodes = ['X', 'Y', 'Z']
+const opponentCodes = ['A', 'B', 'C']
+
+const scoreRound = (opponent, self) => {
+  const scoreShape = (self) => {
+    return selfCodes.indexOf(self) + 1
+  }
+
+  const scoreOutcome = (opponent, self) => {
+    const selfScore = selfCodes.indexOf(self)
+    const oppScore = opponentCodes.indexOf(opponent)
+    // Win
+    if (
+      (selfScore - 1 === oppScore) ||
+      (selfScore === -1 && oppScore === 2)
+    ) {
+      return 6
+    }
+    // Lose
+    if (
+      (oppScore - 1 === selfScore) ||
+      (oppScore === -1 && selfScore === 2)
+    ) {
+      return 0
+    }
+    // Draw
+    if (selfCodes.indexOf(self) === opponentCodes.indexOf(opponent)) {
+      return 3
+    }
+
+    throw new Error(`Could not calculate the results of the match: ${opponent}, ${self}`)
+  }
+
+  return scoreShape(self) + scoreOutcome(opponent, self)
+}
+
+/**
+ * Tallies the results of all rounds in a match
+ * @param {*} guide
+ * @returns
+ */
+const scoreMatch = (guide) => {
+  return guide.map((match) => {
+    return scoreRound(...match)
+  }).reduce((sum, value) => sum + value, 0)
+}
+
+module.exports = {
+  scoreMatch,
+  scoreRound
+}

2022/day-02/rochambeau.test.js

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+/* eslint-env mocha */
+const { expect } = require('chai')
+const { scoreMatch, scoreRound } = require('./rochambeau')
+
+describe.only('--- Day 2: Rock Paper Scissors ---', () => {
+  describe('Part 1', () => {
+    describe('scoreRound', () => {
+      it('calculates the score of a round based on what the opponent played and what you played', () => {
+        expect(scoreRound('A', 'Y')).to.equal(8)
+        expect(scoreRound('B', 'X')).to.equal(1)
+        expect(scoreRound('C', 'Z')).to.equal(6)
+      })
+    })
+    describe('scoreMatch', () => {
+      it('calculates the total score of a match', () => {
+        expect(
+          scoreMatch([
+            ['A', 'Y'],
+            ['B', 'X'],
+            ['C', 'Z']
+          ])
+        ).to.equal(15)
+      })
+    })
+  })
+})