feat(2020-day-04): scan and validate passport records

Author: developher-net

2020/day-04/passports.js

@@ -0,0 +1,49 @@
+// Convert a passport scan into a useable object
+const parseScan = (scan) => {
+  const passport = {}
+  scan.trim()
+    .split(/\s+/)
+    .forEach((field) => {
+      const parsed = field.split(':')
+      passport[parsed[0]] = parsed[1]
+    })
+  return passport
+}
+
+const getType = (passport) => {
+  if (passport.cid) {
+    return 'normal'
+  }
+  return 'polar'
+}
+
+const requiredFields = [
+  'byr',
+  'iyr',
+  'eyr',
+  'hgt',
+  'hcl',
+  'ecl',
+  'pid',
+  'cid'
+]
+
+const validate = (passport) => {
+  const fieldsToCheck = JSON.parse(JSON.stringify(requiredFields)) // quick deep copy
+  // polar records don't have cid, but are otherwise valid
+  if (getType(passport) === 'polar') {
+    delete fieldsToCheck.splice([fieldsToCheck.indexOf('cid')], 1)
+  }
+  // Check for fields
+  fieldsToCheck.forEach((field) => {
+    if (!passport[field]) {
+      throw new Error(`Missing field ${field}`)
+    }
+  })
+  return true
+}
+
+module.exports = {
+  parseScan,
+  validate
+}

2020/day-04/passports.test.js

@@ -0,0 +1,52 @@
+/* eslint-env mocha */
+const { expect } = require('chai')
+const { parseScan, validate } = require('./passports')
+
+const valid = [
+  `ecl:gry pid:860033327 eyr:2020 hcl:#fffffd
+    byr:1937 iyr:2017 cid:147 hgt:183cm`,
+  `hcl:#ae17e1 iyr:2013
+    eyr:2024
+    ecl:brn pid:760753108 byr:1931
+    hgt:179cm`
+]
+
+const invalid = [
+  `iyr:2013 ecl:amb cid:350 eyr:2023 pid:028048884
+    hcl:#cfa07d byr:1929`,
+  `hcl:#cfa07d eyr:2025 pid:166559648
+    iyr:2011 ecl:brn hgt:59in`
+]
+
+describe('--- Day 4: Passport Processing ---', () => {
+  describe('Part 1', () => {
+    describe('parseScan()', () => {
+      it('parses an individual record into an addressable object', () => {
+        const res = parseScan(valid[0])
+        expect(res).to.deep.equal({
+          ecl: 'gry',
+          pid: '860033327',
+          eyr: '2020',
+          hcl: '#fffffd',
+          byr: '1937',
+          iyr: '2017',
+          cid: '147',
+          hgt: '183cm'
+        })
+      })
+    })
+    describe('validate()', () => {
+      it('verifies all required fields in a passport', () => {
+        valid.forEach((scan, idx) => {
+          const passport = parseScan(scan)
+          // Valid when all required fields
+          expect(validate(passport)).to.equal(true)
+        })
+      })
+      it('errors on invalid passports', () => {
+        const passport = parseScan(invalid[0])
+        expect(() => validate(passport)).to.throw('Missing field hgt')
+      })
+    })
+  })
+})

package-lock.json

@@ -37,5 +37,8 @@
     "plop": "^2.7.4",
     "semantic-release": "^17.3.0",
     "standard": "^14.3.4"
+  },
+  "dependencies": {
+    "split2": "^3.2.2"
   }
 }