feat(2020-day-04): optional field-level validation rules

Skip field-level validation with validate(passport, false)

Author: developher-net

2020/day-04/passports.js

@@ -28,17 +28,99 @@ const requiredFields = [
   'cid'
 ]
 
-const validate = (passport) => {
+const rules = {
+  byr: (byr) => {
+    // byr (Birth Year) - four digits; at least 1920 and at most 2002
+    return (
+      String(byr).length === 4 &&
+      Number(byr) >= 1920 &&
+      Number(byr) <= 2002
+    )
+  },
+  iyr: (iyr) => {
+    // iyr (Issue Year) - four digits; at least 2010 and at most 2020.
+    return (
+      String(iyr).length === 4 &&
+      Number(iyr) >= 2010 &&
+      Number(iyr) <= 2020
+    )
+  },
+  eyr: (eyr) => {
+    // eyr (Expiration Year) - four digits; at least 2020 and at most 2030.
+    return (
+      String(eyr).length === 4 &&
+      Number(eyr) >= 2020 &&
+      Number(eyr) <= 2030
+    )
+  },
+  hgt: (hgt) => {
+    // hgt (Height) - a number followed by either cm or in:
+    //     If cm, the number must be at least 150 and at most 193.
+    //     If in, the number must be at least 59 and at most 76.
+    const unit = hgt.slice(hgt.length - 2)
+    const value = hgt.slice(0, hgt.length - 2)
+    return (
+      (
+        unit === 'cm' &&
+        value >= 150 &&
+        value <= 193
+      ) || (
+        unit === 'in' &&
+        value >= 59 &&
+        value <= 76
+      )
+    )
+  },
+  hcl: (hcl) => {
+    // hcl (Hair Color) - a # followed by exactly six characters 0-9 or a-f.
+    const regexp = /^#[0-9a-fA-F]+$/ // hex color
+    return (
+      regexp.test(hcl) &&
+      hcl.length === 7
+    )
+  },
+  ecl: (ecl) => {
+    // ecl (Eye Color) - exactly one of: amb blu brn gry grn hzl oth.
+    const allowed = ['amb', 'blu', 'brn', 'gry', 'grn', 'hzl', 'oth']
+    return allowed.includes(ecl)
+  },
+  pid: (pid) => {
+    // pid (Passport ID) - a nine-digit number, including leading zeroes.
+    return (
+      String(pid).length === 9 &&
+      Number(pid) > 0
+    )
+  },
+  cid: (cid) => {
+    // cid (Country ID) - ignored, missing or not.
+    return true
+  }
+}
+
+const validate = (passport, checkFields = true) => {
   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) => {
+    // Check for required vield
     if (!passport[field]) {
       throw new Error(`Missing field ${field}`)
     }
+    // Skip field validation when disabled
+    if (!checkFields) {
+      return
+    }
+    // Validate field against rules
+    if (
+      !rules[field](
+        passport[field]
+      )
+    ) {
+      throw new Error(`Invalid field value ${field}:${passport[field]}`)
+    }
   })
   return true
 }

2020/day-04/passports.test.js

@@ -18,6 +18,30 @@ const invalid = [
     iyr:2011 ecl:brn hgt:59in`
 ]
 
+const invalidValues = [
+  `eyr:1972 cid:100
+    hcl:#18171d ecl:amb hgt:170 pid:186cm iyr:2018 byr:1926`,
+  `iyr:2019
+    hcl:#602927 eyr:1967 hgt:170cm
+    ecl:grn pid:012533040 byr:1946`,
+  `hcl:dab227 iyr:2012,
+    ecl:brn hgt:182cm pid:021572410 eyr:2020 byr:1992 cid:277`,
+  `hgt:59cm ecl:zzz
+    eyr:2038 hcl:74454a iyr:2023
+    pid:3556412378 byr:2007`
+]
+const validValues = [
+  `pid:087499704 hgt:74in ecl:grn iyr:2012 eyr:2030 byr:1980
+    hcl:#623a2f`,
+  `eyr:2029 ecl:blu cid:129 byr:1989
+    iyr:2014 pid:896056539 hcl:#a97842 hgt:165cm`,
+  `hcl:#888785
+    hgt:164cm byr:2001 iyr:2015 cid:88
+    pid:545766238 ecl:hzl
+    eyr:2022`,
+  'iyr:2010 hgt:158cm hcl:#b6652a ecl:blu byr:1944 eyr:2021 pid:093154719'
+]
+
 describe('--- Day 4: Passport Processing ---', () => {
   describe('Part 1', () => {
     describe('parseScan()', () => {
@@ -36,16 +60,29 @@ describe('--- Day 4: Passport Processing ---', () => {
       })
     })
     describe('validate()', () => {
-      it('verifies all required fields in a passport', () => {
+      it('verifies presences of 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)
+          expect(validate(passport, false)).to.equal(true)
         })
       })
       it('errors on invalid passports', () => {
         const passport = parseScan(invalid[0])
-        expect(() => validate(passport)).to.throw('Missing field hgt')
+        expect(() => validate(passport, false)).to.throw('Missing field hgt')
+      })
+      it('verifies the vield values agaisnt the type rules', () => {
+        validValues.forEach((scan, idx) => {
+          const passport = parseScan(scan)
+          // Valid when all required fields
+          expect(validate(passport)).to.equal(true)
+        })
+      })
+      it('errors on invalid passports', () => {
+        invalidValues.forEach((scan) => {
+          const passport = parseScan(scan)
+          expect(() => validate(passport)).to.throw()
+        })
       })
     })
   })

2020/day-04/solution.js

@@ -1,4 +1,4 @@
-const DEBUG = false;
+const DEBUG = true
 const fs = require('fs')
 const path = require('path')
 const split2 = require('split2')
@@ -17,7 +17,7 @@ const part1 = () => {
     // Handle the record in the buffer
     const passport = parseScan(recordBuffer)
     try {
-      if (validate(passport)) {
+      if (validate(passport, false)) {
         validCount++
       }
     } catch (e) {