magik/tests/deckStore.test.js

import { test } from 'node:test'
import assert from 'node:assert/strict'
import { DECK_SIZE } from '../src/lib/commander.js'
import {
  decodeDeck,
  encodeDeck,
  formatDecklist,
  parseDecklist,
  sortedEntries,
} from '../src/lib/deckStore.js'

/**
 * Decklists arrive as text pasted from other tools and leave as links, so the
 * parser has to survive the formats players actually paste, and the share
 * encoding has to round-trip a full deck.
 */

const SAMPLE = `// Atraxa Beatdown
Commander: Atraxa, Grand Unifier
1 Sol Ring
1 Command Tower

*Lands*
37 Plains
37 Island
5 Swamp

Sideboard
2 Negate
`

test('a decklist is split into commander, cards and quantity', () => {
  const deck = parseDecklist(SAMPLE)
  assert.equal(deck.name, 'Atraxa Beatdown')
  assert.deepEqual(deck.commanders, [{ id: '', name: 'Atraxa, Grand Unifier' }])
  const wanted = Object.fromEntries(deck.cards.map((c) => [c.name, c.qty]))
  assert.equal(wanted['Sol Ring'], 1)
  assert.equal(wanted.Plains, 37)
  assert.equal(wanted.Swamp, 5)
  assert.equal(wanted.Negate, undefined, 'sideboard cards are not part of the deck')
})

test('quantities for the same card are summed', () => {
  const deck = parseDecklist('3 Forest\n2 Forest\n1 Forest')
  assert.equal(deck.cards.length, 1)
  assert.equal(deck.cards[0].qty, 6)
})

test('a set code in brackets is not part of the card name', () => {
  const deck = parseDecklist('1 Lightning Bolt (M10)')
  assert.equal(deck.cards[0].name, 'Lightning Bolt')
})

test('a list with no commander line still parses as a main deck', () => {
  const deck = parseDecklist('1 Sol Ring\n2 Llanowar Elves')
  assert.equal(deck.commanders.length, 0)
  assert.equal(deck.cards.length, 2)
})

test('blank lines, category headers and stray text are ignored', () => {
  const deck = parseDecklist('// Name\n\n*Creatures*\n1 Elvish Mystic\nnot a card line\n1 Sol Ring')
  assert.equal(deck.cards.length, 2)
})

test('a decklist formats back to the standard layout', () => {
  const deck = parseDecklist(SAMPLE)
  const text = formatDecklist(deck)
  assert.match(text, /^\/\/ Atraxa Beatdown/)
  assert.match(text, /^Commander: Atraxa, Grand Unifier$/m)
  assert.match(text, /^37 Plains$/m)
  const round = parseDecklist(text)
  assert.equal(round.name, deck.name)
  assert.equal(round.cards.length, deck.cards.length)
})

test('entries are ordered by type, then mana value, then name', () => {
  const deck = {
    id: 'd',
    name: 'Order',
    commanders: [],
    createdAt: 0,
    updatedAt: 0,
    cards: [
      { id: '1', name: 'Forest', qty: 10 },
      { id: '2', name: 'Giant Growth', qty: 1 },
      { id: '3', name: 'Llanowar Elves', qty: 1 },
      { id: '4', name: 'Sol Ring', qty: 1 },
      { id: '5', name: 'Teferi, Time Raveler', qty: 1 },
    ],
  }
  const typeLine = {
    Forest: 'Basic Land — Forest',
    'Giant Growth': 'Instant',
    'Llanowar Elves': 'Creature — Elf Druid',
    'Sol Ring': 'Artifact',
    'Teferi, Time Raveler': 'Legendary Planeswalker',
  }
  const cost = { 'Giant Growth': 1, 'Llanowar Elves': 1, 'Sol Ring': 1, Forest: 0, 'Teferi, Time Raveler': 2 }
  const order = sortedEntries(deck, {
    cmcOf: (e) => cost[e.name] ?? 0,
    typeOf: (e) => typeLine[e.name] ?? '',
  }).map((e) => e.name)
  // Creature, Artifact, Instant, Planeswalker, then Land — the order a
  // player reads a decklist in, regardless of mana value. The Planeswalker is
  // here because this list used to be a second copy of TYPE_ORDER that had
  // drifted from it, and the exported list then disagreed with the deck on
  // screen. A test without a planeswalker in it cannot catch that.
  assert.deepEqual(order, [
    'Llanowar Elves',
    'Sol Ring',
    'Giant Growth',
    'Teferi, Time Raveler',
    'Forest',
  ])
})

test('a full deck survives a share link round trip', async () => {
  const deck = {
    id: 'local-id',
    name: "Kaer'shir, the Golden Wake",
    commanders: [{ id: '', name: "Ka'erishir, the Golden Wake" }],
    cards: Array.from({ length: DECK_SIZE - 1 }, (_, i) => ({
      id: '',
      name: i === 0 ? 'Sol Ring' : `Card ${i}`,
      qty: i === 0 ? 1 : 1,
    })),
    createdAt: 1,
    updatedAt: 2,
  }
  const url = await encodeDeck(deck)
  // A share link has to survive being pasted into a chat app, so it must be
  // URL-safe and must not carry a base64 padding tail.
  assert.match(url, /^z\.[A-Za-z0-9_-]+$/)

  const back = await decodeDeck(url)
  assert.equal(back.name, deck.name)
  assert.deepEqual(back.commanders, deck.commanders)
  assert.equal(back.cards.length, deck.cards.length)
  assert.equal(back.cards[0].name, 'Sol Ring')
  assert.notEqual(back.id, deck.id, 'a shared deck is copied, not shared by reference')
})

test('a share link is short enough to paste into a chat message', async () => {
  // Discord rejects a message `content` field over 2,000 characters, so that
  // is the budget a share link has to fit inside. A real 100-card deck did
  // not: uncompressed it was 3,519 characters, which no chat app would carry.
  const deck = {
    id: 'x',
    name: "Ka'erishir, the Golden Wake",
    commanders: [{ id: '', name: "Ka'erishir, the Golden Wake" }],
    cards: [
      ...Array.from({ length: 36 }, () => ({ id: '', name: 'Command Tower', qty: 1 })),
      ...Array.from({ length: 36 }, () => ({ id: '', name: 'Fabled Passage', qty: 1 })),
      ...Array.from({ length: 27 }, () => ({ id: '', name: 'Bonto, the Giant Pump', qty: 1 })),
    ],
    createdAt: 0,
    updatedAt: 0,
  }
  const slug = await encodeDeck(deck)
  assert.ok(slug.length < 2000, `share slug is ${slug.length} characters, over the chat budget`)
})

test('a share link written before compression still opens', async () => {
  // Links are already in the wild. The prefix is what tells the two formats
  // apart, so an unprefixed slug must keep decoding as plain base64 JSON.
  const payload = {
    n: 'Legacy',
    c: ['Atraxa, Grand Unifier'],
    d: ['1xSol Ring', '2xForest'],
  }
  const bytes = new TextEncoder().encode(JSON.stringify(payload))
  let binary = ''
  for (const byte of bytes) binary += String.fromCharCode(byte)
  const legacy = btoa(binary).replaceAll('+', '-').replaceAll('/', '_').replace(/=+$/, '')
  assert.equal(legacy.startsWith('z.'), false)

  const deck = await decodeDeck(legacy)
  assert.equal(deck.name, 'Legacy')
  assert.deepEqual(deck.commanders, [{ id: '', name: 'Atraxa, Grand Unifier' }])
  assert.equal(deck.cards.length, 2)
  assert.equal(deck.cards[0].name, 'Sol Ring')
})

test('a deck full of basic lands survives a share link round trip', async () => {
  for (const count of [1, 2, 3, 30, 98, 99]) {
    const deck = {
      id: 'x',
      name: 'Lands'.padEnd((count % 5) + 1, 'a'),
      commanders: [],
      cards: Array.from({ length: count }, (_, i) => ({ id: '', name: `Land ${i}`, qty: 1 })),
      createdAt: 0,
      updatedAt: 0,
    }
    const back = await decodeDeck(await encodeDeck(deck))
    assert.equal(back.cards.length, count, `lost cards at count ${count}`)
    assert.equal(back.name, deck.name)
  }
})

test('a card name containing "x" does not confuse the quantity encoding', async () => {
  const deck = {
    id: 'x',
    name: 'Awkward',
    commanders: [],
    cards: [{ id: '', name: 'Xenodoch Green', qty: 4 }],
    createdAt: 0,
    updatedAt: 0,
  }
  const back = await decodeDeck(await encodeDeck(deck))
  assert.equal(back.cards[0].name, 'Xenodoch Green')
  assert.equal(back.cards[0].qty, 4)
})