Requested by: Nails

In LC (Little Cup) formats (and probably any format that uses NFE [Not Fully Evolved] Pokémon), Pokémon don't have much HP, so the damage percentages aren't very helpful.

Since the BDSP fix (#10) in v1.0.0 was added, there are occasionally missing abilities and moves from gen 8 since the gen 4 dex is being loaded for BDSP.

Reported by:

• camdawgboi
• Shiox
• paolode99

Syncing issues due to the Pokémon ID detection again (most likely culprit is syncBattle()), resulting in non-updated and sometimes duplicate Pokémon.

Torrent/Overgrow/Blaze boosts are not being applied to calcs.

Also affects Psystrike.

Since in v1.0.3, the passed-in Generation object is now fully supplied by the global Dex object available in Showdown, which is missing some key properties, most notably overrideDefensiveStat, which is responsible for making sure Psyshock and Psystrike hits the defending Pokémon's DEF, not SPD.

Note
This SmogonMove is based off of the latest efa6fe7 commit on @smogon/calc, not its v0.6.0 release on npm, which does not include the overrideDefensiveStat, but rather defensiveCategory. The current v0.6.0 release is known to not properly account for Psyshock, hence why this project includes a patch for @smogon/calc.

import { Move as SmogonMove } from '@smogon/calc';

const move = new SmogonMove(8, 'Psyshock');

SmogonMove {
  ability: undefined,
  bp: 80,
  breaksProtect: false,
  category: 'Special',
  drain: undefined,
  flags: {},
  gen: Generation { num: 8, ... },
  hasCrashDamage: false,
  hits: 1,
  ignoreDefensive: false,
  isCrit: false,
  isMax: false,
  isZ: false,
  item: undefined,
  mindBlownRecoil: false,
  name: 'Psyshock',
  originalName: 'Psyshock',
  overrideDefensivePokemon: undefined,
  overrideDefensiveStat: 'def',
  overrideOffensivePokemon: undefined,
  overrideOffensiveStat: undefined,
  overrides: undefined,
  priority: 0,
  recoil: undefined,
  secondaries: undefined,
  species: undefined,
  struggleRecoil: false,
  target: 'any',
  timesUsed: 1,
  timesUsedWithMetronome: undefined,
  type: 'Psychic',
  useMax: undefined,
  useZ: undefined,
}

Dex.forGen(8).moves.get('Psyshock');

Showdown.Move {
  accuracy: 100,
  basePower: 80,
  category: 'Special',
  critRatio: 1,
  desc: 'Deals damage to the target based on its Defense instead of Special Defense.',
  effectType: 'Move',
  exists: true,
  flags: {
    protect: 1,
    mirror: 1,
  },
  gen: 5,
  hasCrashDamage: false,
  heal: null,
  id: 'psyshock',
  isMax: false,
  isNonstandard: null,
  isZ: '',
  maxMove: {
    basePower: 130,
  },
  multihit: null,
  name: 'Psyshock',
  noPPBoosts: false,
  noSketch: false,
  num: 473,
  ohko: null,
  pp: 10,
  pressureTarget: 'normal',
  priority: 0,
  recoil: null,
  secondaries: null,
  shortDesc: 'Damages target based on Defense, not Sp. Def.',
  target: 'normal',
  type: 'Psychic',
  zMove: {
    basePower: 160,
  },
}

Using the global Dex object results in the following SmogonMove:

SmogonMove {
  ability: null,
  bp: 80,
  breaksProtect: false,
  category: 'Special',
  drain: undefined,
  flags: {
    protect: 1,
    mirror: 1,
  },
  gen: Showdown.Dex { gen: 8, modid: 'gen8', ... },
  hasCrashDamage: false,
  hits: 1,
  ignoreDefensive: false,
  isCrit: false,
  isMax: false,
  isZ: false,
  item: undefined,
  mindBlownRecoil: false,
  name: 'Psyshock',
  originalName: 'Psyshock',
  overrideDefensivePokemon: undefined,
  overrideDefensiveStat: undefined,
  overrideOffensivePokemon: undefined,
  overrideOffensiveStat: undefined,
  overrides: undefined,
  priority: 0,
  recoil: 0,
  secondaries: null,
  species: undefined,
  struggleRecoil: false,
  target: 'normal',
  timesUsed: 1,
  timesUsedWithMetronome: undefined,
  type: 'Psychic',
  useMax: false,
  useZ: false,
}

Since @smogon/calc includes its own Generation data in its own data directory, the fix is to supply these missing properties from @smogon/calc's internal data to the data already supplied by Showdown's global Dex object.

Additionally, unlike @pkmn/dex, passing an invalid name for the constructor parameter of SmogonMove won't return undefined, but rather, an instantiated SmogonMove with invalid properties:

// 'Psyshock' is purposefully mistyped here for demonstration purposes
const move = new SmogonMove(8, 'Psyshck');

SmogonMove {
  ability: undefined,
  bp: undefined,
  breaksProtect: false,
  category: 'Status',
  drain: undefined,
  flags: undefined,
  gen: Generation { num: 8, ... },
  hasCrashDamage: false,
  hits: 1,
  ignoreDefensive: false,
  isCrit: false,
  isMax: false,
  isZ: false,
  item: undefined,
  mindBlownRecoil: false,
  name: 'Psyshck',
  originalName: 'Psyshck',
  overrideDefensivePokemon: undefined,
  overrideDefensiveStat: undefined,
  overrideOffensivePokemon: undefined,
  overrideOffensiveStat: undefined,
  overrides: undefined,
  priority: 0,
  recoil: undefined,
  secondaries: undefined,
  struggleRecoil: false,
  target: 'any',
  timesUsed: 1,
  timesUsedWithMetronome: undefined,
  type: undefined,
  useMax: undefined,
  useZ: undefined,
}

Thankfully, Photon Geyser is still working properly, using the corresponding defensive stat (either DEF or SPD) of the defending Pokémon determined by the higher attacking stat (either ATK or SPA) of the attacking Pokémon.

Requested by: TrainerX493

Since in Hackmons, you can start with mega-evolved Pokémon, such as Swampert-Mega, and give them an item that's not their mega-evo item, we should still show the item icon.

Additionally, this might be a bug since we don't pass an item to the Pokemon class constructor of @smogon/calc when we detect the Pokémon in its mega forme.

Reported by: Furret4ssb

DAMNNNNNNNNNNNN YOUUUUUUUUUUU NATIONAL DEXXXXXXXXXXXXXXXXXXXXXXXX !!!!!!!!

Still appears even after "closing" (actually hiding) the Calcdex tab. Doesn't matter if only one or many Calcdexes are open since the refresh prompt will appear when any room's requestLeave() returns false, which for Calcdexes, it does.

Not a big deal, but can get annoying for sure, especially if you're developing and refreshing the page constantly.

Requested by:

• camdawgboi
• Runoisch

Allow Pokémon with alternative formes (like Aegislash(-Shield) & Aegislash-Blade) and megas (like Charizard, Charizard-Mega-X & Charizard-Mega-Y) to be manually switched by the user.

Caused by the abilities dropdown not including the Wandering Spirit ability in the list, which in legal-locked formats, wouldn't be there.

Bug was found in a gen8randombattle with a Runerigus.

Note that in this particular battle, the Runerigus faints on the same turn it obtains the Gluttony ability from the Linoone, so in the battle object, Runerigus still has its ability set to Wandering Spirit for some reason. (May have changed mid-turn, but reverted back once fainted before the next sync tick.)

Requested by:

• lighthouse64
• mdragon13
• kirito_1707

Mozilla offers a pretty cool tool called extensiontest.com, which determines extension compatibility with Firefox from the generated CRX file.

Based on just uploading the CRX that was provided to the Chrome Web Store, seems that it's compatible as-is:

According to the report, this just needs some minor tweaking for the extension ID in the manifest.json:

{
  "compat": [],
  "errors": [
    {
      "message": "\"/manifest_version\" must be <= 2",
      "description": "Your JSON file could not be parsed.",
      "locations": [
        {}
      ]
    },
    {
      "message": "The extension ID is required in Manifest Version 3 and above.",
      "description": "See https://mzl.la/3PLZYdo for more information.",
      "locations": [
        {
          "file": "manifest.json"
        }
      ]
    },
    {
      "message": "File is too large to parse.",
      "description": "This file is not binary and is too large to parse. Files larger than 4MB will not be parsed. Consider moving large lists of data out of JavaScript files and into JSON files, or splitting very large files into smaller ones.",
      "locations": [
        {
          "file": "main.js"
        }
      ]
    }
  ],
  "warnings": [
    {
      "message": "\"runtime.onMessageExternal\" can cause issues when loaded temporarily",
      "description": "This API can cause issues when loaded temporarily using about:debugging in Firefox unless you specify applications|browser_specific_settings > gecko > id in the manifest. Please see: https://mzl.la/2hizK4a for more.",
      "locations": [
        {
          "file": "background.js",
          "line": 1
        }
      ]
    }
  ]
}

Goodra.

Requested by:

• TJ
• Fitah_
• TheDarkPhoenix911

Will add the following sites to the extension's manifest.json:

• https://dawn.psim.us
• https://smogtours.psim.us
• https://sports.psim.us (server seems to be down on this one, though)

This will allow the extension to be loaded into those Showdown clients.

Reported by:

• Runoisch
• MachJacob

Setting SPA/SPD EVs of dexited Pokémon without a set crashes the Calcdex in Gen 8 National Dex formats.

As per the follow-up by Runoisch and MachJacob, the following Pokémon are known to crash:

• Gligar
• Dewgong
• Ursaring
• Smeargle
• Ambipom
• Ariados
• Venomoth
• Ampharos (possibly mega forme too)
• Donphan

The following Pokémon are unaffected:

• Pyroar
• Muk-Alola (base forme may be affected)
• Meloetta
• Zebstrika
• Servine
• Staraptor
• Camerupt-Mega (base forme may be affected)
• Beedrill-Mega (base forme may be affected)

HUH ???

Reported by: Runoisch

Hazards are always included in the damage calculations, even if the Pokémon is already switched-in, resulting in inaccurate damage ranges.

Requested by:

• camdawgboi
• Kibo

Also, Cam said the background of the Psychic type was too dark on dark mode lol.

any BDSP format will crash the Calcdex.

seems that the following error is spat out in the console as it crashes:

TypeError: Cannot read properties of undefined (reading 'hp')

basically means that the Pokemon class from @smogon/calc fails to obtain the baseStats for the passed-in speciesForme, since baseStats.hp (where baseStats is undefined) throws this error.

Reported by:

• Nails
• camdawgboi

Clicking on a move's damage range doesn't copy the description to the clipboard on Smogtours like it does on the main Showdown client.

Reported by:

• dex
• Clastia

Showdown will start to lag after playing or spectating a couple games. This can occasionally lead to the browser itself crashing if the user's host system does not have enough system resources.

Most likely culprit is the thousands of downloaded sets (potentially across multiple gens and formats) in Redux via RTK Query, but more so the way I'm accessing them in usePresets().

First optimization to try is passing a filter function to the RTK Query hooks in usePresets(), so that it doesn't return ALL of the sets for EVERY Pokémon, which the massive array gets memoized for each Calcdex.

Typo exists in the styling that hides the scrollbars in Firefox, which causes both the system and custom scrollbars to overlay on top of each other.

Worse on Windows cause the default system scrollbar is still there.

Whoopsie :o

Update (2022/09/12)
Just thought of a solution to this problem, outlined below.

Note
This also applies to the Hellodex as well, as it includes both light and dark styling.

Best way I thought of to fix this is to store the colorScheme state in Redux instead of the ColorSchemeProvider (via React.Context). There's no clean way to dispatch an update to React once the color scheme is updated, but since we're using Redux, we can simply hook into the client function that updates the color scheme (and makes it available via Dex.prefs()) and dispatch the new value to Redux. (We're able to dispatch to the Redux state via Vanilla JS, despite using react-redux.) This will cause all existing React instances that are hooked into the Redux state to update with the updated color scheme.

Since most components are using the useColorScheme() hook to read the value, we can accomplish a similar functionality to useColorScheme() through Redux, so refactoring should be pretty straightforward (i.e., just need to update the import path of useColorScheme() with no other changes in logic required).

If the lead mon of either teams is Mr-Mime G, or they have it in team preview the extention immidiately crashes. If you have in the back and switch it in/click on its icon to check calcs for it it also crashes. When it crashes it goes blank and shows nothing. I have checked it in AG and gen 8 randbats, don't know if it happens anywhere else but I would assume so. (This app is really cool and I wanted to thank you for making it :))

Gen 1 and 2 pokemon stats have 252 evs in every stat, the calc does not have that and adding more evs just crashes it for some reason

EDIT: Also, gen 1 and 2 calcs stats with dvs (0-15) and doesn't multiply the base by 2 in the stat formula

Requested by: TrainerX493

Smogon makes available Pokémon statistics, which includes commonly used abilities, items, moves, and even spreads. Would be particularly useful for Pokémon without sets, so we can at least build a common set from the statistics.

Fortunately, the same API available on pkmn.github.io has a Smogon Stats API that parses the stats available on https://smogon.com/stats into JSON.

Reported by: 85percent

Calculator uses the HP base stat of the transformed Pokémon, not those of Ditto (or any other Pokémon that has Transform, like Mew).

Requested by: Furret4ssb

Categorize the options in the items dropdown of the Calcdex by item popularity, just like in the Teambuilder.

Requested by: Clastia

Show all the Calcdexes in Redux in the Hellodex and allow users to reopen a Calcdex or unload it completely from Redux.

• This is possible since closing the Calcdex tab doesn't clear it from Redux.
  • This means some slowdowns can occur for lower-end machines when many Calcdexes have been opened in a single client session.
  • Once this is implemented, no need to unload the Calcdex from Redux when the tab is closed.
  • Could be a future setting to automatically unload when the tab is closed though.

Requested by: Baloor

Non-standard CAP moves like Paleo Wave and Shadow Strike provide no damage calculations as they don't exist in the standard Pokémon moveset.

There's a separate set for mega Pokémon in the pkmn API (gen7randombattle.json). When the Pokémon is not-mega'd yet, the non-mega set is loaded in (and set as the Pokémon's preset).

After the Pokémon mega-evolves, the mega set is loaded in, but since the Pokémon's preset is still set to the non-mega set, the dropdown shows "None". However, the user can still manually select the "Randoms" set, which is the mega set.

Just gotta update the preset when the Pokémon's speciesForme changes and the Pokémon's current preset ID no longer exists in the list of sets.

When multiple battles are started, the calc will get confused, possibly treating it as the same battle. Can result in one of your pokemon getting repeated in the calc, which is especially an issue since you can't manually change the Pokemon (known for Chrome)

If you have a single Calcdex tab and the Teambuilder open (with no other tabs, including a ChatRoom or BattlesRoom), the Teambuilder will move to the right panel once the Calcdex tab is closed.

This is caused by the overwritten close tab handler for Calcdex tabs, which causes the Calcdex to visually close, but is actually hidden in order to preserve the state (this was the easiest and quickest way for me to implement re-opening Calcdex tabs before pushing out v1.0.1).

In that close tab handler, I forgot to check if the room we're refocusing into is a side room by reading the room's isSideRoom property. The Teambuilder tab is not a side room, so its isSideRoom property would be false. Filtering would remove the Teambuilder from the list of focusable side rooms, preventing it from opening on the right panel.

(There is logic already in place to hide the right panel if there are no more focusable side rooms. Clicking on the "+" tab would show the hidden right panel again.)

In other words, this should be a straightforward fix.

When refreshing the page mid-battle, a Pokémon's consumed item may still be present, despite the battle reporting that it's been consumed (via the Pokémon's prevItem and prevItemEffect).

Reported by: Runoisch

Damage from stage hazards occasionally applies to the NHKO chance, despite both Pokémon being active on the field.

Not sure the exact scenario that causes this, but hidden power is often calculated incorrectly. An example is hidden power bug on hariyama saying it will OHKO max defensive celebi when this is in fact not the case. (Chrome)

in the screenshot below, the Crustle has +2 ATK from Shell Smash, but -2 ATK from the BRN.

I had to manually set the ATK boost stage to 0 (as indicated by the blue-colored value) in order to obtain the correct damage range for X-Scissor.

additionally, not sure how guessServerSpread() obtained the spread for Darmanitan-Galar. since this was randoms, the Hardy nature is prioritized first when guessing, but ended up on Quiet.

Reported by: 85percent

Calcdex may crash when using Showdown in single-panel mode.

Reported by: Nails

Stat-boosting abilities like Intrepid Sword (typically on Zacian-Crowned) and Download (typically on Genesect-*) will have the boosted stat automatically applied by the calculator, despite not specifying any boosts for that stat.

For example, Intrepid Sword will boost the ATK by 1 stage (only visible in the result description), without having to actually specify +1 for ATK:

However, the Showdown client will also report +1 for the boosted stat, which the Calcdex will feed into the damage calculator, resulting in +2, i.e., double-boostage.

In v1.0.3, a feature was added that turns the EVs label in the Pokémon's stats table cyan if there are unallocated EVs. However, in Randoms, all EVs are set to 84, which is 4 less than the maximum legal EVs (508), as defined by process.env.CALCDEX_POKEMON_MAX_LEGAL_EVS.

General

Hellodex

Calcdex

Players

Pokémon

Calculations

Field

The extension that allows you to install chrome extensions on opera gx just doesn't load on showdown. I can install it but the showdex tab doesn't appear.

Moves that use conditional defensive stats like Psystrike & Psyshock and Photon Geyser always calculate against the defending Pokémon's SPD (since all 3 moves are special), which results in incorrect damage ranges.

• Psystrike & Psyshock are both special moves that hit the defending Pokémon's DEF.
• Photon Geyser is also a special move that hits the defending Pokémon's DEF only if the attacking Pokémon's ATK is greater than (but not equal!) its SPA (otherwise, the defending Pokémon's SPD is used, as you'd expect).

Moves that always result in a critical hit like Frost Breath and Surging Strikes don't calculate as critical hits until the "CRIT" toggle is activated in the Calcdex.

This is how these types of moves work on calc.ps. However, unlike calc.ps, we should not apply the crit when the always critting move is Z/Max'd.

When closing a native tab (i.e., a tab that's already built into Showdown, like the BattlesRoom) that also happens to be the last visible tab open (on the right panel only), the client's default handler will focus the next room in app.rooms, which includes the hidden (i.e., "closed") Calcdex rooms.

Not really a bug, but could be a huge QoL feature. Here's link of original comment.

Reported by:

• camdawgboi
• 85percent

When you are player 2 in the battle state (you can tell if you show up on the bottom side of the Calcdex), the Hellodex will show your opponent's username versing themselves.

Requested by: Ducky

While AAA and Hackmons allow you to select any move, abilities are still locked to their legal sets.

Instead of just supporting AAA and Hackmons, we should lock abilities/moves to only legal sets for certain formats like Randoms, OU, and Ubers, but allow any ability/move for formats not in that list.

This is due to the server reporting a new Showdown.Pokemon (client Pokémon) based on one of the existing Showdown.Pokemon[] when the Zoroark activates its Illusion ability on switch-in, causing the Calcdex to show a duplicate Pokémon, if the copied Pokémon was previously revealed in battle.

For example:

CalcdexBattleState {
  battleId: 'battle-gen8randombattle-...',
  gen: 8,
  format: 'gen8randombattle',
  active: true,
  authPlayerKey: 'p1',
  playerKey: 'p1',
  opponentKey: 'p2',
  p1: CalcdexPlayerSide { ... },
  p2: CalcdexPlayerSide {
    ...,
    pokemon: [
      CalcdexPokemon { calcdexId: '0d7cadb6-...', speciesForme: 'Klefki', level: 82, hp: 228, maxhp: 228, ... },
      CalcdexPokemon { calcdexId: 'c01682c0-...', speciesForme: 'Palkia', level: 74, hp: 510, maxhp: 510, ... },
      CalcdexPokemon { calcdexId: '30904a8a-...', speciesForme: 'Orbeetle', level: 86, hp: 243, maxhp: 243, ... },
      CalcdexPokemon { calcdexId: 'deda7a90-...', speciesForme: 'Centiskorch', level: 84, hp: 305, maxhp: 305, ... },
    ],
  },
  field: CalcdexBattleField { ... },
}

If Zoroark came in as another Orbeetle (as its Illusion), the server will report another Showdown.Pokemon:

Showdown.Pokemon {
  ability: '',
  baseAbility: '',
  boosts: {},
  details: 'Orbeetle, L84, M',
  fainted: false,
  gender: 'M',
  hp: 238,
  hpcolor: '',
  ident: 'p2: Orbeetle',
  item: 'Life Orb',
  itemEffect: '',
  lastMove: 'darkpulse',
  level: 84,
  maxhp: 238,
  moveTrack: [
    ['Dark Pulse', 1],
  ],
  moves: [],
  name: 'Orbeetle',
  prevItem: '',
  prevItemEffect: '',
  searchid: 'p2: Orbeetle|Orbettle, L84, M',
  shiny: false,
  side: Showdown.Side { ... },
  slot: 0,
  speciesForme: 'Orbeetle',
  sprite: Showdown.Sprite { sideid: 'p2', ... },
  status: '???',
  statusData: {
    sleepTurns: 0,
    toxicTurns: 0,
  },
  statusStage: 0,
  turnstatuses: {},
  volatiles: {},
}

With the following stepQueue commands:

|t:|...
|switch|p2a: Orbeetle|Orbeetle, L84, M|238/238
|-status|p2a: Orbeetle|psn
|turn|30
|
|t:|...
|move|p2a: Orbeetle|Dark Pulse|p1a: Greedent
|-damage|p1a: Greedent|16/678
|-damage|p2a: Orbeetle|215/238 psn|[from] item: Life Orb
|move|p1a: Greedent|Max Flare|p2a: Orbeetle
|-damage|p2a: Orbeetle|0 fnt
|-weather|SunnyDay
|replace|p2a: Zoroark|Zoroark, L84, M
|-end|p2a: Zoroark|Illusion
|faint|p2a: Zoroark

This one is of an existing CalcdexPokemon, however, is untagged with a calcdexId, so the Calcdex will assume this is a new Pokémon entirely, adding it to the pokemon array of the CalcdexPlayerSide.

Note that there are some dead giveaways that this Pokémon may be an Illusion, particularly the maxhp value, which is 238 (Zoroark's max HP) instead of 243 (Orbeetle's max HP). (Characteristic of Illusion is that it retains the mimicking Pokémon's level and HP, not those of the mimicked Pokémon.) However, we cannot know this during the battle if the HP Percentage Mod is enabled (which is the case for the format in the example, gen8randombattle), which only reports a max HP of 100 or 1000 (if the Showdown.Pokemon is initialized, but unpopulated).

Once the Illusion ends, another Showdown.Pokemon is created for the actual Zoroark, causing the Calcdex to add an additional Pokémon again. This leaves out the Zoroark if the player revealed 5 of 6 Pokémon, or if more space is available, would eventually leave out the last actual Pokémon.

Showdown.Pokemon {
  ability: 'Illusion',
  baseAbility: 'Illusion',
  boosts: {},
  details: 'Zoroark, L84, M',
  fainted: true,
  gender: 'M',
  hp: 0,
  hpcolor: '',
  ident: 'p2: Zoroark',
  item: '',
  itemEffect: '',
  lastMove: 'darkpulse',
  level: 84,
  maxhp: 238,
  moveTrack: [],
  moves: [],
  movestatuses: {},
  name: 'Zoroark',
  prevItem: '',
  prevItemEffect: '',
  searchid: 'p2: Zoroark|Zoroark, L84, M',
  shiny: false,
  side: Showdown.Side { sideid: 'p2', ... },
  slot: 0,
  speciesForme: 'Zoroark',
  sprite: Showdown.Sprite { ... },
  status: 'psn',
  statusData: {
    sleepTurns: 0,
    toxicTurns: 0,
  },
  statusStage: 0,
  turnstatuses: {},
  volatiles: {},
}

Resulting in the following CalcdexPlayerSide for p2:

CalcdexPlayerSide {
  ...,
  pokemon: [
    CalcdexPokemon { calcdexId: '0d7cadb6-...', speciesForme: 'Klefki', level: 82, hp: 228, maxhp: 228, ... },
    CalcdexPokemon { calcdexId: 'c01682c0-...', speciesForme: 'Palkia', level: 74, hp: 510, maxhp: 510, ... },
    CalcdexPokemon { calcdexId: '30904a8a-...', speciesForme: 'Orbeetle', level: 86, hp: 243, maxhp: 243, ... },
    CalcdexPokemon { calcdexId: 'deda7a90-...', speciesForme: 'Centiskorch', level: 84, hp: 305, maxhp: 305, ... },
    CalcdexPokemon { calcdexId: '973bcac1-...', speciesForme: 'Orbeetle', level: 84, hp: 238, maxhp: 238, ... },
    CalcdexPokemon { calcdexId: '34a4a243-...', speciesForme: 'Zoroark', level: 84, hp: 0, maxhp: 238, ... },
  ],
}

Notice that p2.pokemon.length is now 6, which is the defined limit of the process.env.CALCDEX_PLAYER_MAX_POKEMON environment variable. Hence, when the following commands are added to the battle's stepQueue:

|t:|...
|switch|p2a: Gardevoir|Gardevoir, L82, M|246/246
|-status|p2a: Gardevoir|psn
|-ability|p2a: Gardevoir|Cheeck Pouch|[from] ability: Trace|[of] p1a: Greedent
|turn|31

Showdown.Pokemon {
  ability: 'Cheek Pouch',
  baseAbility: 'Trace',
  boosts: {},
  details: 'Gardevoir, L82, M',
  fainted: false,
  gender: 'M',
  hp: 246,
  hpcolor: '',
  ident: 'p2: Gardevoir',
  item: '',
  itemEffect: '',
  lastMove: 'psyshock',
  level: 82,
  maxhp: 246,
  moveTrack: [
    ['Psyshock', 1],
  ],
  moves: [],
  movestatuses: {},
  name: 'Gardevoir',
  prevItem: '',
  prevItemEffect: '',
  searchid: 'p2: Gardevoir|Gardevoir, L82, M',
  shiny: false,
  side: Showdown.Side { sideid: 'p2', ... },
  speciesForme: 'Gardevoir',
  sprite: Showdown.Sprite { ... },
  status: 'psn',
  statusData: {
    sleepTurns: 0,
    toxicTurns: 0,
  },
  statusStage: 0,
  turnstatuses: {},
  volatiles: {},
}

The switched-in Gardevoir is ignored in the Calcdex since we've already reached the maximum limit of Pokémon.

Thankfully, this does not affect the IDing mechanism since a new untagged Showdown.Pokemon is created, which causes syncBattle() to assign it a new ID, despite the copied Pokémon potentially already existing in the array (would have its own unique ID assigned prior).

Note that in the case of Gardevoir the IDing mechanism assigns it a calcdexId to its Showdown.Pokemon, despite not being in the pokemon array of the CalcdexPlayerSide for p2. Additionally, battle.p2.pokemon.length is 7 due to the Illusion, but the client seems to properly handle this case visually, ignoring the mimicked Orbeetle and showing only 6 unique Pokémon in the battle frame, including the Gardevoir.

Possible solution is to show the duplicate Pokémon as usual, but once a Zoroark (or any Pokémon, for that matter) with the Illusion ability switches in, the syncBattle() should detect if we're attempting to add an Illusion Pokémon and look for and remove the duplicate (the L84 238 HP Orbeetle in this case).

In terms of filtering for the duplicates, we can check which ones have the same speciesForme, including ones that end in '-*', since we can't rule unrevealed formes out just yet (such as Urshifu, whose speciesForme will be 'Urshifu-*' until it's actual forme is revealed, unlike Arceus, whose forme is revealed on switch-in, e.g., Arceus-Bug).

Then, we can compare the duplicate Pokémon's level, to see which one matches the Zoroark's. If they're the same (which they could be in a non-Randoms format where every Pokémon is typically level 100), then we can check if the HP Percentage Mod is disabled and then compare the maxhp values. Otherwise, we can check if one of the duplicates has a falsy ability. If we still can't determine which one is the duplicate through all of this, we'll just remove the one that was most recently added, since the mimicked Showdown.Pokemon and the Zoroark's Showdown.Pokemon should be right next to each other in the pokemon array of p2's Showdown.Side.

Actually, we can probably just remove the last added CalcdexPokemon when processing another Pokémon with the Illusion ability, especially since we can't guarantee that the mimicked Pokémon already exists on the field. May also need to keep track of an "ignored" calcdexId list.

yo can you add support for this website?

this is caused by mega evo items like Mawilite not existing in the Gen 8 Generation object from @pkmn/dex.

import { Dex } from '@pkmn/dex';
import { Generations } from '@pkmn/data';

const gens = new Generations(Dex);
const dexGen8 = gens.get(8);

dexGen8.items.get('Mawilite');

returns:

undefined

we can either load from a previous gen (e.g., gens.get(6)) if dex.items.get() returns undefined, or use the global Dex object from the Showdown client:

Dex.items.get('Mawilite');

returns:

Item {
  id: 'Mawilite',
  num: 681,
  spritenum: 598,
  name: 'Mawilite',
  desc: 'If held by a Mawile, this item allows it to Mega Evolve in battle.',
  shortDesc: 'If held by a Mawile, this item allows it to Mega Evolve in battle.',
  gen: 6,
  exists: true,
  effectType: 'Item',
  itemUser: [
    'Mawile',
  ],
  fling: null,
  isPokeball: false,
  megaEvolves: 'Mawile',
  megaStone: 'Mawile-Mega',
  naturalGift: null,
  onDrive: '',
  onMemory: '',
  onPlate: '',
  zMove: null,
  zMoveFrom: '',
  zMoveType: '',
  zMoveUser: null,
}

note that the following is the return object of dex.items.get() (from @pkmn/dex):

const dexGen6 = gens.get(6);

dexGen6.items.get('Mawilite');

returns:

Item {
  id: 'mawilite',
  num: 681,
  name: 'Mawilite',
  fullName: 'item: Mawilite',
  desc: 'If held by a Mawile, this item allows it to Mega Evolve in battle.',
  shortDesc: '',
  gen: 6,
  exists: true,
  isNonstandard: null,
  kind: 'Item',
  effectType: 'Item',
  itemUser: [
    'Mawile',
  ],
  duration: undefined,
  fling: {
    basePower: 80,
  },
  megaEvolves: 'Mawile',
  megaStone: 'Mawile-Mega',
}

the objects from Dex.items.get() and dex.items.get() share similar properties, but differ slightly, such as the return object from Dex.items.get() not including the isNonstandard property that the return object from dex.items.get() has.