Large Lua files have "Not showing N further errors and warnings"

How are you using the lua-language-server?

Visual Studio Code Extension (sumneko.lua)

Which OS are you using?

Windows

What is the issue affecting?

Diagnostics/Syntax Checking

Problem

Related to: #1522

In large files, you can get into a situation where there are 0 errors reported in the errors pane except for "Not showing N further errors and warnings". Obviously, this makes it impossible to actually fix the errors, since you don't know what they are.

Thus, the bug seems to be that the Lua language server is incorrectly ignoring errors suppressed by the end-user, since they are still counting towards the 250 hardcoded (?) VSCode limit

Reproduction steps

Use the following Lua file:

https://gist.github.com/Zamiell/d0ab9f0b9d0d48efe9a14c293e44f8f0/raw/272057baf5028400e2aefed958b8d31defb01f02/main.lua

With the following .luarc.json file:

{
  "$schema": "https://raw.githubusercontent.com/sumneko/vscode-lua/master/setting/schema.json",
  "diagnostics.globals": [
    "ActionTriggers",
    "ActiveSlot",
    "BabySubType",
    "BackdropType",
    "BatterySubType",
    "BedSubType",
    "BitSet128",
    "BombSubType",
    "BombVariant",
    "ButtonAction",
    "CacheFlag",
    "Card",
    "Challenge",
    "ChampionColor",
    "ChestSubType",
    "CoinSubType",
    "CollectibleType",
    "Color",
    "CppContainer",
    "DamageFlag",
    "Difficulty",
    "Direction",
    "DoorSlot",
    "DoorState",
    "DoorVariant",
    "EffectVariant",
    "Entity",
    "EntityBomb",
    "EntityCollisionClass",
    "EntityEffect",
    "EntityFamiliar",
    "EntityFlag",
    "EntityGridCollisionClass",
    "EntityKnife",
    "EntityLaser",
    "EntityNPC",
    "EntityPartition",
    "EntityPickup",
    "EntityPlayer",
    "EntityProjectile",
    "EntityPtr",
    "EntityRef",
    "EntityTear",
    "EntityType",
    "FamiliarVariant",
    "Font",
    "Game",
    "GameStateFlag",
    "GetPtrHash",
    "GridCollisionClass",
    "GridEntity",
    "GridEntityDesc",
    "GridEntityDoor",
    "GridEntityPit",
    "GridEntityPoop",
    "GridEntityPressurePlate",
    "GridEntityRock",
    "GridEntitySpikes",
    "GridEntityTNT",
    "GridEntityType",
    "GridRooms",
    "HUD",
    "HeartSubType",
    "Input",
    "InputHook",
    "Isaac",
    "ItemConfig",
    "ItemPool",
    "ItemPoolType",
    "ItemType",
    "KColor",
    "KeySubType",
    "Keyboard",
    "LaserOffset",
    "LaserSubType",
    "Level",
    "LevelCurse",
    "LevelStage",
    "LevelStateFlag",
    "LocustSubtypes",
    "ModCallbacks",
    "Mouse",
    "Music",
    "MusicManager",
    "NpcState",
    "NullItemID",
    "Options",
    "PathFinder",
    "PickupPrice",
    "PickupVariant",
    "PillColor",
    "PillEffect",
    "PlayerForm",
    "PlayerSpriteLayer",
    "PlayerType",
    "PlayerTypes",
    "PoopPickupSubType",
    "PoopSpellType",
    "ProjectileFlags",
    "ProjectileParams",
    "ProjectileVariant",
    "QueueItemData",
    "REPENTANCE",
    "RNG",
    "Random",
    "RandomVector",
    "RegisterMod",
    "RenderMode",
    "Room",
    "RoomConfig",
    "RoomDescriptor",
    "RoomShape",
    "RoomTransitionAnim",
    "RoomType",
    "SFXManager",
    "SackSubType",
    "SeedEffect",
    "Seeds",
    "ShockwaveParams",
    "SkinColor",
    "SortingLayer",
    "SoundEffect",
    "Sprite",
    "StageType",
    "StartDebug",
    "TearFlags",
    "TearParams",
    "TearVariant",
    "TemporaryEffect",
    "TemporaryEffects",
    "TrinketType",
    "UseFlag",
    "Vector",
    "WeaponType",
    "AwaitingTextInput",
    "EID",
    "Encyclopedia",
    "ModConfigMenu",
    "MinimapAPI",
    "StageAPI",
    "g",
    "gd",
    "getParentFunctionDescription",
    "sandboxGetTraceback",
    "sandboxTraceback"
  ],
  "preloadFileSize": 5000,
  "runtime.version": "Lua 5.3"
}

Then, you will see that there are Not showing 2551 further errors and warnings. in the "Problems" pane of VSCode.

Reproduce the report with the linked large main.lua file, the provided .luarc.json, and the VS Code Problems pane, then compare the behavior with related issue #1522. Start at the diagnostics/syntax-checking path and determine why suppressed diagnostics still count toward the visible limit. Done means genuine diagnostics remain accessible instead of only showing the "Not showing N further errors and warnings" message.