Incorrect diagnostics with large (~300 members) union

[justarandomgeek]

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

Expected Behaviour

In the Factorio API, we have a function used for registering all our data that takes a very wide union type (which gets generated from the api docs):

---@alias data.AnyPrototype (data.AccumulatorPrototype)|(data.AchievementPrototype)|(data.ActiveDefenseEquipmentPrototype)|(data.AgriculturalTowerPrototype)|(data.AirbornePollutantPrototype)|(data.AmbientSound)|(data.AmmoCategory)|(data.AmmoItemPrototype)|(data.AmmoTurretPrototype)|(data.AnimationPrototype)|(data.ArithmeticCombinatorPrototype)|(data.ArmorPrototype)|(data.ArrowPrototype)|(data.ArtilleryFlarePrototype)|(data.ArtilleryProjectilePrototype)|(data.ArtilleryTurretPrototype)|(data.ArtilleryWagonPrototype)|(data.AssemblingMachinePrototype)|(data.AsteroidChunkPrototype)|(data.AsteroidCollectorPrototype)|(data.AsteroidPrototype)|(data.AutoplaceControl)|(data.BatteryEquipmentPrototype)|(data.BeaconPrototype)|(data.BeamPrototype)|(data.BeltImmunityEquipmentPrototype)|(data.BlueprintBookPrototype)|(data.BlueprintItemPrototype)|(data.BoilerPrototype)|(data.BuildEntityAchievementPrototype)|(data.BurnerGeneratorPrototype)|(data.BurnerUsagePrototype)|(data.CapsulePrototype)|(data.CaptureRobotPrototype)|(data.CarPrototype)|(data.CargoBayPrototype)|(data.CargoLandingPadPrototype)|(data.CargoPodPrototype)|(data.CargoWagonPrototype)|(data.ChainActiveTriggerPrototype)|(data.ChangedSurfaceAchievementPrototype)|(data.CharacterCorpsePrototype)|(data.CharacterPrototype)|(data.CliffPrototype)|(data.CollisionLayerPrototype)|(data.CombatRobotCountAchievementPrototype)|(data.CombatRobotPrototype)|(data.CompleteObjectiveAchievementPrototype)|(data.ConstantCombinatorPrototype)|(data.ConstructWithRobotsAchievementPrototype)|(data.ConstructionRobotPrototype)|(data.ContainerPrototype)|(data.CopyPasteToolPrototype)|(data.CorpsePrototype)|(data.CreatePlatformAchievementPrototype)|(data.CurvedRailAPrototype)|(data.CurvedRailBPrototype)|(data.CustomEventPrototype)|(data.CustomInputPrototype)|(data.DamageType)|(data.DeciderCombinatorPrototype)|(data.DeconstructWithRobotsAchievementPrototype)|(data.DeconstructibleTileProxyPrototype)|(data.DeconstructionItemPrototype)|(data.DecorativePrototype)|(data.DelayedActiveTriggerPrototype)|(data.DeliverByRobotsAchievementPrototype)|(data.DeliverCategory)|(data.DeliverImpactCombination)|(data.DepleteResourceAchievementPrototype)|(data.DestroyCliffAchievementPrototype)|(data.DisplayPanelPrototype)|(data.DontBuildEntityAchievementPrototype)|(data.DontCraftManuallyAchievementPrototype)|(data.DontKillManuallyAchievementPrototype)|(data.DontResearchBeforeResearchingAchievementPrototype)|(data.DontUseEntityInEnergyProductionAchievementPrototype)|(data.EditorControllerPrototype)|(data.ElectricEnergyInterfacePrototype)|(data.ElectricPolePrototype)|(data.ElectricTurretPrototype)|(data.ElevatedCurvedRailAPrototype)|(data.ElevatedCurvedRailBPrototype)|(data.ElevatedHalfDiagonalRailPrototype)|(data.ElevatedStraightRailPrototype)|(data.EnemySpawnerPrototype)|(data.EnergyShieldEquipmentPrototype)|(data.EntityGhostPrototype)|(data.EquipArmorAchievementPrototype)|(data.EquipmentCategory)|(data.EquipmentGhostPrototype)|(data.EquipmentGridPrototype)|(data.ExplosionPrototype)|(data.FireFlamePrototype)|(data.FishPrototype)|(data.FluidPrototype)|(data.FluidStreamPrototype)|(data.FluidTurretPrototype)|(data.FluidWagonPrototype)|(data.FontPrototype)|(data.FuelCategory)|(data.FurnacePrototype)|(data.FusionGeneratorPrototype)|(data.FusionReactorPrototype)|(data.GatePrototype)|(data.GeneratorEquipmentPrototype)|(data.GeneratorPrototype)|(data.GodControllerPrototype)|(data.GroupAttackAchievementPrototype)|(data.GunPrototype)|(data.HalfDiagonalRailPrototype)|(data.HeatInterfacePrototype)|(data.HeatPipePrototype)|(data.HighlightBoxEntityPrototype)|(data.ImpactCategory)|(data.InfinityCargoWagonPrototype)|(data.InfinityContainerPrototype)|(data.InfinityPipePrototype)|(data.InserterPrototype)|(data.InventoryBonusEquipmentPrototype)|(data.ItemEntityPrototype)|(data.ItemGroup)|(data.ItemPrototype)|(data.ItemRequestProxyPrototype)|(data.ItemSubGroup)|(data.ItemWithEntityDataPrototype)|(data.ItemWithInventoryPrototype)|(data.ItemWithLabelPrototype)|(data.ItemWithTagsPrototype)|(data.KillAchievementPrototype)|(data.LabPrototype)|(data.LampPrototype)|(data.LandMinePrototype)|(data.LaneSplitterPrototype)|(data.LegacyCurvedRailPrototype)|(data.LegacyStraightRailPrototype)|(data.LightningAttractorPrototype)|(data.LightningPrototype)|(data.LinkedBeltPrototype)|(data.LinkedContainerPrototype)|(data.Loader1x1Prototype)|(data.Loader1x2Prototype)|(data.LocomotivePrototype)|(data.LogisticContainerPrototype)|(data.LogisticRobotPrototype)|(data.MapSettings)|(data.MarketPrototype)|(data.MiningDrillPrototype)|(data.ModuleCategory)|(data.ModulePrototype)|(data.ModuleTransferAchievementPrototype)|(data.MouseCursor)|(data.MovementBonusEquipmentPrototype)|(data.NamedNoiseExpression)|(data.NamedNoiseFunction)|(data.NightVisionEquipmentPrototype)|(data.OffshorePumpPrototype)|(data.ParticlePrototype)|(data.ParticleSourcePrototype)|(data.PipePrototype)|(data.PipeToGroundPrototype)|(data.PlaceEquipmentAchievementPrototype)|(data.PlanetPrototype)|(data.PlantPrototype)|(data.PlayerDamagedAchievementPrototype)|(data.PlayerPortPrototype)|(data.PowerSwitchPrototype)|(data.ProcessionLayerInheritanceGroup)|(data.ProcessionPrototype)|(data.ProduceAchievementPrototype)|(data.ProducePerHourAchievementPrototype)|(data.ProgrammableSpeakerPrototype)|(data.ProjectilePrototype)|(data.ProxyContainerPrototype)|(data.PumpPrototype)|(data.QualityPrototype)|(data.RadarPrototype)|(data.RailChainSignalPrototype)|(data.RailPlannerPrototype)|(data.RailRampPrototype)|(data.RailRemnantsPrototype)|(data.RailSignalPrototype)|(data.RailSupportPrototype)|(data.ReactorPrototype)|(data.RecipeCategory)|(data.RecipePrototype)|(data.RemoteControllerPrototype)|(data.RepairToolPrototype)|(data.ResearchAchievementPrototype)|(data.ResearchWithSciencePackAchievementPrototype)|(data.ResourceCategory)|(data.ResourceEntityPrototype)|(data.RoboportEquipmentPrototype)|(data.RoboportPrototype)|(data.RocketSiloPrototype)|(data.RocketSiloRocketPrototype)|(data.RocketSiloRocketShadowPrototype)|(data.SegmentPrototype)|(data.SegmentedUnitPrototype)|(data.SelectionToolPrototype)|(data.SelectorCombinatorPrototype)|(data.ShootAchievementPrototype)|(data.ShortcutPrototype)|(data.SimpleEntityPrototype)|(data.SimpleEntityWithForcePrototype)|(data.SimpleEntityWithOwnerPrototype)|(data.SmokeWithTriggerPrototype)|(data.SolarPanelEquipmentPrototype)|(data.SolarPanelPrototype)|(data.SoundPrototype)|(data.SpaceConnectionDistanceTraveledAchievementPrototype)|(data.SpaceConnectionPrototype)|(data.SpaceLocationPrototype)|(data.SpacePlatformHubPrototype)|(data.SpacePlatformStarterPackPrototype)|(data.SpectatorControllerPrototype)|(data.SpeechBubblePrototype)|(data.SpiderLegPrototype)|(data.SpiderUnitPrototype)|(data.SpiderVehiclePrototype)|(data.SpidertronRemotePrototype)|(data.SplitterPrototype)|(data.SpritePrototype)|(data.StickerPrototype)|(data.StorageTankPrototype)|(data.StraightRailPrototype)|(data.SurfacePropertyPrototype)|(data.SurfacePrototype)|(data.TechnologyPrototype)|(data.TemporaryContainerPrototype)|(data.ThrusterPrototype)|(data.TileEffectDefinition)|(data.TileGhostPrototype)|(data.TilePrototype)|(data.TipsAndTricksItem)|(data.TipsAndTricksItemCategory)|(data.ToolPrototype)|(data.TrainPathAchievementPrototype)|(data.TrainStopPrototype)|(data.TransportBeltPrototype)|(data.TreePrototype)|(data.TriggerTargetType)|(data.TrivialSmokePrototype)|(data.TurretPrototype)|(data.TutorialDefinition)|(data.UndergroundBeltPrototype)|(data.UnitPrototype)|(data.UpgradeItemPrototype)|(data.UseEntityInEnergyProductionAchievementPrototype)|(data.UseItemAchievementPrototype)|(data.UtilityConstants)|(data.UtilitySounds)|(data.UtilitySprites)|(data.VirtualSignalPrototype)|(data.WallPrototype)

---@param otherdata (data.AnyPrototype)[] 
function data.extend(otherdata) ... end;

This causes spurious diagnostics when calling it with values of a known type that is within that union, if it's too far down the list:

-- data.raw has defined types, so this comes out as a data.LampPrototype
local lamp = util.table.deepcopy(data.raw["lamp"]["small-lamp"])

-- (do some stuff to it that you don't care about...)

-- then extend it
data.extend{ lamp }

Actual Behaviour

this produces the diagnostic:

Cannot assign `data.LampPrototype` to `data.AccumulatorPrototype|data.AchievementPrototype|data.ActiveDefenseEquipmentPrototype|data.AgriculturalTowerPrototype|data.AirbornePollutantPrototype...(+255)`.
- `data.LampPrototype` cannot match `data.AccumulatorPrototype|data.AchievementPrototype|data.ActiveDefenseEquipmentPrototype|data.AgriculturalTowerPrototype|data.AirbornePollutantPrototype...(+255)`
- `data.LampPrototype` cannot match any subtypes in `data.AccumulatorPrototype|data.AchievementPrototype|data.ActiveDefenseEquipmentPrototype|data.AgriculturalTowerPrototype|data.AirbornePollutantPrototype...(+255)`
- Type `data.LampPrototype` cannot match `data.ExplosionPrototype`
- Type `data.EntityWithOwnerPrototype` cannot match `data.ExplosionPrototype`
- Type `data.EntityWithHealthPrototype` cannot match `data.ExplosionPrototype`
- Type `data.EntityPrototype` cannot match `data.ExplosionPrototype`
- Type `data.Prototype` cannot match `data.ExplosionPrototype`
- Type `data.PrototypeBase` cannot match `data.ExplosionPrototype`
- Type `data.LampPrototype` cannot match `data.EquipmentGridPrototype`
- Type `data.EntityWithOwnerPrototype` cannot match `data.EquipmentGridPrototype`
- Type `data.EntityWithHealthPrototype` cannot match `data.EquipmentGridPrototype`
- Type `data.EntityPrototype` cannot match `data.EquipmentGridPrototype`
...(+575)
- Type `data.EntityPrototype` cannot match `data.ModBoolSettingPrototype`
- Type `data.Prototype` cannot match `data.ModBoolSettingPrototype`
- Type `data.PrototypeBase` cannot match `data.ModBoolSettingPrototype`

Reproduction steps

1. Go to '...'
2. Click '...'
3. See error '...'

Additional Notes

No response

Log File

No response

[tomlau10]

The limitation of checking only first 100 elements in union was added recently by @sumneko in this commit: c8ed198
for performance reason according to the commit message

Maybe this should be a configurable option, eg Lua.type.maxCheckUnionItems 🤔

• default: 100
• user may set it to a larger value if desired
• and for value <= 0: unlimited

[justarandomgeek]

Yes, a setting for this would be excellent! let it be small for most people and those of us that need it to deal with huge types can crank it up! :)

[cprn]

Perhaps an easier example (utilising ready to use ${3rd}/love2d/library definitions) in the closed duplicate ticket.

[LJNIC]

+1 to making this a setting

[justarandomgeek]

this is really killing us, can we please have a setting for this?

[justarandomgeek]

more reports from users impacted by this today. Can we please have an option for this to work correctly with large enums?

[CodeGreen0386]

Hi, this has been bothering me quite a bit of time as well. I have to disable diagnostics everywhere all the time, having a setting would allow people to make the language server correct rather than slightly faster.

[LoupAndSnoop]

I have also had this problem. If this is a setting, it should really be default to have an extremely high limit on enum size, as limits should only really safeguard against silly cases like 10^6 members. Some games have very large enums, and LuaLS is doing its calculations quickly, but the result is just plain incorrect.

[cprn]

Can we close this as a duplicate of #3126 ?

To everyone affected by this: for now you can change every > 100 in script/vm/type.lua to something like > 1000, then save file and restart editor.

You can also submit PR adding the setting.

Thumbs up reaction is usually enough to show support and demand, please don't add extra +1 comments, because they ping everyone subscribed to this ticket.

Also, sorry for this ping.

[justarandomgeek]

well, you may not like the ping, but i'm getting multiple reports from my users every day about this issue that has been ignored for a month now. We really need a fix...