In the future, we want to set a standard of every contribution providing its own tests.

Why?

These automated tests can be run before a build, meaning we have a guarantee that anything in the test files will perform as expected.

On top of that, the tests are run for each pull request before being merged, so if a contribution accidentally breaks or changes the behaviour of other syntax in an unexpected way we will know about this before release.

For example, if I open a pull request that changes parsing behaviour and it accidentally breaks the parsing of an obscure expression, the tests will fail and catch my mistake.

Where do we start?

To begin with, I would like all existing syntax to have tests (where applicable), even if they are just very basic.
Test coverage is incredibly poor currently.

The existing test coverage is displayed below, for anybody who would like to help out by filling in some of these missing gaps.

Expressions

• ExprItemWithCustomModelData
• ExprArrowsStuck
• ExprLevelProgress
• ExprVectorDotProduct
• ExprMaxMinecartSpeed
• ExprParse
• ExprCursorSlot
• ExprLocationFromVector
• ExprPlayerViewDistance
• ExprValueWithin
• ExprSeaPickles
• ExprAttacker
• ExprPermissions
• ExprVehicle
• ExprNoDamageTicks
• ExprTimePlayed
• ExprSpawnReason
• ExprInventoryAction
• ExprValue
• ExprShooter
• ExprSpawnerType
• ExprColoured
• ExprHash
• ExprFallDistance
• ExprLength
• ExprSourceBlock
• ExprSaturation
• ExprTypeOf
• ExprClientViewDistance
• ExprBookAuthor
• ExprIndexOf
• ExprPortal
• ExprDefaultValue
• ExprLocation
• ExprLoot
• ExprEnchantmentOffer
• ExprEnchantItem
• LitAt
• ExprRandomUUID
• ExprCommandInfo
• ExprFireTicks
• ExprShuffledList
• ExprAmount
• ExprTimeSince
• ExprVectorRandom
• ExprCustomModelData
• ExprTime
• ExprMaxHealth
• ExprEnderChest
• ExprRemainingAir
• ExprVersion
• ExprSpecialNumber
• ExprExplosionYield
• ExprLevel
• ExprWorldEnvironment
• ExprUnixDate
• ExprEnchantingExpCost
• ExprAffectedEntities
• ExprTargetedBlock
• ExprVectorFromYawAndPitch
• ExprMetadata
• ExprBlock
• ExprPlain
• ExprExhaustion
• ExprDamagedItem
• ExprEnchantments
• ExprCmdCooldownInfo
• ExprHighestSolidBlock
• ExprLocationOf
• ExprYawPitch
• ExprInventory
• ExprHealReason
• ExprFertilizedBlocks
• ExprMiddleOfLocation
• ExprAbsorbedBlocks
• ExprHumidity
• ExprLocationVectorOffset
• ExprSpeed
• ExprSeed
• ExprFoodLevel
• ExprNow
• ExprMaxFreezeTicks
• ExprSortedList
• ExprSets
• ExprUnixTicks
• ExprParseError
• ExprArmorSlot
• ExprAge
• ExprLastDamageCause
• ExprTimeState
• ExprEnchantmentOfferCost
• ExprNumbers
• ExprHatchingType
• ExprVectorNormalize
• ExprWorlds
• ExprLoopValue
• ExprVersionString
• ExprExperience
• ExprVectorFromXYZ
• ExprLightLevel
• ExprChunk
• ExprPing
• ExprJoinSplit
• ExprNamed
• ExprMaxDurability
• ExprCoordinate
• ExprPlayerlistHeaderFooter
• ExprEventExpression
• ExprAI
• ExprLastColor
• ExprOps
• ExprExplodedBlocks
• ExprItems
• ExprTimes
• ExprInventorySlot
• ExprLastAttacker
• ExprSlotIndex
• ExprTotalExperience
• ExprLeashHolder
• ExprOfflinePlayers
• ExprEyeLocation
• ExprLanguage
• ExprFurnaceSlot
• ExprGlowing
• ExprTamer
• LitPi
• ExprUUID
• ExprAppliedEnchantments
• ExprCommandSender
• ExprHiddenPlayers
• ExprGameMode
• ExprAttackCooldown
• ExprExplosiveYield
• ExprChatRecipients
• ExprScripts
• ExprNumberOfCharacters
• ExprIndices
• ExprBreakSpeed
• ExprFilter
• ExprVectorSquaredLength
• ExprMe
• ExprRandomNumber
• ExprPotionEffectTier
• ExprColorOf
• ExprMoonPhase
• ExprDifference
• ExprMendingRepairAmount
• ExprLastLoadedServerIcon
• ExprSubstring
• ExprPassenger
• ExprVectorOfLocation
• ExprPlayerWeather
• ExprBlockSphere
• ExprBlockData
• ExprBurnCookTime
• ExprRespawnLocation
• ExprVectorSpherical
• ExprExplosionBlockYield
• ExprSeaLevel
• ExprAnvilText
• ExprGravity
• ExprLore
• ExprDirection
• ExprEnchantmentBonus
• ExprProtocolVersion
• ExprPushedBlocks
• ExprLastLoginTime
• ExprProjectileBounceState
• ExprVectorXYZ
• ExprMinecartDerailedFlyingVelocity
• ExprRedstoneBlockPower
• ExprDropsOfBlock
• ExprTemperature
• ExprArrowKnockbackStrength
• ExprInventoryInfo
• ExprStringCase
• ExprScript
• ExprHotbarSlot
• ExprHoverList
• ExprHealAmount
• ExprTarget
• ExprSpectatorTarget
• ExprUnbreakable
• ExprDifficulty
• ExprWorldFromName
• ExprReversedList
• ExprEntityTamer
• ExprEntity
• ExprFinalDamage
• ExprAllBannedEntries
• ExprNearestEntity
• ExprVelocity
• ExprSkull
• ExprArgument
• ExprHotbarButton
• ExprRawString
• ExprBookTitle
• ExprWeather
• ExprSignText
• ExprMOTD
• ExprVectorAngleBetween
• ExprCommand
• ExprIP
• ExprItem
• ExprFreezeTicks
• ExprAllCommands
• ExprDateAgoLater
• ExprEventCancelled
• ExprHatchingNumber
• ExprServerIcon
• ExprPotionEffect
• ExprLastSpawnedEntity
• ExprHanging
• ExprItemsIn
• ExprGameRule
• ExprPlayerProtocolVersion
• ExprLocationAt
• ExprOnlinePlayersCount
• ExprDamageCause
• ExprVectorLength
• ExprTPS
• ExprMaxPlayers
• ExprHealth
• ExprDrops
• ExprTeleportCause
• ExprElement
• ExprFormatDate
• ExprItemAmount
• ExprAmountOfItems
• ExprLastResourcePackResponse
• ExprEnchantmentLevel
• ExprLastDamage
• ExprCompassTarget
• ExprProjectileCriticalState
• ExprBlockHardness
• ExprEntityAttribute
• ExprBed
• ExprTernary
• ExprDamage
• ExprEntities
• LitConsole
• ExprChatFormat
• ExprMessage
• ExprBlocks
• ExprTool
• ExprPlugins
• ExprAltitude
• ExprVectorArithmetic
• ExprOpenedInventory
• ExprWhitelist
• ExprRound
• ExprFacing
• ExprVectorBetweenLocations
• ExprAlphabetList
• ExprDurability
• LitNewLine
• ExprHostname
• ExprChestInventory
• ExprBookPages
• ExprDistance
• ExprVectorCylindrical
• ExprItemFrameSlot
• ExprWorld
• ExprFireworkEffect
• ExprPickupDelay
• ExprItemWithLore
• ExprVectorCrossProduct
• ExprSpawn
• ExprMaxStack
• ExprScoreboardTags
• ExprCreeperMaxFuseTicks
• ExprFlightMode
• ExprCharges
• ExprAttacked
• ExprArrowPierceLevel
• ExprClicked
• ExprRawName
• ExprEgg
• ExprXOf
• ExprRandom
• ExprName
• ExprPotionEffects
• ExprBiome
• ExprGlidingState

Conditions

• CondIsVectorNormalized
• CondIsRiptiding
• CondIsBanned
• CondIsPoisoned
• CondIsFlying
• CondIsOccluding
• CondItemInHand
• CondIsSolid
• CondCompare
• CondIsBlockRedstonePowered
• CondIsSet
• CondIsInteractable
• CondMinecraftVersion
• CondIsInvisible
• CondLeashed
• CondIsEmpty
• CondIsBlock
• CondIncendiary
• CondMatches
• CondPvP
• CondIsPassable
• CondIsSwimming
• CondCancelled
• CondIsSprinting
• CondIsFlammable
• CondIsOp
• CondScriptLoaded
• CondEntityIsInLiquid
• CondIsValid
• CondIsUnbreakable
• CondIsOnGround
• CondIsWhitelisted
• CondResourcePack
• CondWithinRadius
• CondCanSee
• CondIsTameable
• CondIsSkriptCommand
• CondContains
• CondAlphanumeric
• CondIsStackable
• CondIsGliding
• CondHasClientWeather
• CondHasPotion
• CondHasScoreboardTag
• CondPlayedBefore
• CondIsPreferredTool
• CondHasResourcePack
• CondRespawnLocation
• CondIsSlimeChunk
• CondIsInfinite
• CondIsSilent
• CondStartsEndsWith
• CondIsEdible
• CondIsFrozen
• CondAnchorWorks
• CondAI
• CondIsFuel
• CondChance
• CondEntityIsWet
• CondHasCustomModelData
• CondIsSleeping
• CondIsBurning
• CondIsPluginEnabled
• CondIsOfType
• CondHasMetadata
• CondIsRiding
• CondDamageCause
• CondIsSneaking
• CondIsEnchanted
• CondIsOnline
• CondDate
• CondCanHold
• CondIsBlocking
• CondIsInvulnerable
• CondPermission
• CondCanFly
• CondIsWearing
• CondProjectileCanBounce
• CondIsCharged
• CondWillHatch
• CondIgnitionProcess
• CondIsTransparent
• CondIsWithin
• CondIsLoaded
• CondIsAlive

Effects

• EffPush
• EffPathfind
• EffActionBar
• EffBan
• EffColorItems
• EffPlayerInfoVisibility
• EffOp
• EffPlayerVisibility
• IndeterminateDelay
• EffMakeEggHatch
• EffExceptionDebug
• EffShoot
• EffMessage
• EffRespawn
• EffHealth
• EffInvisible
• EffCancelDrops
• EffOpenInventory
• EffKnockback
• EffLeash
• EffCommand
• EffReplace
• EffMakeSay
• EffBroadcast
• Delay
• EffKill
• EffEnchant
• EffVectorRotateAroundAnother
• EffInvulnerability
• EffStopServer
• EffExplodeCreeper
• EffReturn
• EffVisualEffect
• EffLog
• EffForceAttack
• EffExit
• EffMakeFly
• EffExplosion
• EffSilence
• EffPlaySound
• EffPotion
• EffDoIf
• EffContinue
• EffToggle
• EffTree
• EffSendTitle
• EffFeed
• EffKeepInventory
• EffKick
• EffIncendiary
• EffCancelCooldown
• EffPoison
• EffCancelEvent
• EffLoadServerIcon
• EffSendBlockChange
• EffTeleport
• EffDrop
• EffLook
• EffChargeCreeper
• EffFireworkLaunch
• EffOpenBook
• EffSendResourcePack
• EffChange
• EffIgnite
• EffSuppressWarnings
• EffHidePlayerFromServerList
• EffShear
• EffConnect
• EffResetTitle
• EffEquip
• EffSwingHand
• EffLightning
• EffPvP
• EffToggleFlight
• EffVectorRotateXYZ
• EffVehicle
• EffBreakNaturally
• EffStopSound
• EffScriptFile

Sections

• SecLoop
• SecWhile
• SecConditional
• EffSecSpawn

What can we test?

We can test almost anything that can be done on a server without players. This means anything involving items, maths, blocks, most entities, world operations and various and sundry bits and pieces.

We can't (comprehensively) test things involving players, things that have to be tested over a server restart or require something external to be changed. We also can't test things like performance or capacity very easily. These tests need to run automatically on any computer building Skript.

How can I do this?

In practice, this is fairly simple. If my pull request adds or changes the functionality of syntax, I just need to create (or update) the corresponding Skript test file.

A lot of pull requests won't need any extra tests. You'll only need to add/change a test file if you're adding/changing new functionality.
That said, if you think you can improve the existing test for a syntax element you are welcome to.

For example, if I change how ExprDurability works, I need to make sure that the ExprDurability.sk file is updated to test my changes.

(If you add a new syntax you will need to create a new test file for it.)