Finish ECS ( I hope )

go.mod

@@ -8,5 +8,9 @@ require (
 )
 
 require (
+	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
+	github.com/stretchr/testify v1.10.0 // indirect
 	golang.org/x/sys v0.33.0 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
 )

go.sum

@@ -1,8 +1,17 @@
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/gofrs/uuid v4.4.0+incompatible h1:3qXRTX8/NbyulANqlc0lchS1gqAVxRgsuW1YrTJupqA=
 github.com/gofrs/uuid v4.4.0+incompatible/go.mod h1:b2aQJv3Z4Fp6yNu3cdSllBxTCLRxnplIgP/c0N/04lM=
 github.com/google/uuid v1.6.0 h1:NIvaJDMOsjHA8n1jAhLSgzrAzy1Hgr+hNrb57e+94F0=
 github.com/google/uuid v1.6.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/testify v1.10.0 h1:Xv5erBjTwe/5IxqUQTdXv5kgmIvbHo3QQyRwhJsOfJA=
+github.com/stretchr/testify v1.10.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
 golang.org/x/sys v0.33.0 h1:q3i8TbbEz+JRD9ywIRlyRAQbM0qF7hu24q3teo2hbuw=
 golang.org/x/sys v0.33.0/go.mod h1:BJP2sWEmIv4KK5OTEluFJCKSidICx8ciO85XgH3Ak8k=
 golang.org/x/term v0.32.0 h1:DR4lr0TjUs3epypdhTOkMmuF5CDFJ/8pOnbzMZPQ7bg=
 golang.org/x/term v0.32.0/go.mod h1:uZG1FhGx848Sqfsq4/DlJr3xGGsYMu/L5GW4abiaEPQ=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

internal/ecs/ecs.go

@@ -37,27 +37,27 @@ type Component interface {
 	Type() ComponentType
 }
 
-type ComponentStorage[T Component] struct {
+type ComponentStorage struct {
 	forType ComponentType
-	storage map[Entity]T
+	storage map[Entity]Component
 }
 
-func CreateComponentStorage[T Component](forType ComponentType) *ComponentStorage[T] {
-	return &ComponentStorage[T]{
+func CreateComponentStorage(forType ComponentType) *ComponentStorage {
+	return &ComponentStorage{
 		forType: forType,
-		storage: map[Entity]T{},
+		storage: map[Entity]Component{},
 	}
 }
 
-func (cs *ComponentStorage[T]) ComponentType() ComponentType {
+func (cs *ComponentStorage) ComponentType() ComponentType {
 	return cs.forType
 }
 
-func (cs *ComponentStorage[T]) Entities() iter.Seq[Entity] {
+func (cs *ComponentStorage) Entities() iter.Seq[Entity] {
 	return maps.Keys(cs.storage)
 }
 
-func (cs *ComponentStorage[T]) Query(query func(comp T) bool) iter.Seq[Entity] {
+func queryComponents(cs *ComponentStorage, query func(comp Component) bool) iter.Seq[Entity] {
 	return func(yield func(Entity) bool) {
 		for k, v := range cs.storage {
 			if !query(v) {
@@ -71,20 +71,20 @@ func (cs *ComponentStorage[T]) Query(query func(comp T) bool) iter.Seq[Entity] {
 	}
 }
 
-func (cs *ComponentStorage[T]) Set(e Entity, component T) {
+func (cs *ComponentStorage) Set(e Entity, component Component) {
 	cs.storage[e] = component
 }
 
-func (cs *ComponentStorage[T]) Get(e Entity) (component T, ok bool) {
+func (cs *ComponentStorage) Get(e Entity) (component Component, ok bool) {
 	component, ok = cs.storage[e]
 	return
 }
 
-func (cs *ComponentStorage[T]) Delete(e Entity) {
+func (cs *ComponentStorage) Delete(e Entity) {
 	delete(cs.storage, e)
 }
 
-func (cs *ComponentStorage[T]) All() map[Entity]T {
+func (cs *ComponentStorage) All() map[Entity]Component {
 	return cs.storage
 }
 
@@ -116,14 +116,14 @@ func (s *System) Execute(world *World, delta time.Duration) {
 
 type World struct {
 	systems          []*System
-	componentsByType map[ComponentType]any
+	componentsByType map[ComponentType]*ComponentStorage
 	resources        map[Resource]any
 }
 
 func CreateWorld() (world *World) {
 	world = &World{
 		systems:          []*System{},
-		componentsByType: map[ComponentType]any{},
+		componentsByType: map[ComponentType]*ComponentStorage{},
 		resources:        map[Resource]any{},
 	}
 
@@ -138,9 +138,7 @@ func (w *World) Tick(delta time.Duration) {
 
 func DeleteEntity(world *World, entity Entity) {
 	for _, s := range world.componentsByType {
-		storage := s.(*ComponentStorage[Component])
-
-		storage.Delete(entity)
+		s.Delete(entity)
 	}
 }
 
@@ -180,13 +178,13 @@ func registerComponent[T Component](world *World, compType ComponentType) {
 		return
 	}
 
-	world.componentsByType[compType] = CreateComponentStorage[T](compType)
+	world.componentsByType[compType] = CreateComponentStorage(compType)
 }
 
 func SetComponent[T Component](world *World, entity Entity, component T) {
 	registerComponent[T](world, component.Type())
 
-	compStorage := world.componentsByType[component.Type()].(*ComponentStorage[T])
+	compStorage := world.componentsByType[component.Type()]
 
 	compStorage.Set(entity, component)
 }
@@ -194,7 +192,10 @@ func SetComponent[T Component](world *World, entity Entity, component T) {
 func GetComponent[T Component](world *World, entity Entity) (component T, exists bool) {
 	storage := GetComponentStorage[T](world)
 
-	return storage.Get(entity)
+	val, exists := storage.Get(entity)
+	casted, castSuccess := val.(T)
+
+	return casted, (exists && castSuccess)
 }
 
 func DeleteComponent[T Component](world *World, entity Entity) {
@@ -203,14 +204,14 @@ func DeleteComponent[T Component](world *World, entity Entity) {
 	storage.Delete(entity)
 }
 
-func GetComponentStorage[T Component](world *World) (compStorage *ComponentStorage[T]) {
+func GetComponentStorage[T Component](world *World) (compStorage *ComponentStorage) {
 	var zero T
 
 	compType := zero.Type()
 
 	registerComponent[T](world, compType)
 
-	return world.componentsByType[compType].(*ComponentStorage[T])
+	return world.componentsByType[compType]
 }
 
 func IterateEntitiesWithComponent[T Component](world *World) iter.Seq[Entity] {
@@ -222,7 +223,16 @@ func IterateEntitiesWithComponent[T Component](world *World) iter.Seq[Entity] {
 func QueryEntitiesWithComponent[T Component](world *World, query func(comp T) bool) iter.Seq[Entity] {
 	storage := GetComponentStorage[T](world)
 
-	return storage.Query(query)
+	return queryComponents(storage, func(comp Component) bool {
+		val, ok := comp.(T)
+
+		// Cast unsuccessful, assume failure
+		if !ok {
+			return false
+		}
+
+		return query(val)
+	})
 }
 
 func FindEntitiesWithComponents(world *World, componentTypes ...ComponentType) (entities []Entity) {
@@ -236,7 +246,7 @@ func FindEntitiesWithComponents(world *World, componentTypes ...ComponentType) (
 			return
 		}
 
-		storage, ok := world.componentsByType[compType].(*ComponentStorage[Component])
+		storage, ok := world.componentsByType[compType]
 
 		// If we can't find the storage for this component, then it hasn't been used yet.
 		// Therefore, no entity could have all components requested. Return empty.

internal/ecs/ecs_test.go

@@ -0,0 +1,155 @@
+package ecs
+
+import (
+	"testing"
+	"time"
+
+	"github.com/google/uuid"
+	"github.com/stretchr/testify/assert"
+)
+
+type TestComponent struct {
+	Value string
+}
+
+func (tc TestComponent) Type() ComponentType {
+	return 1
+}
+
+func TestEntityCreation(t *testing.T) {
+	u := uuid.New()
+	entity := CreateEntity(u)
+	assert.Equal(t, u, entity.AsUUID())
+
+	newEntity := NewEntity()
+	assert.NotEqual(t, uuid.Nil, newEntity.AsUUID())
+
+	nilEntity := NilEntity()
+	assert.Equal(t, uuid.Nil, nilEntity.AsUUID())
+}
+
+func TestComponentStorage(t *testing.T) {
+	cs := CreateComponentStorage(1)
+	entity := NewEntity()
+	comp := TestComponent{"hello"}
+	cs.Set(entity, comp)
+
+	ret, ok := cs.Get(entity)
+	assert.True(t, ok)
+	assert.Equal(t, comp, ret)
+
+	cs.Delete(entity)
+	_, ok = cs.Get(entity)
+	assert.False(t, ok)
+}
+
+func TestSystemExecution(t *testing.T) {
+	called := false
+	s := CreateSystem("test", 0, func(world *World, delta time.Duration) error {
+		called = true
+		return nil
+	})
+
+	world := CreateWorld()
+	RegisterSystem(world, s)
+	world.Tick(time.Millisecond)
+
+	assert.True(t, called)
+}
+
+func TestWorldComponentLifecycle(t *testing.T) {
+	world := CreateWorld()
+	entity := NewEntity()
+	comp := TestComponent{"value"}
+
+	SetComponent(world, entity, comp)
+	ret, ok := GetComponent[TestComponent](world, entity)
+	assert.True(t, ok)
+	assert.Equal(t, comp, ret)
+
+	DeleteComponent[TestComponent](world, entity)
+	_, ok = GetComponent[TestComponent](world, entity)
+	assert.False(t, ok)
+}
+
+func TestWorldResourceManagement(t *testing.T) {
+	world := CreateWorld()
+	resourceKey := Resource("test_resource")
+	value := "some data"
+
+	SetResource(world, resourceKey, value)
+	ret, err := GetResource[string](world, resourceKey)
+	assert.NoError(t, err)
+	assert.Equal(t, value, ret)
+
+	RemoveResource(world, resourceKey)
+	_, err = GetResource[string](world, resourceKey)
+	assert.Error(t, err)
+}
+
+func TestEntityDeletion(t *testing.T) {
+	world := CreateWorld()
+	entity := NewEntity()
+	comp := TestComponent{"remove me"}
+	SetComponent(world, entity, comp)
+
+	DeleteEntity(world, entity)
+	_, ok := GetComponent[TestComponent](world, entity)
+	assert.False(t, ok)
+}
+
+func TestIterateEntitiesWithComponent(t *testing.T) {
+	world := CreateWorld()
+	entities := []Entity{
+		NewEntity(),
+		NewEntity(),
+		NewEntity(),
+	}
+	for _, e := range entities {
+		SetComponent(world, e, TestComponent{"iter"})
+	}
+
+	count := 0
+	for range IterateEntitiesWithComponent[TestComponent](world) {
+		count++
+	}
+
+	assert.Equal(t, len(entities), count)
+}
+
+func TestQueryEntitiesWithComponent(t *testing.T) {
+	world := CreateWorld()
+	match := NewEntity()
+	nonMatch := NewEntity()
+	SetComponent(world, match, TestComponent{"match"})
+	SetComponent(world, nonMatch, TestComponent{"skip"})
+
+	results := []Entity{}
+
+	for e := range QueryEntitiesWithComponent(world, func(c TestComponent) bool {
+		return c.Value == "match"
+	}) {
+		results = append(results, e)
+	}
+
+	assert.Len(t, results, 1)
+	assert.Equal(t, match, results[0])
+}
+
+type SecondComponent struct{ Flag bool }
+
+func (SecondComponent) Type() ComponentType { return 2 }
+
+func TestFindEntitiesWithComponents(t *testing.T) {
+	world := CreateWorld()
+	entity1 := NewEntity()
+	entity2 := NewEntity()
+
+	SetComponent(world, entity1, TestComponent{"a"})
+	SetComponent(world, entity1, SecondComponent{true})
+	SetComponent(world, entity2, TestComponent{"b"})
+
+	results := FindEntitiesWithComponents(world, 1, 2)
+	assert.Len(t, results, 1)
+	assert.Equal(t, entity1, results[0])
+}

internal/ecs/error.go

@@ -12,12 +12,6 @@ func newECSError(v ...any) *ecsError {
 	}
 }
 
-func newFormattedECSError(format string, v ...any) *ecsError {
-	return &ecsError{
-		err: fmt.Sprintf(format, v...),
-	}
-}
-
 func (err *ecsError) Error() string {
 	return err.err
 }

internal/game/game.go

@@ -129,6 +129,8 @@ func (game *LastMUDGame) consumeOutputs() {
 			contents: contents.Contents,
 		})
 	}
+
+	ecs.DeleteEntities(game.world.World, entities...)
 }
 
 func (game *LastMUDGame) shutdown() {