refactor: make ID an interface

internal/logging/enricher.go

@@ -47,7 +47,7 @@ func (e *ReferenceUpdater[T]) UpdateArgs(args ...any) []any {
 		// Where an argument is of type resource.ID, try and retrieve the
 		// resource corresponding to the ID and replace argument with the
 		// resource.
-		if id, ok := arg.(resource.ID); ok {
+		if id, ok := arg.(resource.MonotonicID); ok {
 			t, err := e.Get(id)
 			if err != nil {
 				continue
@@ -68,7 +68,7 @@ func (e *ReferenceUpdater[T]) UpdateArgs(args ...any) []any {
 		if !f.IsValid() {
 			continue
 		}
-		id, ok := f.Interface().(resource.ID)
+		id, ok := f.Interface().(resource.MonotonicID)
 		if !ok {
 			continue
 		}

internal/logging/enricher_test.go

@@ -8,15 +8,15 @@ import (
 )
 
 func TestReferenceUpdater(t *testing.T) {
-	res := &fakeResource{ID: resource.NewID(resource.Module)}
+	res := &fakeResource{MonotonicID: resource.NewMonotonicID(resource.Module)}
 	updater := &ReferenceUpdater[*fakeResource]{
 		Getter: &fakeResourceGetter{res: res},
 		Name:   "fake",
 		Field:  "FakeResourceID",
 	}
 
 	t.Run("replace resource id with resource", func(t *testing.T) {
-		args := []any{"fake", res.ID}
+		args := []any{"fake", res.MonotonicID}
 		got := updater.UpdateArgs(args...)
 
 		want := []any{"fake", res}
@@ -25,10 +25,10 @@ func TestReferenceUpdater(t *testing.T) {
 
 	t.Run("add resource when referenced from struct with pointer field", func(t *testing.T) {
 		type logMsgArg struct {
-			FakeResourceID *resource.ID
+			FakeResourceID *resource.MonotonicID
 		}
 
-		args := []any{"arg1", logMsgArg{FakeResourceID: &res.ID}}
+		args := []any{"arg1", logMsgArg{FakeResourceID: &res.MonotonicID}}
 		got := updater.UpdateArgs(args...)
 
 		want := append(args, "fake", res)
@@ -37,10 +37,10 @@ func TestReferenceUpdater(t *testing.T) {
 
 	t.Run("add resource when referenced from struct with non-pointer field", func(t *testing.T) {
 		type logMsgArg struct {
-			FakeResourceID resource.ID
+			FakeResourceID resource.MonotonicID
 		}
 
-		args := []any{"arg1", logMsgArg{FakeResourceID: res.ID}}
+		args := []any{"arg1", logMsgArg{FakeResourceID: res.MonotonicID}}
 		got := updater.UpdateArgs(args...)
 
 		want := append(args, "fake", res)
@@ -49,7 +49,7 @@ func TestReferenceUpdater(t *testing.T) {
 
 	t.Run("handle nil pointer from struct", func(t *testing.T) {
 		type logMsgArg struct {
-			FakeResourceID *resource.ID
+			FakeResourceID *resource.MonotonicID
 		}
 
 		args := []any{"arg1", logMsgArg{FakeResourceID: nil}}
@@ -60,7 +60,7 @@ func TestReferenceUpdater(t *testing.T) {
 }
 
 type fakeResource struct {
-	resource.ID
+	resource.MonotonicID
 }
 
 type fakeResourceGetter struct {

internal/logging/message.go

@@ -8,23 +8,19 @@ import (
 
 // Message is the event payload for a log message
 type Message struct {
-	// A message is a pug resource, but only insofar as it makes it easier to
-	// handle consistently alongside all other resources (modules, workspaces,
-	// etc) in the TUI.
-	resource.ID
-
+	ID         resource.MonotonicID
 	Time       time.Time
 	Level      string
 	Message    string `json:"msg"`
 	Attributes []Attr
 }
 
+func (m Message) GetID() resource.ID { return m.ID }
+
 type Attr struct {
+	ID    resource.MonotonicID
 	Key   string
 	Value string
-
-	// An attribute is a pug resource, but only insofar as it makes it easier to
-	// handle consistently alongside all other resources (modules, workspaces,
-	// etc) in the TUI.
-	resource.ID
 }
+
+func (a Attr) GetID() resource.ID { return a.ID }

internal/logging/sort.go

@@ -2,7 +2,7 @@ package logging
 
 // BySerialDesc sorts log messages by their serial.
 func BySerialDesc(i, j Message) int {
-	if i.Serial < j.Serial {
+	if i.ID.Serial < j.ID.Serial {
 		return 1
 	}
 	return -1

internal/logging/writer.go

@@ -19,7 +19,7 @@ func (w *writer) Write(p []byte) (int, error) {
 	d := logfmt.NewDecoder(bytes.NewReader(p))
 	for d.ScanRecord() {
 		msg := Message{
-			ID: resource.NewID(resource.Log),
+			ID: resource.NewMonotonicID(resource.Log),
 		}
 		for d.ScanKeyval() {
 			switch string(d.Key()) {
@@ -37,7 +37,7 @@ func (w *writer) Write(p []byte) (int, error) {
 				msg.Attributes = append(msg.Attributes, Attr{
 					Key:   string(d.Key()),
 					Value: string(d.Value()),
-					ID:    resource.NewID(resource.LogAttr),
+					ID:    resource.NewMonotonicID(resource.LogAttr),
 				})
 			}
 		}

internal/module/module.go

@@ -16,12 +16,12 @@ import (
 
 // Module is a terraform root module.
 type Module struct {
-	resource.ID
+	ID resource.MonotonicID
 
 	// Path relative to pug working directory
 	Path string
 	// The module's current workspace.
-	CurrentWorkspaceID *resource.ID
+	CurrentWorkspaceID resource.ID
 
 	// The module's backend type
 	Backend string
@@ -41,7 +41,7 @@ type Options struct {
 // New constructs a module.
 func New(opts Options) *Module {
 	return &Module{
-		ID:      resource.NewID(resource.Module),
+		ID:      resource.NewMonotonicID(resource.Module),
 		Path:    opts.Path,
 		Backend: opts.Backend,
 	}

internal/module/service.go

@@ -215,7 +215,7 @@ func (s *Service) Init(moduleID resource.ID, upgrade bool) (task.Spec, error) {
 		args = append(args, "-upgrade")
 	}
 	spec := task.Spec{
-		ModuleID:   &mod.ID,
+		ModuleID:   mod.ID,
 		Path:       mod.Path,
 		Identifier: InitTask,
 		Execution: task.Execution{
@@ -236,7 +236,7 @@ func (s *Service) Format(moduleID resource.ID) (task.Spec, error) {
 		return task.Spec{}, err
 	}
 	spec := task.Spec{
-		ModuleID: &mod.ID,
+		ModuleID: mod.ID,
 		Path:     mod.Path,
 		Execution: task.Execution{
 			TerraformCommand: []string{"fmt"},
@@ -253,7 +253,7 @@ func (s *Service) Validate(moduleID resource.ID) (task.Spec, error) {
 		return task.Spec{}, err
 	}
 	spec := task.Spec{
-		ModuleID: &mod.ID,
+		ModuleID: mod.ID,
 		Path:     mod.Path,
 		Execution: task.Execution{
 			TerraformCommand: []string{"validate"},
@@ -284,7 +284,7 @@ func (s *Service) GetByPath(path string) (*Module, error) {
 // SetCurrent sets the current workspace for the module.
 func (s *Service) SetCurrent(moduleID, workspaceID resource.ID) error {
 	_, err := s.table.Update(moduleID, func(existing *Module) error {
-		existing.CurrentWorkspaceID = &workspaceID
+		existing.CurrentWorkspaceID = workspaceID
 		return nil
 	})
 	return err
@@ -297,7 +297,7 @@ func (s *Service) Execute(moduleID resource.ID, program string, args ...string)
 		return task.Spec{}, err
 	}
 	spec := task.Spec{
-		ModuleID: &mod.ID,
+		ModuleID: mod.ID,
 		Path:     mod.Path,
 		Execution: task.Execution{
 			Program: program,

internal/module/service_test.go

@@ -71,11 +71,11 @@ digraph {
 		assert.Len(t, vpc.Dependencies(), 0)
 		// redis
 		if assert.Len(t, redis.Dependencies(), 1) {
-			assert.Equal(t, vpc.ID, redis.Dependencies()[0].GetID())
+			assert.Equal(t, vpc.ID, redis.Dependencies()[0])
 		}
 		// mysql
 		if assert.Len(t, mysql.Dependencies(), 1) {
-			assert.Equal(t, vpc.ID, mysql.Dependencies()[0].GetID())
+			assert.Equal(t, vpc.ID, mysql.Dependencies()[0])
 		}
 		// backend
 		if assert.Len(t, backend.Dependencies(), 3) {

internal/plan/plan.go

@@ -15,8 +15,7 @@ import (
 )
 
 type plan struct {
-	resource.ID
-
+	ID            resource.MonotonicID
 	ModuleID      resource.ID
 	WorkspaceID   resource.ID
 	ModulePath    string
@@ -34,7 +33,7 @@ type plan struct {
 
 	// taskID is the ID of the plan task, and is only set once the task is
 	// created.
-	taskID *resource.ID
+	taskID resource.ID
 }
 
 type CreateOptions struct {
@@ -66,7 +65,7 @@ func (f *factory) newPlan(workspaceID resource.ID, opts CreateOptions) (*plan, e
 		return nil, fmt.Errorf("retrieving module: %w", err)
 	}
 	plan := &plan{
-		ID:                 resource.NewID(resource.Plan),
+		ID:                 resource.NewMonotonicID(resource.Plan),
 		ModuleID:           mod.ID,
 		WorkspaceID:        ws.ID,
 		ModulePath:         mod.Path,
@@ -78,7 +77,7 @@ func (f *factory) newPlan(workspaceID resource.ID, opts CreateOptions) (*plan, e
 		moduleDependencies: mod.Dependencies(),
 	}
 	if opts.planFile {
-		plan.ArtefactsPath = filepath.Join(f.dataDir, fmt.Sprintf("%d", plan.Serial))
+		plan.ArtefactsPath = filepath.Join(f.dataDir, fmt.Sprintf("%d", plan.ID.Serial))
 		if err := os.MkdirAll(plan.ArtefactsPath, 0o755); err != nil {
 			return nil, fmt.Errorf("creating run artefacts directory: %w", err)
 		}
@@ -105,8 +104,8 @@ func (r *plan) planTaskSpec() task.Spec {
 	// TODO: assert planFile is true first
 	spec := task.Spec{
 		Identifier:  PlanTask,
-		ModuleID:    &r.ModuleID,
-		WorkspaceID: &r.WorkspaceID,
+		ModuleID:    r.ModuleID,
+		WorkspaceID: r.WorkspaceID,
 		Path:        r.ModulePath,
 		Env:         r.envs,
 		Execution: task.Execution{
@@ -117,7 +116,7 @@ func (r *plan) planTaskSpec() task.Spec {
 		Blocking:    true,
 		Description: "plan",
 		AfterCreate: func(t *task.Task) {
-			r.taskID = &t.ID
+			r.taskID = t.ID
 		},
 		BeforeExited: func(t *task.Task) (task.Summary, error) {
 			out, err := io.ReadAll(t.NewReader(false))
@@ -153,8 +152,8 @@ func (r *plan) applyTaskSpec() (task.Spec, error) {
 	}
 	spec := task.Spec{
 		Identifier:  ApplyTask,
-		ModuleID:    &r.ModuleID,
-		WorkspaceID: &r.WorkspaceID,
+		ModuleID:    r.ModuleID,
+		WorkspaceID: r.WorkspaceID,
 		Path:        r.ModulePath,
 		Execution: task.Execution{
 			TerraformCommand: []string{"apply"},

internal/plan/service.go

@@ -83,11 +83,11 @@ func (s *Service) ReloadAfterApply(sub <-chan resource.Event[*task.Task]) {
 			if workspaceID == nil {
 				continue
 			}
-			if _, err := s.states.CreateReloadTask(*workspaceID); err != nil {
-				s.logger.Error("reloading state after apply", "error", err, "workspace", *workspaceID)
+			if _, err := s.states.CreateReloadTask(workspaceID); err != nil {
+				s.logger.Error("reloading state after apply", "error", err, "workspace", workspaceID)
 				continue
 			}
-			s.logger.Debug("reloading state after apply", "workspace", *workspaceID)
+			s.logger.Debug("reloading state after apply", "workspace", workspaceID)
 		}
 	}
 }
@@ -150,7 +150,7 @@ func (s *Service) Get(runID resource.ID) (*plan, error) {
 
 func (s *Service) getByTaskID(taskID resource.ID) (*plan, error) {
 	for _, plan := range s.List() {
-		if plan.taskID != nil && *plan.taskID == taskID {
+		if plan.taskID != nil && plan.taskID == taskID {
 			return plan, nil
 		}
 	}

internal/pubsub/broker.go

@@ -17,15 +17,15 @@ type Logger interface {
 }
 
 // Broker allows clients to publish events and subscribe to events
-type Broker[T resource.Resource] struct {
+type Broker[T any] struct {
 	subs   map[chan resource.Event[T]]struct{} // subscriptions
 	mu     sync.Mutex                          // sync access to map
 	done   chan struct{}                       // close when broker is shutting down
 	logger Logger
 }
 
 // NewBroker constructs a pub/sub broker.
-func NewBroker[T resource.Resource](logger Logger) *Broker[T] {
+func NewBroker[T any](logger Logger) *Broker[T] {
 	b := &Broker[T]{
 		subs:   make(map[chan resource.Event[T]]struct{}),
 		done:   make(chan struct{}),

internal/resource/event.go

@@ -11,7 +11,7 @@ type (
 	EventType string
 
 	// Event represents an event in the lifecycle of a resource
-	Event[T Resource] struct {
+	Event[T any] struct {
 		Type    EventType
 		Payload T
 	}

internal/resource/id.go

@@ -1,45 +1,9 @@
 package resource
 
-import (
-	"fmt"
-	"sync"
-)
+// ID uniquely identifies a Pug resource.
+type ID any
 
-var (
-	// nextID provides the next ID for each kind
-	nextID map[Kind]uint = make(map[Kind]uint)
-	mu     sync.Mutex
-)
-
-// ID is a unique identifier for a pug resource.
-type ID struct {
-	Serial uint
-	Kind   Kind
-}
-
-func NewID(kind Kind) ID {
-	mu.Lock()
-	defer mu.Unlock()
-
-	id := nextID[kind]
-	nextID[kind]++
-
-	return ID{
-		Serial: id,
-		Kind:   kind,
-	}
-}
-
-func (id ID) String() string {
-	return fmt.Sprintf("#%d", id.Serial)
-}
-
-// GetID allows ID to be accessed via an interface value.
-func (id ID) GetID() ID {
-	return id
-}
-
-// GetKind allows Kind to be accessed via an interface value.
-func (id ID) GetKind() Kind {
-	return id.Kind
+// Identifiable is a Pug resource with an identity.
+type Identifiable interface {
+	GetID() ID
 }