test(watcher): event dispatch with mock Docker client, per-project serialization, label filtering

Author: alysnnix

internal/watcher/watcher.go

@@ -10,9 +10,16 @@ import (
 	"github.com/docker/docker/api/types/container"
 	"github.com/docker/docker/api/types/events"
 	"github.com/docker/docker/api/types/filters"
-	"github.com/docker/docker/client"
 )
 
+// DockerClient is the subset of the Docker API used by the Watcher.
+// The full client.APIClient satisfies this interface.
+type DockerClient interface {
+	Events(ctx context.Context, options events.ListOptions) (<-chan events.Message, <-chan error)
+	ContainerInspect(ctx context.Context, containerID string) (container.InspectResponse, error)
+	ContainerList(ctx context.Context, options container.ListOptions) ([]container.Summary, error)
+}
+
 type ContainerInfo struct {
 	Project string
 	Service string
@@ -25,12 +32,12 @@ type EventHandler interface {
 }
 
 type Watcher struct {
-	docker    client.APIClient
+	docker    DockerClient
 	handler   EventHandler
 	projectMu sync.Map // map[string]*sync.Mutex
 }
 
-func New(docker client.APIClient, handler EventHandler) *Watcher {
+func New(docker DockerClient, handler EventHandler) *Watcher {
 	return &Watcher{
 		docker:  docker,
 		handler: handler,