add complex translations test to engine

internal/simulation/engine.go

@@ -60,10 +60,10 @@ func NewEngineFromDesign(design design.Design, duration int, tickMs int) *Engine
 		case "cache":
 			simNode = &CacheNode{
 				ID:             n.ID,
-				Label:          n.Props["label"].(string),
+				Label:          asString(n.Props["label"]),
-				CacheTTL:       int(n.Props["cacheTTL"].(float64)),
+				CacheTTL:       int(asFloat64(n.Props["cacheTTL"])),
-				MaxEntries:     int(n.Props["maxEntries"].(float64)),
+				MaxEntries:     int(asFloat64(n.Props["maxEntries"])),
-				EvictionPolicy: n.Props["evictionPolicy"].(string),
+				EvictionPolicy: asString(n.Props["evictionPolicy"]),
 				CurrentLoad:    0,
 				Queue:          []*Request{},
 				Cache:          make(map[string]CacheEntry),
@@ -72,20 +72,20 @@ func NewEngineFromDesign(design design.Design, duration int, tickMs int) *Engine
 		case "database":
 			simNode = &DatabaseNode{
 				ID:          n.ID,
-				Label:       n.Props["label"].(string),
+				Label:       asString(n.Props["label"]),
-				Replication: int(n.Props["replication"].(float64)),
+				Replication: int(asFloat64(n.Props["replication"])),
 				Queue:       []*Request{},
 				Alive:       true,
 			}
 		case "cdn":
 			simNode = &CDNNode{
 				ID:              n.ID,
-				Label:           n.Props["label"].(string),
+				Label:           asString(n.Props["label"]),
-				TTL:             int(n.Props["ttl"].(float64)),
+				TTL:             int(asFloat64(n.Props["ttl"])),
-				GeoReplication:  n.Props["geoReplication"].(string),
+				GeoReplication:  asString(n.Props["geoReplication"]),
-				CachingStrategy: n.Props["cachingStrategy"].(string),
+				CachingStrategy: asString(n.Props["cachingStrategy"]),
-				Compression:     n.Props["compression"].(string),
+				Compression:     asString(n.Props["compression"]),
-				HTTP2:           n.Props["http2"].(string),
+				HTTP2:           asString(n.Props["http2"]),
 				Queue:           []*Request{},
 				Alive:           true,
 				output:          []*Request{},
@@ -94,9 +94,9 @@ func NewEngineFromDesign(design design.Design, duration int, tickMs int) *Engine
 		case "messageQueue":
 			simNode = &MessageQueueNode{
 				ID:         n.ID,
-				Label:      n.Props["label"].(string),
+				Label:      asString(n.Props["label"]),
-				QueueSize:  int(n.Props["maxSize"].(float64)),
+				QueueSize:  int(asFloat64(n.Props["maxSize"])),
-				MessageTTL: int(n.Props["retentionSeconds"].(float64)),
+				MessageTTL: int(asFloat64(n.Props["retentionSeconds"])),
 				DeadLetter: false,
 				Queue:      []*Request{},
 				Alive:      true,
@@ -104,9 +104,9 @@ func NewEngineFromDesign(design design.Design, duration int, tickMs int) *Engine
 		case "microservice":
 			simNode = &MicroserviceNode{
 				ID:             n.ID,
-				Label:          n.Props["label"].(string),
+				Label:          asString(n.Props["label"]),
-				APIEndpoint:    n.Props["apiVersion"].(string),
+				APIEndpoint:    asString(n.Props["apiVersion"]),
-				RateLimit:      int(n.Props["rpsCapacity"].(float64)),
+				RateLimit:      int(asFloat64(n.Props["rpsCapacity"])),
 				CircuitBreaker: true,
 				Queue:          []*Request{},
 				CircuitState:   "closed",
@@ -115,9 +115,9 @@ func NewEngineFromDesign(design design.Design, duration int, tickMs int) *Engine
 		case "third party service":
 			simNode = &ThirdPartyServiceNode{
 				ID:          n.ID,
-				Label:       n.Props["label"].(string),
+				Label:       asString(n.Props["label"]),
-				APIEndpoint: n.Props["provider"].(string),
+				APIEndpoint: asString(n.Props["provider"]),
-				RateLimit:   int(n.Props["latency"].(float64)),
+				RateLimit:   int(asFloat64(n.Props["latency"])),
 				RetryPolicy: "exponential",
 				Queue:       []*Request{},
 				Alive:       true,
@@ -125,20 +125,20 @@ func NewEngineFromDesign(design design.Design, duration int, tickMs int) *Engine
 		case "data pipeline":
 			simNode = &DataPipelineNode{
 				ID:             n.ID,
-				Label:          n.Props["label"].(string),
+				Label:          asString(n.Props["label"]),
-				BatchSize:      int(n.Props["batchSize"].(float64)),
+				BatchSize:      int(asFloat64(n.Props["batchSize"])),
-				Transformation: n.Props["transformation"].(string),
+				Transformation: asString(n.Props["transformation"]),
 				Queue:          []*Request{},
 				Alive:          true,
 			}
 		case "monitoring/alerting":
 			simNode = &MonitoringNode{
 				ID:             n.ID,
-				Label:          n.Props["label"].(string),
+				Label:          asString(n.Props["label"]),
-				Tool:           n.Props["tool"].(string),
+				Tool:           asString(n.Props["tool"]),
-				AlertMetric:    n.Props["metric"].(string),
+				AlertMetric:    asString(n.Props["metric"]),
-				ThresholdValue: int(n.Props["threshold"].(float64)),
+				ThresholdValue: int(asFloat64(n.Props["threshold"])),
-				ThresholdUnit:  n.Props["unit"].(string),
+				ThresholdUnit:  asString(n.Props["unit"]),
 				Queue:          []*Request{},
 				Alive:          true,
 			}
@@ -243,3 +243,20 @@ func shouldInject(tick int) bool {
 func generateRequestID(tick int) string {
 	return fmt.Sprintf("req-%d-%d", tick, rand.Intn(1000))
 }
+
+func asFloat64(v interface{}) float64 {
+	if v == nil {
+		return 0
+	}
+
+	return v.(float64)
+}
+
+func asString(v interface{}) string {
+	s, ok := v.(string)
+	if !ok {
+		return ""
+	}
+
+	return s
+}

internal/simulation/engine_test.go

@@ -1,8 +1,11 @@
 package simulation
 
 import (
+	"os"
+	"path/filepath"
 	"testing"
 
+	"encoding/json"
 	"systemdesigngame/internal/design"
 )
 
@@ -53,3 +56,34 @@ func TestNewEngineFromDesign(t *testing.T) {
 	}
 }
 
+func TestComplexSimulationRun(t *testing.T) {
+	filePath := filepath.Join("testdata", "complex_design.json")
+	data, err := os.ReadFile(filePath)
+	if err != nil {
+		t.Fatalf("Failed to read JSON file: %v", err)
+	}
+
+	var d design.Design
+	if err := json.Unmarshal([]byte(data), &d); err != nil {
+		t.Fatalf("Failed to unmarshal JSON: %v", err)
+	}
+
+	engine := NewEngineFromDesign(d, 10, 100)
+	if engine == nil {
+		t.Fatal("Engine should not be nil")
+	}
+
+	engine.Run()
+
+	if len(engine.Timeline) == 0 {
+		t.Fatal("Expected timeline snapshots after Run, got none")
+	}
+
+	// Optional: check that some nodes received or emitted requests
+	for id, node := range engine.Nodes {
+		if len(node.Emit()) > 0 {
+			t.Logf("Node %s has activity", id)
+		}
+	}
+}
+

internal/simulation/testdata/complex_design.json

@@ -0,0 +1 @@
+{"nodes":[{"id":"node-1","type":"loadBalancer","position":{"x":-4,"y":0},"props":{"label":"Load Balancer","algorithm":"round-robin"}},{"id":"node-2","type":"webserver","position":{"x":-1,"y":0},"props":{"label":"Web Server","instanceSize":"medium"}},{"id":"node-3","type":"database","position":{"x":177,"y":-176},"props":{"label":"Database","replication":1}},{"id":"node-4","type":"cache","position":{"x":204,"y":-78},"props":{"label":"Cache","cacheTTL":60,"maxEntries":100000,"evictionPolicy":"LRU"}},{"id":"node-5","type":"messageQueue","position":{"x":0,"y":0},"props":{"label":"MQ","maxSize":10000,"retentionSeconds":600}},{"id":"node-6","type":"cdn","position":{"x":20,"y":69},"props":{"label":"CDN","ttl":3600,"geoReplication":"global","cachingStrategy":"cache-first","compression":"brotli","http2":"enabled"}},{"id":"node-7","type":"microservice","position":{"x":0,"y":0},"props":{"label":"Service","instanceCount":3,"instanceSize":"medium","scalingStrategy":"auto","apiVersion":"v1"}},{"id":"node-8","type":"data pipeline","position":{"x":-453,"y":-121},"props":{"label":"pipeline","batchSize":500,"transformation":"map"}},{"id":"node-9","type":"monitoring/alerting","position":{"x":0,"y":0},"props":{"label":"monitor","tool":"Prometheus","alertThreshold":80}},{"id":"node-10","type":"third party service","position":{"x":0,"y":0},"props":{"label":"third party service","provider":"Stripe","latency":200}}],"connections":[{"source":"node-0","target":"node-1","label":"Read traffic","direction":"forward","protocol":"HTTP","tls":false,"capacity":1000},{"source":"node-1","target":"node-2","label":"Read traffic","direction":"forward","protocol":"HTTP","tls":false,"capacity":1000},{"source":"node-2","target":"node-3","label":"Read traffic","direction":"forward","protocol":"HTTP","tls":false,"capacity":1000},{"source":"node-3","target":"node-4","label":"Read traffic","direction":"forward","protocol":"HTTP","tls":false,"capacity":1000},{"source":"node-4","target":"node-5","label":"Read traffic","direction":"forward","protocol":"HTTP","tls":false,"capacity":1000},{"source":"node-5","target":"node-6","label":"Read traffic","direction":"forward","protocol":"HTTP","tls":false,"capacity":1000},{"source":"node-6","target":"node-7","label":"Read traffic","direction":"forward","protocol":"HTTP","tls":false,"capacity":1000},{"source":"node-8","target":"node-7","label":"Read traffic","direction":"forward","protocol":"HTTP","tls":false,"capacity":1000},{"source":"node-8","target":"node-10","label":"Read traffic","direction":"forward","protocol":"HTTP","tls":false,"capacity":1000},{"source":"node-10","target":"node-9","label":"Read traffic","direction":"forward","protocol":"HTTP","tls":false,"capacity":1000},{"source":"node-9","target":"node-0","label":"Read traffic","direction":"forward","protocol":"HTTP","tls":false,"capacity":1000}]}