add first test for engine. :P

internal/simulation/engine_test.go

@@ -0,0 +1,55 @@
+package simulation
+
+import (
+	"testing"
+
+	"systemdesigngame/internal/design"
+)
+
+func TestNewEngineFromDesign(t *testing.T) {
+	designInput := &design.Design{
+		Nodes: []design.Node{
+			{
+				ID:   "web1",
+				Type: "webserver",
+				Props: map[string]interface{}{
+					"cpu":            float64(2),
+					"ramGb":          float64(4),
+					"rpsCapacity":    float64(100),
+					"monthlyCostUsd": float64(20),
+				},
+			},
+			{
+				ID:   "cache1",
+				Type: "cache",
+				Props: map[string]interface{}{
+					"label":          "L1 Cache",
+					"cacheTTL":       float64(60),
+					"maxEntries":     float64(1000),
+					"evictionPolicy": "LRU",
+				},
+			},
+		},
+		Connections: []design.Connection{
+			{
+				Source: "web1",
+				Target: "cache1",
+			},
+		},
+	}
+
+	engine := NewEngineFromDesign(*designInput, 10, 100)
+
+	if len(engine.Nodes) != 2 {
+		t.Fatalf("expected 2 nodes, got %d", len(engine.Nodes))
+	}
+
+	if len(engine.Nodes["web1"].GetTargets()) != 1 {
+		t.Fatalf("expected web1 to have 1 target, got %d", len(engine.Nodes["web1"].GetTargets()))
+	}
+
+	if engine.Nodes["web1"].GetTargets()[0] != "cache1" {
+		t.Fatalf("expected web1 target to be cache1")
+	}
+}
+