Harden scan robustness and tests

common/globals_test.go

@@ -1,6 +1,10 @@
 package common
 
-import "testing"
+import (
+	"errors"
+	"strings"
+	"testing"
+)
 
 func TestHostInfoTargetUsesBracketedIPv6(t *testing.T) {
 	info := &HostInfo{Host: "2001:db8::1", Port: 443}
@@ -15,3 +19,49 @@ func TestHostInfoTargetDoesNotDoubleBracketIPv6(t *testing.T) {
 		t.Fatalf("Target() = %q, want %q", got, want)
 	}
 }
+
+func TestGlobalHelpersAndPacketLimitErrors(t *testing.T) {
+	if GetVersion() == "" {
+		t.Fatal("GetVersion returned empty string")
+	}
+	if !ContainsAny("hello fscan", "none", "scan") {
+		t.Fatal("ContainsAny should find a matching substring")
+	}
+	if ContainsAny("hello fscan", "none", "missing") {
+		t.Fatal("ContainsAny should return false when nothing matches")
+	}
+
+	maxErr := &PacketLimitError{Sentinel: ErrMaxPacketReached, Limit: 5, Current: 5}
+	if !errors.Is(maxErr, ErrMaxPacketReached) || !strings.Contains(maxErr.Error(), "5") {
+		t.Fatalf("max packet error = %v", maxErr)
+	}
+
+	rateErr := &PacketLimitError{Sentinel: ErrPacketRateLimited, Limit: 3, Current: 2}
+	if !errors.Is(rateErr, ErrPacketRateLimited) || !strings.Contains(rateErr.Error(), "3") {
+		t.Fatalf("rate limit error = %v", rateErr)
+	}
+}
+
+func TestCanSendPacketUsesGlobalConfigAndState(t *testing.T) {
+	previousConfig := GetGlobalConfig()
+	previousState := GetGlobalState()
+	t.Cleanup(func() {
+		SetGlobalConfig(previousConfig)
+		SetGlobalState(previousState)
+	})
+
+	cfg := NewConfig()
+	cfg.Network.MaxPacketCount = 1
+	state := NewState()
+	state.IncrementPacketCount()
+	SetGlobalConfig(cfg)
+	SetGlobalState(state)
+
+	ok, reason := CanSendPacket()
+	if ok {
+		t.Fatal("CanSendPacket should reject when max packet count is reached")
+	}
+	if reason == "" {
+		t.Fatal("CanSendPacket should return a rejection reason")
+	}
+}