test(limiter/conn): add unit tests for conn limiter and wrappers

limiter/conn/generator_test.go

@@ -0,0 +1,84 @@
+package conn
+
+import (
+	"testing"
+)
+
+func TestConnLimitGenerator(t *testing.T) {
+	g := NewConnLimitGenerator(5)
+	lim := g.Limiter()
+	if lim == nil {
+		t.Fatal("Limiter() should not be nil for non-zero limit")
+	}
+	if lim.Limit() != 5 {
+		t.Fatalf("expected limit 5, got %d", lim.Limit())
+	}
+
+	// Each Limiter() call creates a new instance.
+	lim2 := g.Limiter()
+	if lim2 == lim {
+		t.Fatal("each Limiter() call should create a new instance")
+	}
+}
+
+func TestConnLimitGenerator_Zero(t *testing.T) {
+	g := NewConnLimitGenerator(0)
+	if g == nil {
+		t.Fatal("generator should not be nil")
+	}
+	if lim := g.Limiter(); lim != nil {
+		t.Fatal("Limiter() should be nil for zero limit")
+	}
+}
+
+func TestConnLimitGenerator_Negative(t *testing.T) {
+	g := NewConnLimitGenerator(-5)
+	if lim := g.Limiter(); lim != nil {
+		t.Fatal("Limiter() should be nil for negative limit")
+	}
+}
+
+func TestConnLimitGenerator_NilReceiver(t *testing.T) {
+	var g *connLimitGenerator
+	if lim := g.Limiter(); lim != nil {
+		t.Fatal("nil receiver Limiter() should return nil")
+	}
+}
+
+func TestConnLimitSingleGenerator(t *testing.T) {
+	g := NewConnLimitSingleGenerator(5)
+	lim := g.Limiter()
+	if lim == nil {
+		t.Fatal("Limiter() should not be nil")
+	}
+	if lim.Limit() != 5 {
+		t.Fatalf("expected limit 5, got %d", lim.Limit())
+	}
+
+	// Same instance every call.
+	lim2 := g.Limiter()
+	if lim2 != lim {
+		t.Fatal("single generator should return same instance")
+	}
+}
+
+func TestConnLimitSingleGenerator_Zero(t *testing.T) {
+	g := NewConnLimitSingleGenerator(0)
+	if lim := g.Limiter(); lim != nil {
+		t.Fatal("Limiter() should be nil for zero limit")
+	}
+}
+
+func TestConnLimitSingleGenerator_Negative(t *testing.T) {
+	g := NewConnLimitSingleGenerator(-1)
+	if lim := g.Limiter(); lim != nil {
+		t.Fatal("Limiter() should be nil for negative limit")
+	}
+}
+
+func TestConnLimitSingleGenerator_NilReceiver(t *testing.T) {
+	var g *connLimitSingleGenerator
+	if lim := g.Limiter(); lim != nil {
+		t.Fatal("nil receiver Limiter() should return nil")
+	}
+}