Initial vibeproxy implementation

Self-contained HTTP/HTTPS/TCP/UDP reverse proxy manager written in Go,
with SQLite storage, a Bootstrap 5 admin UI (Go templates, no JS
framework), and a REST API under /api/v1.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01QTXFrNP1imCW7jtfL5SZrw

internal/loadbalancer/loadbalancer_test.go

@@ -0,0 +1,91 @@
+package loadbalancer
+
+import (
+	"testing"
+
+	"github.com/owen/vibeproxy/internal/models"
+)
+
+func TestRoundRobin(t *testing.T) {
+	b1 := NewBackend(models.Backend{Host: "a", Enabled: true, HealthCheckType: models.HealthCheckNone})
+	b2 := NewBackend(models.Backend{Host: "b", Enabled: true, HealthCheckType: models.HealthCheckNone})
+	pool := NewPool("round_robin", []*Backend{b1, b2})
+
+	seen := map[string]int{}
+	for i := 0; i < 10; i++ {
+		b, err := pool.Pick()
+		if err != nil {
+			t.Fatal(err)
+		}
+		seen[b.Model.Host]++
+	}
+	if seen["a"] != 5 || seen["b"] != 5 {
+		t.Fatalf("expected even split, got %v", seen)
+	}
+}
+
+func TestLeastConn(t *testing.T) {
+	b1 := NewBackend(models.Backend{Host: "a", Enabled: true, HealthCheckType: models.HealthCheckNone})
+	b2 := NewBackend(models.Backend{Host: "b", Enabled: true, HealthCheckType: models.HealthCheckNone})
+	pool := NewPool("least_conn", []*Backend{b1, b2})
+
+	b1.Acquire()
+	b1.Acquire()
+	picked, err := pool.Pick()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if picked.Model.Host != "b" {
+		t.Fatalf("expected b (fewer active conns), got %s", picked.Model.Host)
+	}
+}
+
+func TestWeighted(t *testing.T) {
+	b1 := NewBackend(models.Backend{Host: "a", Weight: 3, Enabled: true, HealthCheckType: models.HealthCheckNone})
+	b2 := NewBackend(models.Backend{Host: "b", Weight: 1, Enabled: true, HealthCheckType: models.HealthCheckNone})
+	pool := NewPool("weighted", []*Backend{b1, b2})
+
+	counts := map[string]int{}
+	for i := 0; i < 8; i++ {
+		b, err := pool.Pick()
+		if err != nil {
+			t.Fatal(err)
+		}
+		counts[b.Model.Host]++
+	}
+	if counts["a"] != 6 || counts["b"] != 2 {
+		t.Fatalf("expected 3:1 weighted split (6:2 of 8), got %v", counts)
+	}
+}
+
+func TestNoHealthyBackend(t *testing.T) {
+	b1 := NewBackend(models.Backend{Host: "a", Enabled: true, HealthCheckType: models.HealthCheckTCP, FailureThreshold: 1})
+	pool := NewPool("round_robin", []*Backend{b1})
+	if _, err := pool.Pick(); err != ErrNoHealthyBackend {
+		t.Fatalf("expected ErrNoHealthyBackend, got %v", err)
+	}
+}
+
+func TestRecordCheckThresholds(t *testing.T) {
+	b := NewBackend(models.Backend{Host: "a", Enabled: true, HealthCheckType: models.HealthCheckTCP, FailureThreshold: 2, RecoveryThreshold: 2})
+	if b.Healthy() {
+		t.Fatal("expected backend to start unhealthy pending checks")
+	}
+	b.RecordCheck(true)
+	if b.Healthy() {
+		t.Fatal("should still be unhealthy after 1 of 2 required successes")
+	}
+	changed, healthy := b.RecordCheck(true)
+	if !changed || !healthy {
+		t.Fatal("expected backend to become healthy after 2 successes")
+	}
+
+	b.RecordCheck(false)
+	if !b.Healthy() {
+		t.Fatal("should still be healthy after 1 of 2 required failures")
+	}
+	changed, healthy = b.RecordCheck(false)
+	if !changed || healthy {
+		t.Fatal("expected backend to become unhealthy after 2 failures")
+	}
+}