test(parsing): add 229 unit tests across 18 config/parsing packages

Covering nil-input safety, plugin backends (HTTP/gRPC/default), loaders
(File/HTTP/Redis), selector strategies, edge cases (empty/invalid inputs),
and hop-to-node metadata inheritance. All tests passing.

config/parsing/resolver/parse_test.go

@@ -0,0 +1,146 @@
+package resolver
+
+import (
+	"io"
+	"testing"
+
+	"github.com/go-gost/core/logger"
+	"github.com/go-gost/x/config"
+	xlogger "github.com/go-gost/x/logger"
+)
+
+func TestMain(m *testing.M) {
+	logger.SetDefault(xlogger.NewLogger(xlogger.OutputOption(io.Discard)))
+	m.Run()
+}
+
+func TestParseResolver_Nil(t *testing.T) {
+	r, err := ParseResolver(nil)
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if r != nil {
+		t.Fatal("expected nil for nil config")
+	}
+}
+
+func TestParseResolver_PluginHTTP(t *testing.T) {
+	r, err := ParseResolver(&config.ResolverConfig{
+		Name: "http-res",
+		Plugin: &config.PluginConfig{
+			Type: "http",
+			Addr: "127.0.0.1:9000",
+		},
+	})
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if r == nil {
+		t.Fatal("expected non-nil resolver")
+	}
+}
+
+func TestParseResolver_PluginGRPC(t *testing.T) {
+	r, err := ParseResolver(&config.ResolverConfig{
+		Name: "grpc-res",
+		Plugin: &config.PluginConfig{
+			Type:  "grpc",
+			Addr:  "127.0.0.1:9001",
+			Token: "secret",
+			TLS: &config.TLSConfig{
+				Secure:     true,
+				ServerName: "resolver.local",
+			},
+		},
+	})
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if r == nil {
+		t.Fatal("expected non-nil resolver")
+	}
+}
+
+func TestParseResolver_PluginDefaultType(t *testing.T) {
+	r, err := ParseResolver(&config.ResolverConfig{
+		Name: "default-res",
+		Plugin: &config.PluginConfig{
+			Addr: "127.0.0.1:9002",
+		},
+	})
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if r == nil {
+		t.Fatal("expected non-nil resolver")
+	}
+}
+
+func TestParseResolver_WithNameservers(t *testing.T) {
+	r, err := ParseResolver(&config.ResolverConfig{
+		Name: "ns-res",
+		Nameservers: []*config.NameserverConfig{
+			{Addr: "8.8.8.8", Prefer: "ipv4"},
+			{Addr: "8.8.4.4", Prefer: "ipv4"},
+		},
+	})
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if r == nil {
+		t.Fatal("expected non-nil resolver")
+	}
+}
+
+func TestParseResolver_EmptyNameservers(t *testing.T) {
+	r, err := ParseResolver(&config.ResolverConfig{
+		Name:        "empty-ns",
+		Nameservers: []*config.NameserverConfig{},
+	})
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if r == nil {
+		t.Fatal("expected non-nil resolver even with empty nameservers")
+	}
+}
+
+func TestParseResolver_NameserverWithClientIP(t *testing.T) {
+	r, err := ParseResolver(&config.ResolverConfig{
+		Name: "clientip-res",
+		Nameservers: []*config.NameserverConfig{
+			{Addr: "8.8.8.8", ClientIP: "1.2.3.4"},
+		},
+	})
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if r == nil {
+		t.Fatal("expected non-nil resolver")
+	}
+}
+
+func TestParseResolver_NameserverWithAllFields(t *testing.T) {
+	r, err := ParseResolver(&config.ResolverConfig{
+		Name: "full-res",
+		Nameservers: []*config.NameserverConfig{
+			{
+				Addr:     "8.8.8.8:53",
+				Chain:    "chain1",
+				Prefer:   "ipv4",
+				ClientIP: "1.2.3.4",
+				Hostname: "dns.example.com",
+				TTL:      300,
+				Timeout:  5,
+				Async:    true,
+				Only:     "A",
+			},
+		},
+	})
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if r == nil {
+		t.Fatal("expected non-nil resolver")
+	}
+}