Add GitLab Duo OAuth and PAT support

internal/auth/gitlab/gitlab_test.go

@@ -0,0 +1,72 @@
+package gitlab
+
+import (
+	"context"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+)
+
+func TestNormalizeBaseURL(t *testing.T) {
+	tests := []struct {
+		name string
+		in   string
+		want string
+	}{
+		{name: "default", in: "", want: DefaultBaseURL},
+		{name: "plain host", in: "gitlab.example.com", want: "https://gitlab.example.com"},
+		{name: "trim trailing slash", in: "https://gitlab.example.com/", want: "https://gitlab.example.com"},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			if got := NormalizeBaseURL(tc.in); got != tc.want {
+				t.Fatalf("NormalizeBaseURL(%q) = %q, want %q", tc.in, got, tc.want)
+			}
+		})
+	}
+}
+
+func TestFetchDirectAccess_ParsesModelDetails(t *testing.T) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.Method != http.MethodPost {
+			t.Fatalf("expected POST, got %s", r.Method)
+		}
+		if got := r.Header.Get("Authorization"); got != "Bearer pat-123" {
+			t.Fatalf("expected Authorization header, got %q", got)
+		}
+		w.Header().Set("Content-Type", "application/json")
+		_, _ = w.Write([]byte(`{
+			"base_url":"https://gateway.gitlab.example.com/v1",
+			"token":"duo-gateway-token",
+			"expires_at":2000000000,
+			"headers":{
+				"X-Gitlab-Realm":"saas",
+				"X-Gitlab-Host-Name":"gitlab.example.com"
+			},
+			"model_details":{
+				"model_provider":"anthropic",
+				"model_name":"claude-sonnet-4-5"
+			}
+		}`))
+	}))
+	defer server.Close()
+
+	client := &AuthClient{httpClient: server.Client()}
+	direct, err := client.FetchDirectAccess(context.Background(), server.URL, "pat-123")
+	if err != nil {
+		t.Fatalf("FetchDirectAccess returned error: %v", err)
+	}
+	if direct.BaseURL != "https://gateway.gitlab.example.com/v1" {
+		t.Fatalf("unexpected base_url %q", direct.BaseURL)
+	}
+	if direct.Token != "duo-gateway-token" {
+		t.Fatalf("unexpected token %q", direct.Token)
+	}
+	if direct.ModelDetails == nil || direct.ModelDetails.ModelName != "claude-sonnet-4-5" {
+		t.Fatalf("unexpected model details: %+v", direct.ModelDetails)
+	}
+	if direct.Headers["X-Gitlab-Realm"] != "saas" {
+		t.Fatalf("expected X-Gitlab-Realm header, got %+v", direct.Headers)
+	}
+}