Add configurable error scenarios for /authorize endpoint

go.mod

@@ -9,4 +9,4 @@ require (
 	golang.org/x/oauth2 v0.28.0
 )
 
-require github.com/golang-jwt/jwt/v5 v5.3.0 // indirect
+require github.com/golang-jwt/jwt/v5 v5.3.0

internal/handlers/authorize.go

@@ -29,6 +29,30 @@ func (h *AuthorizeHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
+	// Check if there's an error scenario configured for the authorize endpoint
+	if errorScenario, exists := h.Store.GetErrorScenario("authorize"); exists {
+		// Redirect to the provided redirect URI with error parameters
+		redirectURL, err := url.Parse(redirectURI)
+		if err != nil {
+			http.Error(w, "Invalid redirect URI", http.StatusBadRequest)
+			return
+		}
+
+		query := redirectURL.Query()
+		query.Set("error", errorScenario.ErrorCode)
+		if errorScenario.Description != "" {
+			query.Set("error_description", errorScenario.Description)
+		}
+		if state != "" {
+			query.Set("state", state)
+		}
+		redirectURL.RawQuery = query.Encode()
+
+		log.Printf("Returning error redirect for authorize endpoint: error=%s, description=%s", errorScenario.ErrorCode, errorScenario.Description)
+		http.Redirect(w, r, redirectURL.String(), http.StatusFound)
+		return
+	}
+
 	// Generate authorization code
 	authCode := uuid.New().String()
 	expiration := time.Now().Add(10 * time.Minute)

internal/handlers/authorize_test.go

@@ -7,6 +7,7 @@ import (
 	"testing"
 
 	"github.com/chrisw-dev/golang-mock-oauth2-server/internal/store"
+	"github.com/chrisw-dev/golang-mock-oauth2-server/internal/types"
 )
 
 func TestAuthorizeHandler_ServeHTTP(t *testing.T) {
@@ -74,3 +75,336 @@ func TestAuthorizeHandler_ServeHTTP(t *testing.T) {
 		})
 	}
 }
+
+func TestAuthorizeHandler_ErrorScenarios(t *testing.T) {
+	tests := []struct {
+		name               string
+		errorScenario      types.ErrorScenario
+		queryParams        url.Values
+		expectedStatus     int
+		expectedError      string
+		expectedErrorDesc  string
+		shouldHaveState    bool
+	}{
+		{
+			name: "access_denied error",
+			errorScenario: types.ErrorScenario{
+				Enabled:     true,
+				Endpoint:    "authorize",
+				ErrorCode:   "access_denied",
+				Description: "User denied access",
+			},
+			queryParams: url.Values{
+				"client_id":     {"test-client"},
+				"redirect_uri":  {"http://localhost/callback"},
+				"scope":         {"openid"},
+				"response_type": {"code"},
+				"state":         {"test-state"},
+			},
+			expectedStatus:    http.StatusFound,
+			expectedError:     "access_denied",
+			expectedErrorDesc: "User denied access",
+			shouldHaveState:   true,
+		},
+		{
+			name: "invalid_request error",
+			errorScenario: types.ErrorScenario{
+				Enabled:     true,
+				Endpoint:    "authorize",
+				ErrorCode:   "invalid_request",
+				Description: "Missing client_id parameter",
+			},
+			queryParams: url.Values{
+				"client_id":     {"test-client"},
+				"redirect_uri":  {"http://localhost/callback"},
+				"scope":         {"openid"},
+				"response_type": {"code"},
+			},
+			expectedStatus:    http.StatusFound,
+			expectedError:     "invalid_request",
+			expectedErrorDesc: "Missing client_id parameter",
+			shouldHaveState:   false,
+		},
+		{
+			name: "unauthorized_client error",
+			errorScenario: types.ErrorScenario{
+				Enabled:     true,
+				Endpoint:    "authorize",
+				ErrorCode:   "unauthorized_client",
+				Description: "Client not authorized",
+			},
+			queryParams: url.Values{
+				"client_id":     {"test-client"},
+				"redirect_uri":  {"http://localhost/callback"},
+				"scope":         {"openid"},
+				"response_type": {"code"},
+				"state":         {"test-state-123"},
+			},
+			expectedStatus:    http.StatusFound,
+			expectedError:     "unauthorized_client",
+			expectedErrorDesc: "Client not authorized",
+			shouldHaveState:   true,
+		},
+		{
+			name: "unsupported_response_type error",
+			errorScenario: types.ErrorScenario{
+				Enabled:     true,
+				Endpoint:    "authorize",
+				ErrorCode:   "unsupported_response_type",
+				Description: "Response type not supported",
+			},
+			queryParams: url.Values{
+				"client_id":     {"test-client"},
+				"redirect_uri":  {"http://localhost/callback"},
+				"scope":         {"openid"},
+				"response_type": {"code"},
+			},
+			expectedStatus:    http.StatusFound,
+			expectedError:     "unsupported_response_type",
+			expectedErrorDesc: "Response type not supported",
+			shouldHaveState:   false,
+		},
+		{
+			name: "invalid_scope error",
+			errorScenario: types.ErrorScenario{
+				Enabled:     true,
+				Endpoint:    "authorize",
+				ErrorCode:   "invalid_scope",
+				Description: "Scope 'admin' is not available",
+			},
+			queryParams: url.Values{
+				"client_id":     {"test-client"},
+				"redirect_uri":  {"http://localhost/callback"},
+				"scope":         {"openid admin"},
+				"response_type": {"code"},
+				"state":         {"test-state"},
+			},
+			expectedStatus:    http.StatusFound,
+			expectedError:     "invalid_scope",
+			expectedErrorDesc: "Scope 'admin' is not available",
+			shouldHaveState:   true,
+		},
+		{
+			name: "server_error",
+			errorScenario: types.ErrorScenario{
+				Enabled:     true,
+				Endpoint:    "authorize",
+				ErrorCode:   "server_error",
+				Description: "Internal server error",
+			},
+			queryParams: url.Values{
+				"client_id":     {"test-client"},
+				"redirect_uri":  {"http://localhost/callback"},
+				"scope":         {"openid"},
+				"response_type": {"code"},
+			},
+			expectedStatus:    http.StatusFound,
+			expectedError:     "server_error",
+			expectedErrorDesc: "Internal server error",
+			shouldHaveState:   false,
+		},
+		{
+			name: "temporarily_unavailable error",
+			errorScenario: types.ErrorScenario{
+				Enabled:     true,
+				Endpoint:    "authorize",
+				ErrorCode:   "temporarily_unavailable",
+				Description: "Server is under maintenance",
+			},
+			queryParams: url.Values{
+				"client_id":     {"test-client"},
+				"redirect_uri":  {"http://localhost/callback"},
+				"scope":         {"openid"},
+				"response_type": {"code"},
+				"state":         {"test-state"},
+			},
+			expectedStatus:    http.StatusFound,
+			expectedError:     "temporarily_unavailable",
+			expectedErrorDesc: "Server is under maintenance",
+			shouldHaveState:   true,
+		},
+		{
+			name: "error scenario disabled - should succeed normally",
+			errorScenario: types.ErrorScenario{
+				Enabled:     false, // Disabled
+				Endpoint:    "authorize",
+				ErrorCode:   "access_denied",
+				Description: "This should not appear",
+			},
+			queryParams: url.Values{
+				"client_id":     {"test-client"},
+				"redirect_uri":  {"http://localhost/callback"},
+				"scope":         {"openid"},
+				"response_type": {"code"},
+				"state":         {"test-state"},
+			},
+			expectedStatus:    http.StatusFound,
+			expectedError:     "", // No error expected
+			expectedErrorDesc: "",
+			shouldHaveState:   true,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			// Create a fresh store for each test
+			testStore := store.NewMemoryStore()
+			handler := &AuthorizeHandler{Store: testStore}
+
+			// Configure the error scenario
+			testStore.StoreErrorScenario(tt.errorScenario)
+
+			// Make the request
+			req := httptest.NewRequest(http.MethodGet, "/authorize?"+tt.queryParams.Encode(), nil)
+			resp := httptest.NewRecorder()
+
+			handler.ServeHTTP(resp, req)
+
+			// Check status code
+			if resp.Code != tt.expectedStatus {
+				t.Errorf("expected status %d, got %d", tt.expectedStatus, resp.Code)
+			}
+
+			// Check redirect location
+			location := resp.Header().Get("Location")
+			if location == "" {
+				t.Fatalf("expected redirect location, got empty")
+			}
+
+			// Parse the redirect URL
+			redirectURL, err := url.Parse(location)
+			if err != nil {
+				t.Fatalf("failed to parse redirect URL: %v", err)
+			}
+
+			// Check error parameter
+			if tt.expectedError != "" {
+				errorParam := redirectURL.Query().Get("error")
+				if errorParam != tt.expectedError {
+					t.Errorf("expected error %q, got %q", tt.expectedError, errorParam)
+				}
+
+				// Check error_description parameter
+				errorDesc := redirectURL.Query().Get("error_description")
+				if errorDesc != tt.expectedErrorDesc {
+					t.Errorf("expected error_description %q, got %q", tt.expectedErrorDesc, errorDesc)
+				}
+			} else {
+				// When error scenario is disabled, should get authorization code
+				code := redirectURL.Query().Get("code")
+				if code == "" {
+					t.Errorf("expected authorization code when error scenario is disabled, got none")
+				}
+				errorParam := redirectURL.Query().Get("error")
+				if errorParam != "" {
+					t.Errorf("expected no error when scenario is disabled, got %q", errorParam)
+				}
+			}
+
+			// Check state parameter if expected
+			if tt.shouldHaveState {
+				stateParam := redirectURL.Query().Get("state")
+				expectedState := tt.queryParams.Get("state")
+				if stateParam != expectedState {
+					t.Errorf("expected state %q, got %q", expectedState, stateParam)
+				}
+			}
+		})
+	}
+}
+
+func TestAuthorizeHandler_ErrorScenarioForDifferentEndpoint(t *testing.T) {
+	// Test that error scenario for "token" endpoint doesn't affect "authorize" endpoint
+	testStore := store.NewMemoryStore()
+	handler := &AuthorizeHandler{Store: testStore}
+
+	// Configure error scenario for "token" endpoint (not "authorize")
+	testStore.StoreErrorScenario(types.ErrorScenario{
+		Enabled:     true,
+		Endpoint:    "token", // Different endpoint
+		ErrorCode:   "invalid_grant",
+		Description: "This should not affect authorize",
+	})
+
+	queryParams := url.Values{
+		"client_id":     {"test-client"},
+		"redirect_uri":  {"http://localhost/callback"},
+		"scope":         {"openid"},
+		"response_type": {"code"},
+		"state":         {"test-state"},
+	}
+
+	req := httptest.NewRequest(http.MethodGet, "/authorize?"+queryParams.Encode(), nil)
+	resp := httptest.NewRecorder()
+
+	handler.ServeHTTP(resp, req)
+
+	// Should succeed normally (no error)
+	if resp.Code != http.StatusFound {
+		t.Errorf("expected status %d, got %d", http.StatusFound, resp.Code)
+	}
+
+	location := resp.Header().Get("Location")
+	redirectURL, err := url.Parse(location)
+	if err != nil {
+		t.Fatalf("failed to parse redirect URL: %v", err)
+	}
+
+	// Should have authorization code, not error
+	code := redirectURL.Query().Get("code")
+	if code == "" {
+		t.Errorf("expected authorization code, got none")
+	}
+
+	errorParam := redirectURL.Query().Get("error")
+	if errorParam != "" {
+		t.Errorf("expected no error, got %q", errorParam)
+	}
+}
+
+func TestAuthorizeHandler_ErrorWithoutDescription(t *testing.T) {
+	testStore := store.NewMemoryStore()
+	handler := &AuthorizeHandler{Store: testStore}
+
+	// Configure error scenario without description
+	testStore.StoreErrorScenario(types.ErrorScenario{
+		Enabled:     true,
+		Endpoint:    "authorize",
+		ErrorCode:   "access_denied",
+		Description: "", // No description
+	})
+
+	queryParams := url.Values{
+		"client_id":     {"test-client"},
+		"redirect_uri":  {"http://localhost/callback"},
+		"scope":         {"openid"},
+		"response_type": {"code"},
+		"state":         {"test-state"},
+	}
+
+	req := httptest.NewRequest(http.MethodGet, "/authorize?"+queryParams.Encode(), nil)
+	resp := httptest.NewRecorder()
+
+	handler.ServeHTTP(resp, req)
+
+	if resp.Code != http.StatusFound {
+		t.Errorf("expected status %d, got %d", http.StatusFound, resp.Code)
+	}
+
+	location := resp.Header().Get("Location")
+	redirectURL, err := url.Parse(location)
+	if err != nil {
+		t.Fatalf("failed to parse redirect URL: %v", err)
+	}
+
+	// Should have error but no error_description
+	errorParam := redirectURL.Query().Get("error")
+	if errorParam != "access_denied" {
+		t.Errorf("expected error 'access_denied', got %q", errorParam)
+	}
+
+	errorDesc := redirectURL.Query().Get("error_description")
+	if errorDesc != "" {
+		t.Errorf("expected no error_description, got %q", errorDesc)
+	}
+}