diff --git a/cache_test.go b/cache_test.go
new file mode 100644
index 0000000..2b6bfa4
--- /dev/null
+++ b/cache_test.go
@@ -0,0 +1,306 @@
+package traefikoidc
+
+import (
+	"reflect"
+	"testing"
+	"time"
+)
+
+func TestCache(t *testing.T) {
+	t.Run("Basic Set and Get", func(t *testing.T) {
+		cache := NewCache()
+		key := "test-key"
+		value := "test-value"
+		expiration := 1 * time.Second
+
+		// Test Set
+		cache.Set(key, value, expiration)
+
+		// Test Get
+		got, found := cache.Get(key)
+		if !found {
+			t.Error("Expected to find key in cache")
+		}
+		if got != value {
+			t.Errorf("Expected value %v, got %v", value, got)
+		}
+	})
+
+	t.Run("Expiration", func(t *testing.T) {
+		cache := NewCache()
+		key := "test-key"
+		value := "test-value"
+		expiration := 10 * time.Millisecond
+
+		// Set with short expiration
+		cache.Set(key, value, expiration)
+
+		// Wait for expiration
+		time.Sleep(20 * time.Millisecond)
+
+		// Should not find expired key
+		_, found := cache.Get(key)
+		if found {
+			t.Error("Expected key to be expired")
+		}
+	})
+
+	t.Run("Delete", func(t *testing.T) {
+		cache := NewCache()
+		key := "test-key"
+		value := "test-value"
+		expiration := 1 * time.Second
+
+		// Set and then delete
+		cache.Set(key, value, expiration)
+		cache.Delete(key)
+
+		// Should not find deleted key
+		_, found := cache.Get(key)
+		if found {
+			t.Error("Expected key to be deleted")
+		}
+	})
+
+	t.Run("Cleanup", func(t *testing.T) {
+		cache := NewCache()
+		// Add multiple items with different expirations
+		cache.Set("expired1", "value1", 10*time.Millisecond)
+		cache.Set("expired2", "value2", 10*time.Millisecond)
+		cache.Set("valid", "value3", 1*time.Second)
+
+		// Wait for some items to expire
+		time.Sleep(20 * time.Millisecond)
+
+		// Run cleanup
+		cache.Cleanup()
+
+		// Check expired items are removed
+		_, found1 := cache.Get("expired1")
+		_, found2 := cache.Get("expired2")
+		_, found3 := cache.Get("valid")
+
+		if found1 {
+			t.Error("Expected expired1 to be cleaned up")
+		}
+		if found2 {
+			t.Error("Expected expired2 to be cleaned up")
+		}
+		if !found3 {
+			t.Error("Expected valid item to remain in cache")
+		}
+	})
+
+	t.Run("Concurrent Access", func(t *testing.T) {
+		cache := NewCache()
+		done := make(chan bool)
+
+		// Start multiple goroutines to access cache concurrently
+		for i := 0; i < 10; i++ {
+			go func(id int) {
+				key := "key"
+				value := "value"
+				expiration := 1 * time.Second
+
+				// Perform multiple operations
+				cache.Set(key, value, expiration)
+				cache.Get(key)
+				cache.Delete(key)
+				cache.Cleanup()
+
+				done <- true
+			}(i)
+		}
+
+		// Wait for all goroutines to complete
+		for i := 0; i < 10; i++ {
+			<-done
+		}
+	})
+
+	t.Run("Zero Expiration", func(t *testing.T) {
+		cache := NewCache()
+		key := "test-key"
+		value := "test-value"
+
+		// Set with zero expiration
+		cache.Set(key, value, 0)
+
+		// Should not find the key
+		_, found := cache.Get(key)
+		if found {
+			t.Error("Expected key with zero expiration to be immediately expired")
+		}
+	})
+
+	t.Run("Negative Expiration", func(t *testing.T) {
+		cache := NewCache()
+		key := "test-key"
+		value := "test-value"
+
+		// Set with negative expiration
+		cache.Set(key, value, -1*time.Second)
+
+		// Should not find the key
+		_, found := cache.Get(key)
+		if found {
+			t.Error("Expected key with negative expiration to be immediately expired")
+		}
+	})
+
+	t.Run("Update Existing Key", func(t *testing.T) {
+		cache := NewCache()
+		key := "test-key"
+		value1 := "value1"
+		value2 := "value2"
+		expiration := 1 * time.Second
+
+		// Set initial value
+		cache.Set(key, value1, expiration)
+
+		// Update value
+		cache.Set(key, value2, expiration)
+
+		// Check updated value
+		got, found := cache.Get(key)
+		if !found {
+			t.Error("Expected to find key in cache")
+		}
+		if got != value2 {
+			t.Errorf("Expected updated value %v, got %v", value2, got)
+		}
+	})
+
+	t.Run("Different Value Types", func(t *testing.T) {
+		cache := NewCache()
+		expiration := 1 * time.Second
+
+		// Test with different value types
+		testCases := []struct {
+			key   string
+			value interface{}
+		}{
+			{"string", "test"},
+			{"int", 42},
+			{"float", 3.14},
+			{"bool", true},
+			{"slice", []string{"a", "b", "c"}},
+			{"map", map[string]int{"a": 1, "b": 2}},
+			{"struct", struct{ Name string }{"test"}},
+		}
+
+		for _, tc := range testCases {
+			t.Run(tc.key, func(t *testing.T) {
+				cache.Set(tc.key, tc.value, expiration)
+				got, found := cache.Get(tc.key)
+				if !found {
+					t.Error("Expected to find key in cache")
+				}
+				// Use reflect.DeepEqual for comparing complex types like slices and maps
+				if !reflect.DeepEqual(got, tc.value) {
+					t.Errorf("Expected value %v, got %v", tc.value, got)
+				}
+			})
+		}
+	})
+}
+
+func TestTokenCache(t *testing.T) {
+	t.Run("Basic Operations", func(t *testing.T) {
+		tc := NewTokenCache()
+		token := "test-token"
+		claims := map[string]interface{}{
+			"sub":   "1234567890",
+			"name":  "John Doe",
+			"admin": true,
+		}
+		expiration := 1 * time.Second
+
+		// Test Set and Get
+		tc.Set(token, claims, expiration)
+		gotClaims, found := tc.Get(token)
+		if !found {
+			t.Error("Expected to find token in cache")
+		}
+		if len(gotClaims) != len(claims) {
+			t.Errorf("Expected %d claims, got %d", len(claims), len(gotClaims))
+		}
+		for k, v := range claims {
+			if gotClaims[k] != v {
+				t.Errorf("Expected claim %s to be %v, got %v", k, v, gotClaims[k])
+			}
+		}
+
+		// Test Delete
+		tc.Delete(token)
+		_, found = tc.Get(token)
+		if found {
+			t.Error("Expected token to be deleted")
+		}
+	})
+
+	t.Run("Expiration", func(t *testing.T) {
+		tc := NewTokenCache()
+		token := "test-token"
+		claims := map[string]interface{}{"sub": "1234567890"}
+		expiration := 10 * time.Millisecond
+
+		// Set with short expiration
+		tc.Set(token, claims, expiration)
+
+		// Wait for expiration
+		time.Sleep(20 * time.Millisecond)
+
+		// Should not find expired token
+		_, found := tc.Get(token)
+		if found {
+			t.Error("Expected token to be expired")
+		}
+	})
+
+	t.Run("Cleanup", func(t *testing.T) {
+		tc := NewTokenCache()
+
+		// Add multiple tokens with different expirations
+		tc.Set("expired1", map[string]interface{}{"sub": "1"}, 10*time.Millisecond)
+		tc.Set("expired2", map[string]interface{}{"sub": "2"}, 10*time.Millisecond)
+		tc.Set("valid", map[string]interface{}{"sub": "3"}, 1*time.Second)
+
+		// Wait for some tokens to expire
+		time.Sleep(20 * time.Millisecond)
+
+		// Run cleanup
+		tc.Cleanup()
+
+		// Check expired tokens are removed
+		_, found1 := tc.Get("expired1")
+		_, found2 := tc.Get("expired2")
+		_, found3 := tc.Get("valid")
+
+		if found1 {
+			t.Error("Expected expired1 to be cleaned up")
+		}
+		if found2 {
+			t.Error("Expected expired2 to be cleaned up")
+		}
+		if !found3 {
+			t.Error("Expected valid token to remain in cache")
+		}
+	})
+
+	t.Run("Token Prefix", func(t *testing.T) {
+		tc := NewTokenCache()
+		token := "test-token"
+		claims := map[string]interface{}{"sub": "1234567890"}
+		expiration := 1 * time.Second
+
+		// Set token
+		tc.Set(token, claims, expiration)
+
+		// Verify internal storage uses prefix
+		_, found := tc.cache.Get("t-" + token)
+		if !found {
+			t.Error("Expected to find prefixed token in underlying cache")
+		}
+	})
+}
diff --git a/settings.go b/settings.go
index 95cbaaf..2ae5209 100644
--- a/settings.go
+++ b/settings.go
@@ -187,8 +187,10 @@ func NewLogger(logLevel string) *Logger {
 	logDebug := log.New(io.Discard, "DEBUG: TraefikOidcPlugin: ", log.Ldate|log.Ltime)
 
 	logError.SetOutput(os.Stderr)
-	logInfo.SetOutput(os.Stdout)
-
+	
+	if logLevel == "debug" || logLevel == "info" {
+		logInfo.SetOutput(os.Stdout)
+	}
 	if logLevel == "debug" {
 		logDebug.SetOutput(os.Stdout)
 	}
diff --git a/settings_test.go b/settings_test.go
new file mode 100644
index 0000000..0662c97
--- /dev/null
+++ b/settings_test.go
@@ -0,0 +1,362 @@
+package traefikoidc
+
+import (
+	"bytes"
+	"log"
+	"net/http"
+	"testing"
+)
+
+func TestCreateConfig(t *testing.T) {
+	t.Run("Default Values", func(t *testing.T) {
+		config := CreateConfig()
+
+		// Check default scopes
+		expectedScopes := []string{"openid", "profile", "email"}
+		if len(config.Scopes) != len(expectedScopes) {
+			t.Errorf("Expected %d default scopes, got %d", len(expectedScopes), len(config.Scopes))
+		}
+		for i, scope := range expectedScopes {
+			if config.Scopes[i] != scope {
+				t.Errorf("Expected scope %s at position %d, got %s", scope, i, config.Scopes[i])
+			}
+		}
+
+		// Check default log level
+		if config.LogLevel != "info" {
+			t.Errorf("Expected default log level 'info', got '%s'", config.LogLevel)
+		}
+
+		// Check default rate limit
+		if config.RateLimit != 100 {
+			t.Errorf("Expected default rate limit 100, got %d", config.RateLimit)
+		}
+	})
+
+	t.Run("Custom Values Preserved", func(t *testing.T) {
+		config := CreateConfig()
+		config.Scopes = []string{"custom_scope"}
+		config.LogLevel = "debug"
+		config.RateLimit = 50
+
+		// Verify custom values are not overwritten
+		if len(config.Scopes) != 1 || config.Scopes[0] != "custom_scope" {
+			t.Error("Custom scopes were overwritten")
+		}
+		if config.LogLevel != "debug" {
+			t.Error("Custom log level was overwritten")
+		}
+		if config.RateLimit != 50 {
+			t.Error("Custom rate limit was overwritten")
+		}
+	})
+}
+
+func TestConfigValidate(t *testing.T) {
+	tests := []struct {
+		name          string
+		config        *Config
+		expectedError string
+	}{
+		{
+			name:          "Empty Config",
+			config:        &Config{},
+			expectedError: "providerURL is required",
+		},
+		{
+			name: "Missing CallbackURL",
+			config: &Config{
+				ProviderURL: "https://provider.com",
+			},
+			expectedError: "callbackURL is required",
+		},
+		{
+			name: "Missing ClientID",
+			config: &Config{
+				ProviderURL: "https://provider.com",
+				CallbackURL: "/callback",
+			},
+			expectedError: "clientID is required",
+		},
+		{
+			name: "Missing ClientSecret",
+			config: &Config{
+				ProviderURL: "https://provider.com",
+				CallbackURL: "/callback",
+				ClientID:    "client-id",
+			},
+			expectedError: "clientSecret is required",
+		},
+		{
+			name: "Missing SessionEncryptionKey",
+			config: &Config{
+				ProviderURL:  "https://provider.com",
+				CallbackURL:  "/callback",
+				ClientID:     "client-id",
+				ClientSecret: "client-secret",
+			},
+			expectedError: "sessionEncryptionKey is required",
+		},
+		{
+			name: "Invalid ProviderURL",
+			config: &Config{
+				ProviderURL:          "not-a-url",
+				CallbackURL:          "/callback",
+				ClientID:             "client-id",
+				ClientSecret:         "client-secret",
+				SessionEncryptionKey: "encryption-key",
+			},
+			expectedError: "providerURL must be a valid URL",
+		},
+		{
+			name: "Invalid CallbackURL",
+			config: &Config{
+				ProviderURL:          "https://provider.com",
+				CallbackURL:          "callback", // Missing leading slash
+				ClientID:             "client-id",
+				ClientSecret:         "client-secret",
+				SessionEncryptionKey: "encryption-key",
+			},
+			expectedError: "callbackURL must start with /",
+		},
+		{
+			name: "Short SessionEncryptionKey",
+			config: &Config{
+				ProviderURL:          "https://provider.com",
+				CallbackURL:          "/callback",
+				ClientID:             "client-id",
+				ClientSecret:         "client-secret",
+				SessionEncryptionKey: "short",
+			},
+			expectedError: "sessionEncryptionKey must be at least 32 characters long",
+		},
+		{
+			name: "Negative RateLimit",
+			config: &Config{
+				ProviderURL:          "https://provider.com",
+				CallbackURL:          "/callback",
+				ClientID:             "client-id",
+				ClientSecret:         "client-secret",
+				SessionEncryptionKey: "this-is-a-long-enough-encryption-key",
+				RateLimit:            -1,
+			},
+			expectedError: "rateLimit must be non-negative",
+		},
+		{
+			name: "Invalid LogLevel",
+			config: &Config{
+				ProviderURL:          "https://provider.com",
+				CallbackURL:          "/callback",
+				ClientID:             "client-id",
+				ClientSecret:         "client-secret",
+				SessionEncryptionKey: "this-is-a-long-enough-encryption-key",
+				LogLevel:             "invalid",
+			},
+			expectedError: "logLevel must be one of: debug, info, error",
+		},
+		{
+			name: "Valid Config",
+			config: &Config{
+				ProviderURL:          "https://provider.com",
+				CallbackURL:          "/callback",
+				ClientID:             "client-id",
+				ClientSecret:         "client-secret",
+				SessionEncryptionKey: "this-is-a-long-enough-encryption-key",
+				LogLevel:             "debug",
+				RateLimit:            100,
+			},
+			expectedError: "",
+		},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			err := tc.config.Validate()
+			if tc.expectedError == "" {
+				if err != nil {
+					t.Errorf("Expected no error, got: %v", err)
+				}
+			} else {
+				if err == nil {
+					t.Errorf("Expected error containing '%s', got nil", tc.expectedError)
+				} else if err.Error() != tc.expectedError {
+					t.Errorf("Expected error '%s', got '%s'", tc.expectedError, err.Error())
+				}
+			}
+		})
+	}
+}
+
+func TestLogger(t *testing.T) {
+	// Capture log output
+	var debugBuf, infoBuf, errorBuf bytes.Buffer
+
+	tests := []struct {
+		name     string
+		logLevel string
+		testFunc func(*Logger)
+		checkFunc func(t *testing.T, debugOut, infoOut, errorOut string)
+	}{
+		{
+			name:     "Debug Level",
+			logLevel: "debug",
+			testFunc: func(l *Logger) {
+				l.Debug("debug message")
+				l.Info("info message")
+				l.Error("error message")
+			},
+			checkFunc: func(t *testing.T, debugOut, infoOut, errorOut string) {
+				if debugOut == "" {
+					t.Error("Expected debug message in output")
+				}
+				if infoOut == "" {
+					t.Error("Expected info message in output")
+				}
+				if errorOut == "" {
+					t.Error("Expected error message in output")
+				}
+			},
+		},
+		{
+			name:     "Info Level",
+			logLevel: "info",
+			testFunc: func(l *Logger) {
+				l.Debug("debug message")
+				l.Info("info message")
+				l.Error("error message")
+			},
+			checkFunc: func(t *testing.T, debugOut, infoOut, errorOut string) {
+				if debugOut != "" {
+					t.Error("Did not expect debug message in output")
+				}
+				if infoOut == "" {
+					t.Error("Expected info message in output")
+				}
+				if errorOut == "" {
+					t.Error("Expected error message in output")
+				}
+			},
+		},
+		{
+			name:     "Error Level",
+			logLevel: "error",
+			testFunc: func(l *Logger) {
+				l.Debug("debug message")
+				l.Info("info message")
+				l.Error("error message")
+			},
+			checkFunc: func(t *testing.T, debugOut, infoOut, errorOut string) {
+				if debugOut != "" {
+					t.Error("Did not expect debug message in output")
+				}
+				if infoOut != "" {
+					t.Error("Did not expect info message in output")
+				}
+				if errorOut == "" {
+					t.Error("Expected error message in output")
+				}
+			},
+		},
+		{
+			name:     "Printf Methods",
+			logLevel: "debug",
+			testFunc: func(l *Logger) {
+				l.Debugf("debug %s", "formatted")
+				l.Infof("info %s", "formatted")
+				l.Errorf("error %s", "formatted")
+			},
+			checkFunc: func(t *testing.T, debugOut, infoOut, errorOut string) {
+				if !bytes.Contains([]byte(debugOut), []byte("debug formatted")) {
+					t.Error("Expected formatted debug message")
+				}
+				if !bytes.Contains([]byte(infoOut), []byte("info formatted")) {
+					t.Error("Expected formatted info message")
+				}
+				if !bytes.Contains([]byte(errorOut), []byte("error formatted")) {
+					t.Error("Expected formatted error message")
+				}
+			},
+		},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			// Reset buffers
+			debugBuf.Reset()
+			infoBuf.Reset()
+			errorBuf.Reset()
+
+			// Create logger with test buffers
+			logger := NewLogger(tc.logLevel)
+			logger.logError.SetOutput(&errorBuf)
+			
+			if tc.logLevel == "debug" || tc.logLevel == "info" {
+				logger.logInfo.SetOutput(&infoBuf)
+			}
+			if tc.logLevel == "debug" {
+				logger.logDebug.SetOutput(&debugBuf)
+			}
+
+			// Run test
+			tc.testFunc(logger)
+
+			// Check results
+			tc.checkFunc(t, debugBuf.String(), infoBuf.String(), errorBuf.String())
+		})
+	}
+}
+
+func TestHandleError(t *testing.T) {
+	// Create a test logger with captured output
+	var errorBuf bytes.Buffer
+	logger := &Logger{
+		logError: log.New(&errorBuf, "ERROR: ", log.Ldate|log.Ltime),
+	}
+	logger.logError.SetOutput(&errorBuf)
+
+	// Create a test response recorder
+	rr := &testResponseRecorder{
+		headers: make(map[string][]string),
+	}
+
+	// Test error handling
+	message := "test error message"
+	code := 400
+	handleError(rr, message, code, logger)
+
+	// Check response code
+	if rr.statusCode != code {
+		t.Errorf("Expected status code %d, got %d", code, rr.statusCode)
+	}
+
+	// Check response body
+	expectedBody := message + "\n"
+	if rr.body != expectedBody {
+		t.Errorf("Expected body %q, got %q", expectedBody, rr.body)
+	}
+
+	// Check error was logged
+	if !bytes.Contains(errorBuf.Bytes(), []byte(message)) {
+		t.Error("Error message was not logged")
+	}
+}
+
+// Test helper types
+type testResponseRecorder struct {
+	statusCode int
+	body       string
+	headers    map[string][]string
+}
+
+func (r *testResponseRecorder) Header() http.Header {
+	return r.headers
+}
+
+func (r *testResponseRecorder) Write(b []byte) (int, error) {
+	r.body = string(b)
+	return len(b), nil
+}
+
+func (r *testResponseRecorder) WriteHeader(code int) {
+	r.statusCode = code
+}