Implement Contract/Feature Tests (T002-T022) for Dynamic Reload & Health Aggregation Features

internal/decorator/decorator_order_tiebreak_test.go

@@ -0,0 +1,177 @@
+package decorator
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+// TestDecoratorOrderingAndTiebreak verifies that decorator ordering and tie-breaking
+// works correctly when multiple decorators have the same priority.
+// This test should fail initially as the enhanced decorator system doesn't exist yet.
+func TestDecoratorOrderingAndTiebreak(t *testing.T) {
+	// RED test: This tests decorator ordering contracts that don't exist yet
+
+	t.Run("decorators should have priority metadata", func(t *testing.T) {
+		// Expected: A Decorator interface should support priority
+		var decorator interface {
+			GetPriority() int
+			GetName() string
+			GetRegistrationOrder() int
+			Decorate(target interface{}) interface{}
+		}
+
+		// This will fail because we don't have the enhanced interface yet
+		assert.NotNil(t, decorator, "Decorator with priority should be defined")
+
+		// Expected behavior: decorators should be orderable by priority
+		assert.Fail(t, "Decorator priority metadata not implemented - this test should pass once T033 is implemented")
+	})
+
+	t.Run("higher priority decorators should be applied first", func(t *testing.T) {
+		// Expected: A DecoratorChain should exist that orders by priority
+		var chain interface {
+			AddDecorator(decorator interface{}, priority int) error
+			ApplyDecorators(target interface{}) interface{}
+			GetOrderedDecorators() []interface{}
+		}
+
+		assert.NotNil(t, chain, "DecoratorChain interface should be defined")
+
+		// Expected behavior: priority 100 should be applied before priority 50
+		assert.Fail(t, "Priority-based decorator ordering not implemented")
+	})
+
+	t.Run("registration order should break ties", func(t *testing.T) {
+		// Expected: when priorities are equal, registration order determines application order
+		assert.Fail(t, "Registration order tie-breaking not implemented")
+	})
+
+	t.Run("should support explicit ordering hints", func(t *testing.T) {
+		// Expected: decorators should be able to specify ordering relative to others
+		assert.Fail(t, "Explicit ordering hints not implemented")
+	})
+}
+
+// TestDecoratorTiebreakStrategies tests different tie-breaking strategies
+func TestDecoratorTiebreakStrategies(t *testing.T) {
+	t.Run("should support name-based tie-breaking", func(t *testing.T) {
+		// Expected: decorator names should be usable for deterministic ordering
+		assert.Fail(t, "Name-based tie-breaking not implemented")
+	})
+
+	t.Run("should support explicit before/after relationships", func(t *testing.T) {
+		// Expected: decorators should be able to specify dependencies
+		var decorator interface {
+			GetBefore() []string
+			GetAfter() []string
+			GetName() string
+		}
+
+		assert.NotNil(t, decorator, "Decorator with ordering relationships should be defined")
+		assert.Fail(t, "Before/after relationship tie-breaking not implemented")
+	})
+
+	t.Run("should detect circular dependencies in ordering", func(t *testing.T) {
+		// Expected: should detect and reject circular before/after relationships
+		assert.Fail(t, "Circular dependency detection not implemented")
+	})
+
+	t.Run("should support configurable tie-break strategy", func(t *testing.T) {
+		// Expected: tie-break strategy should be configurable (name, registration order, etc.)
+		assert.Fail(t, "Configurable tie-break strategy not implemented")
+	})
+}
+
+// TestDecoratorChainValidation tests validation of decorator chains
+func TestDecoratorChainValidation(t *testing.T) {
+	t.Run("should validate decorator compatibility", func(t *testing.T) {
+		// Expected: should check that decorators are compatible with target type
+		assert.Fail(t, "Decorator compatibility validation not implemented")
+	})
+
+	t.Run("should validate ordering constraints", func(t *testing.T) {
+		// Expected: should validate that all ordering constraints can be satisfied
+		assert.Fail(t, "Ordering constraint validation not implemented")
+	})
+
+	t.Run("should detect conflicting decorators", func(t *testing.T) {
+		// Expected: should detect when decorators conflict with each other
+		assert.Fail(t, "Conflicting decorator detection not implemented")
+	})
+
+	t.Run("should provide ordering diagnostic information", func(t *testing.T) {
+		// Expected: should explain how decorators were ordered
+		var diagnostics interface {
+			ExplainOrdering(target interface{}) ([]string, error)
+			GetOrderingRationale() ([]interface{}, error)
+		}
+
+		assert.NotNil(t, diagnostics, "DecoratorOrderingDiagnostics should be defined")
+		assert.Fail(t, "Ordering diagnostic information not implemented")
+	})
+}
+
+// TestDecoratorMetadata tests decorator metadata handling
+func TestDecoratorMetadata(t *testing.T) {
+	t.Run("should track decorator application order", func(t *testing.T) {
+		// Expected: should track the actual order decorators were applied
+		assert.Fail(t, "Decorator application order tracking not implemented")
+	})
+
+	t.Run("should support decorator tags and categories", func(t *testing.T) {
+		// Expected: decorators should support categorization for filtering
+		assert.Fail(t, "Decorator tags and categories not implemented")
+	})
+
+	t.Run("should track decorator performance impact", func(t *testing.T) {
+		// Expected: should measure time/memory impact of each decorator
+		assert.Fail(t, "Decorator performance tracking not implemented")
+	})
+
+	t.Run("should support conditional decorator application", func(t *testing.T) {
+		// Expected: decorators should be applicable based on conditions
+		assert.Fail(t, "Conditional decorator application not implemented")
+	})
+}
+
+// TestDecoratorChainOptimization tests optimization of decorator chains
+func TestDecoratorChainOptimization(t *testing.T) {
+	t.Run("should optimize duplicate decorator removal", func(t *testing.T) {
+		// Expected: should remove or merge duplicate decorators
+		assert.Fail(t, "Duplicate decorator optimization not implemented")
+	})
+
+	t.Run("should support decorator chain caching", func(t *testing.T) {
+		// Expected: should cache decorator chains for repeated use
+		assert.Fail(t, "Decorator chain caching not implemented")
+	})
+
+	t.Run("should optimize no-op decorator chains", func(t *testing.T) {
+		// Expected: should optimize away chains that don't modify the target
+		assert.Fail(t, "No-op decorator chain optimization not implemented")
+	})
+
+	t.Run("should support lazy decorator application", func(t *testing.T) {
+		// Expected: should support applying decorators only when needed
+		assert.Fail(t, "Lazy decorator application not implemented")
+	})
+}
+
+// TestDecoratorEvents tests decorator-related events
+func TestDecoratorEvents(t *testing.T) {
+	t.Run("should emit events when decorators are applied", func(t *testing.T) {
+		// Expected: should emit DecoratorApplied events
+		assert.Fail(t, "Decorator application events not implemented")
+	})
+
+	t.Run("should emit events when chains are optimized", func(t *testing.T) {
+		// Expected: should emit DecoratorChainOptimized events
+		assert.Fail(t, "Decorator optimization events not implemented")
+	})
+
+	t.Run("should emit events on ordering conflicts", func(t *testing.T) {
+		// Expected: should emit DecoratorOrderingConflict events
+		assert.Fail(t, "Decorator conflict events not implemented")
+	})
+}