adding test units

pkg/agent/loop_test.go

@@ -3,6 +3,7 @@ package agent
 import (
 	"context"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"net/http"
 	"net/http/httptest"
@@ -2817,3 +2818,111 @@ func TestFilterClientWebSearch_EmptyInput(t *testing.T) {
 		t.Fatalf("len(result) = %d, want 0", len(result))
 	}
 }
+
+type overflowProvider struct {
+	calls        int
+	lastMessages []providers.Message
+	chatFunc     func(ctx context.Context, messages []providers.Message, tools []providers.ToolDefinition, model string, opts map[string]any) (*providers.LLMResponse, error)
+}
+
+func (p *overflowProvider) Chat(
+	ctx context.Context,
+	messages []providers.Message,
+	tools []providers.ToolDefinition,
+	model string,
+	opts map[string]any,
+) (*providers.LLMResponse, error) {
+	p.calls++
+	p.lastMessages = append([]providers.Message(nil), messages...)
+
+	if p.chatFunc != nil {
+		return p.chatFunc(ctx, messages, tools, model, opts)
+	}
+
+	if p.calls == 1 {
+		return nil, errors.New("context_window_exceeded")
+	}
+
+	return &providers.LLMResponse{
+		Content: "Recovered from overflow",
+	}, nil
+}
+
+func (p *overflowProvider) GetDefaultModel() string {
+	return "test-model"
+}
+
+func TestProcessMessage_ContextOverflowRecovery(t *testing.T) {
+	al, cfg, _, _, cleanup := newTestAgentLoop(t)
+	defer cleanup()
+	_ = cfg
+
+	provider := &overflowProvider{}
+	al.registry = NewAgentRegistry(al.cfg, provider)
+
+	sessionKey := "agent:main:test-session"
+	agent := al.GetRegistry().GetDefaultAgent()
+
+	for i := 0; i < 5; i++ {
+		agent.Sessions.AddFullMessage(sessionKey, providers.Message{Role: "user", Content: "heavy message"})
+		agent.Sessions.AddFullMessage(sessionKey, providers.Message{Role: "assistant", Content: "response"})
+	}
+
+	response, err := al.processMessage(context.Background(), bus.InboundMessage{
+		Channel:    "test",
+		ChatID:     "chat1",
+		SenderID:   "user1",
+		SessionKey: "test-session",
+		Content:    "trigger recovery",
+	})
+	if err != nil {
+		t.Fatalf("processMessage() error = %v", err)
+	}
+	if response != "Recovered from overflow" {
+		t.Fatalf("response = %q, want %q", response, "Recovered from overflow")
+	}
+
+	if provider.calls != 2 {
+		t.Fatalf("expected 2 calls, got %d", provider.calls)
+	}
+}
+
+func TestProcessMessage_ContextOverflow_AnthropicStyle(t *testing.T) {
+	al, cfg, _, _, cleanup := newTestAgentLoop(t)
+	defer cleanup()
+	_ = cfg
+
+	provider := &overflowProvider{}
+	al.registry = NewAgentRegistry(al.cfg, provider)
+
+	recoveryMsg := "error: status 400: context_window_exceeded"
+
+	provider.chatFunc = func(
+		ctx context.Context,
+		messages []providers.Message,
+		tools []providers.ToolDefinition,
+		model string,
+		opts map[string]any,
+	) (*providers.LLMResponse, error) {
+		if provider.calls == 1 {
+			return nil, errors.New(recoveryMsg)
+		}
+		return &providers.LLMResponse{Content: "Anthropic recovery success"}, nil
+	}
+
+	response, err := al.processMessage(context.Background(), bus.InboundMessage{
+		Channel:  "test",
+		ChatID:   "chat1",
+		SenderID: "user1",
+		Content:  "hello",
+	})
+	if err != nil {
+		t.Fatalf("processMessage() error = %v", err)
+	}
+	if !strings.Contains(response, "Anthropic recovery success") {
+		t.Fatalf("response = %q, want success message", response)
+	}
+	if provider.calls != 2 {
+		t.Fatalf("expected 2 calls for retry, got %d", provider.calls)
+	}
+}

pkg/providers/error_classifier_test.go

@@ -221,6 +221,30 @@ func TestClassifyError_ImageDimensionError(t *testing.T) {
 	}
 }
 
+func TestClassifyError_ContextOverflowPatterns(t *testing.T) {
+	patterns := []string{
+		"context_length_exceeded",
+		"context_window_exceeded",
+		"maximum context length",
+		"token limit",
+		"too many tokens",
+		"prompt is too long",
+		"request too large",
+	}
+
+	for _, msg := range patterns {
+		err := errors.New(msg)
+		result := ClassifyError(err, "openai", "gpt-4")
+		if result == nil {
+			t.Errorf("pattern %q: expected non-nil", msg)
+			continue
+		}
+		if result.Reason != FailoverContextOverflow {
+			t.Errorf("pattern %q: reason = %q, want context_overflow", msg, result.Reason)
+		}
+	}
+}
+
 func TestClassifyError_ImageSizeError(t *testing.T) {
 	err := errors.New("image exceeds 20 mb limit")
 	result := ClassifyError(err, "openai", "gpt-4o")
@@ -265,6 +289,7 @@ func TestFailoverError_IsRetriable(t *testing.T) {
 		{FailoverTimeout, true},
 		{FailoverOverloaded, true},
 		{FailoverFormat, false},
+		{FailoverContextOverflow, false},
 		{FailoverUnknown, true},
 	}