tests: add coverage for model-native search

pkg/agent/loop_test.go

@@ -1318,3 +1318,78 @@ func TestResolveMediaRefs_MixedImageAndFile(t *testing.T) {
 		t.Fatalf("expected content %q, got %q", expectedContent, result[0].Content)
 	}
 }
+
+// --- Native search helper tests ---
+
+type nativeSearchProvider struct {
+	supported bool
+}
+
+func (p *nativeSearchProvider) Chat(ctx context.Context, msgs []providers.Message, tools []providers.ToolDefinition, model string, opts map[string]any) (*providers.LLMResponse, error) {
+	return &providers.LLMResponse{Content: "ok"}, nil
+}
+
+func (p *nativeSearchProvider) GetDefaultModel() string { return "test-model" }
+
+func (p *nativeSearchProvider) SupportsNativeSearch() bool { return p.supported }
+
+type plainProvider struct{}
+
+func (p *plainProvider) Chat(ctx context.Context, msgs []providers.Message, tools []providers.ToolDefinition, model string, opts map[string]any) (*providers.LLMResponse, error) {
+	return &providers.LLMResponse{Content: "ok"}, nil
+}
+
+func (p *plainProvider) GetDefaultModel() string { return "test-model" }
+
+func TestIsNativeSearchProvider_Supported(t *testing.T) {
+	if !isNativeSearchProvider(&nativeSearchProvider{supported: true}) {
+		t.Fatal("expected true for provider that supports native search")
+	}
+}
+
+func TestIsNativeSearchProvider_NotSupported(t *testing.T) {
+	if isNativeSearchProvider(&nativeSearchProvider{supported: false}) {
+		t.Fatal("expected false for provider that does not support native search")
+	}
+}
+
+func TestIsNativeSearchProvider_NoInterface(t *testing.T) {
+	if isNativeSearchProvider(&plainProvider{}) {
+		t.Fatal("expected false for provider that does not implement NativeSearchCapable")
+	}
+}
+
+func TestFilterClientWebSearch_RemovesWebSearch(t *testing.T) {
+	defs := []providers.ToolDefinition{
+		{Type: "function", Function: providers.ToolFunctionDefinition{Name: "web_search"}},
+		{Type: "function", Function: providers.ToolFunctionDefinition{Name: "read_file"}},
+		{Type: "function", Function: providers.ToolFunctionDefinition{Name: "exec"}},
+	}
+	result := filterClientWebSearch(defs)
+	if len(result) != 2 {
+		t.Fatalf("len(result) = %d, want 2", len(result))
+	}
+	for _, td := range result {
+		if td.Function.Name == "web_search" {
+			t.Fatal("web_search should be filtered out")
+		}
+	}
+}
+
+func TestFilterClientWebSearch_NoWebSearch(t *testing.T) {
+	defs := []providers.ToolDefinition{
+		{Type: "function", Function: providers.ToolFunctionDefinition{Name: "read_file"}},
+		{Type: "function", Function: providers.ToolFunctionDefinition{Name: "exec"}},
+	}
+	result := filterClientWebSearch(defs)
+	if len(result) != 2 {
+		t.Fatalf("len(result) = %d, want 2", len(result))
+	}
+}
+
+func TestFilterClientWebSearch_EmptyInput(t *testing.T) {
+	result := filterClientWebSearch(nil)
+	if len(result) != 0 {
+		t.Fatalf("len(result) = %d, want 0", len(result))
+	}
+}

pkg/config/config_test.go

@@ -384,6 +384,45 @@ func TestDefaultConfig_OpenAIWebSearchEnabled(t *testing.T) {
 	}
 }
 
+func TestDefaultConfig_WebPreferNativeEnabled(t *testing.T) {
+	cfg := DefaultConfig()
+	if !cfg.Tools.Web.PreferNative {
+		t.Fatal("DefaultConfig().Tools.Web.PreferNative should be true")
+	}
+}
+
+func TestLoadConfig_WebPreferNativeDefaultsTrueWhenUnset(t *testing.T) {
+	dir := t.TempDir()
+	configPath := filepath.Join(dir, "config.json")
+	if err := os.WriteFile(configPath, []byte(`{"tools":{"web":{"enabled":true}}}`), 0o600); err != nil {
+		t.Fatalf("WriteFile() error: %v", err)
+	}
+
+	cfg, err := LoadConfig(configPath)
+	if err != nil {
+		t.Fatalf("LoadConfig() error: %v", err)
+	}
+	if !cfg.Tools.Web.PreferNative {
+		t.Fatal("PreferNative should remain true when unset in config file")
+	}
+}
+
+func TestLoadConfig_WebPreferNativeCanBeDisabled(t *testing.T) {
+	dir := t.TempDir()
+	configPath := filepath.Join(dir, "config.json")
+	if err := os.WriteFile(configPath, []byte(`{"tools":{"web":{"prefer_native":false}}}`), 0o600); err != nil {
+		t.Fatalf("WriteFile() error: %v", err)
+	}
+
+	cfg, err := LoadConfig(configPath)
+	if err != nil {
+		t.Fatalf("LoadConfig() error: %v", err)
+	}
+	if cfg.Tools.Web.PreferNative {
+		t.Fatal("PreferNative should be false when disabled in config file")
+	}
+}
+
 func TestDefaultConfig_ExecAllowRemoteEnabled(t *testing.T) {
 	cfg := DefaultConfig()
 	if !cfg.Tools.Exec.AllowRemote {

pkg/providers/openai_compat/provider_test.go

@@ -824,6 +824,232 @@ func TestSupportsPromptCacheKey(t *testing.T) {
 	}
 }
 
+func TestBuildToolsList_NativeSearchAddsWebSearchPreview(t *testing.T) {
+	tools := []ToolDefinition{
+		{Type: "function", Function: ToolFunctionDefinition{Name: "read_file", Description: "read"}},
+	}
+	result := buildToolsList(tools, true)
+	if len(result) != 2 {
+		t.Fatalf("len(result) = %d, want 2", len(result))
+	}
+	wsEntry, ok := result[1].(map[string]any)
+	if !ok {
+		t.Fatalf("web search entry is %T, want map[string]any", result[1])
+	}
+	if wsEntry["type"] != "web_search_preview" {
+		t.Fatalf("type = %v, want web_search_preview", wsEntry["type"])
+	}
+}
+
+func TestBuildToolsList_NativeSearchFiltersClientWebSearch(t *testing.T) {
+	tools := []ToolDefinition{
+		{Type: "function", Function: ToolFunctionDefinition{Name: "web_search", Description: "search"}},
+		{Type: "function", Function: ToolFunctionDefinition{Name: "read_file", Description: "read"}},
+	}
+	result := buildToolsList(tools, true)
+	for _, entry := range result {
+		if td, ok := entry.(ToolDefinition); ok && strings.EqualFold(td.Function.Name, "web_search") {
+			t.Fatal("client-side web_search should be filtered out when native search is enabled")
+		}
+	}
+	if len(result) != 2 { // read_file + web_search_preview
+		t.Fatalf("len(result) = %d, want 2 (read_file + web_search_preview)", len(result))
+	}
+}
+
+func TestBuildToolsList_NoNativeSearchPassesThrough(t *testing.T) {
+	tools := []ToolDefinition{
+		{Type: "function", Function: ToolFunctionDefinition{Name: "web_search", Description: "search"}},
+		{Type: "function", Function: ToolFunctionDefinition{Name: "read_file", Description: "read"}},
+	}
+	result := buildToolsList(tools, false)
+	if len(result) != 2 {
+		t.Fatalf("len(result) = %d, want 2", len(result))
+	}
+}
+
+func TestIsNativeSearchHost(t *testing.T) {
+	tests := []struct {
+		apiBase string
+		want    bool
+	}{
+		{"https://api.openai.com/v1", true},
+		{"https://myresource.openai.azure.com/openai/deployments/gpt-4", true},
+		{"https://api.mistral.ai/v1", false},
+		{"https://api.deepseek.com/v1", false},
+		{"https://api.groq.com/openai/v1", false},
+		{"http://localhost:11434/v1", false},
+		{"", false},
+	}
+	for _, tt := range tests {
+		if got := isNativeSearchHost(tt.apiBase); got != tt.want {
+			t.Errorf("isNativeSearchHost(%q) = %v, want %v", tt.apiBase, got, tt.want)
+		}
+	}
+}
+
+func TestSupportsNativeSearch_OpenAI(t *testing.T) {
+	p := NewProvider("key", "https://api.openai.com/v1", "")
+	if !p.SupportsNativeSearch() {
+		t.Fatal("OpenAI provider should support native search")
+	}
+}
+
+func TestSupportsNativeSearch_NonOpenAI(t *testing.T) {
+	p := NewProvider("key", "https://api.deepseek.com/v1", "")
+	if p.SupportsNativeSearch() {
+		t.Fatal("DeepSeek provider should not support native search")
+	}
+}
+
+func TestProviderChat_NativeSearchToolInjected(t *testing.T) {
+	var requestBody map[string]any
+
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if err := json.NewDecoder(r.Body).Decode(&requestBody); err != nil {
+			http.Error(w, err.Error(), http.StatusBadRequest)
+			return
+		}
+		resp := map[string]any{
+			"choices": []map[string]any{
+				{
+					"message":       map[string]any{"content": "ok"},
+					"finish_reason": "stop",
+				},
+			},
+		}
+		w.Header().Set("Content-Type", "application/json")
+		json.NewEncoder(w).Encode(resp)
+	}))
+	defer server.Close()
+
+	p := NewProvider("key", server.URL, "")
+	p.apiBase = "https://api.openai.com/v1"
+	p.httpClient = &http.Client{
+		Transport: roundTripperFunc(func(r *http.Request) (*http.Response, error) {
+			r.URL, _ = url.Parse(server.URL + r.URL.Path)
+			return http.DefaultTransport.RoundTrip(r)
+		}),
+	}
+	tools := []ToolDefinition{
+		{Type: "function", Function: ToolFunctionDefinition{Name: "read_file", Description: "read"}},
+	}
+	_, err := p.Chat(
+		t.Context(),
+		[]Message{{Role: "user", Content: "hi"}},
+		tools,
+		"gpt-5.4",
+		map[string]any{"native_search": true},
+	)
+	if err != nil {
+		t.Fatalf("Chat() error = %v", err)
+	}
+
+	toolsRaw, ok := requestBody["tools"].([]any)
+	if !ok {
+		t.Fatalf("tools is %T, want []any", requestBody["tools"])
+	}
+	if len(toolsRaw) != 2 {
+		t.Fatalf("len(tools) = %d, want 2 (read_file + web_search_preview)", len(toolsRaw))
+	}
+
+	lastTool, ok := toolsRaw[1].(map[string]any)
+	if !ok {
+		t.Fatalf("last tool is %T, want map[string]any", toolsRaw[1])
+	}
+	if lastTool["type"] != "web_search_preview" {
+		t.Fatalf("last tool type = %v, want web_search_preview", lastTool["type"])
+	}
+}
+
+func TestProviderChat_NativeSearchNotInjectedWithoutOption(t *testing.T) {
+	var requestBody map[string]any
+
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if err := json.NewDecoder(r.Body).Decode(&requestBody); err != nil {
+			http.Error(w, err.Error(), http.StatusBadRequest)
+			return
+		}
+		resp := map[string]any{
+			"choices": []map[string]any{
+				{
+					"message":       map[string]any{"content": "ok"},
+					"finish_reason": "stop",
+				},
+			},
+		}
+		w.Header().Set("Content-Type", "application/json")
+		json.NewEncoder(w).Encode(resp)
+	}))
+	defer server.Close()
+
+	p := NewProvider("key", server.URL, "")
+	tools := []ToolDefinition{
+		{Type: "function", Function: ToolFunctionDefinition{Name: "web_search", Description: "search"}},
+	}
+	_, err := p.Chat(
+		t.Context(),
+		[]Message{{Role: "user", Content: "hi"}},
+		tools,
+		"gpt-5.4",
+		map[string]any{},
+	)
+	if err != nil {
+		t.Fatalf("Chat() error = %v", err)
+	}
+
+	toolsRaw, ok := requestBody["tools"].([]any)
+	if !ok {
+		t.Fatalf("tools is %T, want []any", requestBody["tools"])
+	}
+	if len(toolsRaw) != 1 {
+		t.Fatalf("len(tools) = %d, want 1 (web_search only)", len(toolsRaw))
+	}
+}
+
+// TestProviderChat_NativeSearchIgnoredOnNonOpenAI verifies that when native_search
+// is true in options but the provider's apiBase is not OpenAI (e.g. fallback to DeepSeek),
+// we do not inject web_search_preview to avoid API errors.
+func TestProviderChat_NativeSearchIgnoredOnNonOpenAI(t *testing.T) {
+	var requestBody map[string]any
+
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if err := json.NewDecoder(r.Body).Decode(&requestBody); err != nil {
+			http.Error(w, err.Error(), http.StatusBadRequest)
+			return
+		}
+		resp := map[string]any{
+			"choices": []map[string]any{
+				{
+					"message":       map[string]any{"content": "ok"},
+					"finish_reason": "stop",
+				},
+			},
+		}
+		w.Header().Set("Content-Type", "application/json")
+		json.NewEncoder(w).Encode(resp)
+	}))
+	defer server.Close()
+
+	// Use server.URL so host is not api.openai.com — simulates DeepSeek/other provider
+	p := NewProvider("key", server.URL, "")
+	_, err := p.Chat(
+		t.Context(),
+		[]Message{{Role: "user", Content: "hi"}},
+		nil,
+		"deepseek-chat",
+		map[string]any{"native_search": true},
+	)
+	if err != nil {
+		t.Fatalf("Chat() error = %v", err)
+	}
+
+	// Should not have tools at all (no tools passed, and we must not add web_search_preview)
+	if toolsRaw, ok := requestBody["tools"]; ok {
+		t.Fatalf("tools should be omitted for non-OpenAI when only native_search was requested, got %v", toolsRaw)
+	}
+}
+
 func TestSerializeMessages_StripsSystemParts(t *testing.T) {
 	messages := []protocoltypes.Message{
 		{