refactor(lsp,llm,hexailsp,appconfig): split long funcs; add tests

- Extract helpers to keep funcs <=50 lines; no behavior changes
- Add tests for prompt removal, code actions, and LLM request builders
- Table-drive TestInParamList; run gofmt

1 files changed, 119 insertions, 109 deletions

diff --git a/internal/appconfig/config.go b/internal/appconfig/config.go
index 4fa3441..3067dd1 100644
--- a/internal/appconfig/config.go
+++ b/internal/appconfig/config.go
@@ -13,57 +13,57 @@ import (
 
 // App holds user-configurable settings read from ~/.config/hexai/config.json.
 type App struct {
-    MaxTokens          int    `json:"max_tokens"`
+	MaxTokens          int    `json:"max_tokens"`
 	ContextMode        string `json:"context_mode"`
 	ContextWindowLines int    `json:"context_window_lines"`
 	MaxContextTokens   int    `json:"max_context_tokens"`
-    LogPreviewLimit    int    `json:"log_preview_limit"`
-    // Single knob for LSP requests; if set, overrides hardcoded temps in LSP.
-    CodingTemperature  *float64 `json:"coding_temperature"`
+	LogPreviewLimit    int    `json:"log_preview_limit"`
+	// Single knob for LSP requests; if set, overrides hardcoded temps in LSP.
+	CodingTemperature *float64 `json:"coding_temperature"`
 
 	TriggerCharacters []string `json:"trigger_characters"`
 	Provider          string   `json:"provider"`
 
-    // Provider-specific options
-    OpenAIBaseURL  string `json:"openai_base_url"`
-    OpenAIModel    string `json:"openai_model"`
-    // Default temperature for OpenAI requests (nil means use provider default)
-    OpenAITemperature *float64 `json:"openai_temperature"`
-    OllamaBaseURL  string `json:"ollama_base_url"`
-    OllamaModel    string `json:"ollama_model"`
-    // Default temperature for Ollama requests (nil means use provider default)
-    OllamaTemperature *float64 `json:"ollama_temperature"`
-    CopilotBaseURL string `json:"copilot_base_url"`
-    CopilotModel   string `json:"copilot_model"`
-    // Default temperature for Copilot requests (nil means use provider default)
-    CopilotTemperature *float64 `json:"copilot_temperature"`
+	// Provider-specific options
+	OpenAIBaseURL string `json:"openai_base_url"`
+	OpenAIModel   string `json:"openai_model"`
+	// Default temperature for OpenAI requests (nil means use provider default)
+	OpenAITemperature *float64 `json:"openai_temperature"`
+	OllamaBaseURL     string   `json:"ollama_base_url"`
+	OllamaModel       string   `json:"ollama_model"`
+	// Default temperature for Ollama requests (nil means use provider default)
+	OllamaTemperature *float64 `json:"ollama_temperature"`
+	CopilotBaseURL    string   `json:"copilot_base_url"`
+	CopilotModel      string   `json:"copilot_model"`
+	// Default temperature for Copilot requests (nil means use provider default)
+	CopilotTemperature *float64 `json:"copilot_temperature"`
 }
 
 // Constructor: defaults for App (kept first among functions)
 func newDefaultConfig() App {
-    // Coding-friendly default temperature across providers
-    // Users can override per provider in config.json (including 0.0).
-    t := 0.2
-    return App{
-        MaxTokens:          4000,
-        ContextMode:        "always-full",
-        ContextWindowLines: 120,
-        MaxContextTokens:   4000,
-        LogPreviewLimit:    100,
-        CodingTemperature:  &t,
-        OpenAITemperature:  &t,
-        OllamaTemperature:  &t,
-        CopilotTemperature: &t,
-    }
+	// Coding-friendly default temperature across providers
+	// Users can override per provider in config.json (including 0.0).
+	t := 0.2
+	return App{
+		MaxTokens:          4000,
+		ContextMode:        "always-full",
+		ContextWindowLines: 120,
+		MaxContextTokens:   4000,
+		LogPreviewLimit:    100,
+		CodingTemperature:  &t,
+		OpenAITemperature:  &t,
+		OllamaTemperature:  &t,
+		CopilotTemperature: &t,
+	}
 }
 
 // Load reads configuration from a file and merges with defaults.
 // It respects the XDG Base Directory Specification.
 func Load(logger *log.Logger) App {
-    cfg := newDefaultConfig()
-    if logger == nil {
-        return cfg // Return defaults if no logger is provided (e.g. in tests)
-    }
+	cfg := newDefaultConfig()
+	if logger == nil {
+		return cfg // Return defaults if no logger is provided (e.g. in tests)
+	}
 
 	configPath, err := getConfigPath()
 	if err != nil {
@@ -76,91 +76,101 @@ func Load(logger *log.Logger) App {
 		return cfg
 	}
 
-    cfg.mergeWith(fileCfg)
-    return cfg
+	cfg.mergeWith(fileCfg)
+	return cfg
 }
 
 // Private helpers
 func loadFromFile(path string, logger *log.Logger) (*App, error) {
-    f, err := os.Open(path)
-    if err != nil {
-        if !os.IsNotExist(err) && logger != nil {
-            logger.Printf("cannot open config file %s: %v", path, err)
-        }
-        return nil, err
-    }
-    defer f.Close()
+	f, err := os.Open(path)
+	if err != nil {
+		if !os.IsNotExist(err) && logger != nil {
+			logger.Printf("cannot open config file %s: %v", path, err)
+		}
+		return nil, err
+	}
+	defer f.Close()
 
-    dec := json.NewDecoder(f)
-    var fileCfg App
-    if err := dec.Decode(&fileCfg); err != nil {
-        if logger != nil {
-            logger.Printf("invalid config file %s: %v", path, err)
-        }
-        return nil, err
-    }
-    return &fileCfg, nil
+	dec := json.NewDecoder(f)
+	var fileCfg App
+	if err := dec.Decode(&fileCfg); err != nil {
+		if logger != nil {
+			logger.Printf("invalid config file %s: %v", path, err)
+		}
+		return nil, err
+	}
+	return &fileCfg, nil
 }
 
 func (a *App) mergeWith(other *App) {
-    if other.MaxTokens > 0 {
-        a.MaxTokens = other.MaxTokens
-    }
-    if strings.TrimSpace(other.ContextMode) != "" {
-        a.ContextMode = other.ContextMode
-    }
-    if other.ContextWindowLines > 0 {
-        a.ContextWindowLines = other.ContextWindowLines
-    }
-    if other.MaxContextTokens > 0 {
-        a.MaxContextTokens = other.MaxContextTokens
-    }
-    if other.LogPreviewLimit >= 0 {
-        a.LogPreviewLimit = other.LogPreviewLimit
-    }
-    if other.CodingTemperature != nil { // allow explicit 0.0
-        a.CodingTemperature = other.CodingTemperature
-    }
-    if len(other.TriggerCharacters) > 0 {
-        a.TriggerCharacters = slices.Clone(other.TriggerCharacters)
-    }
-    if strings.TrimSpace(other.Provider) != "" {
-        a.Provider = other.Provider
-    }
-    if strings.TrimSpace(other.OpenAIBaseURL) != "" {
-        a.OpenAIBaseURL = other.OpenAIBaseURL
-    }
-    if strings.TrimSpace(other.OpenAIModel) != "" {
-        a.OpenAIModel = other.OpenAIModel
-    }
-    if other.OpenAITemperature != nil { // allow explicit 0.0
-        a.OpenAITemperature = other.OpenAITemperature
-    }
-    if strings.TrimSpace(other.OllamaBaseURL) != "" {
-        a.OllamaBaseURL = other.OllamaBaseURL
-    }
-    if strings.TrimSpace(other.OllamaModel) != "" {
-        a.OllamaModel = other.OllamaModel
-    }
-    if other.OllamaTemperature != nil { // allow explicit 0.0
-        a.OllamaTemperature = other.OllamaTemperature
-    }
-    if strings.TrimSpace(other.CopilotBaseURL) != "" {
-        a.CopilotBaseURL = other.CopilotBaseURL
-    }
-    if strings.TrimSpace(other.CopilotModel) != "" {
-        a.CopilotModel = other.CopilotModel
-    }
-    if other.CopilotTemperature != nil { // allow explicit 0.0
-        a.CopilotTemperature = other.CopilotTemperature
-    }
+	a.mergeBasics(other)
+	a.mergeProviderFields(other)
+}
+
+// mergeBasics merges general (non-provider) fields.
+func (a *App) mergeBasics(other *App) {
+	if other.MaxTokens > 0 {
+		a.MaxTokens = other.MaxTokens
+	}
+	if s := strings.TrimSpace(other.ContextMode); s != "" {
+		a.ContextMode = s
+	}
+	if other.ContextWindowLines > 0 {
+		a.ContextWindowLines = other.ContextWindowLines
+	}
+	if other.MaxContextTokens > 0 {
+		a.MaxContextTokens = other.MaxContextTokens
+	}
+	if other.LogPreviewLimit >= 0 {
+		a.LogPreviewLimit = other.LogPreviewLimit
+	}
+	if other.CodingTemperature != nil { // allow explicit 0.0
+		a.CodingTemperature = other.CodingTemperature
+	}
+	if len(other.TriggerCharacters) > 0 {
+		a.TriggerCharacters = slices.Clone(other.TriggerCharacters)
+	}
+	if s := strings.TrimSpace(other.Provider); s != "" {
+		a.Provider = s
+	}
+}
+
+// mergeProviderFields merges per-provider configuration.
+func (a *App) mergeProviderFields(other *App) {
+	if s := strings.TrimSpace(other.OpenAIBaseURL); s != "" {
+		a.OpenAIBaseURL = s
+	}
+	if s := strings.TrimSpace(other.OpenAIModel); s != "" {
+		a.OpenAIModel = s
+	}
+	if other.OpenAITemperature != nil { // allow explicit 0.0
+		a.OpenAITemperature = other.OpenAITemperature
+	}
+	if s := strings.TrimSpace(other.OllamaBaseURL); s != "" {
+		a.OllamaBaseURL = s
+	}
+	if s := strings.TrimSpace(other.OllamaModel); s != "" {
+		a.OllamaModel = s
+	}
+	if other.OllamaTemperature != nil { // allow explicit 0.0
+		a.OllamaTemperature = other.OllamaTemperature
+	}
+	if s := strings.TrimSpace(other.CopilotBaseURL); s != "" {
+		a.CopilotBaseURL = s
+	}
+	if s := strings.TrimSpace(other.CopilotModel); s != "" {
+		a.CopilotModel = s
+	}
+	if other.CopilotTemperature != nil { // allow explicit 0.0
+		a.CopilotTemperature = other.CopilotTemperature
+	}
 }
 
 func getConfigPath() (string, error) {
-    var configPath string
-    if xdgConfigHome := os.Getenv("XDG_CONFIG_HOME"); xdgConfigHome != "" {
-        configPath = filepath.Join(xdgConfigHome, "hexai", "config.json")
-    } else {
+	var configPath string
+	if xdgConfigHome := os.Getenv("XDG_CONFIG_HOME"); xdgConfigHome != "" {
+		configPath = filepath.Join(xdgConfigHome, "hexai", "config.json")
+	} else {
 		home, err := os.UserHomeDir()
 		if err != nil {
 			return "", fmt.Errorf("cannot find user home directory: %v", err)