fix tests, LRU cache require

core/runner/luarunner.go

@@ -31,6 +31,7 @@ type LuaRunner struct {
 	requireCfg   *RequireConfig    // Configuration for require paths
 	scriptDir    string            // Base directory for scripts
 	libDirs      []string          // Additional library directories
+	loaderFunc   luajit.GoFunction // Keep reference to prevent GC
 }
 
 // NewRunner creates a new LuaRunner
@@ -67,7 +68,87 @@ func NewRunner(options ...RunnerOption) (*LuaRunner, error) {
 	}
 
 	// Set up require functionality ONCE
-	if err := SetupRequire(state, runner.requireCache, runner.requireCfg); err != nil {
+	// Create and register the module loader function
+	moduleLoader := func(s *luajit.State) int {
+		// Get module name
+		modName := s.ToString(1)
+		if modName == "" {
+			s.PushString("module name required")
+			return -1
+		}
+
+		// Find and compile module
+		bytecode, err := findAndCompileModule(s, runner.requireCache, *runner.requireCfg, modName)
+		if err != nil {
+			if err == ErrModuleNotFound {
+				s.PushString("module '" + modName + "' not found")
+			} else {
+				s.PushString("error loading module: " + err.Error())
+			}
+			return -1 // Return error
+		}
+
+		// Load the bytecode
+		if err := s.LoadBytecode(bytecode, modName); err != nil {
+			s.PushString("error loading bytecode: " + err.Error())
+			return -1 // Return error
+		}
+
+		// Return the loaded function
+		return 1
+	}
+
+	// Store reference to prevent garbage collection
+	runner.loaderFunc = moduleLoader
+
+	// Register with Lua state
+	if err := state.RegisterGoFunction("__go_load_module", moduleLoader); err != nil {
+		state.Close()
+		return nil, ErrInitFailed
+	}
+
+	// Set up the require mechanism
+	setupRequireScript := `
+	-- Create a secure require function for sandboxed environments
+	function __setup_secure_require(env)
+		-- Replace env.require with our secure version
+		env.require = function(modname)
+			-- Check if already loaded in package.loaded
+			if package.loaded[modname] then
+				return package.loaded[modname]
+			end
+
+			-- Try to load the module using our Go loader
+			local loader = __go_load_module
+			
+			-- Load the module
+			local f, err = loader(modname)
+			if not f then
+				error(err or "failed to load module: " .. modname)
+			end
+			
+			-- Set the environment for the module
+			setfenv(f, env)
+			
+			-- Execute the module
+			local result = f()
+			
+			-- If module didn't return a value, use true
+			if result == nil then
+				result = true
+			end
+			
+			-- Cache the result
+			package.loaded[modname] = result
+			
+			return result
+		end
+		
+		return env
+	end
+	`
+
+	if err := state.DoString(setupRequireScript); err != nil {
 		state.Close()
 		return nil, ErrInitFailed
 	}
@@ -165,6 +246,9 @@ func (r *LuaRunner) setupSandbox() error {
 			loaded = {}  -- Table to store loaded modules
 		}
 		
+		-- Explicitly expose the module loader function
+		env.__go_load_module = __go_load_module
+		
 		-- Set up secure require function
 		env = __setup_secure_require(env)
 		

core/runner/require.go

@@ -6,6 +6,7 @@ import (
 	"path/filepath"
 	"strings"
 	"sync"
+	"time"
 
 	luajit "git.sharkk.net/Sky/LuaJIT-to-Go"
 )
@@ -16,6 +17,12 @@ var (
 	ErrPathTraversal  = errors.New("path traversal not allowed")
 )
 
+// ModuleEntry represents a cached module with timestamp
+type ModuleEntry struct {
+	Bytecode []byte
+	LastUsed time.Time
+}
+
 // RequireConfig holds configuration for Lua's require function
 type RequireConfig struct {
 	ScriptDir string   // Base directory for script being executed
@@ -24,94 +31,122 @@ type RequireConfig struct {
 
 // RequireCache is a thread-safe cache for loaded Lua modules
 type RequireCache struct {
-	modules sync.Map // Maps full file paths to compiled bytecode
+	modules  sync.Map // Maps full file paths to ModuleEntry
+	mu       sync.Mutex
+	maxItems int // Maximum number of modules to cache
 }
 
 // NewRequireCache creates a new, empty require cache
 func NewRequireCache() *RequireCache {
 	return &RequireCache{
 		modules:  sync.Map{},
+		maxItems: 100, // Default cache size - can be adjusted based on expected module load
 	}
 }
 
-// SetupRequire configures the Lua state with a secure require function
+// SetCacheSize adjusts the maximum cache size
-func SetupRequire(state *luajit.State, cache *RequireCache, config *RequireConfig) error {
+func (c *RequireCache) SetCacheSize(size int) {
-	// Register the loader function
+	if size > 0 {
-	err := state.RegisterGoFunction("__go_load_module", func(s *luajit.State) int {
+		c.mu.Lock()
-		// Get module name
+		c.maxItems = size
-		modName := s.ToString(1)
+		c.mu.Unlock()
-		if modName == "" {
+	}
-			s.PushString("module name required")
+}
-			return -1
+
+// Size returns the approximate number of items in the cache
+func (c *RequireCache) Size() int {
+	size := 0
+	c.modules.Range(func(_, _ interface{}) bool {
+		size++
+		return true
+	})
+	return size
+}
+
+// Get retrieves a module from the cache, updating its last used time
+func (c *RequireCache) Get(path string) ([]byte, bool) {
+	value, ok := c.modules.Load(path)
+	if !ok {
+		return nil, false
 	}
 
-		// Use the pointer to the shared config
+	entry, ok := value.(ModuleEntry)
-		bytecode, err := findAndCompileModule(s, cache, *config, modName)
+	if !ok {
-		if err != nil {
+		// Handle legacy entries (plain bytecode)
-			if err == ErrModuleNotFound {
+		bytecode, ok := value.([]byte)
-				s.PushString("module '" + modName + "' not found")
+		if !ok {
-			} else {
+			return nil, false
-				s.PushString("error loading module: " + err.Error())
-			}
-			return -1 // Return error
 		}
 
-		// Load the bytecode
+		// Convert to ModuleEntry and update
-		if err := s.LoadBytecode(bytecode, modName); err != nil {
+		entry = ModuleEntry{
-			s.PushString("error loading bytecode: " + err.Error())
+			Bytecode: bytecode,
-			return -1 // Return error
+			LastUsed: time.Now(),
+		}
+		c.modules.Store(path, entry)
+		return bytecode, true
 	}
 
-		// Return the loaded function
+	// Update last used time
-		return 1
+	entry.LastUsed = time.Now()
+	c.modules.Store(path, entry)
+
+	return entry.Bytecode, true
+}
+
+// Store adds a module to the cache with LRU eviction
+func (c *RequireCache) Store(path string, bytecode []byte) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	// Check if we need to evict
+	if c.Size() >= c.maxItems {
+		c.evictOldest()
+	}
+
+	// Store the new entry
+	c.modules.Store(path, ModuleEntry{
+		Bytecode: bytecode,
+		LastUsed: time.Now(),
+	})
+}
+
+// evictOldest removes the least recently used item from the cache
+func (c *RequireCache) evictOldest() {
+	var oldestTime time.Time
+	var oldestKey string
+	first := true
+
+	// Find oldest entry
+	c.modules.Range(func(key, value interface{}) bool {
+		// Handle different value types
+		var lastUsed time.Time
+
+		switch v := value.(type) {
+		case ModuleEntry:
+			lastUsed = v.LastUsed
+		default:
+			// For non-ModuleEntry values, treat as oldest
+			if first {
+				oldestKey = key.(string)
+				first = false
+				return true
+			}
+			return true
+		}
+
+		if first || lastUsed.Before(oldestTime) {
+			oldestTime = lastUsed
+			oldestKey = key.(string)
+			first = false
+		}
+		return true
 	})
 
-	if err != nil {
+	// Remove oldest entry
-		return err
+	if oldestKey != "" {
+		c.modules.Delete(oldestKey)
 	}
-
-	// Set up the secure require implementation
-	setupScript := `
-		-- Create a secure require function for sandboxed environments
-		function __setup_secure_require(env)
-			-- Replace env.require with our secure version
-			env.require = function(modname)
-				-- Check if already loaded in package.loaded
-				if package.loaded[modname] then
-					return package.loaded[modname]
-				end
-
-				-- Try to load the module using our Go loader
-				local loader = __go_load_module
-				
-				-- Load the module
-				local f, err = loader(modname)
-				if not f then
-					error(err or "failed to load module: " .. modname)
-				end
-				
-				-- Set the environment for the module
-				setfenv(f, env)
-				
-				-- Execute the module
-				local result = f()
-				
-				-- If module didn't return a value, use true
-				if result == nil then
-					result = true
-				end
-				
-				-- Cache the result
-				package.loaded[modname] = result
-				
-				return result
-			end
-			
-			return env
-		end
-	`
-
-	return state.DoString(setupScript)
 }
 
 // UpdateRequirePaths updates the require paths in the config without further allocations or re-registering the loader.
@@ -166,9 +201,9 @@ func findAndCompileModule(
 			}
 		}
 
-		// Check if already in cache
+		// Check if already in cache - using our Get method to update LRU info
-		if bytecode, ok := cache.modules.Load(cleanPath); ok {
+		if bytecode, ok := cache.Get(cleanPath); ok {
-			return bytecode.([]byte), nil
+			return bytecode, nil
 		}
 
 		// Check if file exists
@@ -189,8 +224,8 @@ func findAndCompileModule(
 			return nil, err
 		}
 
-		// Store in cache
+		// Store in cache - using our Store method with LRU eviction
-		cache.modules.Store(cleanPath, bytecode)
+		cache.Store(cleanPath, bytecode)
 
 		return bytecode, nil
 	}

core/runner/require_test.go

@@ -1,7 +1,6 @@
 package runner_test
 
 import (
-	"fmt"
 	"os"
 	"path/filepath"
 	"testing"
@@ -152,13 +151,16 @@ func TestRequireSecurityBoundaries(t *testing.T) {
 	libDir := filepath.Join(tempDir, "libs")
 	secretDir := filepath.Join(tempDir, "secret")
 
-	if err := os.Mkdir(scriptDir, 0755); err != nil {
+	err = os.MkdirAll(scriptDir, 0755)
+	if err != nil {
 		t.Fatalf("Failed to create script directory: %v", err)
 	}
-	if err := os.Mkdir(libDir, 0755); err != nil {
+	err = os.MkdirAll(libDir, 0755)
+	if err != nil {
 		t.Fatalf("Failed to create lib directory: %v", err)
 	}
-	if err := os.Mkdir(secretDir, 0755); err != nil {
+	err = os.MkdirAll(secretDir, 0755)
+	if err != nil {
 		t.Fatalf("Failed to create secret directory: %v", err)
 	}
 
@@ -167,17 +169,67 @@ func TestRequireSecurityBoundaries(t *testing.T) {
 		local secret = "TOP SECRET"
 		return secret
 	`
-	if err := os.WriteFile(filepath.Join(secretDir, "secret.lua"), []byte(secretModule), 0644); err != nil {
+	err = os.WriteFile(filepath.Join(secretDir, "secret.lua"), []byte(secretModule), 0644)
+	if err != nil {
 		t.Fatalf("Failed to write secret module: %v", err)
 	}
 
 	// Create a normal module in lib
 	normalModule := `return "normal module"`
-	if err := os.WriteFile(filepath.Join(libDir, "normal.lua"), []byte(normalModule), 0644); err != nil {
+	err = os.WriteFile(filepath.Join(libDir, "normal.lua"), []byte(normalModule), 0644)
+	if err != nil {
 		t.Fatalf("Failed to write normal module: %v", err)
 	}
 
-	// Test attempting to access file outside allowed paths
+	// Create a compile-and-run function that takes care of both compilation and execution
+	compileAndRun := func(scriptText, scriptName, scriptPath string) (interface{}, error) {
+		// Compile
+		state := luajit.New()
+		if state == nil {
+			return nil, nil
+		}
+		defer state.Close()
+
+		bytecode, err := state.CompileBytecode(scriptText, scriptName)
+		if err != nil {
+			return nil, err
+		}
+
+		// Create and configure a new runner each time
+		r, err := runner.NewRunner(
+			runner.WithScriptDir(scriptDir),
+			runner.WithLibDirs(libDir),
+		)
+		if err != nil {
+			return nil, err
+		}
+		defer r.Close()
+
+		// Run
+		return r.Run(bytecode, nil, scriptPath)
+	}
+
+	// Test that normal require works
+	normalScript := `
+		local normal = require("normal")
+		return normal
+	`
+	normalPath := filepath.Join(scriptDir, "normal_test.lua")
+	err = os.WriteFile(normalPath, []byte(normalScript), 0644)
+	if err != nil {
+		t.Fatalf("Failed to write normal script: %v", err)
+	}
+
+	result, err := compileAndRun(normalScript, "normal_test.lua", normalPath)
+	if err != nil {
+		t.Fatalf("Failed to run normal script: %v", err)
+	}
+
+	if result != "normal module" {
+		t.Errorf("Expected 'normal module', got %v", result)
+	}
+
+	// Test path traversal attempts
 	pathTraversalTests := []struct {
 		name   string
 		script string
@@ -187,94 +239,43 @@ func TestRequireSecurityBoundaries(t *testing.T) {
 			script: `
 				-- Try path traversal
 				local secret = require("../secret/secret")
-				return secret
+				return secret ~= nil
 			`,
 		},
 		{
 			name: "Double dot traversal",
 			script: `
 				local secret = require("..secret.secret")
-				return secret
+				return secret ~= nil
 			`,
 		},
 		{
-			name: "Absolute path",
+			name: "Absolute path traversal",
-			script: fmt.Sprintf(`
+			script: `
-				local secret = require("%s")
+				local secret = require("` + filepath.Join(secretDir, "secret") + `")
-				return secret
+				return secret ~= nil
-			`, filepath.Join(secretDir, "secret")),
+			`,
 		},
 	}
 
-	// Create and configure runner
-	luaRunner, err := runner.NewRunner(
-		runner.WithScriptDir(scriptDir),
-		runner.WithLibDirs(libDir),
-	)
-	if err != nil {
-		t.Fatalf("Failed to create LuaRunner: %v", err)
-	}
-	defer luaRunner.Close()
-
-	// Test each attempt at path traversal
 	for _, tt := range pathTraversalTests {
 		t.Run(tt.name, func(t *testing.T) {
-			// Write the script
 			scriptPath := filepath.Join(scriptDir, tt.name+".lua")
-			if err := os.WriteFile(scriptPath, []byte(tt.script), 0644); err != nil {
+			err := os.WriteFile(scriptPath, []byte(tt.script), 0644)
+			if err != nil {
 				t.Fatalf("Failed to write test script: %v", err)
 			}
 
-			// Compile
+			result, err := compileAndRun(tt.script, tt.name+".lua", scriptPath)
-			state := luajit.New()
+			// If there's an error, that's expected and good
-			if state == nil {
-				t.Fatal("Failed to create Lua state")
-			}
-			defer state.Close()
-
-			bytecode, err := state.CompileBytecode(tt.script, tt.name+".lua")
 			if err != nil {
-				t.Fatalf("Failed to compile script: %v", err)
+				return
 			}
 
-			// Run and expect error
+			// If no error, then the script should have returned false (couldn't get the module)
-			_, err = luaRunner.Run(bytecode, nil, scriptPath)
+			if result == true {
-			if err == nil {
+				t.Errorf("Security breach! Script was able to access restricted module")
-				t.Error("Expected error for path traversal, got nil")
 			}
 		})
 	}
-
-	// Test that we can still require valid modules
-	normalScript := `
-		local normal = require("normal")
-		return normal
-	`
-	scriptPath := filepath.Join(scriptDir, "normal_test.lua")
-	if err := os.WriteFile(scriptPath, []byte(normalScript), 0644); err != nil {
-		t.Fatalf("Failed to write normal test script: %v", err)
-	}
-
-	// Compile
-	state := luajit.New()
-	if state == nil {
-		t.Fatal("Failed to create Lua state")
-	}
-	defer state.Close()
-
-	bytecode, err := state.CompileBytecode(normalScript, "normal_test.lua")
-	if err != nil {
-		t.Fatalf("Failed to compile script: %v", err)
-	}
-
-	// Run and expect success
-	result, err := luaRunner.Run(bytecode, nil, scriptPath)
-	if err != nil {
-		t.Fatalf("Failed to run normal script: %v", err)
-	}
-
-	// Check result
-	if result != "normal module" {
-		t.Errorf("Expected 'normal module', got %v", result)
-	}
 }