style: test conversions and prune code

example/src/test/java/party/iroiro/luajava/FullCoverageJunkTest.java

@@ -36,7 +36,6 @@ public void fullCoverageJunk() throws NoSuchMethodException {
         Lua54Consts lua54Consts = new Lua54Consts() {};
         LuaJitConsts luaJitConsts = new LuaJitConsts() {};
         LuaJConsts luaJConsts = new LuaJConsts() {};
-        assertNull(JuaAPI.CONSTRUCTOR_WRAPPER.getName(FullCoverageJunkTest.class.getConstructor()));
 
         Lua51 L = new Lua51();
         ImmutableLuaValue.NIL(L);

example/suite/src/main/java/party/iroiro/luajava/LuaScriptSuite.java

@@ -234,6 +234,8 @@ public static class OtherTypes {
         public Override annotation;
         public Runnable intf;
         public Buffer buffer;
+
+        public Object any;
     }
 
     public static abstract class AbstractClass {

example/suite/src/main/java/party/iroiro/luajava/LuaTestSuite.java

@@ -11,6 +11,7 @@
 import java.math.BigInteger;
 import java.nio.Buffer;
 import java.nio.ByteBuffer;
+import java.nio.charset.StandardCharsets;
 import java.util.*;
 import java.util.concurrent.ConcurrentSkipListSet;
 import java.util.concurrent.atomic.AtomicInteger;
@@ -395,10 +396,13 @@ private void testRequire() {
             L.run("assert(1024 == require('party.iroiro.luajava.JavaLibTest.open').getNumber())");
         }
         try (T L = constructor.get()) {
+            L.setExternalLoader(new ClassPathLoader());
             assertThrowsLua(
                     LuaError.RUNTIME,
                     () -> L.require("luajava.wrongLuaFile")
             );
+            L.require("suite.luajava-compat");
+            L.require("suite.empty");
         }
     }
 
@@ -875,14 +879,22 @@ private void testLuaToJavaConversions() {
         for (int i = 0; i < classes.size(); i += 3) {
             for (int j = 0; j < 3; j++) {
                 Object o = L.toObject(-1, classes.get(i + j));
-                assertInstanceOf(classes.get(i + 2), Objects.requireNonNull(o));
+                assertNotNull(o);
+                assertInstanceOf(classes.get(i + 2), o);
                 assertInstanceOf(Number.class, o);
                 assertEquals(127.0, ((Number) Objects.requireNonNull(o)).doubleValue(), 0.000001);
             }
         }
         assertNull(L.toObject(-1, BigDecimal.class));
         L.pop(1);
 
+        L.push("100");
+        assertEquals(STRING, L.type(-1));
+        Object buffer = L.toObject(-1, ByteBuffer.class);
+        assertNotNull(buffer);
+        assertEquals("100", StandardCharsets.UTF_8.decode(assertInstanceOf(ByteBuffer.class, buffer)).toString());
+        L.pop(1);
+
         testToMap(luaNative);
 
         testToList();

example/suite/src/main/java/party/iroiro/luajava/value/LuaValueSuite.java

@@ -51,6 +51,16 @@ public void test() {
         assertEquals(0, L.getTop());
         luaStateTest();
         assertEquals(0, L.getTop());
+        bufferTest();
+        assertEquals(0, L.getTop());
+    }
+
+    private void bufferTest() {
+        ByteBuffer buffer = L.from(100).toBuffer();
+        assertNotNull(buffer);
+        assertEquals(0, buffer.position());
+        assertEquals(3, buffer.remaining());
+        assertEquals("100", StandardCharsets.UTF_8.decode(buffer).toString());
     }
 
     @SuppressWarnings("SuspiciousMethodCalls")
@@ -126,6 +136,8 @@ private void stringTest() {
 
         L.openLibrary("string");
         assertEquals('t', L.require("string").get("byte").call("test", 1)[0].toInteger());
+
+        assertEquals("sss", L.from("sss").toString());
     }
 
     private void luaStateTest() {

example/suite/src/main/resources/suite/otherConvTest.lua

@@ -59,3 +59,13 @@ assert(others.buffer:limit() == 3)
 assert(others.buffer:get(0) == s:byte(1))
 assert(others.buffer:get(1) == s:byte(2))
 assert(others.buffer:get(2) == s:byte(3))
+
+assert(others.any == nil)
+others.any = true
+assert(others.any == true)
+others.any = 1
+assert(others.any == 1)
+others.any = '2'
+assert(others.any == '2')
+others.any = {1, 2, 3}
+others.any = function() end

luaj/src/main/java/party/iroiro/luajava/luaj/LuaJNatives.java

@@ -540,6 +540,10 @@ public long lua_topointer(long ptr, int index) {
     public String lua_tostring(long ptr, int index) {
         LuaJState L = instances.get((int) ptr);
         LuaValue value = L.toLuaValue(index);
+        if (value.isnumber()) {
+            value = value.tostring();
+            L.replace(index, value);
+        }
         return value.tojstring();
     }
 
@@ -997,6 +1001,10 @@ public Object luaJ_tobuffer(long ptr, int index) {
         if (!value.isstring()) {
             return null;
         }
+        if (!(value instanceof LuaString)) {
+            value = value.tostring();
+            L.replace(index, value);
+        }
         byte[] bytes = ((LuaString) value).m_bytes;
         ByteBuffer buffer = ByteBuffer.allocateDirect(bytes.length);
         buffer.put(bytes);

luajava/src/main/java/party/iroiro/luajava/AbstractLua.java

@@ -362,38 +362,11 @@ public boolean toBoolean(int index) {
 
     @Override
     public @Nullable Object toObject(int index, Class<?> type) {
-        Object converted = toObject(index);
-        if (converted == null) {
+        try {
+            return JuaAPI.convertFromLua(this, type, index);
+        } catch (IllegalArgumentException ignored) {
             return null;
-        } else if (type.isAssignableFrom(converted.getClass())) {
-            return converted;
-        } else if (Number.class.isAssignableFrom(converted.getClass())) {
-            Number number = ((Number) converted);
-            if (type == byte.class || type == Byte.class) {
-                return number.byteValue();
-            }
-            if (type == short.class || type == Short.class) {
-                return number.shortValue();
-            }
-            if (type == int.class || type == Integer.class) {
-                return number.intValue();
-            }
-            if (type == long.class || type == Long.class) {
-                return number.longValue();
-            }
-            if (type == float.class || type == Float.class) {
-                return number.floatValue();
-            }
-            if (type == double.class || type == Double.class) {
-                return number.doubleValue();
-            }
-        } else {
-            try {
-                return JuaAPI.convertFromLua(this, type, index);
-            } catch (IllegalArgumentException ignored) {
-            }
         }
-        return null;
     }
 
     @Override
@@ -1108,7 +1081,7 @@ public LuaValue require(String module) throws LuaException {
             }
         }
         LuaValue[] results = req.call(module);
-        return results.length > 0 ? results[0] : fromNull();
+        return results[0];
     }
 
     @Override

luajava/src/main/java/party/iroiro/luajava/JuaAPI.java

@@ -39,6 +39,7 @@
  * Most reflection features on the lua side rely on this class.
  * </p>
  */
+@SuppressWarnings({"Convert2Lambda", "Anonymous2MethodRef"})
 public abstract class JuaAPI {
     /**
      * Allocates a direct buffer whose memory is managed by Java
@@ -928,7 +929,9 @@ private static Constructor<?> matchMethod(Class<?> clazz, String notSignature) {
         }
         Class<?>[] classes = getClasses(notSignature);
         try {
-            return clazz.getConstructor(classes);
+            Constructor<?> constructor = clazz.getConstructor(classes);
+            CONSTRUCTOR_CACHE.put(clazz, notSignature, constructor);
+            return constructor;
         } catch (NoSuchMethodException e) {
             return null;
         }
@@ -944,13 +947,16 @@ private static Constructor<?> matchMethod(Class<?> clazz, String notSignature) {
      */
     @Nullable
     private static Method matchMethod(Class<?> clazz, String name, String notSignature) {
-        Method cached = METHOD_CACHE.get(clazz, name + ",," + notSignature);
+        String key = name + ",," + notSignature;
+        Method cached = METHOD_CACHE.get(clazz, key);
         if (cached != null) {
             return cached;
         }
         Class<?>[] classes = getClasses(notSignature);
         try {
-            return clazz.getMethod(name, classes);
+            Method method = clazz.getMethod(name, classes);
+            METHOD_CACHE.put(clazz, key, method);
+            return method;
         } catch (NoSuchMethodException e) {
             return null;
         }
@@ -976,7 +982,7 @@ public static Object convertFromLua(Lua L, Class<?> clazz, int index)
                 return null;
             }
         } else if (type == Lua.LuaType.BOOLEAN) {
-            if (clazz == boolean.class || clazz == Boolean.class) {
+            if (clazz == boolean.class || clazz.isAssignableFrom(Boolean.class)) {
                 return L.toBoolean(index);
             }
         } else if (type == Lua.LuaType.STRING) {
@@ -1003,8 +1009,13 @@ public static Object convertFromLua(Lua L, Class<?> clazz, int index)
             }
         } else if (type == Lua.LuaType.USERDATA) {
             Object object = L.toJavaObject(index);
-            if (object != null && clazz.isAssignableFrom(object.getClass())) {
-                return object;
+            if (object != null) {
+                if (clazz.isAssignableFrom(object.getClass())) {
+                    return object;
+                }
+                if (Number.class.isAssignableFrom(object.getClass())) {
+                    return convertNumber((Number) object, clazz);
+                }
             }
         } else if (type == Lua.LuaType.TABLE) {
             if (clazz.isAssignableFrom(List.class)) {
@@ -1101,19 +1112,11 @@ public static Class<?>[] getClasses(String notSignature) {
      * since {@code Executable} is not introduced until Java 8.
      */
     interface ExecutableWrapper<T> {
-        @Nullable
-        String getName(T executable);
-
         Class<?>[] getParameterTypes(T executable);
     }
 
     final static ExecutableWrapper<Constructor<?>> CONSTRUCTOR_WRAPPER =
             new ExecutableWrapper<Constructor<?>>() {
-                @Override
-                public @Nullable String getName(Constructor<?> executable) {
-                    return null;
-                }
-
                 @Override
                 public Class<?>[] getParameterTypes(Constructor<?> executable) {
                     return executable.getParameterTypes();
@@ -1122,11 +1125,6 @@ public Class<?>[] getParameterTypes(Constructor<?> executable) {
 
     final static ExecutableWrapper<Method> METHOD_WRAPPER =
             new ExecutableWrapper<Method>() {
-                @Override
-                public String getName(Method executable) {
-                    return executable.getName();
-                }
-
                 @Override
                 public Class<?>[] getParameterTypes(Method executable) {
                     return executable.getParameterTypes();