From 9a3f6161ce02c59a654cb4e3f2bd7a4e1b730851 Mon Sep 17 00:00:00 2001 From: James Roseborough Date: Mon, 1 Jul 2013 05:51:27 +0000 Subject: [PATCH] Fix pluggable scripting engine lookup, simplify implementation, and add unit tests. --- README.html | 3 +- examples/jse/ScriptEngineSample.java | 11 +- .../org/luaj/vm2/script/LuaScriptEngine.java | 178 ++++++------- src/jse/org/luaj/vm2/script/LuajBindings.java | 211 ---------------- src/jse/org/luaj/vm2/script/LuajContext.java | 17 -- test/junit/org/luaj/vm2/AllTests.java | 7 +- .../luaj/vm2/script/ScriptEngineTests.java | 237 ++++++++++++++++++ 7 files changed, 343 insertions(+), 321 deletions(-) delete mode 100644 src/jse/org/luaj/vm2/script/LuajBindings.java create mode 100644 test/junit/org/luaj/vm2/script/ScriptEngineTests.java diff --git a/README.html b/README.html index 5b15dbd9..2f97658b 100644 --- a/README.html +++ b/README.html @@ -301,7 +301,7 @@ The standard use of JSR-223 scripting engines may be used: 
 	ScriptEngineManager mgr = new ScriptEngineManager();
-	ScriptEngine e = mgr.getEngineByExtension(".lua");
+	ScriptEngine e = mgr.getEngineByName("luaj");
 	e.put("x", 25);
 	e.eval("y = math.sqrt(x)");
 	System.out.println( "y="+e.get("y") );
@@ -846,6 +846,7 @@ Files are no longer hosted at LuaForge.
 
   3.0-beta1
 
diff --git a/examples/jse/ScriptEngineSample.java b/examples/jse/ScriptEngineSample.java
index 5dc75e63..f77ce9c1 100644
--- a/examples/jse/ScriptEngineSample.java
+++ b/examples/jse/ScriptEngineSample.java
@@ -15,8 +15,6 @@ import javax.script.SimpleBindings;
 
 import org.luaj.vm2.LuaValue;
 import org.luaj.vm2.lib.OneArgFunction;
-import org.luaj.vm2.script.LuaScriptEngine;
-import org.luaj.vm2.script.LuajBindings;
 
 public class ScriptEngineSample {
     
@@ -27,8 +25,7 @@ public class ScriptEngineSample {
     	// System.setProperty("luaj.debug", "true");
 
         ScriptEngineManager sem = new ScriptEngineManager();
-        ScriptEngine e = sem.getEngineByExtension(".lua");
-        e = new LuaScriptEngine();
+        ScriptEngine e = sem.getEngineByName("luaj");
         ScriptEngineFactory f = e.getFactory();
 
         // uncomment to enable the lua-to-java bytecode compiler 
@@ -73,8 +70,8 @@ public class ScriptEngineSample {
             System.out.println( "y="+b1.get("y") );
             System.out.println( "y="+b2.get("y") );
             
-            // In Luaj 3.0, client bindings must derive from LuajBindings. 
-            Bindings sb = new LuajBindings();
+            // In Luaj 3.0, client bindings can just be SimpleBindings. 
+            Bindings sb = new SimpleBindings();
             sb.put("x", 2);
             System.out.println( "eval: "+cs.eval(sb) );
 
@@ -134,7 +131,7 @@ public class ScriptEngineSample {
     	testBindings(e, e.createBindings());
     }
     public static void testClientBindings(ScriptEngine e) throws ScriptException {
-    	testBindings(e, new LuajBindings());
+    	testBindings(e, new SimpleBindings());
     }
     public static void testBindings(ScriptEngine e, Bindings b) throws ScriptException {
         CompiledScript cs = ((Compilable)e).compile(
diff --git a/src/jse/org/luaj/vm2/script/LuaScriptEngine.java b/src/jse/org/luaj/vm2/script/LuaScriptEngine.java
index 400d570d..e726caea 100644
--- a/src/jse/org/luaj/vm2/script/LuaScriptEngine.java
+++ b/src/jse/org/luaj/vm2/script/LuaScriptEngine.java
@@ -22,9 +22,13 @@
 package org.luaj.vm2.script;
 
 import java.io.*;
+
 import javax.script.*;
 
 import org.luaj.vm2.*;
+import org.luaj.vm2.lib.ThreeArgFunction;
+import org.luaj.vm2.lib.TwoArgFunction;
+import org.luaj.vm2.lib.jse.CoerceJavaToLua;
 
 /**
  * Implementation of the ScriptEngine interface which can compile and execute
@@ -37,7 +41,7 @@ import org.luaj.vm2.*;
  * and for client bindings use the default engine scoped bindings or
  * construct a {@link LuajBindings} directly.
  */
-public class LuaScriptEngine implements ScriptEngine, Compilable {
+public class LuaScriptEngine extends AbstractScriptEngine implements ScriptEngine, Compilable {
     
 	private static final String __ENGINE_VERSION__   = Lua._VERSION;
     private static final String __NAME__             = "Luaj";
@@ -67,74 +71,16 @@ public class LuaScriptEngine implements ScriptEngine, Compilable {
         put(NAME, __SHORT_NAME__);
         put("THREADING", null);
     }
-    
-    public Object eval(String script) throws ScriptException {
-        return eval(new StringReader(script));
-    }
-    
-    public Object eval(String script, ScriptContext context) throws ScriptException {
-    	return eval(new StringReader(script), context);
-    }
-    
-    public Object eval(String script, Bindings bindings) throws ScriptException {
-        return eval(new StringReader(script), bindings);
-    }
-    
-    public Object eval(Reader reader) throws ScriptException {
-        return compile(reader).eval();
-    }
-    
-    public Object eval(Reader reader, ScriptContext scriptContext) throws ScriptException {
-    	return compile(reader).eval(scriptContext);
-    }
-    
-    public Object eval(Reader reader, Bindings bindings) throws ScriptException {
-    	return compile(reader).eval(bindings);
-    }
-    
-    public void put(String key, Object value) {
-		Bindings b = getBindings(ScriptContext.ENGINE_SCOPE);
-		b.put(key, value);
-    }
-    
-    public Object get(String key) {
-		Bindings b = getBindings(ScriptContext.ENGINE_SCOPE);
-		return b.get(key);
-    }
-
-    public Bindings getBindings(int scope) {
-        return getContext().getBindings(scope);
-    }
-    
-    public void setBindings(Bindings bindings, int scope) {
-        getContext().setBindings(bindings, scope);
-    }
-    
-    public Bindings createBindings() {
-        return new LuajBindings();
-    }
-    
-    public ScriptContext getContext() {
-        return context;
-    }
-    
-    public void setContext(ScriptContext context) {
-		if (!(context instanceof LuajContext))
-			throw new IllegalArgumentException("LuaScriptEngine can only be used with LuajScriptContext");
-    	this.context = (LuajContext) context;
-    }
-    
-    public ScriptEngineFactory getFactory() {
-        return myFactory;
-    }
 
+	@Override
 	public CompiledScript compile(String script) throws ScriptException {
 		return compile(new StringReader(script));
 	}
-	
-	public CompiledScript compile(Reader reader) throws ScriptException {
+
+	@Override
+	public CompiledScript compile(Reader script) throws ScriptException {
 		try {
-	    	InputStream is = new Utf8Encoder(reader);
+	    	InputStream is = new Utf8Encoder(script);
 	    	try {
 	    		final Globals g = context.globals;
 	    		final LuaFunction f = LoadState.load(is, "script", "bt", g);
@@ -149,6 +95,29 @@ public class LuaScriptEngine implements ScriptEngine, Compilable {
 		}
 	}
 
+	@Override
+	public Bindings createBindings() {
+		return new SimpleBindings();
+	}
+
+	@Override
+	public Object eval(String script, ScriptContext context)
+			throws ScriptException {
+		return eval(new StringReader(script), context);
+	}
+
+	@Override
+	public Object eval(Reader reader, ScriptContext context)
+			throws ScriptException {
+        return compile(reader).eval();
+	}
+
+	@Override
+	public ScriptEngineFactory getFactory() {
+		return myFactory;
+	}
+
+
 	class LuajCompiledScript extends CompiledScript {
 		final LuaFunction function;
 		final Globals compiling_globals;
@@ -166,31 +135,25 @@ public class LuaScriptEngine implements ScriptEngine, Compilable {
 	    }
 	    
 	    public Object eval(Bindings bindings) throws ScriptException {
-	    	ScriptContext c = getContext();
-	        Bindings current = c.getBindings(ScriptContext.ENGINE_SCOPE);
-	        try {
-		        c.setBindings(bindings, ScriptContext.ENGINE_SCOPE);
-		        Object result = eval(c);
-		        return result;
-	        } finally {
-		        c.setBindings(current, ScriptContext.ENGINE_SCOPE);
-	        }
+	    	return eval(((LuajContext) getContext()).globals, bindings);
 	    }
 
 	    public Object eval(ScriptContext context) throws ScriptException {
-			Globals g = ((LuajContext) context).globals;
+	    	return eval(((LuajContext) context).globals, context.getBindings(ScriptContext.ENGINE_SCOPE));
+		}
+	    
+	    private Object eval(Globals g, Bindings b) throws ScriptException {
+	    	g.setmetatable(new BindingsMetatable(b));
 			LuaFunction f = function;
-			if (g != compiling_globals) {
-				if (f.isclosure())
-					f = new LuaClosure(f.checkclosure().p, g);
-				else {
-					try {
-						f = f.getClass().newInstance();
-					} catch (Exception e) {
-						throw new ScriptException(e);
-					}
-					f.initupvalue1(g);
+			if (f.isclosure())
+				f = new LuaClosure(f.checkclosure().p, g);
+			else {
+				try {
+					f = f.getClass().newInstance();
+				} catch (Exception e) {
+					throw new ScriptException(e);
 				}
+				f.initupvalue1(g);
 			}
 			return f.invoke(LuaValue.NONE);
 		}
@@ -224,4 +187,51 @@ public class LuaScriptEngine implements ScriptEngine, Compilable {
 			}
 		}
 	}
+	
+	static class BindingsMetatable extends LuaTable {
+
+		BindingsMetatable(final Bindings bindings) {
+			this.rawset(LuaValue.INDEX, new TwoArgFunction() {
+				public LuaValue call(LuaValue table, LuaValue key) {
+					if (key.isstring()) 
+						return toLua(bindings.get(key.tojstring()));
+					else
+						return this.rawget(key);
+				}
+			});
+			this.rawset(LuaValue.NEWINDEX, new ThreeArgFunction() {
+				public LuaValue call(LuaValue table, LuaValue key, LuaValue value) {
+					if (key.isstring()) {
+						final String k = key.tojstring();
+						final Object v = toJava(value);
+						if (v == null)
+							bindings.remove(k);
+						else
+							bindings.put(k, v);
+					} else {
+						this.rawset(key, value);
+					}
+					return LuaValue.NONE;
+				}
+			});
+		}
+		
+		static private Object toJava(LuaValue luajValue) {
+			switch ( luajValue.type() ) {
+			case LuaValue.TNIL: return null;
+			case LuaValue.TSTRING: return luajValue.tojstring();
+			case LuaValue.TUSERDATA: return luajValue.checkuserdata(Object.class);
+			case LuaValue.TNUMBER: return luajValue.isinttype()? 
+					(Object) new Integer(luajValue.toint()): 
+					(Object) new Double(luajValue.todouble());
+			default: return luajValue;
+			}
+		}
+
+		static private LuaValue toLua(Object javaValue) {
+			return javaValue == null? LuaValue.NIL:
+				javaValue instanceof LuaValue? (LuaValue) javaValue:
+				CoerceJavaToLua.coerce(javaValue);
+		}
+	}
 }
diff --git a/src/jse/org/luaj/vm2/script/LuajBindings.java b/src/jse/org/luaj/vm2/script/LuajBindings.java
deleted file mode 100644
index fe262c5b..00000000
--- a/src/jse/org/luaj/vm2/script/LuajBindings.java
+++ /dev/null
@@ -1,211 +0,0 @@
-/*******************************************************************************
-* Copyright (c) 2013 LuaJ. All rights reserved.
-*
-* Permission is hereby granted, free of charge, to any person obtaining a copy
-* of this software and associated documentation files (the "Software"), to deal
-* in the Software without restriction, including without limitation the rights
-* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-* copies of the Software, and to permit persons to whom the Software is
-* furnished to do so, subject to the following conditions:
-*
-* The above copyright notice and this permission notice shall be included in
-* all copies or substantial portions of the Software.
-* 
-* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
-* THE SOFTWARE.
-******************************************************************************/
-
-package org.luaj.vm2.script;
-
-import java.util.ArrayList;
-import java.util.Collection;
-import java.util.HashMap;
-import java.util.HashSet;
-import java.util.List;
-import java.util.Map;
-import java.util.Set;
-
-import javax.script.Bindings;
-
-import org.luaj.vm2.LuaTable;
-import org.luaj.vm2.LuaValue;
-import org.luaj.vm2.lib.ThreeArgFunction;
-import org.luaj.vm2.lib.jse.CoerceJavaToLua;
-
-/**
- * Implementation of Bindings that may be used with Luaj ScriptEngine implementaiton.
- * 
- * 

- * Normally this will not be created directly, but instead will be created fro the script
- * engine using something like:
- * 
- *       ScriptEngineManager manager = new ScriptEngineManager();
- *       ScriptEngine engine = manager.getEngineByExtension(".lua");
- *       Bindings luaj_bindings = engine.createBindings();
- * 

- * 
- * 

- * Each instance of LuajBindings holds its own global state.  
- * Calls to get(), put(), and so on will coerce the lua values
- * into Java values on-the-fly, so that any performance or 
- * memory occur at that point.
- * 
- * 

- * Only Java String keys may be used for get(), put(), and similar
- * operations, or ClassCastException will be thrown. 
- * 
- * 

- * When iterating over the globals, only values which have string keys
- * will be returned.
- */
-public class LuajBindings implements Bindings {
-
-	/** Values that are in these bindings.  This table is linked to the metatable
-	 * of the context when it is executed via the metatable.
-	 */
-	public final LuaTable env;
-
-	/** Metatable to be used on bindings that will forards gets and sets into our table of bindings.
-	 */
-	final LuaTable metatable;
-	
-	/** Construct an empty LuajBindings.
-	 * 

-	 * Each LuajBindings has its own environment table, which will 
-	 * delegate to the context on global reads during execution.
-	 */
-	public LuajBindings() {
-		env = new LuaTable();
-		metatable = new LuaTable();
-		metatable.set(LuaValue.INDEX, env);
-		metatable.set(LuaValue.NEWINDEX, new ThreeArgFunction() {
-			public LuaValue call(LuaValue table, LuaValue key, LuaValue value) {
-				env.rawset(key, value);
-				return LuaValue.NONE;
-			}
-		});
-	}
-	
-	/** Coerce a value from luaj types to Java types.
-	 * @param luajValue any value that derives from LuaValue.
-	 * @return If luajValue is: 
-	 *  {@link #NIL}, null; 
-	 *  {@link #LuaString}: String; 
-	 *  {@link #LuaUserdata}: Object; 
-	 *  {@link #LuaNumber}: Integer or Double; 
-	 *  otherwise: the raw {@link #LuaValue}.
-	 */
-	public Object toJava(LuaValue luajValue) {
-		switch ( luajValue.type() ) {
-		case LuaValue.TNIL: return null;
-		case LuaValue.TSTRING: return luajValue.tojstring();
-		case LuaValue.TUSERDATA: return luajValue.checkuserdata(Object.class);
-		case LuaValue.TNUMBER: return luajValue.isinttype()? 
-				(Object) new Integer(luajValue.toint()): 
-				(Object) new Double(luajValue.todouble());
-		default: return luajValue;
-		}
-	}
-
-	/** Coerce a value from Java types to luaj types.
-	 * @param javaValue  Any Java value, including possibly null.
-	 * @return LuaValue for this Java Value. If javaValue is 
-	 *  null: {@link #NIL}; 
-	 *  {@link #LuaValue}: the value; 
-	 *  String: {@link #LuaString}; 
-	 *  Integer: {@link #LuaInteger}; 
-	 *  Double: {@link #LuaDouble}; 
-	 *  array: {@link #LuaTable} containing list of values;
-	 *  otherwise  {@link #LuaUserdata} from behavior of {@link CoerceJavaToLua.coerce(Object)}
-	 * @see CoerceJavaToLua
-	 */
-	public LuaValue toLua(Object javaValue) {
-		return javaValue == null? LuaValue.NIL:
-			javaValue instanceof LuaValue? (LuaValue) javaValue:
-			CoerceJavaToLua.coerce(javaValue);
-	}
-
-	@Override
-	public void clear() {
-		for (LuaValue key : env.keys())
-			env.rawset(key,  LuaValue.NIL);
-	}
-
-	@Override
-	public boolean containsValue(Object string_key) {
-		return !env.rawget((String)string_key).isnil();
-	}
-
-	@Override
-	public Set> entrySet() {
-		HashMap map = new HashMap();
-		for (LuaValue key : env.keys())
-			if (key.type() == LuaValue.TSTRING)
-				map.put(key.tojstring(), toJava(env.rawget(key)));
-		return map.entrySet();
-	}
-
-	@Override
-	public boolean isEmpty() {
-		return keySet().isEmpty();
-	}
-
-	@Override
-	public Set keySet() {
-		Set set = new HashSet();
-		for (LuaValue key : env.keys())
-			if (key.type() == LuaValue.TSTRING)
-				set.add(key.tojstring());
-		return set;
-	}
-
-	@Override
-	public int size() {
-		return keySet().size();
-	}
-
-	@Override
-	public Collection values() {
-		List values = new ArrayList();
-		for (LuaValue key : env.keys())
-			if (key.type() == LuaValue.TSTRING)
-				values.add(toJava(env.rawget(key)));
-		return values;
-	}
-
-	@Override
-	public boolean containsKey(Object key) {
-		return keySet().contains(key);
-	}
-
-	@Override
-	public Object get(Object string_key) {
-		return toJava(env.rawget((String)string_key));
-	}
-
-	@Override
-	public Object put(String string_key, Object java_value) {
-		Object previous = get(string_key);
-		env.rawset((String)string_key, toLua(java_value));
-		return previous;
-	}
-
-	@Override
-	public void putAll(Map values) {
-		for (java.util.Map.Entry e : values.entrySet())
-			env.rawset(e.getKey(), toLua(e.getValue()));
-	}
-
-	@Override
-	public Object remove(Object string_key) {
-		Object previous = get(string_key);
-		env.rawset((String)string_key, LuaValue.NIL);
-		return previous;
-	}
-
-}
diff --git a/src/jse/org/luaj/vm2/script/LuajContext.java b/src/jse/org/luaj/vm2/script/LuajContext.java
index ab7d1bdf..1b940987 100644
--- a/src/jse/org/luaj/vm2/script/LuajContext.java
+++ b/src/jse/org/luaj/vm2/script/LuajContext.java
@@ -83,22 +83,6 @@ public class LuajContext extends SimpleScriptContext implements ScriptContext {
     	stderr = globals.STDERR;
 	}
 	
-	public Bindings getBindings(int scope) {
-		if (scope != ScriptContext.ENGINE_SCOPE)
-			throw new IllegalArgumentException("LuajScriptContext only supports ENGINE_SCOPE");
-		return super.getBindings(ENGINE_SCOPE);
-	}
-
-	public void setBindings(Bindings bindings, int scope) {
-		if (!(bindings instanceof LuajBindings))
-			throw new IllegalArgumentException("LuajScriptContext can only be used with LuajBindings");
-		if (scope != ScriptContext.ENGINE_SCOPE)
-			throw new IllegalArgumentException("LuajScriptContext only supports ENGINE_SCOPE");
-		LuajBindings luaj_bindings = (LuajBindings) bindings;
-		globals.setmetatable(luaj_bindings.metatable);
-		super.setBindings(bindings, scope);
-	}
-
 	@Override
 	public void setErrorWriter(Writer writer) {
 		globals.STDERR = writer != null?
@@ -139,5 +123,4 @@ public class LuajContext extends SimpleScriptContext implements ScriptContext {
 			return r.read();
 		}
 	}
-
 }
diff --git a/test/junit/org/luaj/vm2/AllTests.java b/test/junit/org/luaj/vm2/AllTests.java
index 1abf3cb5..6fee66b8 100644
--- a/test/junit/org/luaj/vm2/AllTests.java
+++ b/test/junit/org/luaj/vm2/AllTests.java
@@ -35,6 +35,7 @@ import org.luaj.vm2.compiler.SimpleTests;
 import org.luaj.vm2.lib.jse.LuaJavaCoercionTest;
 import org.luaj.vm2.lib.jse.LuajavaAccessibleMembersTest;
 import org.luaj.vm2.lib.jse.LuajavaClassMembersTest;
+import org.luaj.vm2.script.ScriptEngineTests;
 
 public class AllTests {
 
@@ -82,10 +83,14 @@ public class AllTests {
 		lib.addTestSuite(LuaJavaCoercionTest.class);
 		lib.addTestSuite(RequireClassTest.class);
 		suite.addTest(lib);
+
+		// Script engine tests.
+		TestSuite script = ScriptEngineTests.suite();
+		suite.addTest(script);
 		
 		// compatiblity tests
 		TestSuite compat = CompatibiltyTest.suite();
-		suite.addTest( compat );
+		suite.addTest(compat);
 		compat.addTestSuite(ErrorsTest.class);
 		
 		return suite;
diff --git a/test/junit/org/luaj/vm2/script/ScriptEngineTests.java b/test/junit/org/luaj/vm2/script/ScriptEngineTests.java
new file mode 100644
index 00000000..60618dc1
--- /dev/null
+++ b/test/junit/org/luaj/vm2/script/ScriptEngineTests.java
@@ -0,0 +1,237 @@
+/*******************************************************************************
+ * Copyright (c) 2013 Luaj.org. All rights reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ ******************************************************************************/
+package org.luaj.vm2.script;
+
+import java.io.CharArrayReader;
+import java.io.CharArrayWriter;
+import java.io.Reader;
+
+import javax.script.Bindings;
+import javax.script.Compilable;
+import javax.script.CompiledScript;
+import javax.script.ScriptEngine;
+import javax.script.ScriptEngineFactory;
+import javax.script.ScriptEngineManager;
+import javax.script.ScriptException;
+import javax.script.SimpleBindings;
+
+import junit.framework.TestCase;
+import junit.framework.TestSuite;
+
+import org.luaj.vm2.LuaFunction;
+import org.luaj.vm2.LuaValue;
+import org.luaj.vm2.lib.OneArgFunction;
+
+public class ScriptEngineTests extends TestSuite  {
+
+	public static TestSuite suite() {
+		TestSuite suite = new TestSuite("Script Engine Tests");
+		suite.addTest( new TestSuite( LookupEngineTestCase.class,   "Lookup Engine" ) );
+		suite.addTest( new TestSuite( SimpleBindingsTest.class,   "Simple Bindings" ) );
+		suite.addTest( new TestSuite( DefaultBindingsTest.class,   "Default Bindings" ) );
+		suite.addTest( new TestSuite( LuaJCBindingsTest.class,   "LuaJC Bindings" ) );
+		return suite;
+	}
+	
+	public static class LookupEngineTestCase extends TestCase {	
+		public void testGetEngineByExtension() {
+	        ScriptEngine e = new ScriptEngineManager().getEngineByExtension(".lua");
+	        assertNotNull(e);
+	        assertEquals(LuaScriptEngine.class, e.getClass());
+		}
+		public void testGetEngineByName() {
+	        ScriptEngine e = new ScriptEngineManager().getEngineByName("luaj");
+	        assertNotNull(e);
+	        assertEquals(LuaScriptEngine.class, e.getClass());
+		}
+		public void testGetEngineByMimeType() {
+	        ScriptEngine e = new ScriptEngineManager().getEngineByMimeType("text/lua");
+	        assertNotNull(e);
+	        assertEquals(LuaScriptEngine.class, e.getClass());
+		}
+		public void testFactoryMetadata() {
+	        ScriptEngine e = new ScriptEngineManager().getEngineByName("luaj");
+	        ScriptEngineFactory f = e.getFactory();
+	        assertEquals("Luaj", f.getEngineName());
+	        assertEquals("Luaj 0.0", f.getEngineVersion());
+	        assertEquals("lua", f.getLanguageName());
+	        assertEquals("5.2", f.getLanguageVersion());
+		}
+	}
+	
+	public static class SimpleBindingsTest extends EngineTestCase {
+		protected Bindings createBindings() {
+			return new SimpleBindings();
+		}
+		public void testCompiledFunctionIsClosure() throws ScriptException {
+            CompiledScript cs = ((Compilable)e).compile("return 'foo'");
+            assertTrue(((LuaScriptEngine.LuajCompiledScript)cs).function.isclosure());
+		}
+	}
+	
+	public static class DefaultBindingsTest extends EngineTestCase {
+		protected Bindings createBindings() {
+			return e.createBindings();
+		}
+	}
+
+	public static class LuaJCBindingsTest extends EngineTestCase {
+		protected Bindings createBindings() {
+			return new SimpleBindings();
+		}
+		public void setUp() {
+			super.setUp();
+		    org.luaj.vm2.luajc.LuaJC.install();
+		}
+		public void testCompiledFunctionIsNotClosure() throws ScriptException {
+            CompiledScript cs = ((Compilable)e).compile("return 'foo'");
+            assertFalse(((LuaScriptEngine.LuajCompiledScript)cs).function.isclosure());
+		}
+	}
+
+	abstract public static class EngineTestCase extends TestCase {	
+		protected ScriptEngine e;
+		protected Bindings b;
+		abstract protected Bindings createBindings();
+		public void setUp() {
+	       	this.e = new ScriptEngineManager().getEngineByName("luaj");
+			this.b = createBindings();
+		}
+		public void testSqrtIntResult() throws ScriptException {
+            e.put("x", 25);
+            e.eval("y = math.sqrt(x)");
+            Object y = e.get("y");
+            assertEquals(5, y);
+		}
+		public void testOneArgFunction() throws ScriptException {
+            e.put("x", 25);
+            e.eval("y = math.sqrt(x)");
+            Object y = e.get("y");
+            assertEquals(5, y);
+            e.put("f", new OneArgFunction() {
+ 				public LuaValue call(LuaValue arg) {
+ 					return LuaValue.valueOf(arg.toString()+"123");
+ 				}
+             });
+            Object r = e.eval("return f('abc')");
+            assertEquals("abc123", r.toString());
+		}
+		public void testCompiledScript() throws ScriptException {
+            CompiledScript cs = ((Compilable)e).compile("y = math.sqrt(x); return y");
+            b.put("x", 144);
+            assertEquals("12", cs.eval(b).toString());
+		}
+		public void testBuggyLuaScript() {
+	        try {
+	        	e.eval("\n\nbuggy lua code\n\n");
+	        } catch ( ScriptException se ) {
+	        	assertEquals("eval threw javax.script.ScriptException: [string \"script\"]:3: syntax error", se.getMessage());
+	        	return;
+	        }
+	        fail("buggy script did not throw ScriptException as expected.");
+		}
+		public void testScriptRedirection() throws ScriptException {
+            Reader input = new CharArrayReader("abcdefg\nhijk".toCharArray());
+            CharArrayWriter output = new CharArrayWriter();
+            CharArrayWriter errors = new CharArrayWriter();
+            String script = 
+            		"print(\"string written using 'print'\")\n" +
+            		"io.write(\"string written using 'io.write()'\\n\")\n" +
+            		"io.stdout:write(\"string written using 'io.stdout:write()'\\n\")\n" +
+            		"io.stderr:write(\"string written using 'io.stderr:write()'\\n\")\n" +
+            		"io.write([[string read using 'io.stdin:read(\"*l\")':]]..io.stdin:read(\"*l\")..\"\\n\")\n";
+
+            // Evaluate script with redirection set
+            e.getContext().setReader(input);
+            e.getContext().setWriter(output);
+            e.getContext().setErrorWriter(errors);
+            e.eval(script);
+            final String expectedOutput = "string written using 'print'\n"+
+            		"string written using 'io.write()'\n"+
+            		"string written using 'io.stdout:write()'\n"+
+            		"string read using 'io.stdin:read(\"*l\")':abcdefg\n";
+            assertEquals(expectedOutput, output.toString());
+            final String expectedErrors = "string written using 'io.stderr:write()'\n";
+            assertEquals(expectedErrors, errors.toString());
+
+            // Evaluate script with redirection reset
+            output.reset();
+            errors.reset();
+            // e.getContext().setReader(null); // This will block if using actual STDIN
+            e.getContext().setWriter(null);
+            e.getContext().setErrorWriter(null);
+            e.eval(script);
+            assertEquals("", output.toString());
+            assertEquals("", errors.toString());			
+		}
+		public void testBindingJavaInt() throws ScriptException {
+	        CompiledScript cs = ((Compilable)e).compile("y = x; return 'x '..type(x)..' '..tostring(x)\n");
+	        b.put("x", 111);
+	        assertEquals("x number 111", cs.eval(b).toString());
+	        assertEquals(111, b.get("y"));
+		}
+		public void testBindingJavaDouble() throws ScriptException {
+	        CompiledScript cs = ((Compilable)e).compile("y = x; return 'x '..type(x)..' '..tostring(x)\n");
+	        b.put("x", 125.125);
+	        assertEquals("x number 125.125", cs.eval(b).toString());
+	        assertEquals(125.125, b.get("y"));
+		}
+		public void testBindingJavaString() throws ScriptException {
+	        CompiledScript cs = ((Compilable)e).compile("y = x; return 'x '..type(x)..' '..tostring(x)\n");
+	        b.put("x", "foo");
+	        assertEquals("x string foo", cs.eval(b).toString());
+	        assertEquals("foo", b.get("y"));
+		}
+		public void testBindingJavaObject() throws ScriptException {
+	        CompiledScript cs = ((Compilable)e).compile("y = x; return 'x '..type(x)..' '..tostring(x)\n");
+	        b.put("x", new SomeUserClass());
+	        assertEquals("x userdata some-user-value", cs.eval(b).toString());
+	        assertEquals(SomeUserClass.class, b.get("y").getClass());
+		}
+		public void testBindingJavaArray() throws ScriptException {
+	        CompiledScript cs = ((Compilable)e).compile("y = x; return 'x '..type(x)..' '..x[1]..' '..x[2]\n");
+	        b.put("x", new int[] { 777, 888 });
+	        assertEquals("x userdata 777 888", cs.eval(b).toString());
+	        assertEquals(int[].class, b.get("y").getClass());
+		}
+		public void testBindingLuaFunction() throws ScriptException {
+	        CompiledScript cs = ((Compilable)e).compile("y = function(x) return 678 + x end; return 'foo'");
+	        assertEquals("foo", cs.eval(b).toString());
+	        assertTrue(b.get("y") instanceof LuaFunction);
+	        assertEquals(LuaValue.valueOf(801), ((LuaFunction) b.get("y")).call(LuaValue.valueOf(123)));
+		}
+	    public void testUserClasses() throws ScriptException {
+	        CompiledScript cs = ((Compilable)e).compile(
+	        		"x = x or luajava.newInstance('java.lang.String', 'test')\n" +
+	        		"return 'x ' ..  type(x) .. ' ' .. tostring(x)\n");
+	        assertEquals("x string test", cs.eval(b).toString());
+	        b.put("x", new SomeUserClass());
+	        assertEquals("x userdata some-user-value", cs.eval(b).toString());
+	    }	
+	}
+
+	public static class SomeUserClass {
+    	public String toString() {
+    		return "some-user-value";
+    	}
+    }
+}