Support compilation of varargs invocations in SpEL for array subtypes

This commit merges support for compiling SpEL expressions that contain
varargs invocations where the supplied array is a subtype of the
declared varargs array type.

Closes gh-32804

spring-expression/src/main/java/org/springframework/expression/spel/ast/SpelNodeImpl.java

@@ -16,13 +16,13 @@
 
 package org.springframework.expression.spel.ast;
 
-import java.lang.reflect.Constructor;
+import java.lang.reflect.Executable;
 import java.lang.reflect.Member;
-import java.lang.reflect.Method;
 import java.util.function.Supplier;
 
 import org.springframework.asm.MethodVisitor;
 import org.springframework.asm.Opcodes;
+import org.springframework.asm.Type;
 import org.springframework.expression.EvaluationException;
 import org.springframework.expression.TypedValue;
 import org.springframework.expression.common.ExpressionUtils;
@@ -33,7 +33,9 @@ import org.springframework.expression.spel.SpelMessage;
 import org.springframework.expression.spel.SpelNode;
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
+import org.springframework.util.ClassUtils;
 import org.springframework.util.ObjectUtils;
+import org.springframework.util.StringUtils;
 
 /**
  * The common supertype of all AST nodes in a parsed Spring Expression Language
@@ -216,20 +218,37 @@ public abstract class SpelNodeImpl implements SpelNode, Opcodes {
 	 * @param cf the current codeflow
 	 * @param member the method or constructor for which arguments are being set up
 	 * @param arguments the expression nodes for the expression supplied argument values
+	 * @deprecated As of Spring Framework 6.2, in favor of
+	 * {@link #generateCodeForArguments(MethodVisitor, CodeFlow, Executable, SpelNodeImpl[])}
 	 */
+	@Deprecated(since = "6.2")
 	protected static void generateCodeForArguments(MethodVisitor mv, CodeFlow cf, Member member, SpelNodeImpl[] arguments) {
-		String[] paramDescriptors = null;
-		boolean isVarargs = false;
-		if (member instanceof Constructor<?> ctor) {
-			paramDescriptors = CodeFlow.toDescriptors(ctor.getParameterTypes());
-			isVarargs = ctor.isVarArgs();
+		if (member instanceof Executable executable) {
+			generateCodeForArguments(mv, cf, executable, arguments);
 		}
-		else { // Method
-			Method method = (Method)member;
-			paramDescriptors = CodeFlow.toDescriptors(method.getParameterTypes());
-			isVarargs = method.isVarArgs();
-		}
-		if (isVarargs) {
+		throw new IllegalArgumentException(
+				"The supplied member must be an instance of java.lang.reflect.Executable: " + member);
+	}
+
+	/**
+	 * Generate code that handles building the argument values for the specified
+	 * {@link Executable} (method or constructor).
+	 * <p>This method takes into account whether the invoked executable was
+	 * declared to accept varargs, and if it was then the argument values will be
+	 * appropriately packaged into an array.
+	 * @param mv the method visitor where code should be generated
+	 * @param cf the current {@link CodeFlow}
+	 * @param executable the {@link Executable} (method or constructor) for which
+	 * arguments are being set up
+	 * @param arguments the expression nodes for the expression supplied argument
+	 * values
+	 * @since 6.2
+	 */
+	protected static void generateCodeForArguments(MethodVisitor mv, CodeFlow cf, Executable executable, SpelNodeImpl[] arguments) {
+		Class<?>[] parameterTypes = executable.getParameterTypes();
+		String[] paramDescriptors = CodeFlow.toDescriptors(parameterTypes);
+
+		if (executable.isVarArgs()) {
 			// The final parameter may or may not need packaging into an array, or nothing may
 			// have been passed to satisfy the varargs and so something needs to be built.
 			int p = 0; // Current supplied argument being processed
@@ -241,13 +260,18 @@ public abstract class SpelNodeImpl implements SpelNode, Opcodes {
 			}
 
 			SpelNodeImpl lastChild = (childCount == 0 ? null : arguments[childCount - 1]);
-			String arrayType = paramDescriptors[paramDescriptors.length - 1];
+			ClassLoader classLoader = executable.getDeclaringClass().getClassLoader();
+			Class<?> lastChildType = (lastChild != null ?
+					loadClassForExitDescriptor(lastChild.getExitDescriptor(), classLoader) : null);
+			Class<?> lastParameterType = parameterTypes[parameterTypes.length - 1];
+
 			// Determine if the final passed argument is already suitably packaged in array
 			// form to be passed to the method
-			if (lastChild != null && arrayType.equals(lastChild.getExitDescriptor())) {
+			if (lastChild != null && lastChildType != null && lastParameterType.isAssignableFrom(lastChildType)) {
 				cf.generateCodeForArgument(mv, lastChild, paramDescriptors[p]);
 			}
 			else {
+				String arrayType = paramDescriptors[paramDescriptors.length - 1];
 				arrayType = arrayType.substring(1); // trim the leading '[', may leave other '['
 				// build array big enough to hold remaining arguments
 				CodeFlow.insertNewArrayCode(mv, childCount - p, arrayType);
@@ -270,6 +294,19 @@ public abstract class SpelNodeImpl implements SpelNode, Opcodes {
 		}
 	}
 
+	@Nullable
+	private static Class<?> loadClassForExitDescriptor(@Nullable String exitDescriptor, ClassLoader classLoader) {
+		if (!StringUtils.hasText(exitDescriptor)) {
+			return null;
+		}
+		String typeDescriptor = exitDescriptor;
+		if (typeDescriptor.startsWith("[") || typeDescriptor.startsWith("L")) {
+			typeDescriptor += ";";
+		}
+		String className = Type.getType(typeDescriptor).getClassName();
+		return ClassUtils.resolveClassName(className, classLoader);
+	}
+
 	/**
 	 * Ask an argument to generate its bytecode and then follow it up
 	 * with any boxing/unboxing/checkcasting to ensure it matches the expected parameter descriptor.

spring-expression/src/test/java/org/springframework/expression/spel/SpelCompilationCoverageTests.java

@@ -28,8 +28,10 @@ import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
+import java.util.Objects;
 import java.util.Set;
 import java.util.StringTokenizer;
+import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
 import example.Color;
@@ -2267,6 +2269,12 @@ public class SpelCompilationCoverageTests extends AbstractExpressionTests {
 		return a+b;
 	}
 
+	public static String concat2(Object... args) {
+		return Arrays.stream(args)
+				.map(Objects::toString)
+				.collect(Collectors.joining());
+	}
+
 	public static String join(String...strings) {
 		StringBuilder buf = new StringBuilder();
 		for (String string: strings) {
@@ -2277,9 +2285,9 @@ public class SpelCompilationCoverageTests extends AbstractExpressionTests {
 
 	@Test
 	void compiledExpressionShouldWorkWhenUsingCustomFunctionWithVarargs() throws Exception {
-		StandardEvaluationContext context = null;
+		StandardEvaluationContext context;
 
-		// Here the target method takes Object... and we are passing a string
+		// single string argument
 		expression = parser.parseExpression("#doFormat('hey %s', 'there')");
 		context = new StandardEvaluationContext();
 		context.registerFunction("doFormat",
@@ -2287,10 +2295,11 @@ public class SpelCompilationCoverageTests extends AbstractExpressionTests {
 		((SpelExpression) expression).setEvaluationContext(context);
 
 		assertThat(expression.getValue(String.class)).isEqualTo("hey there");
-		assertThat(((SpelNodeImpl) ((SpelExpression) expression).getAST()).isCompilable()).isTrue();
+		assertThat(((SpelExpression) expression).getAST().isCompilable()).isTrue();
 		assertCanCompile(expression);
 		assertThat(expression.getValue(String.class)).isEqualTo("hey there");
 
+		// single string argument from root array access
 		expression = parser.parseExpression("#doFormat([0], 'there')");
 		context = new StandardEvaluationContext(new Object[] {"hey %s"});
 		context.registerFunction("doFormat",
@@ -2298,10 +2307,11 @@ public class SpelCompilationCoverageTests extends AbstractExpressionTests {
 		((SpelExpression) expression).setEvaluationContext(context);
 
 		assertThat(expression.getValue(String.class)).isEqualTo("hey there");
-		assertThat(((SpelNodeImpl) ((SpelExpression) expression).getAST()).isCompilable()).isTrue();
+		assertThat(((SpelExpression) expression).getAST().isCompilable()).isTrue();
 		assertCanCompile(expression);
 		assertThat(expression.getValue(String.class)).isEqualTo("hey there");
 
+		// single string from variable
 		expression = parser.parseExpression("#doFormat([0], #arg)");
 		context = new StandardEvaluationContext(new Object[] {"hey %s"});
 		context.registerFunction("doFormat",
@@ -2310,7 +2320,19 @@ public class SpelCompilationCoverageTests extends AbstractExpressionTests {
 		((SpelExpression) expression).setEvaluationContext(context);
 
 		assertThat(expression.getValue(String.class)).isEqualTo("hey there");
-		assertThat(((SpelNodeImpl) ((SpelExpression) expression).getAST()).isCompilable()).isTrue();
+		assertThat(((SpelExpression) expression).getAST().isCompilable()).isTrue();
+		assertCanCompile(expression);
+		assertThat(expression.getValue(String.class)).isEqualTo("hey there");
+
+		// string array argument
+		expression = parser.parseExpression("#doFormat('hey %s', #arg)");
+		context = new StandardEvaluationContext();
+		context.registerFunction("doFormat",
+				DelegatingStringFormat.class.getDeclaredMethod("format", String.class, Object[].class));
+		context.setVariable("arg", new String[] { "there" });
+		((SpelExpression) expression).setEvaluationContext(context);
+		assertThat(expression.getValue(String.class)).isEqualTo("hey there");
+		assertThat(((SpelExpression) expression).getAST().isCompilable()).isTrue();
 		assertCanCompile(expression);
 		assertThat(expression.getValue(String.class)).isEqualTo("hey there");
 	}
@@ -2319,7 +2341,11 @@ public class SpelCompilationCoverageTests extends AbstractExpressionTests {
 	void functionReference() throws Exception {
 		EvaluationContext ctx = new StandardEvaluationContext();
 		Method m = getClass().getDeclaredMethod("concat", String.class, String.class);
-		ctx.setVariable("concat",m);
+		ctx.setVariable("concat", m);
+		Method m2 = getClass().getDeclaredMethod("concat2", Object[].class);
+		ctx.setVariable("concat2", m2);
+		Method m3 = getClass().getDeclaredMethod("join", String[].class);
+		ctx.setVariable("join", m3);
 
 		expression = parser.parseExpression("#concat('a','b')");
 		assertThat(expression.getValue(ctx)).isEqualTo("ab");
@@ -2331,6 +2357,20 @@ public class SpelCompilationCoverageTests extends AbstractExpressionTests {
 		assertCanCompile(expression);
 		assertThat(expression.getValue(ctx)).isEqualTo('b');
 
+		// varargs
+		expression = parser.parseExpression("#join(#stringArray)");
+		ctx.setVariable("stringArray", new String[] { "a", "b", "c" });
+		assertThat(expression.getValue(ctx)).isEqualTo("abc");
+		assertCanCompile(expression);
+		assertThat(expression.getValue(ctx)).isEqualTo("abc");
+
+		// varargs with argument component type that is a subtype of the varargs component type.
+		expression = parser.parseExpression("#concat2(#stringArray)");
+		ctx.setVariable("stringArray", new String[] { "a", "b", "c" });
+		assertThat(expression.getValue(ctx)).isEqualTo("abc");
+		assertCanCompile(expression);
+		assertThat(expression.getValue(ctx)).isEqualTo("abc");
+
 		expression = parser.parseExpression("#concat(#a,#b)");
 		ctx.setVariable("a", "foo");
 		ctx.setVariable("b", "bar");
@@ -2465,173 +2505,172 @@ public class SpelCompilationCoverageTests extends AbstractExpressionTests {
 
 		expression = parser.parseExpression("#append('a','b','c')");
 		assertThat(expression.getValue(context).toString()).isEqualTo("abc");
-		assertThat(((SpelNodeImpl)((SpelExpression) expression).getAST()).isCompilable()).isTrue();
+		assertThat(((SpelExpression) expression).getAST().isCompilable()).isTrue();
 		assertCanCompile(expression);
 		assertThat(expression.getValue(context).toString()).isEqualTo("abc");
 
 		expression = parser.parseExpression("#append('a')");
 		assertThat(expression.getValue(context).toString()).isEqualTo("a");
-		assertThat(((SpelNodeImpl)((SpelExpression) expression).getAST()).isCompilable()).isTrue();
+		assertThat(((SpelExpression) expression).getAST().isCompilable()).isTrue();
 		assertCanCompile(expression);
 		assertThat(expression.getValue(context).toString()).isEqualTo("a");
 
 		expression = parser.parseExpression("#append()");
 		assertThat(expression.getValue(context).toString()).isEmpty();
-		assertThat(((SpelNodeImpl)((SpelExpression) expression).getAST()).isCompilable()).isTrue();
+		assertThat(((SpelExpression) expression).getAST().isCompilable()).isTrue();
 		assertCanCompile(expression);
 		assertThat(expression.getValue(context).toString()).isEmpty();
 
 		expression = parser.parseExpression("#append(#stringArray)");
 		assertThat(expression.getValue(context).toString()).isEqualTo("xyz");
-		assertThat(((SpelNodeImpl)((SpelExpression) expression).getAST()).isCompilable()).isTrue();
+		assertThat(((SpelExpression) expression).getAST().isCompilable()).isTrue();
 		assertCanCompile(expression);
 		assertThat(expression.getValue(context).toString()).isEqualTo("xyz");
 
 		// This is a methodreference invocation, to compare with functionreference
 		expression = parser.parseExpression("append(#stringArray)");
 		assertThat(expression.getValue(context, new SomeCompareMethod2()).toString()).isEqualTo("xyz");
-		assertThat(((SpelNodeImpl)((SpelExpression) expression).getAST()).isCompilable()).isTrue();
+		assertThat(((SpelExpression) expression).getAST().isCompilable()).isTrue();
 		assertCanCompile(expression);
 		assertThat(expression.getValue(context, new SomeCompareMethod2()).toString()).isEqualTo("xyz");
 
 		expression = parser.parseExpression("#append2('a','b','c')");
 		assertThat(expression.getValue(context).toString()).isEqualTo("abc");
-		assertThat(((SpelNodeImpl)((SpelExpression) expression).getAST()).isCompilable()).isTrue();
+		assertThat(((SpelExpression) expression).getAST().isCompilable()).isTrue();
 		assertCanCompile(expression);
 		assertThat(expression.getValue(context).toString()).isEqualTo("abc");
 
 		expression = parser.parseExpression("append2('a','b')");
 		assertThat(expression.getValue(context, new SomeCompareMethod2()).toString()).isEqualTo("ab");
-		assertThat(((SpelNodeImpl)((SpelExpression) expression).getAST()).isCompilable()).isTrue();
+		assertThat(((SpelExpression) expression).getAST().isCompilable()).isTrue();
 		assertCanCompile(expression);
 		assertThat(expression.getValue(context, new SomeCompareMethod2()).toString()).isEqualTo("ab");
 
 		expression = parser.parseExpression("#append2('a','b')");
 		assertThat(expression.getValue(context).toString()).isEqualTo("ab");
-		assertThat(((SpelNodeImpl)((SpelExpression) expression).getAST()).isCompilable()).isTrue();
+		assertThat(((SpelExpression) expression).getAST().isCompilable()).isTrue();
 		assertCanCompile(expression);
 		assertThat(expression.getValue(context).toString()).isEqualTo("ab");
 
 		expression = parser.parseExpression("#append2()");
 		assertThat(expression.getValue(context).toString()).isEmpty();
-		assertThat(((SpelNodeImpl)((SpelExpression) expression).getAST()).isCompilable()).isTrue();
+		assertThat(((SpelExpression) expression).getAST().isCompilable()).isTrue();
 		assertCanCompile(expression);
 		assertThat(expression.getValue(context).toString()).isEmpty();
 
 		expression = parser.parseExpression("#append3(#stringArray)");
 		assertThat(expression.getValue(context, new SomeCompareMethod2()).toString()).isEqualTo("xyz");
-		assertThat(((SpelNodeImpl)((SpelExpression) expression).getAST()).isCompilable()).isTrue();
+		assertThat(((SpelExpression) expression).getAST().isCompilable()).isTrue();
 		assertCanCompile(expression);
 		assertThat(expression.getValue(context, new SomeCompareMethod2()).toString()).isEqualTo("xyz");
 
-		// TODO Determine why the String[] is passed as the first element of the Object... varargs array instead of the entire varargs array.
-		// expression = parser.parseExpression("#append2(#stringArray)");
-		// assertThat(expression.getValue(context)).hasToString("xyz");
-		// assertThat(((SpelNodeImpl) ((SpelExpression) expression).getAST()).isCompilable()).isTrue();
-		// assertCanCompile(expression);
-		// assertThat(expression.getValue(context)).hasToString("xyz");
+		expression = parser.parseExpression("#append2(#stringArray)");
+		assertThat(expression.getValue(context)).hasToString("xyz");
+		assertThat(((SpelExpression) expression).getAST().isCompilable()).isTrue();
+		assertCanCompile(expression);
+		assertThat(expression.getValue(context)).hasToString("xyz");
 
 		expression = parser.parseExpression("#sum(1,2,3)");
 		assertThat(expression.getValue(context)).isEqualTo(6);
-		assertThat(((SpelNodeImpl)((SpelExpression) expression).getAST()).isCompilable()).isTrue();
+		assertThat(((SpelExpression) expression).getAST().isCompilable()).isTrue();
 		assertCanCompile(expression);
 		assertThat(expression.getValue(context)).isEqualTo(6);
 
 		expression = parser.parseExpression("#sum(2)");
 		assertThat(expression.getValue(context)).isEqualTo(2);
-		assertThat(((SpelNodeImpl)((SpelExpression) expression).getAST()).isCompilable()).isTrue();
+		assertThat(((SpelExpression) expression).getAST().isCompilable()).isTrue();
 		assertCanCompile(expression);
 		assertThat(expression.getValue(context)).isEqualTo(2);
 
 		expression = parser.parseExpression("#sum()");
 		assertThat(expression.getValue(context)).isEqualTo(0);
-		assertThat(((SpelNodeImpl)((SpelExpression) expression).getAST()).isCompilable()).isTrue();
+		assertThat(((SpelExpression) expression).getAST().isCompilable()).isTrue();
 		assertCanCompile(expression);
 		assertThat(expression.getValue(context)).isEqualTo(0);
 
 		expression = parser.parseExpression("#sum(#intArray)");
 		assertThat(expression.getValue(context)).isEqualTo(20);
-		assertThat(((SpelNodeImpl)((SpelExpression) expression).getAST()).isCompilable()).isTrue();
+		assertThat(((SpelExpression) expression).getAST().isCompilable()).isTrue();
 		assertCanCompile(expression);
 		assertThat(expression.getValue(context)).isEqualTo(20);
 
 		expression = parser.parseExpression("#sumDouble(1.0d,2.0d,3.0d)");
 		assertThat(expression.getValue(context)).isEqualTo(6);
-		assertThat(((SpelNodeImpl)((SpelExpression) expression).getAST()).isCompilable()).isTrue();
+		assertThat(((SpelExpression) expression).getAST().isCompilable()).isTrue();
 		assertCanCompile(expression);
 		assertThat(expression.getValue(context)).isEqualTo(6);
 
 		expression = parser.parseExpression("#sumDouble(2.0d)");
 		assertThat(expression.getValue(context)).isEqualTo(2);
-		assertThat(((SpelNodeImpl)((SpelExpression) expression).getAST()).isCompilable()).isTrue();
+		assertThat(((SpelExpression) expression).getAST().isCompilable()).isTrue();
 		assertCanCompile(expression);
 		assertThat(expression.getValue(context)).isEqualTo(2);
 
 		expression = parser.parseExpression("#sumDouble()");
 		assertThat(expression.getValue(context)).isEqualTo(0);
-		assertThat(((SpelNodeImpl)((SpelExpression) expression).getAST()).isCompilable()).isTrue();
+		assertThat(((SpelExpression) expression).getAST().isCompilable()).isTrue();
 		assertCanCompile(expression);
 		assertThat(expression.getValue(context)).isEqualTo(0);
 
 		expression = parser.parseExpression("#sumDouble(#doubleArray)");
 		assertThat(expression.getValue(context)).isEqualTo(20);
-		assertThat(((SpelNodeImpl)((SpelExpression) expression).getAST()).isCompilable()).isTrue();
+		assertThat(((SpelExpression) expression).getAST().isCompilable()).isTrue();
 		assertCanCompile(expression);
 		assertThat(expression.getValue(context)).isEqualTo(20);
 
 		expression = parser.parseExpression("#sumFloat(1.0f,2.0f,3.0f)");
 		assertThat(expression.getValue(context)).isEqualTo(6);
-		assertThat(((SpelNodeImpl)((SpelExpression) expression).getAST()).isCompilable()).isTrue();
+		assertThat(((SpelExpression) expression).getAST().isCompilable()).isTrue();
 		assertCanCompile(expression);
 		assertThat(expression.getValue(context)).isEqualTo(6);
 
 		expression = parser.parseExpression("#sumFloat(2.0f)");
 		assertThat(expression.getValue(context)).isEqualTo(2);
-		assertThat(((SpelNodeImpl)((SpelExpression) expression).getAST()).isCompilable()).isTrue();
+		assertThat(((SpelExpression) expression).getAST().isCompilable()).isTrue();
 		assertCanCompile(expression);
 		assertThat(expression.getValue(context)).isEqualTo(2);
 
 		expression = parser.parseExpression("#sumFloat()");
 		assertThat(expression.getValue(context)).isEqualTo(0);
-		assertThat(((SpelNodeImpl)((SpelExpression) expression).getAST()).isCompilable()).isTrue();
+		assertThat(((SpelExpression) expression).getAST().isCompilable()).isTrue();
 		assertCanCompile(expression);
 		assertThat(expression.getValue(context)).isEqualTo(0);
 
 		expression = parser.parseExpression("#sumFloat(#floatArray)");
 		assertThat(expression.getValue(context)).isEqualTo(20);
-		assertThat(((SpelNodeImpl)((SpelExpression) expression).getAST()).isCompilable()).isTrue();
+		assertThat(((SpelExpression) expression).getAST().isCompilable()).isTrue();
 		assertCanCompile(expression);
 		assertThat(expression.getValue(context)).isEqualTo(20);
 
 
 		expression = parser.parseExpression("#appendChar('abc'.charAt(0),'abc'.charAt(1))");
 		assertThat(expression.getValue(context)).isEqualTo("ab");
-		assertThat(((SpelNodeImpl)((SpelExpression) expression).getAST()).isCompilable()).isTrue();
+		assertThat(((SpelExpression) expression).getAST().isCompilable()).isTrue();
 		assertCanCompile(expression);
 		assertThat(expression.getValue(context)).isEqualTo("ab");
 
 
 		expression = parser.parseExpression("#append4('a','b','c')");
 		assertThat(expression.getValue(context).toString()).isEqualTo("a::bc");
-		assertThat(((SpelNodeImpl)((SpelExpression) expression).getAST()).isCompilable()).isTrue();
+		assertThat(((SpelExpression) expression).getAST().isCompilable()).isTrue();
 		assertCanCompile(expression);
 		assertThat(expression.getValue(context).toString()).isEqualTo("a::bc");
 
 		expression = parser.parseExpression("#append4('a','b')");
 		assertThat(expression.getValue(context).toString()).isEqualTo("a::b");
-		assertThat(((SpelNodeImpl)((SpelExpression) expression).getAST()).isCompilable()).isTrue();
+		assertThat(((SpelExpression) expression).getAST().isCompilable()).isTrue();
 		assertCanCompile(expression);
 		assertThat(expression.getValue(context).toString()).isEqualTo("a::b");
 
 		expression = parser.parseExpression("#append4('a')");
 		assertThat(expression.getValue(context).toString()).isEqualTo("a::");
-		assertThat(((SpelNodeImpl)((SpelExpression) expression).getAST()).isCompilable()).isTrue();
+		assertThat(((SpelExpression) expression).getAST().isCompilable()).isTrue();
 		assertCanCompile(expression);
 		assertThat(expression.getValue(context).toString()).isEqualTo("a::");
 
 		expression = parser.parseExpression("#append4('a',#stringArray)");
 		assertThat(expression.getValue(context).toString()).isEqualTo("a::xyz");
-		assertThat(((SpelNodeImpl)((SpelExpression) expression).getAST()).isCompilable()).isTrue();
+		assertThat(((SpelExpression) expression).getAST().isCompilable()).isTrue();
 		assertCanCompile(expression);
 		assertThat(expression.getValue(context).toString()).isEqualTo("a::xyz");
 	}
@@ -4878,6 +4917,28 @@ public class SpelCompilationCoverageTests extends AbstractExpressionTests {
 		tc8 = (TestClass8) o;
 		assertThat(tc8.i).isEqualTo(42);
 
+		// varargs
+		expression = parser.parseExpression("new " + testclass8 + "(#root)");
+		Object[] objectArray = { "a", "b", "c" };
+		o = expression.getValue(objectArray);
+		assertThat(o).isExactlyInstanceOf(TestClass8.class);
+		assertCanCompile(expression);
+		o = expression.getValue(objectArray);
+		assertThat(o).isExactlyInstanceOf(TestClass8.class);
+		tc8 = (TestClass8) o;
+		assertThat(tc8.args).containsExactly("a", "b", "c");
+
+		// varargs with argument component type that is a subtype of the varargs component type.
+		expression = parser.parseExpression("new " + testclass8 + "(#root)");
+		String[] stringArray = { "a", "b", "c" };
+		o = expression.getValue(stringArray);
+		assertThat(o).isExactlyInstanceOf(TestClass8.class);
+		assertCanCompile(expression);
+		o = expression.getValue(stringArray);
+		assertThat(o).isExactlyInstanceOf(TestClass8.class);
+		tc8 = (TestClass8) o;
+		assertThat(tc8.args).containsExactly("a", "b", "c");
+
 		// private class, can't compile it
 		String testclass9 = "org.springframework.expression.spel.SpelCompilationCoverageTests$TestClass9";
 		expression = parser.parseExpression("new " + testclass9 + "(42)");
@@ -4984,6 +5045,7 @@ public class SpelCompilationCoverageTests extends AbstractExpressionTests {
 		assertThat(tc.s).isEqualTo("aaabbbccc");
 		tc.reset();
 
+		// varargs object
 		expression = parser.parseExpression("sixteen('aaa','bbb','ccc')");
 		assertCannotCompile(expression);
 		expression.getValue(tc);
@@ -4994,27 +5056,38 @@ public class SpelCompilationCoverageTests extends AbstractExpressionTests {
 		assertThat(tc.s).isEqualTo("aaabbbccc");
 		tc.reset();
 
+		// string array from property in varargs object
 		expression = parser.parseExpression("sixteen(seventeen)");
 		assertCannotCompile(expression);
 		expression.getValue(tc);
 		assertThat(tc.s).isEqualTo("aaabbbccc");
 		assertCanCompile(expression);
 		tc.reset();
-		// see TODO below
-		// expression.getValue(tc);
-		// assertThat(tc.s).isEqualTo("aaabbbccc");
-		// tc.reset();
-
-		// TODO Determine why the String[] is passed as the first element of the Object... varargs array instead of the entire varargs array.
-		// expression = parser.parseExpression("sixteen(stringArray)");
-		// assertCannotCompile(expression);
-		// expression.getValue(tc);
-		// assertThat(tc.s).isEqualTo("aaabbbccc");
-		// assertCanCompile(expression);
-		// tc.reset();
-		// expression.getValue(tc);
-		// assertThat(tc.s).isEqualTo("aaabbbccc");
-		// tc.reset();
+		expression.getValue(tc);
+		assertThat(tc.s).isEqualTo("aaabbbccc");
+		tc.reset();
+
+		// string array from variable in varargs object
+		expression = parser.parseExpression("sixteen(stringArray)");
+		assertCannotCompile(expression);
+		expression.getValue(tc);
+		assertThat(tc.s).isEqualTo("aaabbbccc");
+		assertCanCompile(expression);
+		tc.reset();
+		expression.getValue(tc);
+		assertThat(tc.s).isEqualTo("aaabbbccc");
+		tc.reset();
+
+		// string array in varargs object with other parameter
+		expression = parser.parseExpression("eighteen('AAA', stringArray)");
+		assertCannotCompile(expression);
+		expression.getValue(tc);
+		assertThat(tc.s).isEqualTo("AAA::aaabbbccc");
+		assertCanCompile(expression);
+		tc.reset();
+		expression.getValue(tc);
+		assertThat(tc.s).isEqualTo("AAA::aaabbbccc");
+		tc.reset();
 
 		// varargs int
 		expression = parser.parseExpression("twelve(1,2,3)");
@@ -6863,6 +6936,18 @@ public class SpelCompilationCoverageTests extends AbstractExpressionTests {
 		public String[] seventeen() {
 			return new String[] { "aaa", "bbb", "ccc" };
 		}
+
+		public void eighteen(String a, Object... vargs) {
+			if (vargs == null) {
+				s = a + "::";
+			}
+			else {
+				s = a + "::";
+				for (Object varg: vargs) {
+					s += varg;
+				}
+			}
+		}
 	}
 
 
@@ -6911,6 +6996,7 @@ public class SpelCompilationCoverageTests extends AbstractExpressionTests {
 		public String s;
 		public double d;
 		public boolean z;
+		public Object[] args;
 
 		public TestClass8(int i, String s, double d, boolean z) {
 			this.i = i;
@@ -6926,6 +7012,10 @@ public class SpelCompilationCoverageTests extends AbstractExpressionTests {
 			this.i = i;
 		}
 
+		public TestClass8(Object... args) {
+			this.args = args;
+		}
+
 		@SuppressWarnings("unused")
 		private TestClass8(String a, String b) {
 			this.s = a+b;