Merge branch '6.1.x'

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

Author: sbrannen

spring-expression/src/main/java/org/springframework/expression/spel/support/ReflectionHelper.java

@@ -448,24 +448,29 @@ private static boolean isFirstEntryInArray(Object value, @Nullable Object possib
 	}
 
 	/**
-	 * Package up the arguments so that they correctly match what is expected in requiredParameterTypes.
-	 * <p>For example, if requiredParameterTypes is {@code (int, String[])} because the second parameter
-	 * was declared {@code String...}, then if arguments is {@code [1,"a","b"]} then it must be
-	 * repackaged as {@code [1,new String[]{"a","b"}]} in order to match the expected types.
+	 * Package up the supplied {@code args} so that they correctly match what is
+	 * expected in {@code requiredParameterTypes}.
+	 * <p>For example, if {@code requiredParameterTypes} is {@code (int, String[])}
+	 * because the second parameter was declared as {@code String...}, then if
+	 * {@code args} is {@code [1, "a", "b"]} it must be repackaged as
+	 * {@code [1, new String[] {"a", "b"}]} in order to match the expected types.
 	 * @param requiredParameterTypes the types of the parameters for the invocation
-	 * @param args the arguments to be setup ready for the invocation
-	 * @return a repackaged array of arguments where any varargs setup has been done
+	 * @param args the arguments to be set up for the invocation
+	 * @return a repackaged array of arguments where any varargs setup has performed
 	 */
 	public static Object[] setupArgumentsForVarargsInvocation(Class<?>[] requiredParameterTypes, Object... args) {
-		// Check if array already built for final argument
+		Assert.notEmpty(requiredParameterTypes, "Required parameter types array must not be empty");
+
 		int parameterCount = requiredParameterTypes.length;
+		Class<?> lastRequiredParameterType = requiredParameterTypes[parameterCount - 1];
+		Assert.isTrue(lastRequiredParameterType.isArray(),
+				"The last required parameter type must be an array to support varargs invocation");
+
 		int argumentCount = args.length;
+		Object lastArgument = (argumentCount > 0 ? args[argumentCount - 1] : null);
 
 		// Check if repackaging is needed...
-		if (parameterCount != args.length ||
-				requiredParameterTypes[parameterCount - 1] !=
-						(args[argumentCount - 1] != null ? args[argumentCount - 1].getClass() : null)) {
-
+		if (parameterCount != argumentCount || !lastRequiredParameterType.isInstance(lastArgument)) {
 			// Create an array for the leading arguments plus the varargs array argument.
 			Object[] newArgs = new Object[parameterCount];
 			// Copy all leading arguments to the new array, omitting the varargs array argument.
@@ -477,7 +482,7 @@ public static Object[] setupArgumentsForVarargsInvocation(Class<?>[] requiredPar
 			if (argumentCount >= parameterCount) {
 				varargsArraySize = argumentCount - (parameterCount - 1);
 			}
-			Class<?> componentType = requiredParameterTypes[parameterCount - 1].componentType();
+			Class<?> componentType = lastRequiredParameterType.componentType();
 			Object varargsArray = Array.newInstance(componentType, varargsArraySize);
 			for (int i = 0; i < varargsArraySize; i++) {
 				Array.set(varargsArray, i, args[parameterCount - 1 + i]);
@@ -486,6 +491,7 @@ public static Object[] setupArgumentsForVarargsInvocation(Class<?>[] requiredPar
 			newArgs[newArgs.length - 1] = varargsArray;
 			return newArgs;
 		}
+
 		return args;
 	}
 

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

@@ -4994,9 +4994,20 @@ void methodReferenceVarargs() {
 		assertThat(tc.s).isEqualTo("aaabbbccc");
 		tc.reset();
 
+		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)");
-		// assertCantCompile(expression);
+		// assertCannotCompile(expression);
 		// expression.getValue(tc);
 		// assertThat(tc.s).isEqualTo("aaabbbccc");
 		// assertCanCompile(expression);
@@ -6848,6 +6859,10 @@ public void sixteen(Object... vargs) {
 				}
 			}
 		}
+
+		public String[] seventeen() {
+			return new String[] { "aaa", "bbb", "ccc" };
+		}
 	}
 
 

spring-expression/src/test/java/org/springframework/expression/spel/support/ReflectionHelperTests.java

@@ -40,6 +40,8 @@
 
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
+import static org.assertj.core.api.Assertions.assertThatIllegalArgumentException;
+import static org.assertj.core.api.InstanceOfAssertFactories.array;
 import static org.springframework.expression.spel.support.ReflectionHelper.ArgumentsMatchKind.CLOSE;
 import static org.springframework.expression.spel.support.ReflectionHelper.ArgumentsMatchKind.EXACT;
 import static org.springframework.expression.spel.support.ReflectionHelper.ArgumentsMatchKind.REQUIRES_CONVERSION;
@@ -250,16 +252,73 @@ void convertAllArguments() throws Exception {
 		checkArguments(args, "3", null, "3.0");
 	}
 
+	@Test
+	void setupArgumentsForVarargsInvocationPreconditions() {
+		assertThatIllegalArgumentException()
+				.isThrownBy(() -> ReflectionHelper.setupArgumentsForVarargsInvocation(new Class[] {}, "a"))
+				.withMessage("Required parameter types array must not be empty");
+
+		assertThatIllegalArgumentException()
+				.isThrownBy(() -> ReflectionHelper.setupArgumentsForVarargsInvocation(
+						new Class<?>[] { Integer.class, Integer.class }, 123))
+				.withMessage("The last required parameter type must be an array to support varargs invocation");
+	}
+
 	@Test
 	void setupArgumentsForVarargsInvocation() {
-		Object[] newArray = ReflectionHelper.setupArgumentsForVarargsInvocation(
-				new Class<?>[] {String[].class}, "a", "b", "c");
-
-		assertThat(newArray).hasSize(1);
-		Object firstParam = newArray[0];
-		assertThat(firstParam.getClass().componentType()).isEqualTo(String.class);
-		Object[] firstParamArray = (Object[]) firstParam;
-		assertThat(firstParamArray).containsExactly("a", "b", "c");
+		Object[] newArray;
+
+		newArray = ReflectionHelper.setupArgumentsForVarargsInvocation(new Class<?>[] { String[].class }, "a", "b", "c");
+		assertThat(newArray)
+				.singleElement()
+				.asInstanceOf(array(String[].class))
+				.containsExactly("a", "b", "c");
+
+		newArray = ReflectionHelper.setupArgumentsForVarargsInvocation(new Class<?>[] { Object[].class }, "a", "b", "c");
+		assertThat(newArray)
+				.singleElement()
+				.asInstanceOf(array(Object[].class))
+				.containsExactly("a", "b", "c");
+
+		newArray = ReflectionHelper.setupArgumentsForVarargsInvocation(
+				new Class<?>[] { Integer.class, Integer.class, String[].class }, 123, 456, "a", "b", "c");
+		assertThat(newArray).satisfiesExactly(
+				one -> assertThat(one).isEqualTo(123),
+				two -> assertThat(two).isEqualTo(456),
+				three -> assertThat(three).asInstanceOf(array(String[].class)).containsExactly("a", "b", "c"));
+
+		newArray = ReflectionHelper.setupArgumentsForVarargsInvocation(new Class<?>[] { String[].class });
+		assertThat(newArray)
+				.singleElement()
+				.asInstanceOf(array(String[].class))
+				.isEmpty();
+
+		newArray = ReflectionHelper.setupArgumentsForVarargsInvocation(
+				new Class<?>[] { String[].class }, new Object[] { new String[] { "a", "b", "c" } });
+		assertThat(newArray)
+				.singleElement()
+				.asInstanceOf(array(String[].class))
+				.containsExactly("a", "b", "c");
+
+		newArray = ReflectionHelper.setupArgumentsForVarargsInvocation(
+				new Class<?>[] { Object[].class }, new Object[] { new String[] { "a", "b", "c" } });
+		assertThat(newArray)
+				.singleElement()
+				.asInstanceOf(array(Object[].class))
+				.containsExactly("a", "b", "c");
+
+		newArray = ReflectionHelper.setupArgumentsForVarargsInvocation(new Class<?>[] { String[].class }, "a");
+		assertThat(newArray)
+				.singleElement()
+				.asInstanceOf(array(String[].class))
+				.containsExactly("a");
+
+		newArray = ReflectionHelper.setupArgumentsForVarargsInvocation(new Class<?>[] { String[].class }, new Object[] { null });
+		assertThat(newArray)
+				.singleElement()
+				.asInstanceOf(array(String[].class))
+				.singleElement()
+				.isNull();
 	}
 
 	@Test