Address feedback: fix argumentsFrom to unpack List properly, update test accordingly

Author: mariokhoury4

junit-jupiter-params/src/main/java/org/junit/jupiter/params/provider/Arguments.java

@@ -129,81 +129,29 @@ static ArgumentSet argumentSet(String name, @Nullable Object... arguments) {
 		return new ArgumentSet(name, arguments);
 	}
 
-	/**
-	 * Specialization of {@link Arguments} that associates a {@link #getName() name}
-	 * with a set of {@link #get() arguments}.
-	 *
-	 * @since 5.11
-	 * @see Arguments#argumentSet(String, Object...)
-	 * @see org.junit.jupiter.params.ParameterizedTest#ARGUMENT_SET_NAME_PLACEHOLDER
-	 * @see org.junit.jupiter.params.ParameterizedTest#ARGUMENT_SET_NAME_OR_ARGUMENTS_WITH_NAMES_PLACEHOLDER
-	 */
-	@API(status = EXPERIMENTAL, since = "5.11")
-	final class ArgumentSet implements Arguments {
-
-		private final String name;
-
-		private final @Nullable Object[] arguments;
-
-		private ArgumentSet(String name, @Nullable Object[] arguments) {
-			Preconditions.notBlank(name, "name must not be null or blank");
-			Preconditions.notNull(arguments, "arguments array must not be null");
-			this.name = name;
-			this.arguments = arguments;
-		}
-
-		/**
-		 * Get the name of this {@code ArgumentSet}.
-		 * @return the name of this {@code ArgumentSet}; never {@code null} or blank
-		 */
-		public String getName() {
-			return this.name;
-		}
-
-		@Override
-		public @Nullable Object[] get() {
-			return this.arguments;
-		}
-
-		/**
-		 * Return the {@link #getName() name} of this {@code ArgumentSet}.
-		 * @return the name of this {@code ArgumentSet}
-		 */
-		@Override
-		public String toString() {
-			return getName();
-		}
-
-	}
-
 	/**
 	 * Factory method for creating an instance of {@code Arguments} based on
 	 * the supplied {@code arguments} as a {@link List}.
 	 *
 	 * @param arguments the arguments as a List to be used for an invocation
 	 * of the test method; must not be {@code null} but may contain {@code null}
 	 * @return an instance of {@code Arguments}; never {@code null}
-	 * @see #arguments(List)
+	 * @since 6.0
+	 * @see #argumentsFrom(List)
 	 */
 	@API(status = EXPERIMENTAL, since = "6.0")
-	static Arguments of(@Nullable List<@Nullable Object> arguments) {
-		if (arguments == null) {
-			return of((Object) null); // Properly wrap null
-		}
-		if (arguments.isEmpty()) {
-			// Must still return empty arguments array
-			return of(new Object[0]);
-		}
-		return () -> arguments.toArray(new Object[0]);
+	static Arguments from(List<@Nullable Object> arguments) {
+		Preconditions.notNull(arguments, "arguments must not be null");
+		return of(arguments.toArray());
 	}
 
 	/**
 	 * Factory method for creating an instance of {@code Arguments} based on
 	 * the supplied {@code arguments} as a {@link List}.
 	 *
-	 * <p>This method is an <em>alias</em> for {@link Arguments#of} and is
+	 * <p>This method is an <em>alias</em> for {@link Arguments#from} and is
 	 * intended to be used when statically imported &mdash; for example, via:
-	 * {@code import static org.junit.jupiter.params.provider.Arguments.arguments;}
+	 * {@code import static org.junit.jupiter.params.provider.Arguments.argumentsFrom;}
 	 *
 	 * @param arguments the arguments as a List to be used for an invocation of the test
 	 * method; must not be {@code null} but may contain {@code null}
@@ -212,29 +160,37 @@ static Arguments of(@Nullable List<@Nullable Object> arguments) {
 	 * @see #argumentSet(String, Object...)
 	 */
 	@API(status = EXPERIMENTAL, since = "6.0")
-	static Arguments arguments(List<@Nullable Object> arguments) {
-		return of(arguments);
+	static Arguments argumentsFrom(List<@Nullable Object> arguments) {
+		return from(arguments);
 	}
 
 	/**
 	 * Factory method for creating an {@link ArgumentSet} based on the supplied
-	 * {@code name} and {@code arguments} as a List.
+	 * {@code name} and {@code arguments} as a {@link List}.
+	 *
+	 * <p>This method is a convenient alternative to {@link #argumentSet(String, Object...)}
+	 * when working with {@link List} based inputs.
 	 *
 	 * @param name the name of the argument set; must not be {@code null} or blank
 	 * @param arguments the arguments list to be used for an invocation of the test
 	 * method; must not be {@code null} but may contain {@code null}
 	 * @return an {@code ArgumentSet}; never {@code null}
 	 * @since 6.0
+	 * @see #argumentSet(String, Object...)
 	 */
 	@API(status = EXPERIMENTAL, since = "6.0")
-	static ArgumentSet argumentSet(String name, List<@Nullable Object> arguments) {
+	static ArgumentSet argumentSetFrom(String name, List<@Nullable Object> arguments) {
 		Preconditions.notBlank(name, "name must not be null or blank");
 		Preconditions.notNull(arguments, "arguments list must not be null");
-		return new ArgumentSet(name, arguments.toArray(new Object[0]));
+		return new ArgumentSet(name, arguments.toArray());
 	}
 
 	/**
-	 * Convert the arguments to a mutable List.
+	 * Convert the arguments to a new mutable {@link List} containing the same
+	 * elements as {@link #get()}.
+	 *
+	 * <p>This is useful for test logic that benefits from {@code List} operations such as filtering,
+	 * transformation, or assertions.
 	 *
 	 * @return a mutable List of arguments; never {@code null} but may contain {@code null}
 	 * @since 6.0
@@ -244,4 +200,50 @@ static ArgumentSet argumentSet(String name, List<@Nullable Object> arguments) {
 		return new ArrayList<>(Arrays.asList(get()));
 	}
 
+	/**
+	 * Specialization of {@link Arguments} that associates a {@link #getName() name}
+	 * with a set of {@link #get() arguments}.
+	 *
+	 * @since 5.11
+	 * @see Arguments#argumentSet(String, Object...)
+	 * @see org.junit.jupiter.params.ParameterizedTest#ARGUMENT_SET_NAME_PLACEHOLDER
+	 * @see org.junit.jupiter.params.ParameterizedTest#ARGUMENT_SET_NAME_OR_ARGUMENTS_WITH_NAMES_PLACEHOLDER
+	 */
+	@API(status = EXPERIMENTAL, since = "5.11")
+	final class ArgumentSet implements Arguments {
+
+		private final String name;
+
+		private final @Nullable Object[] arguments;
+
+		private ArgumentSet(String name, @Nullable Object[] arguments) {
+			Preconditions.notBlank(name, "name must not be null or blank");
+			Preconditions.notNull(arguments, "arguments array must not be null");
+			this.name = name;
+			this.arguments = arguments;
+		}
+
+		/**
+		 * Get the name of this {@code ArgumentSet}.
+		 * @return the name of this {@code ArgumentSet}; never {@code null} or blank
+		 */
+		public String getName() {
+			return this.name;
+		}
+
+		@Override
+		public @Nullable Object[] get() {
+			return this.arguments;
+		}
+
+		/**
+		 * Return the {@link #getName() name} of this {@code ArgumentSet}.
+		 * @return the name of this {@code ArgumentSet}
+		 */
+		@Override
+		public String toString() {
+			return getName();
+		}
+
+	}
 }

junit-jupiter-params/src/main/java/org/junit/jupiter/params/provider/EmptyArgumentsProvider.java

@@ -57,7 +57,7 @@ public Stream<? extends Arguments> provideArguments(ParameterDeclarations parame
 			return Stream.of(arguments(Collections.emptySet()));
 		}
 		if (List.class.equals(parameterType)) {
-			return Stream.of(Arguments.of((Object) Collections.emptyList()));
+			return Stream.of(arguments(Collections.emptyList()));
 		}
 		if (Set.class.equals(parameterType)) {
 			return Stream.of(arguments(Collections.emptySet()));

jupiter-tests/src/test/java/org/junit/jupiter/params/provider/ArgumentsTests.java

@@ -63,31 +63,31 @@ void argumentsReturnsSameArrayUsedForCreating() {
 	@Test
 	void ofSupportsList() {
 		List<Object> input = Arrays.asList(1, "two", null, 3.0);
-		Arguments arguments = Arguments.of(input);
+		Arguments arguments = Arguments.from(input);
 
 		assertArrayEquals(new Object[] { 1, "two", null, 3.0 }, arguments.get());
 	}
 
 	@Test
 	void argumentsSupportsListAlias() {
 		List<Object> input = Arrays.asList("a", 2, null);
-		Arguments arguments = Arguments.arguments(input);
+		Arguments arguments = Arguments.argumentsFrom(input);
 
 		assertArrayEquals(new Object[] { "a", 2, null }, arguments.get());
 	}
 
 	@Test
 	void argumentSetSupportsList() {
 		List<Object> input = Arrays.asList("x", null, 42);
-		ArgumentSet argumentSet = Arguments.argumentSet("list-test", input);
+		ArgumentSet argumentSet = Arguments.argumentSetFrom("list-test", input);
 
 		assertArrayEquals(new Object[] { "x", null, 42 }, argumentSet.get());
 		assertThat(argumentSet.getName()).isEqualTo("list-test");
 	}
 
 	@Test
 	void toListReturnsMutableListOfArguments() {
-		Arguments arguments = Arguments.of(Arrays.asList("a", 2, null));
+		Arguments arguments = Arguments.from(Arrays.asList("a", 2, null));
 
 		List<Object> result = arguments.toList();
 
@@ -98,7 +98,7 @@ void toListReturnsMutableListOfArguments() {
 
 	@Test
 	void toListWorksOnEmptyArguments() {
-		Arguments arguments = Arguments.of(Arrays.asList());
+		Arguments arguments = Arguments.from(Arrays.asList());
 
 		List<Object> result = arguments.toList();