Value.isList accepts List<Object> where only the first element is a Value

[javicv]

java-sdk/src/main/java/dev/openfeature/sdk/Value.java

Lines 133 to 137 in ed2e963

	public boolean isList() {
	return this.innerObject instanceof List
	&& (((List) this.innerObject).isEmpty()
	|| ((List) this.innerObject).get(0) instanceof Value);
	}

This method isList() is used in constructor

java-sdk/src/main/java/dev/openfeature/sdk/Value.java

Line 37 in ed2e963

public Value(Object value) throws InstantiationException {

but it's checking only the first element of the list. With this check a List<Object> can be added if only the first element is a Value while the other aren't.

In my opinion this test must pass, but it fails because the exception isn't thrown

@Test
public void listMustContainOnlyValues() {
    String item = "item";
    List<Object> list = new ArrayList<>();
    list.add(new Value(item));
    list.add(item);
    try {
        new Value((Object) list);
        fail("Should fail because list contains values and non-values and the exception should be thrown.");
    } catch (InstantiationException e) {
        assertEquals("Invalid value type: class java.util.ArrayList", e.getMessage());
    }
}

Maybe the constructor with Object parameter shouldn't accept lists to force the use of constructor with List<Value> where the list will only contain elements of type Value

java-sdk/src/main/java/dev/openfeature/sdk/Value.java

Lines 75 to 77 in ed2e963

	public Value(List<Value> value) {
	this.innerObject = value;
	}

[beeme1mr]

FYI @justinabrahms @Kavindu-Dodan @toddbaert

[Kavindu-Dodan]

@javicv thank you for noticing this. In my view isList() should be expanded to check for all entries of the collection.

I will work to fix this and add tests to cover the scenario.

[Kavindu-Dodan]

@javicv PR is ready for review - #350

@toddbaert @justinabrahms hope you can review :)

[toddbaert]

This is my concern.