On Wed, 8 May 2024 13:13:33 GMT, Pavel Rappo <pra...@openjdk.org> wrote:
>> I haven't given it a try, but a brief look at the code suggests that if the
>> console implementation backed by JLine gets used, then a `null` prompt may
>> not generate a `NullPointerException` (since JLine appears to allow `null`)
>> whereas if the internal JDK console implementation gets used then a
>> `NullPointerException` will get thrown. If the expectation is to disallow a
>> `null` prompt, then perhaps `Objects.requireNonNull(prompt)` before we hand
>> off to the underlying console implementations might be required.
>
> Good catch!
> `jdk.internal.org.jline.JdkConsoleProviderImpl.JdkConsoleImpl.readln(null)`
> does not throw `NullPointerException` (NPE), which it must. I'll fix the bug
> and add a test.
>
> Speaking of NPE. The newly added `Console.print` and `Console.println`
> methods do not throw NPE if passed null. While that's how it should be, they
> don't specify that, so the class-level NPE clause applies:
>
> * Unless otherwise specified, passing a {@code null} argument to any
> method
> * in this class will cause a {@link NullPointerException} to be thrown.
> ...
> public sealed class Console implements Flushable permits ProxyingConsole {
>
> I'll fix that.
>
> We should also specify NPE (or absence thereof) on methods of `IO`.
> Otherwise, this package clause applies:
>
> * Unless otherwise noted, passing a {@code null} argument to a
> constructor or
> * method in any class or interface in this package will cause a
> * {@code NullPointerException} to be thrown.
> ...
> package java.io;
>
> @stuart-marks speaking of exceptions. Do we need to add explicit `@throws`
> tag to `IO` methods?
>
> @throws {@code IOError} if {@code System.console()} returns {@code null}
>
> While it would make sense, it would also look superfluous: we already specify
> that error condition in the class comment and then in every method's main
> description. Do we need to add one more note on `IOError`?
Most of these are defined in terms of `String.valueOf(Object)` which if passed
a null reference will return the String object containing `null`. So no, I
don't think NPE should be thrown. It might be worth mentioning this explicitly
somewhere though.
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PR Review Comment: https://git.openjdk.org/jdk/pull/19112#discussion_r1594282580
