RFR: JDK-8216319: Refactor JavadocTester to allow more on-by-default checkers; add A11YChecker

[Hannes Wallnöfer]

In A11yChecker#checkHeading(String) I think the currLevel = level assignment should always be executed. Currently it is only executed if there’s an error, that doesn’t look right.

In LinkChecker there are unused private fields: xml, errors; badSchemes is assigned but never read.

Other than that everything looks good to me.

Hannes

> Am 08.01.2019 um 02:06 schrieb Jonathan Gibbons <jonathan.gibbons at oracle.com>:
> 
> Please review a medium-simple change to refactor JavadocTester to allow more on-by-default checkers, and to introduce a new checker
> 
> The nested classes for HtmlParser and LinkChecker are moved out of JavadocTester to become top-level classes; a new interface HtmlChecker is introduced between HtmlParser and LinkChecker, and a new subtype of that interface is added.
> 
> The A11YChecker is currently simple ... when enabled, it checks for content outside of a region in HTML 5 files, and it checks for out-of-order headings. We may want to add additional checks in future.
> 
> Architectural limitations in JavadocTester mean it is simpler/easier to read each file for each checker, meaning that if both checkers are enabled, the files will be read/parsed twice. This is in contrast to DocCheck where each file is read once and the checkers are run in parallel. However, relatively speaking the number and size of the files is small (compared to, say, the JDK API docs), and the overhead is not noticeable, and preferable to any more substantial refactoring of JavadocTester at this time.
> 
> A11yChecker is not enabled by default at this time: it finds lots of errors related to out-of-order headings; however, it is expected that when we fix that issue, A11yChecker will then be enabled by default.
> 
> -- Jon
> 
> JBS: https://bugs.openjdk.java.net/browse/JDK-8216319
> Webrev: http://cr.openjdk.java.net/~jjg/8216319/webrev.00/
> 
>