Adds "Appending B. Painless API Reference", a reference of all classes
and methods available from Painless. Removes links to java packages
because they contain methods that we don't expose and don't contain
methods that we do expose (the ones in Augmentation). Instead this
generates a list of every class and every exposed method using the same
type information available to the
interpreter/compiler/whatever-we-call-it. From there you can jump to
the relevant docs.
Right now you build all the asciidoc files by running
```
gradle generatePainlessApi
```
These files are expected to be committed because we build the docs
without running `gradle`.
Also changes the output of `Debug.explain` so that it is easy to
search for the class in the generated reference documentation.
You can also run it in an IDE safely if you pass the path to the
directory in which to generate the docs as the first parameter. It'll
blow away the entire directory an recreate it from scratch so be careful.
And then you can build the docs by running something like:
```
../docs/build_docs.pl --out ../built_docs/ --doc docs/reference/index.asciidoc --open
```
That is, if you have checked out https://github.com/elastic/docs in
`../docs`. Wait a minute or two and your browser will pop open in with
all of Elasticsearch's reference documentation. If you go to
`http://localhost:8000/painless-api-reference.html` you can see this
list. Or you can get there by following the links to `Modules` and
`Scripting` and `Painless` and then clicking the link in the paragraphs
below titled `Appendix B. Painless API Reference`.
I like having these in asciidoc because we can deep link to them from the
rest of the guide with constructs like
`<<painless-api-reference-Object-hashCode-0>>` and
`<<painless-api-reference->>` and we get link checking. Then the only
brittle link maintenance bit is the link generation for javadoc. Which
sucks. But I think it is important that we link to the methods directly
so they are easy to find.
Relates to #22720
Sends the `error_trace` parameter with all requests sent by the
yaml test framework, including the doc snippet tests. This can be
overridden by settings `error_trace: false`. While this drift's
core's handling of the yaml tests from the client's slightly this
should only be a problem for tests that rely on the default value,
both of which I've fixed by setting the value explicitly.
This also escapes `\n` and `\t` in the `Stash dump on failure` so
the `stack_trace` is more readable.
Also fixes `RestUpdateSettingsAction` to not think of the `error_trace`
parameter as a setting.
You can use `Debug.explain(someObject)` in painless to throw an
`Error` that can't be caught by painless code and contains an
object's class. This is useful because painless's sandbox doesn't
allow you to call `someObject.getClass()`.
Closes#20263
Nik Everett