Luca Cavanna 6d987a9b69 Remove support for empty queries (#22092)
Our query DSL supports empty queries (`{}`), which have a different meaning depending on the query that holds it, either ignored, match_all or match_none. We deprecated the support for empty queries in 5.0, where we log a deprecation warning wherever they are used.

The way we supported it once we moved query parsing to the coordinating node was having an Optional<QueryBuilder> return type in all of our parse methods (called fromXContent). See #17624. The central place for this was QueryParseContext#parseInnerQueryBuilder. We can now remove all the optional return types and simply throw an exception whenever an empty query is found.
2016-12-12 12:37:12 +01:00
..
2016-12-07 11:24:28 -07:00

The Elasticsearch docs are in AsciiDoc format and can be built using the
Elasticsearch documentation build process.

See: https://github.com/elastic/docs

Snippets marked with `// CONSOLE` are automatically annotated with "VIEW IN
SENSE" in the documentation and are automatically tested by the command
`gradle :docs:check`. To test just the docs from a single page, use e.g.
`gradle :docs:check -Dtest.method=*rollover*`.

By default `// CONSOLE` snippet runs as its own isolated
test. You can manipulate the test execution in the following ways:

* `// TEST`: Explicitly marks a snippet as a test. Snippets marked this way
are tests even if they don't have `// CONSOLE`.
  * `// TEST[s/foo/bar/]`: Replace `foo` with `bar` in the test. This should be
  used sparingly because it makes the test "lie". Sometimes, though, you can use
  it to make the tests more clear.
  * `// TEST[catch:foo]`: Used to expect errors in the requests. Replace `foo`
  with `request` to expect a 400 error, for example. If the snippet contains
  multiple requests then only the last request will expect the error.
  * `// TEST[continued]`: Continue the test started in the last snippet. Between
  tests the nodes are cleaned: indexes are removed, etc. This will prevent that.
  This is really useful when you have text and snippets that work together to
  tell the story of some use case because it merges the snippets (and thus the
  use case) into one big test.
  * `// TEST[skip:reason]`: Skip this test. Replace `reason` with the actual
  reason to skip the test. Snippets without `// TEST` or `// CONSOLE` aren't
  considered tests anyway but this is useful for explicitly documenting the
  reason why the test shouldn't be run.
  * `// TEST[setup:name]`: Run some setup code before running the snippet. This
  is useful for creating and populating indexes used in the snippet. The setup
  code is defined in `docs/build.gradle`.
  * `// TEST[warning:some warning]`: Expect the response to include a `Warning`
  header. If the response doesn't include a `Warning` header with the exact
  text then the test fails. If the response includes `Warning` headers that
  aren't expected then the test fails.
* `// TESTRESPONSE`: Matches this snippet against the body of the response of
  the last test. If the response is JSON then order is ignored. With
  `// TEST[continued]` you can make tests that contain multiple command snippets
  and multiple response snippets.
  * `// TESTRESPONSE[s/foo/bar/]`: Substitutions. See `// TEST[s/foo/bar]`.
  * `// TESTRESPONSE[_cat]`: Add substitutions for testing `_cat` responses. Use
  this after all other substitutions so it doesn't make other substitutions
  difficult.
* `// TESTSETUP`: Marks this snippet as the "setup" for all other snippets in
  this file. This is a somewhat natural way of structuring documentation. You
  say "this is the data we use to explain this feature" then you add the
  snippet that you mark `// TESTSETUP` and then every snippet will turn into
  a test that runs the setup snippet first. See the "painless" docs for a file
  that puts this to good use. This is fairly similar to `// TEST[setup:name]`
  but rather than the setup defined in `docs/build.gradle` the setup is defined
  right in the documentation file.

Any place you can use json you can use elements like `$body.path.to.thing`
which is replaced on the fly with the contents of the thing at `path.to.thing`
in the last response.