There currently are small differences between search api and count, exists, validate query, explain api when it comes to reading query_string parameters. `analyze_wildcard`, `lowercase_expanded_terms` and `lenient` are only read by the search api and ignored by all other mentioned apis. Unified code to fix this and make sure it doesn't happen again. Also shared some code when it comes to printing out the query as part of SearchSourceBuilder conversion to ToXContent.
Extended REST spec to include all the supported params (some that were already supported weren't listed), and added REST tests (also some basic tests for count and search_exists which weren't tested at all).
Closes#11057
* `ignore_unavailable` - Controls whether to ignore if any specified indices are unavailable, this includes indices that don't exist or closed indices. Either `true` or `false` can be specified.
* `allow_no_indices` - Controls whether to fail if a wildcard indices expressions results into no concrete indices. Either `true` or `false` can be specified. For example if the wildcard expression `foo*` is specified and no indices are available that start with `foo` then depending on this setting the request will fail. This setting is also applicable when `_all`, `*` or no index has been specified.
* `expand_wildcards` - Controls to what kind of concrete indices wildcard indices expression expand to. If `open` is specified then the wildcard expression if expanded to only open indices and if `closed` is specified then the wildcard expression if expanded only to closed indices. Also both values (`open,closed`) can be specified to expand to all indices.
Closes to #4436
The following APIs now accept the query in a top level `query` field like:
* delete_by_query
* validate_query
* count
These APIs used to accept the query directly in the request body which was inconsistent with the search and explain APIs. For this reason t
Closes#4074