Example that shows how using a `facet_filter` with a `nested` filter fails to return `nested` facet terms.

facet-filter-with-nested-filter-fails.sh

#!/bin/bash
#
# Description:
#   Example that shows how using a `facet_filter` with a `nested` filter fails to return `nested` facet terms.

# Remove index if it exists already
curl -XDELETE http://localhost:9200/nested

# Create a fresh index 
curl -XPOST http://localhost:9200/nested

# Create a nested mapping
curl -XPOST http://localhost:9200/nested/type/_mapping -d '
{
   "type":{
      "properties":{
         "nested1":{
            "type":"nested"
         }
      }
   }
}'

# Insert a document with a nested doc
curl -XPOST http://localhost:9200/nested/type/ -d '
{
   "nested1":[
      {
         "x":1
      }
   ]
}'

# Ensure the previous document is searchable
curl -XPOST 'http://localhost:9200/nested/_refresh'

# Demonstrate that the following query with `facet_filter` and `nested` filter fails to return any terms. Note that
# removing the `facet_filter` gives the expected results.
#
# Expected: 
#   { ... "hits":{"total":1,"max_score":1.0,"hits":[]},"facets":{"nested1":{"_type":"terms","missing":0,"total":1,"other":0,"terms":[{"term":1,"count":1}]}}}
# Actual: 
#   { ... "hits":{"total":0,"max_score":null,"hits":[]},"facets":{"nested1":{"_type":"terms","missing":0,"total":0,"other":0,"terms":[]}}}
curl -XGET http://localhost:9200/nested/type/_search -d '
{
   "size":0,
   "query":{
      "match_all":{}
   },
   "facets":{
      "nested1":{
         "terms":{
            "field":"x"
         },
         "nested":"nested1",
         "facet_filter":{
            "nested":{
               "path":"nested1",
               "query":{
                  "match_all":{}
               }
            }
         }
      }
   }
}'