Add text field support in the Painless scripting fields API

docs/changelog/89396.yaml

@@ -0,0 +1,5 @@
+pr: 89396
+summary: Add text field support in the Painless scripting fields API
+area: Mapping
+type: enhancement
+issues: []

modules/lang-painless/src/yamlRestTest/resources/rest-api-spec/test/painless/50_script_doc_values.yml

@@ -70,6 +70,11 @@ setup:
                             type: scaled_float
                             scaling_factor: 100
                             doc_values: false
+                        text:
+                            type: text
+                            fielddata: true
+                        text_no_field_data:
+                            type: text
                         token_count:
                             type: token_count
                             analyzer: standard
@@ -110,6 +115,8 @@ setup:
                 half_float_no_doc_values: 3.140625
                 scaled_float: 3.14
                 scaled_float_no_doc_values: 3.14
+                text: "Lots of text."
+                text_no_field_data: "Lots of text."
                 token_count: count all these words please
 
     - do:
@@ -150,6 +157,8 @@ setup:
               half_float_no_doc_values: [2.234, 1.123]
               scaled_float: [-3.5, 2.5]
               scaled_float_no_doc_values: [2.5, -3.5]
+              text: ["Lots of text.", "even more text", "SOOOOO much text"]
+              text_no_field_data: ["Lots of text.", "even more text", "SOOOOO much text"]
 
 
     - do:
@@ -2719,6 +2728,264 @@ setup:
                 source: "int value = field('dne').get(1, 1); value"
   - match: { hits.hits.0.fields.field.0: 1 }
 
+---
+"text":
+  - do:
+      search:
+        rest_total_hits_as_int: true
+        body:
+          query: { term: { _id: "1" } }
+          script_fields:
+            field:
+              script:
+                source: "doc['text'].get(0)"
+  - match: { hits.hits.0.fields.field.0: lots }
+
+  - do:
+      search:
+        rest_total_hits_as_int: true
+        body:
+          query: { term: { _id: "1" } }
+          script_fields:
+            field:
+              script:
+                source: "doc['text'].value"
+  - match: { hits.hits.0.fields.field.0: lots }
+
+  - do:
+      search:
+        rest_total_hits_as_int: true
+        body:
+          sort: [ { rank: asc } ]
+          script_fields:
+            field:
+              script:
+                source: "field('text').get('')"
+  - match: { hits.hits.0.fields.field.0: "Lots of text." }
+  - match: { hits.hits.1.fields.field.0: "" }
+  - match: { hits.hits.2.fields.field.0: "Lots of text." }
+
+  - do:
+      search:
+        rest_total_hits_as_int: true
+        body:
+          sort: [ { rank: asc } ]
+          script_fields:
+            field:
+              script:
+                source: "/* avoid yaml stash */ $('text', '')"
+  - match: { hits.hits.0.fields.field.0: "Lots of text." }
+  - match: { hits.hits.1.fields.field.0: "" }
+  - match: { hits.hits.2.fields.field.0: "Lots of text." }
+
+  - do:
+      search:
+        rest_total_hits_as_int: true
+        body:
+          sort: [ { rank: asc } ]
+          script_fields:
+            field:
+              script:
+                source: "String defaultText = 'default text'; field('text').get(defaultText)"
+  - match: { hits.hits.0.fields.field.0: "Lots of text." }
+  - match: { hits.hits.1.fields.field.0: "default text" }
+  - match: { hits.hits.2.fields.field.0: "Lots of text." }
+
+  - do:
+      search:
+        rest_total_hits_as_int: true
+        body:
+          sort: [ { rank: asc } ]
+          script_fields:
+            field:
+              script:
+                source: "String defaultText = 'default text'; $('text', defaultText)"
+  - match: { hits.hits.0.fields.field.0: "Lots of text." }
+  - match: { hits.hits.1.fields.field.0: "default text" }
+  - match: { hits.hits.2.fields.field.0: "Lots of text." }
+
+  - do:
+      search:
+        rest_total_hits_as_int: true
+        body:
+          sort: [ { rank: asc } ]
+          script_fields:
+            field:
+              script:
+                source: "field('text').get(1, '')"
+  - match: { hits.hits.0.fields.field.0: "" }
+  - match: { hits.hits.1.fields.field.0: "" }
+  - match: { hits.hits.2.fields.field.0: "SOOOOO much text" }
+
+  - do:
+      search:
+        rest_total_hits_as_int: true
+        body:
+          sort: [ { rank: asc } ]
+          script_fields:
+            field:
+              script:
+                source: "String defaultText = 'default text'; field('text').get(1, defaultText)"
+  - match: { hits.hits.0.fields.field.0: "default text" }
+  - match: { hits.hits.1.fields.field.0: "default text" }
+  - match: { hits.hits.2.fields.field.0: "SOOOOO much text" }
+
+  - do:
+      search:
+        rest_total_hits_as_int: true
+        body:
+          sort: [ { rank: asc } ]
+          script_fields:
+            field:
+              script:
+                source: "field('text').get(1, '')"
+  - match: { hits.hits.0.fields.field.0: "" }
+  - match: { hits.hits.1.fields.field.0: "" }
+  - match: { hits.hits.2.fields.field.0: "SOOOOO much text" }
+
+  - do:
+      search:
+        rest_total_hits_as_int: true
+        body:
+          sort: [ { rank: asc } ]
+          script_fields:
+            field:
+              script:
+                source: "String cat = ''; for (String s : field('text')) { cat += s; } cat + field('text').size();"
+  - match: { hits.hits.0.fields.field.0: "Lots of text.1" }
+  - match: { hits.hits.1.fields.field.0: "0" }
+  - match: { hits.hits.2.fields.field.0: "Lots of text.SOOOOO much texteven more text3" }
+
+---
+"text_no_field_data":
+  - do:
+      catch: bad_request
+      search:
+        rest_total_hits_as_int: true
+        body:
+          query: { term: { _id: "1" } }
+          script_fields:
+            field:
+              script:
+                source: "doc['text_no_field_data'].get(0)"
+  - match: { error.failed_shards.0.reason.caused_by.type: "illegal_argument_exception" }
+
+  - do:
+      catch: bad_request
+      search:
+        rest_total_hits_as_int: true
+        body:
+          query: { term: { _id: "1" } }
+          script_fields:
+            field:
+              script:
+                source: "doc['text_no_field_data'].value"
+  - match: { error.failed_shards.0.reason.caused_by.type: "illegal_argument_exception" }
+
+  - do:
+      search:
+        rest_total_hits_as_int: true
+        body:
+          sort: [ { rank: asc } ]
+          script_fields:
+            field:
+              script:
+                source: "field('text_no_field_data').get('')"
+  - match: { hits.hits.0.fields.field.0: "Lots of text." }
+  - match: { hits.hits.1.fields.field.0: "" }
+  - match: { hits.hits.2.fields.field.0: "Lots of text." }
+
+  - do:
+      search:
+        rest_total_hits_as_int: true
+        body:
+          sort: [ { rank: asc } ]
+          script_fields:
+            field:
+              script:
+                source: "/* avoid yaml stash */ $('text_no_field_data', '')"
+  - match: { hits.hits.0.fields.field.0: "Lots of text." }
+  - match: { hits.hits.1.fields.field.0: "" }
+  - match: { hits.hits.2.fields.field.0: "Lots of text." }
+
+  - do:
+      search:
+        rest_total_hits_as_int: true
+        body:
+          sort: [ { rank: asc } ]
+          script_fields:
+            field:
+              script:
+                source: "String defaultText = 'default text'; field('text_no_field_data').get(defaultText)"
+  - match: { hits.hits.0.fields.field.0: "Lots of text." }
+  - match: { hits.hits.1.fields.field.0: "default text" }
+  - match: { hits.hits.2.fields.field.0: "Lots of text." }
+
+  - do:
+      search:
+        rest_total_hits_as_int: true
+        body:
+          sort: [ { rank: asc } ]
+          script_fields:
+            field:
+              script:
+                source: "String defaultText = 'default text'; $('text_no_field_data', defaultText)"
+  - match: { hits.hits.0.fields.field.0: "Lots of text." }
+  - match: { hits.hits.1.fields.field.0: "default text" }
+  - match: { hits.hits.2.fields.field.0: "Lots of text." }
+
+  - do:
+      search:
+        rest_total_hits_as_int: true
+        body:
+          sort: [ { rank: asc } ]
+          script_fields:
+            field:
+              script:
+                source: "field('text_no_field_data').get(1, '')"
+  - match: { hits.hits.0.fields.field.0: "" }
+  - match: { hits.hits.1.fields.field.0: "" }
+  - match: { hits.hits.2.fields.field.0: "SOOOOO much text" }
+
+  - do:
+      search:
+        rest_total_hits_as_int: true
+        body:
+          sort: [ { rank: asc } ]
+          script_fields:
+            field:
+              script:
+                source: "String defaultText = 'default text'; field('text_no_field_data').get(1, defaultText)"
+  - match: { hits.hits.0.fields.field.0: "default text" }
+  - match: { hits.hits.1.fields.field.0: "default text" }
+  - match: { hits.hits.2.fields.field.0: "SOOOOO much text" }
+
+  - do:
+      search:
+        rest_total_hits_as_int: true
+        body:
+          sort: [ { rank: asc } ]
+          script_fields:
+            field:
+              script:
+                source: "field('text_no_field_data').get(1, '')"
+  - match: { hits.hits.0.fields.field.0: "" }
+  - match: { hits.hits.1.fields.field.0: "" }
+  - match: { hits.hits.2.fields.field.0: "SOOOOO much text" }
+
+  - do:
+      search:
+        rest_total_hits_as_int: true
+        body:
+          sort: [ { rank: asc } ]
+          script_fields:
+            field:
+              script:
+                source: "String cat = ''; for (String s : field('text_no_field_data')) { cat += s; } cat + field('text_no_field_data').size();"
+  - match: { hits.hits.0.fields.field.0: "Lots of text.1" }
+  - match: { hits.hits.1.fields.field.0: "0" }
+  - match: { hits.hits.2.fields.field.0: "Lots of text.SOOOOO much texteven more text3" }
+
 ---
 "version and sequence number":
   - do:

server/src/main/java/org/elasticsearch/index/fielddata/SourceValueFetcherSortedBinaryIndexFieldData.java

@@ -91,8 +91,8 @@ public static class SourceValueFetcherSortedBinaryDocValues extends SortedBinary
         private final ValueFetcher valueFetcher;
         private final SourceLookup sourceLookup;
 
-        private SortedSet<Object> values;
-        private Iterator<Object> iterator;
+        private final SortedSet<BytesRef> values;
+        private Iterator<BytesRef> iterator;
 
         public SourceValueFetcherSortedBinaryDocValues(
             LeafReaderContext leafReaderContext,
@@ -102,12 +102,19 @@ public SourceValueFetcherSortedBinaryDocValues(
             this.leafReaderContext = leafReaderContext;
             this.valueFetcher = valueFetcher;
             this.sourceLookup = sourceLookup;
+
+            values = new TreeSet<>();
         }
 
         @Override
         public boolean advanceExact(int doc) throws IOException {
             sourceLookup.setSegmentAndDocument(leafReaderContext, doc);
-            values = new TreeSet<>(valueFetcher.fetchValues(sourceLookup, Collections.emptyList()));
+            values.clear();
+
+            for (Object object : valueFetcher.fetchValues(sourceLookup, Collections.emptyList())) {
+                values.add(new BytesRef(object.toString()));
+            }
+
             iterator = values.iterator();
 
             return true;
@@ -121,7 +128,7 @@ public int docValueCount() {
         @Override
         public BytesRef nextValue() throws IOException {
             assert iterator.hasNext();
-            return new BytesRef(iterator.next().toString());
+            return iterator.next();
         }
     }
 }