Remove types from explain API (#46926)

We no longer need a type to get the source of a document, so we can remove it from
the explain API as well.

Relates to #41059

client/rest-high-level/src/main/java/org/elasticsearch/client/RequestConverters.java

@@ -504,9 +504,7 @@ static Request count(CountRequest countRequest) throws IOException {
     }
 
     static Request explain(ExplainRequest explainRequest) throws IOException {
-        String endpoint = explainRequest.type().equals(MapperService.SINGLE_MAPPING_NAME)
-            ? endpoint(explainRequest.index(), "_explain", explainRequest.id())
-            : endpoint(explainRequest.index(), explainRequest.type(), explainRequest.id(), "_explain");
+        String endpoint = endpoint(explainRequest.index(), "_explain", explainRequest.id());
         Request request = new Request(HttpGet.METHOD_NAME, endpoint);
 
         Params params = new Params();

client/rest-high-level/src/test/java/org/elasticsearch/client/RequestConvertersTests.java

@@ -1415,21 +1415,6 @@ public void testExplain() throws IOException {
         assertToXContentBody(explainRequest, request.getEntity());
     }
 
-    public void testExplainWithType() throws IOException {
-        String index = randomAlphaOfLengthBetween(3, 10);
-        String type = randomAlphaOfLengthBetween(3, 10);
-        String id = randomAlphaOfLengthBetween(3, 10);
-
-        ExplainRequest explainRequest = new ExplainRequest(index, type, id);
-        explainRequest.query(QueryBuilders.termQuery(randomAlphaOfLengthBetween(3, 10), randomAlphaOfLengthBetween(3, 10)));
-
-        Request request = RequestConverters.explain(explainRequest);
-        assertEquals(HttpGet.METHOD_NAME, request.getMethod());
-        assertEquals("/" + index + "/" + type + "/" + id + "/_explain", request.getEndpoint());
-
-        assertToXContentBody(explainRequest, request.getEntity());
-    }
-
     public void testTermVectors() throws IOException {
         String index = randomAlphaOfLengthBetween(3, 10);
         String id = randomAlphaOfLengthBetween(3, 10);

client/rest-high-level/src/test/java/org/elasticsearch/client/SearchIT.java

@@ -1093,7 +1093,6 @@ public void testExplain() throws IOException {
             ExplainResponse explainResponse = execute(explainRequest, highLevelClient()::explain, highLevelClient()::explainAsync);
 
             assertThat(explainResponse.getIndex(), equalTo("index1"));
-            assertThat(explainResponse.getType(), equalTo("_doc"));
             assertThat(Integer.valueOf(explainResponse.getId()), equalTo(1));
             assertTrue(explainResponse.isExists());
             assertTrue(explainResponse.isMatch());
@@ -1108,7 +1107,6 @@ public void testExplain() throws IOException {
             ExplainResponse explainResponse = execute(explainRequest, highLevelClient()::explain, highLevelClient()::explainAsync);
 
             assertThat(explainResponse.getIndex(), equalTo("index1"));
-            assertThat(explainResponse.getType(), equalTo("_doc"));
             assertThat(Integer.valueOf(explainResponse.getId()), equalTo(1));
             assertTrue(explainResponse.isExists());
             assertTrue(explainResponse.isMatch());
@@ -1123,7 +1121,6 @@ public void testExplain() throws IOException {
             ExplainResponse explainResponse = execute(explainRequest, highLevelClient()::explain, highLevelClient()::explainAsync);
 
             assertThat(explainResponse.getIndex(), equalTo("index1"));
-            assertThat(explainResponse.getType(), equalTo("_doc"));
             assertThat(Integer.valueOf(explainResponse.getId()), equalTo(1));
             assertTrue(explainResponse.isExists());
             assertFalse(explainResponse.isMatch());
@@ -1139,7 +1136,6 @@ public void testExplain() throws IOException {
             ExplainResponse explainResponse = execute(explainRequest, highLevelClient()::explain, highLevelClient()::explainAsync);
 
             assertThat(explainResponse.getIndex(), equalTo("index1"));
-            assertThat(explainResponse.getType(), equalTo("_doc"));
             assertThat(Integer.valueOf(explainResponse.getId()), equalTo(1));
             assertTrue(explainResponse.isExists());
             assertFalse(explainResponse.isMatch());
@@ -1167,7 +1163,6 @@ public void testExplainNonExistent() throws IOException {
             ExplainResponse explainResponse = execute(explainRequest, highLevelClient()::explain, highLevelClient()::explainAsync);
 
             assertThat(explainResponse.getIndex(), equalTo("index1"));
-            assertThat(explainResponse.getType(), equalTo("_doc"));
             assertThat(explainResponse.getId(), equalTo("999"));
             assertFalse(explainResponse.isExists());
             assertFalse(explainResponse.isMatch());

docs/reference/search/explain.asciidoc

@@ -103,7 +103,6 @@ The API returns the following response:
 --------------------------------------------------
 {
    "_index":"twitter",
-   "_type":"_doc",
    "_id":"0",
    "matched":true,
    "explanation":{

modules/parent-join/src/test/java/org/elasticsearch/join/query/ChildQuerySearchIT.java

@@ -564,7 +564,7 @@ public void testExplainUsage() throws Exception {
         assertHitCount(searchResponse, 1L);
         assertThat(searchResponse.getHits().getAt(0).getExplanation().getDescription(), containsString("join value p1"));
 
-        ExplainResponse explainResponse = client().prepareExplain("test", "doc", parentId)
+        ExplainResponse explainResponse = client().prepareExplain("test", parentId)
                 .setQuery(hasChildQuery("child", termQuery("c_field", "1"), ScoreMode.Max))
                 .get();
         assertThat(explainResponse.isExists(), equalTo(true));

rest-api-spec/src/main/resources/rest-api-spec/api/explain.json

@@ -23,32 +23,6 @@
               "description":"The name of the index"
             }
           }
-        },
-        {
-          "path":"/{index}/{type}/{id}/_explain",
-          "methods":[
-            "GET",
-            "POST"
-          ],
-          "parts":{
-            "id":{
-              "type":"string",
-              "description":"The document ID"
-            },
-            "index":{
-              "type":"string",
-              "description":"The name of the index"
-            },
-            "type":{
-              "type":"string",
-              "description":"The type of the document",
-              "deprecated":true
-            }
-          },
-          "deprecated":{
-            "version":"7.0.0",
-            "description":"Specifying types in urls has been deprecated"
-          }
         }
       ]
     },

rest-api-spec/src/main/resources/rest-api-spec/test/explain/10_basic.yml

@@ -32,7 +32,6 @@ setup:
   - is_true: matched
   - match: { explanation.value: 1 }
   - match: { _index: test_1 }
-  - match: { _type: _doc }
   - match: { _id: id_1 }
 
 ---
@@ -49,7 +48,6 @@ setup:
   - is_true: matched
   - match: { explanation.value: 1 }
   - match: { _index: test_1 }
-  - match: { _type: _doc }
   - match: { _id: id_1 }
 
 ---

rest-api-spec/src/main/resources/rest-api-spec/test/explain/20_source_filtering.yml

@@ -14,7 +14,6 @@
   - do:
       explain: { index:  test_1, id: 1, _source: false, body: { query: { match_all: {}} } }
   - match:   { _index:   test_1  }
-  - match:   { _type:    _doc    }
   - match:   { _id:      "1"       }
   - is_false:  get._source