Remove remaining `index.mapper.single_type` setting usage from tests (#25388)

This change removes the remaining explicitly specified `index.mapper.single_type`
settings from tests in order to allow the removal of the setting.
This is the already approved part of #25375 broken out to simplfiy reviews on

5 files changed, 236 insertions, 116 deletions

diff --git a/rest-api-spec/src/main/resources/rest-api-spec/test/indices.exists_type/10_basic.yml b/rest-api-spec/src/main/resources/rest-api-spec/test/indices.exists_type/10_basic.yml
index fb56ab4e4d..278fd1ca8e 100644
--- a/rest-api-spec/src/main/resources/rest-api-spec/test/indices.exists_type/10_basic.yml
+++ b/rest-api-spec/src/main/resources/rest-api-spec/test/indices.exists_type/10_basic.yml
@@ -2,14 +2,12 @@
 "Exists type":
  - skip:
     version: "5.99.99 - "# this will only run in a mixed cluster environment with at least 1 5.x node
-    reason:  mapping.single_type can not be changed on 6.x indices onwards
+    reason:  multiple types are not supported on 6.x indices onwards
 
  - do:
      indices.create:
        index: test_1
        body:
-         settings:
-           mapping.single_type: false
          mappings:
            type_1: {}
            type_2: {}
diff --git a/rest-api-spec/src/main/resources/rest-api-spec/test/indices.get_mapping/10_basic.yml b/rest-api-spec/src/main/resources/rest-api-spec/test/indices.get_mapping/10_basic.yml
index b17f2512b6..90bb2747a7 100644
--- a/rest-api-spec/src/main/resources/rest-api-spec/test/indices.get_mapping/10_basic.yml
+++ b/rest-api-spec/src/main/resources/rest-api-spec/test/indices.get_mapping/10_basic.yml
@@ -4,21 +4,14 @@ setup:
         indices.create:
           index: test_1
           body:
-              settings:
-                mapping.single_type: false
               mappings:
-                type_1: {}
-                type_2: {}
+                doc: {}
   - do:
         indices.create:
           index: test_2
           body:
-              settings:
-                mapping.single_type: false
               mappings:
-                type_2: {}
-                type_3: {}
-
+                doc: {}
 ---
 "Get /{index}/_mapping with empty mappings":
 
@@ -35,191 +28,117 @@ setup:
 ---
 "Get /_mapping":
 
- - skip:
-    version: "5.99.99 - "# this will only run in a mixed cluster environment with at least 1 5.x node
-    reason:  mapping.single_type can not be changed on 6.x indices onwards
-
  - do:
     indices.get_mapping: {}
 
- - is_true: test_1.mappings.type_1
- - is_true: test_1.mappings.type_2
- - is_true: test_2.mappings.type_2
- - is_true: test_2.mappings.type_3
+ - is_true: test_1.mappings.doc
+ - is_true: test_2.mappings.doc
 
 ---
 "Get /{index}/_mapping":
 
- - skip:
-    version: "5.99.99 - "# this will only run in a mixed cluster environment with at least 1 5.x node
-    reason:  mapping.single_type can not be changed on 6.x indices onwards
-
  - do:
     indices.get_mapping:
         index: test_1
 
- - is_true: test_1.mappings.type_1
- - is_true: test_1.mappings.type_2
+ - is_true: test_1.mappings.doc
  - is_false: test_2
 
 
 ---
 "Get /{index}/_mapping/_all":
 
- - skip:
-    version: "5.99.99 - "# this will only run in a mixed cluster environment with at least 1 5.x node
-    reason:  mapping.single_type can not be changed on 6.x indices onwards
-
  - do:
     indices.get_mapping:
         index: test_1
         type:  _all
 
- - is_true: test_1.mappings.type_1
- - is_true: test_1.mappings.type_2
+ - is_true: test_1.mappings.doc
  - is_false: test_2
 
 ---
 "Get /{index}/_mapping/*":
 
- - skip:
-    version: "5.99.99 - "# this will only run in a mixed cluster environment with at least 1 5.x node
-    reason:  mapping.single_type can not be changed on 6.x indices onwards
-
  - do:
     indices.get_mapping:
         index: test_1
         type:  '*'
 
- - is_true: test_1.mappings.type_1
- - is_true: test_1.mappings.type_2
+ - is_true: test_1.mappings.doc
  - is_false: test_2
 
 ---
 "Get /{index}/_mapping/{type}":
 
- - skip:
-    version: "5.99.99 - "# this will only run in a mixed cluster environment with at least 1 5.x node
-    reason:  mapping.single_type can not be changed on 6.x indices onwards
-
  - do:
     indices.get_mapping:
         index: test_1
-        type:  type_1
+        type:  doc
 
- - is_false: test_1.mappings.type_2
- - is_false: test_2
-
----
-"Get /{index}/_mapping/{type,type}":
-
- - skip:
-    version: "5.99.99 - "# this will only run in a mixed cluster environment with at least 1 5.x node
-    reason:  mapping.single_type can not be changed on 6.x indices onwards
-
- - do:
-    indices.get_mapping:
-        index: test_1
-        type:  type_1,type_2
-
- - is_true: test_1.mappings.type_1
- - is_true: test_1.mappings.type_2
+ - is_true: test_1.mappings.doc
  - is_false: test_2
 
 ---
 "Get /{index}/_mapping/{type*}":
 
- - skip:
-    version: "5.99.99 - "# this will only run in a mixed cluster environment with at least 1 5.x node
-    reason:  mapping.single_type can not be changed on 6.x indices onwards
-
  - do:
     indices.get_mapping:
         index: test_1
-        type:  '*2'
+        type:  'd*'
 
- - is_true: test_1.mappings.type_2
- - is_false: test_1.mappings.type_1
+ - is_true: test_1.mappings.doc
  - is_false: test_2
 
 ---
 "Get /_mapping/{type}":
 
- - skip:
-    version: "5.99.99 - "# this will only run in a mixed cluster environment with at least 1 5.x node
-    reason:  mapping.single_type can not be changed on 6.x indices onwards
-
  - do:
     indices.get_mapping:
-        type: type_2
+        type: doc
 
- - is_true: test_1.mappings.type_2
- - is_true: test_2.mappings.type_2
- - is_false: test_1.mappings.type_1
- - is_false: test_2.mappings.type_3
+ - is_true: test_1.mappings.doc
+ - is_true: test_2.mappings.doc
 
 ---
 "Get /_all/_mapping/{type}":
 
- - skip:
-    version: "5.99.99 - "# this will only run in a mixed cluster environment with at least 1 5.x node
-    reason:  mapping.single_type can not be changed on 6.x indices onwards
-
  - do:
     indices.get_mapping:
         index: _all
-        type: type_2
+        type: doc
 
- - is_true: test_1.mappings.type_2
- - is_true: test_2.mappings.type_2
- - is_false: test_1.mappings.type_1
- - is_false: test_2.mappings.type_3
+ - is_true: test_1.mappings.doc
+ - is_true: test_2.mappings.doc
 
 ---
 "Get /*/_mapping/{type}":
 
- - skip:
-    version: "5.99.99 - "# this will only run in a mixed cluster environment with at least 1 5.x node
-    reason:  mapping.single_type can not be changed on 6.x indices onwards
-
  - do:
     indices.get_mapping:
         index: '*'
-        type: type_2
+        type: doc
 
- - is_true: test_1.mappings.type_2
- - is_true: test_2.mappings.type_2
- - is_false: test_1.mappings.type_1
- - is_false: test_2.mappings.type_3
+ - is_true: test_1.mappings.doc
+ - is_true: test_2.mappings.doc
 
 ---
 "Get /index,index/_mapping/{type}":
 
- - skip:
-    version: "5.99.99 - "# this will only run in a mixed cluster environment with at least 1 5.x node
-    reason:  mapping.single_type can not be changed on 6.x indices onwards
-
  - do:
     indices.get_mapping:
         index: test_1,test_2
-        type: type_2
+        type: doc
 
- - is_true: test_1.mappings.type_2
- - is_true: test_2.mappings.type_2
- - is_false: test_2.mappings.type_3
+ - is_true: test_1.mappings.doc
+ - is_true: test_2.mappings.doc
 
 ---
 "Get /index*/_mapping/{type}":
 
- - skip:
-    version: "5.99.99 - "# this will only run in a mixed cluster environment with at least 1 5.x node
-    reason:  mapping.single_type can not be changed on 6.x indices onwards
-
  - do:
     indices.get_mapping:
         index: '*2'
-        type: type_2
+        type: doc
 
- - is_true: test_2.mappings.type_2
+ - is_true: test_2.mappings.doc
  - is_false: test_1
- - is_false: test_2.mappings.type_3
diff --git a/rest-api-spec/src/main/resources/rest-api-spec/test/indices.get_mapping/70_legacy_multi_type.yml b/rest-api-spec/src/main/resources/rest-api-spec/test/indices.get_mapping/70_legacy_multi_type.yml
new file mode 100644
index 0000000000..9b36ac1535
--- /dev/null
+++ b/rest-api-spec/src/main/resources/rest-api-spec/test/indices.get_mapping/70_legacy_multi_type.yml
@@ -0,0 +1,208 @@
+---
+setup:
+  - do:
+        indices.create:
+          index: test_1
+          body:
+              mappings:
+                type_1: {}
+                type_2: {}
+  - do:
+        indices.create:
+          index: test_2
+          body:
+              mappings:
+                type_2: {}
+                type_3: {}
+
+---
+"Get /_mapping":
+
+ - skip:
+    version: "5.99.99 - "# this will only run in a mixed cluster environment with at least 1 5.x node
+    reason:  multiple types are not supported on 6.x indices onwards
+
+ - do:
+    indices.get_mapping: {}
+
+ - is_true: test_1.mappings.type_1
+ - is_true: test_1.mappings.type_2
+ - is_true: test_2.mappings.type_2
+ - is_true: test_2.mappings.type_3
+
+---
+"Get /{index}/_mapping":
+
+ - skip:
+    version: "5.99.99 - "# this will only run in a mixed cluster environment with at least 1 5.x node
+    reason:  multiple types are not supported on 6.x indices onwards
+
+ - do:
+    indices.get_mapping:
+        index: test_1
+
+ - is_true: test_1.mappings.type_1
+ - is_true: test_1.mappings.type_2
+ - is_false: test_2
+
+
+---
+"Get /{index}/_mapping/_all":
+
+ - skip:
+    version: "5.99.99 - "# this will only run in a mixed cluster environment with at least 1 5.x node
+    reason:  multiple types are not supported on 6.x indices onwards
+
+ - do:
+    indices.get_mapping:
+        index: test_1
+        type:  _all
+
+ - is_true: test_1.mappings.type_1
+ - is_true: test_1.mappings.type_2
+ - is_false: test_2
+
+---
+"Get /{index}/_mapping/*":
+
+ - skip:
+    version: "5.99.99 - "# this will only run in a mixed cluster environment with at least 1 5.x node
+    reason:  multiple types are not supported on 6.x indices onwards
+
+ - do:
+    indices.get_mapping:
+        index: test_1
+        type:  '*'
+
+ - is_true: test_1.mappings.type_1
+ - is_true: test_1.mappings.type_2
+ - is_false: test_2
+
+---
+"Get /{index}/_mapping/{type}":
+
+ - skip:
+    version: "5.99.99 - "# this will only run in a mixed cluster environment with at least 1 5.x node
+    reason:  multiple types are not supported on 6.x indices onwards
+
+ - do:
+    indices.get_mapping:
+        index: test_1
+        type:  type_1
+
+ - is_false: test_1.mappings.type_2
+ - is_false: test_2
+
+---
+"Get /{index}/_mapping/{type,type}":
+
+ - skip:
+    version: "5.99.99 - "# this will only run in a mixed cluster environment with at least 1 5.x node
+    reason:  multiple types are not supported on 6.x indices onwards
+
+ - do:
+    indices.get_mapping:
+        index: test_1
+        type:  type_1,type_2
+
+ - is_true: test_1.mappings.type_1
+ - is_true: test_1.mappings.type_2
+ - is_false: test_2
+
+---
+"Get /{index}/_mapping/{type*}":
+
+ - skip:
+    version: "5.99.99 - "# this will only run in a mixed cluster environment with at least 1 5.x node
+    reason:  multiple types are not supported on 6.x indices onwards
+
+ - do:
+    indices.get_mapping:
+        index: test_1
+        type:  '*2'
+
+ - is_true: test_1.mappings.type_2
+ - is_false: test_1.mappings.type_1
+ - is_false: test_2
+
+---
+"Get /_mapping/{type}":
+
+ - skip:
+    version: "5.99.99 - "# this will only run in a mixed cluster environment with at least 1 5.x node
+    reason:  multiple types are not supported on 6.x indices onwards
+
+ - do:
+    indices.get_mapping:
+        type: type_2
+
+ - is_true: test_1.mappings.type_2
+ - is_true: test_2.mappings.type_2
+ - is_false: test_1.mappings.type_1
+ - is_false: test_2.mappings.type_3
+
+---
+"Get /_all/_mapping/{type}":
+
+ - skip:
+    version: "5.99.99 - "# this will only run in a mixed cluster environment with at least 1 5.x node
+    reason:  multiple types are not supported on 6.x indices onwards
+
+ - do:
+    indices.get_mapping:
+        index: _all
+        type: type_2
+
+ - is_true: test_1.mappings.type_2
+ - is_true: test_2.mappings.type_2
+ - is_false: test_1.mappings.type_1
+ - is_false: test_2.mappings.type_3
+
+---
+"Get /*/_mapping/{type}":
+
+ - skip:
+    version: "5.99.99 - "# this will only run in a mixed cluster environment with at least 1 5.x node
+    reason:  multiple types are not supported on 6.x indices onwards
+
+ - do:
+    indices.get_mapping:
+        index: '*'
+        type: type_2
+
+ - is_true: test_1.mappings.type_2
+ - is_true: test_2.mappings.type_2
+ - is_false: test_1.mappings.type_1
+ - is_false: test_2.mappings.type_3
+
+---
+"Get /index,index/_mapping/{type}":
+
+ - skip:
+    version: "5.99.99 - "# this will only run in a mixed cluster environment with at least 1 5.x node
+    reason:  multiple types are not supported on 6.x indices onwards
+
+ - do:
+    indices.get_mapping:
+        index: test_1,test_2
+        type: type_2
+
+ - is_true: test_1.mappings.type_2
+ - is_true: test_2.mappings.type_2
+ - is_false: test_2.mappings.type_3
+
+---
+"Get /index*/_mapping/{type}":
+
+ - skip:
+    version: "5.99.99 - "# this will only run in a mixed cluster environment with at least 1 5.x node
+    reason:  multiple types are not supported on 6.x indices onwards
+
+ - do:
+    indices.get_mapping:
+        index: '*2'
+        type: type_2
+
+ - is_true: test_2.mappings.type_2
+ - is_false: test_1
+ - is_false: test_2.mappings.type_3
diff --git a/rest-api-spec/src/main/resources/rest-api-spec/test/mget/15_ids.yml b/rest-api-spec/src/main/resources/rest-api-spec/test/mget/15_ids.yml
index 7827965ec6..1dd851554b 100644
--- a/rest-api-spec/src/main/resources/rest-api-spec/test/mget/15_ids.yml
+++ b/rest-api-spec/src/main/resources/rest-api-spec/test/mget/15_ids.yml
@@ -2,14 +2,11 @@
 "IDs":
   - skip:
         version: "5.99.99 - "# this will only run in a mixed cluster environment with at least 1 5.x node
-        reason:  mapping.single_type can not be changed on 6.x indices onwards
+        reason:  multiple types are not supported on 6.x indices onwards
 
   - do:
         indices.create:
           index: test_1
-          body:
-              settings:
-                mapping.single_type: false
 
   - do:
       index:
diff --git a/rest-api-spec/src/main/resources/rest-api-spec/test/search.inner_hits/10_basic.yml b/rest-api-spec/src/main/resources/rest-api-spec/test/search.inner_hits/10_basic.yml
index 3c2eba90e6..e90fda9fe0 100644
--- a/rest-api-spec/src/main/resources/rest-api-spec/test/search.inner_hits/10_basic.yml
+++ b/rest-api-spec/src/main/resources/rest-api-spec/test/search.inner_hits/10_basic.yml
@@ -4,8 +4,6 @@ setup:
       indices.create:
         index: test
         body:
-            settings:
-              mapping.single_type: false
             mappings:
               type_1:
                 properties:
@@ -16,7 +14,7 @@ setup:
 "Nested inner hits":
     - skip:
         version: "5.99.99 - "# this will only run in a mixed cluster environment with at least 1 5.x node
-        reason:  mapping.single_type can not be changed on 6.x indices onwards
+        reason:  multiple types are not supported on 6.x indices onwards
     - do:
         index:
           index: test