Basic explain tests

rest-api-spec/test/explain/10_basic.yaml

@@ -0,0 +1,25 @@
+---
+"Basic mlt":
+  - do:
+      index:
+          index:  test_1
+          type:   test
+          id:     1
+          body:   { foo: bar, title: howdy }
+
+  - do:
+      indices.refresh: {}
+
+  - do:
+      explain:
+          index:  test_1
+          type:   test
+          id:     1
+          body:
+            query:
+              match_all: {}
+        
+  - is_true: matched
+  - is_true: ok
+  - match: {explanation.value: 1.0}
+