Added tests for default document type in `get` and `get_source` APIs

rest-api-spec/test/get/15_default_values.yaml

@@ -0,0 +1,20 @@
+---
+"Default values":
+
+  - do:
+      index:
+        index: test_1
+        type:  test
+        id:    1
+        body:  { "foo": "bar" }
+
+  - do:
+      get:
+        index: test_1
+        id:    1
+
+  - match: { _index:   test_1 }
+  - match: { _type:    test   }
+  - match: { _id:      '1'    }
+  - match: { _source:  { foo: "bar" } }
+

rest-api-spec/test/get/20_fields.yaml

@@ -16,7 +16,7 @@
 
   - match:   { _index:   test_1  }
   - match:   { _type:    test    }
-  - match:   { _id:      "1"       }
+  - match:   { _id:      '1'     }
   - match:   { fields.foo:  bar  }
   - is_false:  _source
 

rest-api-spec/test/get_source/15_default_values.yaml

@@ -0,0 +1,16 @@
+---
+"Default values":
+
+  - do:
+      index:
+        index: test_1
+        type:  test
+        id:    1
+        body:  { "foo": "bar" }
+
+  - do:
+      get_source:
+        index: test_1
+        id:    1
+
+  - match: { '':  { foo: bar } }