Consistent Indices API: Added tests to make sure requests on aliases return the concrete index

Relates elastic#4071

Author: spinscale

rest-api-spec/test/indices.get_mapping/40_aliases.yaml

@@ -0,0 +1,26 @@
+---
+"Getting mapping for aliases should return the real index as key":
+
+  - do:
+        indices.create:
+          index: test_index
+          body:
+              mappings:
+                test_type:
+                  properties:
+                    text:
+                      type:     string
+                      analyzer: whitespace
+
+  - do:
+      indices.put_alias:
+        index: test_index
+        name:  test_alias
+
+  - do:
+      indices.get_mapping:
+        index: test_alias
+
+  - match: {test_index.test_type.properties.text.type:     string}
+  - match: {test_index.test_type.properties.text.analyzer: whitespace}
+

rest-api-spec/test/indices.get_settings/20_aliases.yaml

@@ -0,0 +1,26 @@
+---
+"Getting settings for aliases should return the real index as key":
+
+  - do:
+      indices.create:
+        index: test-index
+        body:
+          settings:
+            index:
+              refresh_interval: -1
+              number_of_shards: 2
+              number_of_replicas: 3
+
+  - do:
+      indices.put_alias:
+        index: test-index
+        name:  test-alias
+
+  - do:
+      indices.get_settings:
+        index: test-alias
+
+  - match: { test-index.settings.index.number_of_replicas: "3" }
+  - match: { test-index.settings.index.number_of_shards: "2" }
+  - match: { test-index.settings.index.refresh_interval: "-1" }
+

rest-api-spec/test/indices.put_warmer/20_aliases.yaml

@@ -0,0 +1,30 @@
+---
+"Getting warmer for aliases should return the real index as key":
+
+  - do:
+      indices.create:
+          index: test_index
+
+  - do:
+      cluster.health:
+        wait_for_status: yellow
+
+  - do:
+      indices.put_warmer:
+          index: test_index
+          name: test_warmer
+          body:
+            query:
+              match_all: {}
+
+  - do:
+      indices.put_alias:
+          index: test_index
+          name:  test_alias
+
+  - do:
+      indices.get_warmer:
+          index: test_alias
+
+  - match: {test_index.warmers.test_warmer.source.query.match_all: {}}
+