add state root endpoint

apis/beacon/states/root.yaml

@@ -0,0 +1,17 @@
+get:
+  operationId: "getStateRoot"
+  summary: "Get state SSZ HashTreeRoot"
+  description: "Calculates HashTreeRoot for state with given 'stateId'. If stateId is root, same value will be returned."
+  tags:
+    - Beacon
+  parameters:
+    - name: stateId
+      $ref: '../../../beacon-node-oapi.yaml#/components/parameters/StateId'
+  responses:
+    "200":
+      description: Success
+      content:
+        application/json:
+          schema:
+            $ref: '../../../beacon-node-oapi.yaml#/components/schemas/Root'
+

beacon-node-oapi.yaml

@@ -32,6 +32,9 @@ paths:
 
   /v1/beacon/genesis:
     $ref: "./apis/beacon/genesis.yaml"
+  /v1/beacon/states/{stateId}/root:
+    $ref: "./apis/beacon/states/root.yaml"
+
 #  /v1/beacon/fork:
 #    $ref: "./apis/beacon/fork.yaml#/single"
 #  /v1/beacon/fork/stream:
@@ -69,6 +72,8 @@ paths:
 
 components:
   schemas:
+    BeaconState:
+      $ref: './types/state.yaml#/BeaconState'
     BeaconBlock:
       $ref: './types/block.yaml#/schemas/BeaconBlock'
     SignedBeaconBlock:
@@ -105,6 +110,11 @@ components:
       $ref: './types/primitive.yaml#/schemas/Root'
     Signature:
       $ref: './types/primitive.yaml#/schemas/Signature'
+
+  parameters:
+    StateId:
+      $ref: './params/index.yaml#/StateId'
+
   responses:
     InvalidRequest:
       $ref: './types/http.yaml#/responses/InvalidRequest'

dist/index.html

@@ -42,6 +42,7 @@
         url: "https://petstore.swagger.io/v2/swagger.json",
         dom_id: '#swagger-ui',
         deepLinking: true,
+        showExtensions: true,
         presets: [
           SwaggerUIBundle.presets.apis,
           SwaggerUIStandalonePreset

params/index.yaml

@@ -0,0 +1,9 @@
+StateId:
+  name: stateId
+  in: path
+  required: true
+  schema:
+    type: string
+  description: |
+    State identifier.
+    Can be one of: "head" (canonical head in node's view), "genesis", "finalized", "justified", \<slot\>, \<stateRoot\>.

types/state.yaml

@@ -1,4 +1,3 @@
-schemas:
 BeaconState:
   type: object
   description: "The [`BeaconState`](https://github.com/ethereum/eth2.0-specs/blob/v0.11.1/specs/phase0/beacon-chain.md#beaconblock) object from the Eth2.0 spec."