feature: add top-level activeStake_aggregate query

Closes #345

packages/api-cardano-db-hasura/hasura/project/metadata/tables.yaml

@@ -3,6 +3,7 @@
     name: ActiveStake
   configuration:
     custom_root_fields:
+      select_aggregate: activeStake_aggregate
       select: activeStake
     custom_column_names: {}
   object_relationships:

packages/api-cardano-db-hasura/schema.graphql

@@ -23,6 +23,12 @@ type Query {
     offset: Int
     where: ActiveStake_bool_exp
   ): [ActiveStake]!
+  activeStake_aggregate (
+    limit: Int
+    order_by: [ActiveStake_order_by!]
+    offset: Int
+    where: ActiveStake_bool_exp
+  ): ActiveStake_aggregate!
   blocks (
     limit: Int
     order_by: [Block_order_by!]

packages/api-cardano-db-hasura/src/example_queries/active_stake/averageActiveStakeForAddress.graphql

@@ -0,0 +1,12 @@
+query averageActiveStakeForAddress (
+    $address: StakeAddress!
+) {
+    activeStake_aggregate (where: { address: { _eq: $address }}) {
+        aggregate {
+            count
+            avg {
+                amount
+            }
+        }
+    }
+}

packages/api-cardano-db-hasura/src/executableSchema.ts

@@ -55,6 +55,16 @@ export async function buildSchema (hasuraClient: HasuraClient, genesis: Genesis)
             schema: hasuraSchema
           })
         },
+        activeStake_aggregate: (_root, args, context, info) => {
+          return delegateToSchema({
+            args,
+            context,
+            fieldName: 'activeStake_aggregate',
+            info,
+            operation: 'query',
+            schema: hasuraSchema
+          })
+        },
         blocks: (_root, args, context, info) => {
           return delegateToSchema({
             args,

packages/api-cardano-db-hasura/test/activeStake.query.test.ts

@@ -35,4 +35,14 @@ describe('activeStake', () => {
     expect(activeStake[0].epochNo).toBeDefined()
     expect(activeStake[0].registeredWith.hash).toBeDefined()
   })
+
+  it('can return aggregated active stake information for an address', async () => {
+    const result = await client.query({
+      query: await loadQueryNode('averageActiveStakeForAddress'),
+      variables: { address: 'stake1u8atejkgfn8772722rh03lmnxyshvjakk260gfsefamc6sga68ag2' }
+    })
+    const { activeStake_aggregate } = result.data
+    expect(activeStake_aggregate.aggregate.count).toBeDefined()
+    expect(activeStake_aggregate.aggregate.avg.amount).toBeDefined()
+  })
 })