Support for query fragments with Apollo (aws#103)

This changeset enables the use of graphQL query fragments with Apollo Server:

-changed Apollo event handler to pass along any query fragments to the resolver
-added logic to the resolver to detect referenced fragments in the query AST and replace them with the appropriate fragment's selection set
-changed App Sync event handlers to throw an Error if a fragment is detected in the query so that the user is presented with an appropriate error message 'Fragments are not supported' instead of failing downstream and presenting a cryptic error message
-changed functions in the resolver which require fragments data to accept a single object argument instead of multiple arguments for easier readability when calling the function
-updated airports.customized.graphql test schema to have separate input types for create and update mutations so that the resolver unit test could verify test cases for mutations with fragments
-note that this changeset does not address inline fragments

Author: andreachild

CHANGELOG.md

@@ -55,4 +55,5 @@ This release contains new support for Apollo Server integration.
 * Set limit on the expensive query which is retrieving distinct to and from labels for edges ([#89](https://github.com/aws/amazon-neptune-for-graphql/pull/89))
 * Added distinct input types for create and update mutations ([#93](https://github.com/aws/amazon-neptune-for-graphql/pull/93))
 * Enabled mutations for the Apollo Server ([#98](https://github.com/aws/amazon-neptune-for-graphql/pull/98))
-* Refactored integration tests to be less vulnerable to resolver logic changes ([#99](https://github.com/aws/amazon-neptune-for-graphql/pull/99))
+* Refactored integration tests to be less vulnerable to resolver logic changes ([#99](https://github.com/aws/amazon-neptune-for-graphql/pull/99))
+* Enabled usage of query fragments with Apollo Server ([#103](https://github.com/aws/amazon-neptune-for-graphql/pull/103))

README.md

@@ -311,6 +311,8 @@ When using custom scalars in your schema (specified via `--input-schema-file`),
 - Querying Neptune via SDK is not yet supported for Apollo Server, only HTTPS is supported.
 - Schemas specified by `--input-schema-file` with `--create-update-aws-pipeline` may not contain custom scalars. See [AWS App Sync Scalar types in GraphQL](https://docs.aws.amazon.com/appsync/latest/devguide/scalars.html) for more information.
 - Schemas specified by `--input-schema-file` with `--create-update-apollo-server` or `--create-update-apollo-server-subgraph` which contain custom scalars require manual steps to add custom scalar resolvers for additional query validation.
+- Query fragments are supported for Apollo Server but not yet for App Sync
+- Inline fragments are not yet supported
   <br>
 
 # Roadmap

src/pipelineResources.js

@@ -578,7 +578,11 @@ export function request(ctx) {
 }
     
 export function response(ctx) {
-    return ctx.result;
+    const { error, result } = ctx;
+    if (error) {
+        util.appendError(error.message, error.type, result);
+    }
+    return result;
 }`
 
     };

src/test/airports.customized.graphql

@@ -14,6 +14,20 @@ code: StringScalarFilters
 desc: StringScalarFilters
 }
 
+input ContinentCreateInput {
+  _id: ID @id
+  type: String
+  code: String
+  desc: String
+}
+
+input ContinentUpdateInput {
+  _id: ID! @id
+  type: String
+  code: String
+  desc: String
+}
+
 type Country @alias(property:"country") {
 _id: ID! @id
 type: String
@@ -30,6 +44,20 @@ code: StringScalarFilters
 desc: StringScalarFilters
 }
 
+input CountryCreateInput {
+  _id: ID @id
+  type: String
+  code: String
+  desc: String
+}
+
+input CountryUpdateInput {
+  _id: ID! @id
+  type: String
+  code: String
+  desc: String
+}
+
 type Version @alias(property:"version") {
 _id: ID! @id
 date: String
@@ -48,6 +76,24 @@ type: StringScalarFilters
 code: StringScalarFilters
 }
 
+input VersionCreateInput {
+  _id: ID @id
+  date: String
+  desc: String
+  author: String
+  type: String
+  code: String
+}
+
+input VersionUpdateInput {
+  _id: ID! @id
+  date: String
+  desc: String
+  author: String
+  type: String
+  code: String
+}
+
 type Airport @alias(property:"airport") {
 _id: ID! @id
 type: String
@@ -87,6 +133,38 @@ region: StringScalarFilters
 elev: Int
 }
 
+input AirportCreateInput {
+  _id: ID @id
+  type: String
+  city: String
+  icao: String
+  code: String
+  country: String
+  lat: Float
+  longest: Int
+  runways: Int
+  desc: String
+  lon: Float
+  region: String
+  elev: Int
+}
+
+input AirportUpdateInput {
+  _id: ID! @id
+  type: String
+  city: String
+  icao: String
+  code: String
+  country: String
+  lat: Float
+  longest: Int
+  runways: Int
+  desc: String
+  lon: Float
+  region: String
+  elev: Int
+}
+
 type Contains @alias(property:"contains") {
 _id: ID! @id
 }
@@ -130,12 +208,12 @@ getCountriesCount: Int @graphQuery(statement: "g.V().hasLabel('country').count()
 }
 
 type Mutation {
-createNodeAirport(input: AirportInput!): Airport
-updateNodeAirport(input: AirportInput!): Airport
+createNodeAirport(input: AirportCreateInput!): Airport
+updateNodeAirport(input: AirportUpdateInput!): Airport
 connectNodeCountryToNodeAirportEdgeContains(from_id: ID!, to_id: ID!): Contains
 deleteEdgeContainsFromCountryToAirport(from_id: ID!, to_id: ID!): Boolean
 updateEdgeRouteFromAirportToAirport(from_id: ID!, to_id: ID!, edge: RouteInput!): Route
-createAirport(input: AirportInput!): Airport @graphQuery(statement: "CREATE (this:airport {$input}) RETURN this")
+createAirport(input: AirportCreateInput!): Airport @graphQuery(statement: "CREATE (this:airport {$input}) RETURN this")
 }
 
 schema {