Bug(GraphQL): Fixed HYP-336 (#70)

Description: Made the embedding parameeter, by, to be NonNull for
`querySimilar<Type>ById `& `querySimilar<Type>ByEmbedding ` queries.
This fixes the backend panic.

However, the postman client fails to show the dropdown as in the input
for the parameter. It shows it as a simple text input box. The client,
while editing the query text in the editor pane shows valid enum values
as part of the autocomplete feature.

Fixes: HYP-336

graphql/resolve/resolver_error_test.go

@@ -83,6 +83,14 @@ type Author {
 	postsNullableListRequired: [Post]!
 }
 
+type Product {
+  id: String! @id
+  description: String
+  title: String
+  imageUrl: String
+  productVector: [Float] @hm_embedding
+}
+
 type Post {
 	id: ID!
 	title: String!

graphql/resolve/schema.graphql

@@ -499,4 +499,12 @@ type CricketTeam implements Team {
 type LibraryManager  {
     name: String! @id
     manages: [LibraryMember]
-}
+}
+
+type Product {
+  id: String! @id
+  description: String
+  title: String
+  imageUrl: String
+  productVector: [Float] @hm_embedding
+}

graphql/schema/gqlschema.go

@@ -2079,7 +2079,7 @@ func addSimilarByEmbeddingQuery(schema *ast.Schema, defn *ast.Definition) {
 	//Accept the name of embedding field
 	qry.Arguments = append(qry.Arguments, &ast.ArgumentDefinition{
 		Name: SimilarByArgName,
-		Type: &ast.Type{NamedType: enumName},
+		Type: &ast.Type{NamedType: enumName, NonNull: true},
 	})
 
 	// Accept the topK, number of nearest neighbors to
@@ -2100,6 +2100,7 @@ func addSimilarByEmbeddingQuery(schema *ast.Schema, defn *ast.Definition) {
 				NamedType: "Float",
 				NonNull:   true,
 			},
+			NonNull: true,
 		},
 	})
 
@@ -2220,7 +2221,7 @@ func addSimilarByIdQuery(schema *ast.Schema, defn *ast.Definition,
 	// Accept the name of the embedding field.
 	qry.Arguments = append(qry.Arguments, &ast.ArgumentDefinition{
 		Name: SimilarByArgName,
-		Type: &ast.Type{NamedType: enumName},
+		Type: &ast.Type{NamedType: enumName, NonNull: true},
 	})
 
 	// Accept the topK, number of nearest neighbors to

graphql/schema/testdata/schemagen/output/embedding-directive-with-similar-queries.graphql

@@ -553,15 +553,15 @@ input UserRef {
 
 type Query {
 	getProduct(id: String!): Product
-	querySimilarProductById(id: String!, by: ProductEmbedding, topK: Int!): [ProductWithDistance]
-	querySimilarProductByEmbedding(by: ProductEmbedding, topK: Int!, vector: [Float!]): [ProductWithDistance]
+	querySimilarProductById(id: String!, by: ProductEmbedding!, topK: Int!): [ProductWithDistance]
+	querySimilarProductByEmbedding(by: ProductEmbedding!, topK: Int!, vector: [Float!]!): [ProductWithDistance]
 	queryProduct(filter: ProductFilter, order: ProductOrder, first: Int, offset: Int): [Product]
 	aggregateProduct(filter: ProductFilter): ProductAggregateResult
 	queryPurchase(filter: PurchaseFilter, order: PurchaseOrder, first: Int, offset: Int): [Purchase]
 	aggregatePurchase(filter: PurchaseFilter): PurchaseAggregateResult
 	getUser(email: String!): User
-	querySimilarUserById(email: String!, by: UserEmbedding, topK: Int!): [UserWithDistance]
-	querySimilarUserByEmbedding(by: UserEmbedding, topK: Int!, vector: [Float!]): [UserWithDistance]
+	querySimilarUserById(email: String!, by: UserEmbedding!, topK: Int!): [UserWithDistance]
+	querySimilarUserByEmbedding(by: UserEmbedding!, topK: Int!, vector: [Float!]!): [UserWithDistance]
 	queryUser(filter: UserFilter, order: UserOrder, first: Int, offset: Int): [User]
 	aggregateUser(filter: UserFilter): UserAggregateResult
 }