feat: add filtering and pagination to subjects

ent.graphql

@@ -279,6 +279,22 @@ type Query {
     """Filtering options for Dsses returned from the connection."""
     where: DsseWhereInput
   ): DsseConnection!
+  subjects(
+    """Returns the elements in the list that come after the specified cursor."""
+    after: Cursor
+
+    """Returns the first _n_ elements from the list."""
+    first: Int
+
+    """Returns the elements in the list that come before the specified cursor."""
+    before: Cursor
+
+    """Returns the last _n_ elements from the list."""
+    last: Int
+
+    """Filtering options for Subjects returned from the connection."""
+    where: SubjectWhereInput
+  ): SubjectConnection!
 }
 type Signature implements Node {
   id: ID!
@@ -338,7 +354,22 @@ input SignatureWhereInput {
 type Statement implements Node {
   id: ID!
   predicate: String!
-  subjects: [Subject!]
+  subjects(
+    """Returns the elements in the list that come after the specified cursor."""
+    after: Cursor
+
+    """Returns the first _n_ elements from the list."""
+    first: Int
+
+    """Returns the elements in the list that come before the specified cursor."""
+    before: Cursor
+
+    """Returns the last _n_ elements from the list."""
+    last: Int
+
+    """Filtering options for Subjects returned from the connection."""
+    where: SubjectWhereInput
+  ): SubjectConnection!
   attestationCollections: AttestationCollection
   dsse: [Dsse!]
 }
@@ -389,6 +420,15 @@ type Subject implements Node {
   subjectDigests: [SubjectDigest!]
   statement: Statement
 }
+"""A connection to a list of items."""
+type SubjectConnection {
+  """A list of edges."""
+  edges: [SubjectEdge]
+  """Information to aid in pagination."""
+  pageInfo: PageInfo!
+  """Identifies the total count of items in the connection."""
+  totalCount: Int!
+}
 type SubjectDigest implements Node {
   id: ID!
   algorithm: String!
@@ -444,6 +484,13 @@ input SubjectDigestWhereInput {
   hasSubject: Boolean
   hasSubjectWith: [SubjectWhereInput!]
 }
+"""An edge in a connection."""
+type SubjectEdge {
+  """The item at the end of the edge."""
+  node: Subject
+  """A cursor for use in pagination."""
+  cursor: Cursor!
+}
 """
 SubjectWhereInput is used for filtering Subject objects.
 Input was generated by ent.

ent.resolvers.go

@@ -1,3 +1,17 @@
+// Copyright 2022 The Archivist Contributors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
 package archivist
 
 // This file will be automatically regenerated based on the schema, any resolver implementations
@@ -21,6 +35,10 @@ func (r *queryResolver) Dsses(ctx context.Context, after *ent.Cursor, first *int
 	return r.client.Dsse.Query().Paginate(ctx, after, first, before, last, ent.WithDsseFilter(where.Filter))
 }
 
+func (r *queryResolver) Subjects(ctx context.Context, after *ent.Cursor, first *int, before *ent.Cursor, last *int, where *ent.SubjectWhereInput) (*ent.SubjectConnection, error) {
+	return r.client.Subject.Query().Paginate(ctx, after, first, before, last, ent.WithSubjectFilter(where.Filter))
+}
+
 // Query returns QueryResolver implementation.
 func (r *Resolver) Query() QueryResolver { return &queryResolver{r} }
 

ent/schema/statement.go

@@ -15,6 +15,7 @@
 package schema
 
 import (
+	"entgo.io/contrib/entgql"
 	"entgo.io/ent"
 	"entgo.io/ent/schema/edge"
 	"entgo.io/ent/schema/field"
@@ -36,7 +37,7 @@ func (Statement) Fields() []ent.Field {
 // Edges of the Statement.
 func (Statement) Edges() []ent.Edge {
 	return []ent.Edge{
-		edge.To("subjects", Subject.Type),
+		edge.To("subjects", Subject.Type).Annotations(entgql.RelayConnection()),
 		edge.To("attestation_collections", AttestationCollection.Type).Unique(),
 
 		edge.From("dsse", Dsse.Type).Ref("statement"),

ent/schema/subject.go

@@ -15,7 +15,9 @@
 package schema
 
 import (
+	"entgo.io/contrib/entgql"
 	"entgo.io/ent"
+	"entgo.io/ent/schema"
 	"entgo.io/ent/schema/edge"
 	"entgo.io/ent/schema/field"
 	"entgo.io/ent/schema/index"
@@ -49,3 +51,10 @@ func (Subject) Indexes() []ent.Index {
 		index.Fields("name"),
 	}
 }
+
+func (Subject) Annotations() []schema.Annotation {
+	return []schema.Annotation{
+		entgql.RelayConnection(),
+		entgql.QueryField(),
+	}
+}