pass directives from schema modules through buildServiceDefinition

packages/apollo-tools/src/__tests__/buildServiceDefinition.test.ts

@@ -111,6 +111,23 @@ Array [
     });
   });
 
+  describe(`directive definitions`, () => {
+    it(`should include directive`, () => {
+      const service = buildServiceDefinition([
+        gql`
+          directive @something on FIELD_DEFINITION
+        `
+      ]);
+
+      expect(service.errors).toBeUndefined();
+
+      expect(service.schema).toBeDefined();
+      const schema = service.schema!;
+      const directive = schema.getDirective("something");
+      expect(directive).toBeDefined();
+    });
+  });
+
   describe(`type extension`, () => {
     it(`should allow extending a type from the same module`, () => {
       const service = buildServiceDefinition([

packages/apollo-tools/src/buildServiceDefinition.ts

@@ -2,6 +2,7 @@ import {
   GraphQLSchema,
   DocumentNode,
   TypeDefinitionNode,
+  DirectiveDefinitionNode,
   isTypeDefinitionNode,
   TypeExtensionNode,
   isTypeExtensionNode,
@@ -41,6 +42,10 @@ export function buildServiceDefinition(
     [name: string]: TypeExtensionNode[];
   } = Object.create(null);
 
+  const directivesMap: {
+    [name: string]: DirectiveDefinitionNode[];
+  } = Object.create(null);
+
   const schemaDefinitions: SchemaDefinitionNode[] = [];
   const schemaExtensions: SchemaExtensionNode[] = [];
 
@@ -65,6 +70,14 @@ export function buildServiceDefinition(
         } else {
           typeExtensionsMap[typeName] = [definition];
         }
+      } else if (definition.kind === Kind.DIRECTIVE_DEFINITION) {
+        const typeName = definition.name.value;
+
+        if (directivesMap[typeName]) {
+          directivesMap[typeName].push(definition);
+        } else {
+          directivesMap[typeName] = [definition];
+        }
       } else if (definition.kind === Kind.SCHEMA_DEFINITION) {
         schemaDefinitions.push(definition);
       } else if (definition.kind === Kind.SCHEMA_EXTENSION) {
@@ -170,6 +183,15 @@ export function buildServiceDefinition(
       });
     }
 
+    const directiveExtensions = Object.values(directivesMap).flat();
+
+    if (directiveExtensions.length > 0) {
+      schema = extendSchema(schema, {
+        kind: Kind.DOCUMENT,
+        definitions: directiveExtensions
+      });
+    }
+
     for (const module of modules) {
       if (!module.resolvers) continue;