feat(utils): makeExtendSchemaPlugin accepts typeDef array (#574)

packages/graphile-utils/__tests__/ExtendSchemaPlugin.test.js

@@ -223,6 +223,97 @@ it("allows adding a non-null list of non-null type", async () => {
   expect(data.randomNumbers).toEqual([5, 3, 6]);
 });
 
+it("accepts an array of typedefs", async () => {
+  const schema = await buildSchema([
+    ...simplePlugins,
+    makeExtendSchemaPlugin(_build => ({
+      typeDefs: [
+        gql`
+          extend type Query {
+            """
+            A random number generated by a fair dice roll.
+            """
+            randomNumber: Int!
+          }
+        `,
+        gql`
+          extend type Query {
+            """
+            Gives a list of numbers that were randomly generated by fair dice roll
+            """
+            randomNumbers: [Int!]!
+          }
+        `,
+      ],
+      resolvers,
+    })),
+  ]);
+  expect(schema).toMatchSnapshot();
+  const { data } = await graphql(
+    schema,
+    `
+      {
+        randomNumber
+        randomNumbers
+      }
+    `
+  );
+  expect(data.randomNumber).toEqual(4);
+  expect(data.randomNumbers).toEqual([5, 3, 6]);
+});
+
+it("throws the proper error if an array of typeDefs aren't all DocumentNodes", () => {
+  return expect(
+    buildSchema([
+      ...simplePlugins,
+      makeExtendSchemaPlugin(_build => ({
+        typeDefs: [
+          gql`
+            extend type Query {
+              """
+              A random number generated by a fair dice roll.
+              """
+              randomNumber: Int!
+            }
+          `,
+          `
+            extend type Query {
+              """
+              Gives a list of numbers that were randomly generated by fair dice roll
+              """
+              randomNumbers: [Int!]!
+            }
+          `,
+        ],
+        resolvers,
+      })),
+    ])
+  ).rejects.toMatchInlineSnapshot(
+    `[Error: The first argument to makeExtendSchemaPlugin must be generated by the \`gql\` helper, or be an array of the same.]`
+  );
+});
+
+it("throws the proper error if a single typeDef isn't a DocumentNode", () => {
+  return expect(
+    buildSchema([
+      ...simplePlugins,
+      makeExtendSchemaPlugin(_build => ({
+        typeDefs: `
+            extend type Query {
+              """
+              Gives a list of numbers that were randomly generated by fair dice roll
+              """
+              randomNumbers: [Int!]!
+            }
+          `,
+        resolvers,
+      })),
+    ])
+  ).rejects.toMatchInlineSnapshot(
+    `[Error: The first argument to makeExtendSchemaPlugin must be generated by the \`gql\` helper, or be an array of the same.]`
+  );
+});
+
 it("allows adding a field with arguments", async () => {
   const schema = await buildSchema([
     ...simplePlugins,

packages/graphile-utils/__tests__/__snapshots__/ExtendSchemaPlugin.test.js.snap

@@ -1,5 +1,23 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
+exports[`accepts an array of typedefs 1`] = `
+"""The root query type which gives access points into the data universe."""
+type Query {
+  """
+  Exposes the root query type nested one level down. This is helpful for Relay 1
+  which can only query top level fields if they are in a particular form.
+  """
+  query: Query!
+
+  """A random number generated by a fair dice roll."""
+  randomNumber: Int!
+
+  """Gives a list of numbers that were randomly generated by fair dice roll"""
+  randomNumbers: [Int!]!
+}
+
+`;
+
 exports[`allows adding a field with arguments 1`] = `
 """The root query type which gives access points into the data universe."""
 type Query {

packages/graphile-utils/src/makeExtendSchemaPlugin.ts

@@ -22,6 +22,7 @@ import {
 
   // Nodes:
   DirectiveNode,
+  DefinitionNode,
   DocumentNode,
   EnumValueDefinitionNode,
   FieldDefinitionNode,
@@ -80,7 +81,7 @@ export interface Resolvers<TSource = any, TContext = any> {
 }
 
 export interface ExtensionDefinition {
-  typeDefs: DocumentNode;
+  typeDefs: DocumentNode | DocumentNode[];
   resolvers?: Resolvers;
 }
 
@@ -118,11 +119,21 @@ export default function makeExtendSchemaPlugin(
         typeof generator === "function"
           ? generator(build, schemaOptions)
           : generator;
-      if (!(typeDefs as any) || (typeDefs as any).kind !== "Document") {
-        throw new Error(
-          "The first argument to makeExtendSchemaPlugin must be generated by the `gql` helper"
-        );
-      }
+
+      const typeDefsArr = Array.isArray(typeDefs) ? typeDefs : [typeDefs];
+      const mergedTypeDefinitions = typeDefsArr.reduce(
+        (definitions, typeDef) => {
+          if (!(typeDef as any) || (typeDef as any).kind !== "Document") {
+            throw new Error(
+              "The first argument to makeExtendSchemaPlugin must be generated by the `gql` helper, or be an array of the same."
+            );
+          }
+          definitions.push(...typeDef.definitions);
+          return definitions;
+        },
+        [] as DefinitionNode[]
+      );
+
       const typeExtensions = {
         GraphQLSchema: {
           directives: [] as Array<any>,
@@ -132,7 +143,7 @@ export default function makeExtendSchemaPlugin(
         GraphQLObjectType: {},
       };
       const newTypes: Array<NewTypeDef> = [];
-      typeDefs.definitions.forEach(definition => {
+      mergedTypeDefinitions.forEach(definition => {
         if (definition.kind === "EnumTypeDefinition") {
           newTypes.push({
             type: GraphQLEnumType,