Don't parse the GraphQL schema twice on load (#3069)

.changeset/four-trains-turn.md

@@ -0,0 +1,7 @@
+---
+'@keystonejs/keystone': major
+---
+
+Prevented parsing the GraphQL schema twice.
+- `keystone.getTypeDefs` now returns the parsed GraphQL AST instead of the raw SDL.
+- `keystone.dumpSchema` now returns the GraphQL schema as a string instead of writing it to file. Additionally, its first `file` argument was removed and now only takes a the schema name, which defaults to `public`.

packages/keystone/lib/Keystone/index.js

@@ -1,4 +1,3 @@
-const fs = require('fs');
 const gql = require('graphql-tag');
 const flattenDeep = require('lodash.flattendeep');
 const memoize = require('micro-memoize');
@@ -560,7 +559,7 @@ module.exports = class Keystone {
       subscriptions.length > 0 && `type Subscription { ${subscriptions.join('\n')} }`,
     ]
       .filter(s => s)
-      .map(s => print(gql(s)));
+      .map(s => gql(s));
   }
 
   getResolvers({ schemaName }) {
@@ -585,16 +584,11 @@ module.exports = class Keystone {
     );
   }
 
-  dumpSchema(file, schemaName) {
+  dumpSchema(schemaName = 'public') {
     // The 'Upload' scalar is normally automagically added by Apollo Server
     // See: https://blog.apollographql.com/file-uploads-with-apollo-server-2-0-5db2f3f60675
-    // Since we don't execute apollo server over this schema, we have to
-    // reinsert it.
-    const schema = `
-      scalar Upload
-      ${this.getTypeDefs({ schemaName }).join('\n')}
-    `;
-    fs.writeFileSync(file, schema);
+    // Since we don't execute apollo server over this schema, we have to reinsert it.
+    return ['scalar Upload', ...this.getTypeDefs({ schemaName }).map(t => print(t))].join('\n');
   }
 
   createItem(listKey, itemData) {

packages/keystone/tests/Keystone.test.js

@@ -97,8 +97,7 @@ test('unique typeDefs', () => {
       hero: { type: MockFieldType },
     },
   });
-  const schemaName = 'public';
-  const schema = keystone.getTypeDefs({ schemaName }).join('\n');
+  const schema = keystone.dumpSchema();
   expect(schema.match(/scalar Foo/g) || []).toHaveLength(1);
   expect(schema.match(/getFoo: Boolean/g) || []).toHaveLength(1);
   expect(schema.match(/mutateFoo: Boolean/g) || []).toHaveLength(1);
@@ -200,8 +199,7 @@ describe('Keystone.extendGraphQLSchema()', () => {
     });
 
     keystone.extendGraphQLSchema({ types: [{ type: 'type FooBar { foo: Int, bar: Float }' }] });
-    const schemaName = 'public';
-    const schema = keystone.getTypeDefs({ schemaName }).join('\n');
+    const schema = keystone.dumpSchema();
     expect(schema.match(/type FooBar {\s*foo: Int\s*bar: Float\s*}/g) || []).toHaveLength(1);
   });
 
@@ -227,8 +225,7 @@ describe('Keystone.extendGraphQLSchema()', () => {
         },
       ],
     });
-    const schemaName = 'public';
-    const schema = keystone.getTypeDefs({ schemaName }).join('\n');
+    const schema = keystone.dumpSchema();
     expect(schema.match(/double\(x: Int\): Int/g) || []).toHaveLength(1);
     expect(keystone._customProvider._extendedQueries).toHaveLength(1);
   });
@@ -255,8 +252,7 @@ describe('Keystone.extendGraphQLSchema()', () => {
         },
       ],
     });
-    const schemaName = 'public';
-    const schema = keystone.getTypeDefs({ schemaName }).join('\n');
+    const schema = keystone.dumpSchema();
     expect(schema.match(/double\(x: Int\): Int/g) || []).toHaveLength(1);
     expect(keystone._customProvider._extendedMutations).toHaveLength(1);
   });