Don't use string for relationship direction in relation directive

Instead use the _RelationDirections enum

package.json

@@ -22,6 +22,7 @@
     "test-all": "nyc ava --verbose",
     "test-isolated": "nyc ava test/**/*.test.js --verbose --match='!*not-isolated*'",
     "test-gateway": "nyc --reporter=lcov ava --fail-fast test/integration/gateway.test.js",
+    "test-infer": "nyc --reporter=lcov ava --fail-fast test/unit/neo4j-schema/*.js",
     "debug": "nodemon ./example/apollo-server/movies.js --exec babel-node --inspect-brk=9229 --nolazy",
     "debug-typedefs": "nodemon ./example/apollo-server/movies-typedefs.js --exec babel-node --inspect-brk=9229 --nolazy",
     "debug-interface": "nodemon ./example/apollo-server/interfaceError.js --exec babel-node --inspect-brk=9229 --nolazy",

src/inferSchema.js

@@ -57,7 +57,7 @@ const generateGraphQLTypeForTreeEntry = (tree, key) => {
 
         const tag = `@relation(name: "${extractRelationshipType(
           relId
-        )}", direction: "OUT")`;
+        )}", direction: OUT)`;
         const targetTypeName = allTargetLabels[0];
 
         return `   ${targetTypeName.toLowerCase()}s: [${targetTypeName}] ${tag}\n`;

src/neo4j-schema/graphQLMapper.js

@@ -6,7 +6,7 @@ import Debug from 'debug';
 const debug = Debug('neo4j-graphql-js');
 
 const relationDirective = (relType, direction) =>
-  `@relation(name: "${relType}", direction: "${direction}")`;
+  `@relation(name: "${relType}", direction: ${direction})`;
 
 const mapOutboundRels = (tree, node, config) => {
   const labels = node.getLabels();
@@ -25,9 +25,7 @@ const mapOutboundRels = (tree, node, config) => {
         // (:Customer)-[:BUYS]->(:Service)
         // In this case, without type unions the destination type for :BUYS is ambiguous.
         console.warn(
-          `RelID ${
-            rel.id
-          } for label set ${labels} has > 1 target type (${targetLabels}); skipping`
+          `RelID ${rel.id} for label set ${labels} has > 1 target type (${targetLabels}); skipping`
         );
         return null;
       }
@@ -79,9 +77,7 @@ const mapInboundRels = (tree, node, config) => {
 
       if (originLabels.length > 1) {
         console.warn(
-          `RelID ${
-            rel.id
-          } for label set ${labels} has > 1 origin type (${originLabels}); skipping`
+          `RelID ${rel.id} for label set ${labels} has > 1 origin type (${originLabels}); skipping`
         );
         return null;
       }

test/unit/neo4j-schema/graphQLMapperTest.test.js

@@ -107,12 +107,12 @@ test('Defines properties with correct types', t => {
 test('Defines relationships BOTH WAYS with right order and @relation directive', t => {
   t.true(
     typeDefs.indexOf(
-      'lives_in: [State] @relation(name: "LIVES_IN", direction: "OUT")'
+      'lives_in: [State] @relation(name: "LIVES_IN", direction: OUT)'
     ) > -1
   );
   t.true(
     typeDefs.indexOf(
-      'customers: [Customer] @relation(name: "LIVES_IN", direction: "IN")'
+      'customers: [Customer] @relation(name: "LIVES_IN", direction: IN)'
     ) > -1
   );
 });
@@ -123,13 +123,13 @@ test('Deconflicts names for multi-targeted relationships by using relationship l
   // conflict.  This tests that the module has worked around this.
   t.true(
     typeDefs.indexOf(
-      'customers_buys: [Customer] @relation(name: "BUYS", direction: "IN")'
+      'customers_buys: [Customer] @relation(name: "BUYS", direction: IN)'
     ) > -1
   );
 
   t.true(
     typeDefs.indexOf(
-      'customers_reviewed: [Customer] @relation(name: "REVIEWED", direction: "IN")'
+      'customers_reviewed: [Customer] @relation(name: "REVIEWED", direction: IN)'
     ) > -1
   );
 });