Don't break in compat mode when root field is not named Query

Summary:
Fixes #1667 and #1624

I tested using this branch of the example repo: https://github.com/relayjs/relay-examples/compare/master...robrichard:custom-query-name?expand=1

kassens
Closes #1962

Differential Revision: D5518631

Pulled By: leebyron

fbshipit-source-id: 13af016f4224885f9fd7be370f5c288693db9e30

packages/babel-plugin-relay/createClassicNode.js

@@ -16,6 +16,7 @@
 const GraphQL = require('graphql');
 
 const compileRelayQLTag = require('./compileRelayQLTag');
+const getClassicTransformer = require('./getClassicTransformer');
 const getFragmentNameParts = require('./getFragmentNameParts');
 const invariant = require('./invariant');
 
@@ -295,17 +296,44 @@ function createObject(t, obj: any) {
   );
 }
 
+function getSchemaOption(state) {
+  const schema = state.opts && state.opts.schema;
+  invariant(
+    schema,
+    'babel-plugin-relay: Missing schema option. ' +
+      'Check your .babelrc file or wherever you configure your Babel ' +
+      'plugins to ensure the "relay" plugin has a "schema" option.\n' +
+      'https://facebook.github.io/relay/docs/babel-plugin-relay.html#additional-options',
+  );
+  return schema;
+}
+
 function createFragmentForOperation(t, path, operation, state) {
   let type;
+  const schema = getSchemaOption(state);
+  const fileOpts = (state.file && state.file.opts) || {};
+  const transformer = getClassicTransformer(schema, state.opts || {}, fileOpts);
   switch (operation.operation) {
     case 'query':
-      type = 'Query';
+      const queryType = transformer.schema.getQueryType();
+      if (!queryType) {
+        throw new Error('Schema does not contain a root query type.');
+      }
+      type = queryType.name;
       break;
     case 'mutation':
-      type = 'Mutation';
+      const mutationType = transformer.schema.getMutationType();
+      if (!mutationType) {
+        throw new Error('Schema does not contain a root mutation type.');
+      }
+      type = mutationType.name;
       break;
     case 'subscription':
-      type = 'Subscription';
+      const subscriptionType = transformer.schema.getSubscriptionType();
+      if (!subscriptionType) {
+        throw new Error('Schema does not contain a root subscription type.');
+      }
+      type = subscriptionType.name;
       break;
     default:
       throw new Error(
@@ -335,14 +363,7 @@ function createFragmentForOperation(t, path, operation, state) {
 }
 
 function createRelayQLTemplate(t, path, node, state) {
-  const schema = state.opts && state.opts.schema;
-  invariant(
-    schema,
-    'babel-plugin-relay: Missing schema option. ' +
-      'Check your .babelrc file or wherever you configure your Babel ' +
-      'plugins to ensure the "relay" plugin has a "schema" option.\n' +
-      'https://facebook.github.io/relay/docs/babel-plugin-relay.html#additional-options',
-  );
+  const schema = getSchemaOption(state);
   const [documentName, propName] = getFragmentNameParts(node.name.value);
   const text = GraphQL.print(node);
   const quasi = t.templateLiteral(

packages/react-relay/classic/store/RelayStoreConstants.js

@@ -20,12 +20,6 @@
  */
 const ROOT_ID = 'client:root';
 
-/**
- * The type of the root record.
- */
-const ROOT_TYPE = 'Query';
-
 module.exports = {
   ROOT_ID,
-  ROOT_TYPE,
 };

packages/react-relay/classic/store/RelayStoreData.js

@@ -73,7 +73,7 @@ import type {
 
 const {CLIENT_MUTATION_ID} = RelayConnectionInterface;
 const {ID, ID_TYPE, NODE, NODE_TYPE, TYPENAME} = RelayNodeInterface;
-const {ROOT_ID, ROOT_TYPE} = require('RelayStoreConstants');
+const {ROOT_ID} = require('RelayStoreConstants');
 const {EXISTENT} = RelayClassicRecordState;
 
 const idField = RelayQuery.Field.build({
@@ -350,7 +350,7 @@ class RelayStoreData {
 
       // Ensure the root record exists
       const path = RelayQueryPath.getRootRecordPath();
-      recordWriter.putRecord(ROOT_ID, ROOT_TYPE, path);
+      recordWriter.putRecord(ROOT_ID, query.getType(), path);
       if (this._queuedStore.getRecordState(ROOT_ID) !== EXISTENT) {
         changeTracker.createID(ROOT_ID);
       } else {