Fix for parsing a repeatable keyword as an identifier (#600)

Author: vepanimas

gen/com/intellij/lang/jsgraphql/GraphQLParser.java

@@ -140,7 +140,7 @@ private argument_recover ::= !(')' | argument)
 
 identifier ::=
   NAME | 'fragment' | 'query' | 'mutation' | 'subscription' | 'schema' | 'scalar' | 'type' |
-  'interface' | 'implements' | 'enum' | 'union' | 'input' | 'extend' | 'directive' | 'on'
+  'interface' | 'implements' | 'enum' | 'union' | 'input' | 'extend' | 'directive' | 'on' | 'repeatable'
   {
     mixin="com.intellij.lang.jsgraphql.psi.impl.GraphQLReferenceMixin"
     implements="com.intellij.lang.jsgraphql.psi.GraphQLReferenceElement"

src/grammars/GraphQLParser.bnf

@@ -47,6 +47,10 @@ public void testEmoji() {
         doTest(true, true);
     }
 
+    public void testKeywordsAsIdentifiers() {
+        doTest(true, true);
+    }
+
     @Override
     protected String getTestDataPath() {
         return "test-resources/testData/graphql/parser";

src/test/com/intellij/lang/jsgraphql/parser/GraphQLParserTest.java

@@ -0,0 +1,4 @@
+type Foo {
+    type: Boolean
+    repeatable: Boolean
+}

test-resources/testData/graphql/parser/KeywordsAsIdentifiers.graphql

@@ -0,0 +1,30 @@
+GraphQL(0,54)
+  GraphQLObjectTypeDefinitionImpl(OBJECT_TYPE_DEFINITION)(0,54)
+    PsiElement(type)('type')(0,4)
+    PsiWhiteSpace(' ')(4,5)
+    GraphQLTypeNameDefinitionImpl(TYPE_NAME_DEFINITION)(5,8)
+      GraphQLIdentifierImpl(IDENTIFIER)(5,8)
+        PsiElement(NAME)('Foo')(5,8)
+    PsiWhiteSpace(' ')(8,9)
+    GraphQLFieldsDefinitionImpl(FIELDS_DEFINITION)(9,54)
+      PsiElement({)('{')(9,10)
+      PsiWhiteSpace('\n    ')(10,15)
+      GraphQLFieldDefinitionImpl(FIELD_DEFINITION)(15,28)
+        GraphQLIdentifierImpl(IDENTIFIER)(15,19)
+          PsiElement(type)('type')(15,19)
+        PsiElement(:)(':')(19,20)
+        PsiWhiteSpace(' ')(20,21)
+        GraphQLTypeNameImpl(TYPE_NAME)(21,28)
+          GraphQLIdentifierImpl(IDENTIFIER)(21,28)
+            PsiElement(NAME)('Boolean')(21,28)
+      PsiWhiteSpace('\n    ')(28,33)
+      GraphQLFieldDefinitionImpl(FIELD_DEFINITION)(33,52)
+        GraphQLIdentifierImpl(IDENTIFIER)(33,43)
+          PsiElement(repeatable)('repeatable')(33,43)
+        PsiElement(:)(':')(43,44)
+        PsiWhiteSpace(' ')(44,45)
+        GraphQLTypeNameImpl(TYPE_NAME)(45,52)
+          GraphQLIdentifierImpl(IDENTIFIER)(45,52)
+            PsiElement(NAME)('Boolean')(45,52)
+      PsiWhiteSpace('\n')(52,53)
+      PsiElement(})('}')(53,54)