GraphQL: Support repeatable directive definition printing (clos… (#7227)

src/language-graphql/printer-graphql.js

@@ -380,6 +380,7 @@ function genericPrint(path, options, print) {
               ])
             )
           : "",
+        n.repeatable ? " repeatable" : "",
         concat([" on ", join(" | ", path.map(print, "locations"))])
       ]);
     }

tests/graphql_directive_decl/__snapshots__/jsfmt.spec.js.snap

@@ -12,8 +12,10 @@ directive @a(as: String = 1) on QUERY
 directive @a(as: String, b: Int!) on QUERY
 directive @a(as: String! = 1 @deprecated) on QUERY
 directive @a(as: String! = 1 @deprecated) on QUERY | MUTATION
+directive @a(as: String! = 1 @deprecated) repeatable on QUERY | MUTATION
 
 directive @a on QUERY
+directive @a repeatable on QUERY
 
 
 directive @a(as: String) on QUERY
@@ -30,8 +32,10 @@ directive @a(as: String = 1) on QUERY
 directive @a(as: String, b: Int!) on QUERY
 directive @a(as: String! = 1 @deprecated) on QUERY
 directive @a(as: String! = 1 @deprecated) on QUERY | MUTATION
+directive @a(as: String! = 1 @deprecated) repeatable on QUERY | MUTATION
 
 directive @a on QUERY
+directive @a repeatable on QUERY
 
 directive @a(as: String) on QUERY
 

tests/graphql_directive_decl/directive_decl.graphql

@@ -4,8 +4,10 @@ directive @a(as: String = 1) on QUERY
 directive @a(as: String, b: Int!) on QUERY
 directive @a(as: String! = 1 @deprecated) on QUERY
 directive @a(as: String! = 1 @deprecated) on QUERY | MUTATION
+directive @a(as: String! = 1 @deprecated) repeatable on QUERY | MUTATION
 
 directive @a on QUERY
+directive @a repeatable on QUERY
 
 
 directive @a(as: String) on QUERY