From 0211bc8730fb39e05779c2d957f3472f370cdd02 Mon Sep 17 00:00:00 2001
From: Ilmo Raunio <ilmo.raunio@sok.fi>
Date: Fri, 26 Apr 2024 23:26:58 +0300
Subject: [PATCH] fix: Restrict sequential selection sets

---
 src/oksa/parse.cljc           | 11 +++++++----
 test/oksa/alpha/api_test.cljc | 12 ++++++++----
 test/oksa/core_test.cljc      |  6 +++++-
 3 files changed, 20 insertions(+), 9 deletions(-)

diff --git a/src/oksa/parse.cljc b/src/oksa/parse.cljc
index 08316cc..2eee3b6 100644
--- a/src/oksa/parse.cljc
+++ b/src/oksa/parse.cljc
@@ -154,11 +154,14 @@
                                 [:? [:schema [:ref ::TypeOpts]]]
                                 [:schema [:ref ::Type]]]
    ::SelectionSet [:orn
-                   [::SelectionSet [:+ [:catn
-                                        [::node [:schema [:ref ::Selection]]]
-                                        [::children [:? [:schema [:ref ::SelectionSet]]]]]]]]
+                   [::SelectionSet [:+ [:alt
+                                        [:catn
+                                         [::node [:schema [:ref ::Selection]]]
+                                         [::children [:? [:schema [:ref ::SelectionSet]]]]]
+                                        [:catn
+                                         [::node [:schema [:ref ::FieldSelection]]]]]]]]
+   ::FieldSelection [:orn [::WrappedField [:schema [:ref ::Field]]]]
    ::Selection [:orn
-                [::WrappedField [:schema [:ref ::Field]]]
                 [::NakedField [:schema [:ref ::NakedField]]]
                 [::FragmentSpread [:schema [:ref ::FragmentSpread]]]
                 [::InlineFragment [:schema [:ref ::InlineFragment]]]]
diff --git a/test/oksa/alpha/api_test.cljc b/test/oksa/alpha/api_test.cljc
index 3c51ad9..35e4b7e 100644
--- a/test/oksa/alpha/api_test.cljc
+++ b/test/oksa/alpha/api_test.cljc
@@ -1,6 +1,7 @@
 (ns oksa.alpha.api-test
   (:require [#?(:clj clojure.test
                 :cljs cljs.test) :as t]
+            [oksa.core :as oksa]
             [oksa.alpha.api :as api])
   #?(:clj (:import [graphql.parser Parser])))
 
@@ -98,9 +99,6 @@
              (unparse-and-validate (api/select :bar
                                      (api/select :qux
                                       (api/select :baz))))
-             (unparse-and-validate (api/select (api/field :bar)
-                                     (api/select (api/field :qux)
-                                       (api/select (api/field :baz)))))
              (unparse-and-validate (api/select
                                      (api/field :bar
                                        (api/select
@@ -469,4 +467,10 @@
     (t/is (= "query ($foo:Bar @fooDirective(fooArg:123)){fooField}"
              (unparse-and-validate (api/query (api/opts (api/variable :foo (api/opts (api/directive :fooDirective {:fooArg 123}))
                                                           :Bar))
-                                     (api/select :fooField)))))))
+                                     (api/select :fooField))))))
+  (t/testing "sequential selection sets should throw an exception"
+    (t/is (thrown? #?(:clj Exception :cljs js/Error)
+                   (oksa/gql
+                     (api/select (api/field :foo
+                                            (api/select :qux :baz))
+                                 (api/select :basho)))))))
diff --git a/test/oksa/core_test.cljc b/test/oksa/core_test.cljc
index 1f9dba3..f150e6b 100644
--- a/test/oksa/core_test.cljc
+++ b/test/oksa/core_test.cljc
@@ -1,6 +1,7 @@
 (ns oksa.core-test
   (:require [#?(:clj clojure.test
                 :cljs cljs.test) :as t]
+            [oksa.core :as oksa]
             [oksa.test-util :refer [unparse-and-validate]]
             [oksa.alpha.api :as api])
   #?(:clj (:import [graphql.parser Parser])))
@@ -290,7 +291,10 @@
                                     [:fooField]])))
     (t/is (= "query ($foo:Bar @fooDirective(fooArg:123)){fooField}"
              (unparse-and-validate [:oksa/query {:variables [:foo {:directives [[:fooDirective {:arguments {:fooArg 123}}]]} :Bar]}
-                                    [:fooField]])))))
+                                    [:fooField]]))))
+  (t/testing "sequential selection sets should throw an exception"
+    (t/is (thrown? #?(:clj Exception :cljs js/Error)
+                   (oksa/gql [[:foo {} [:qux :baz]] [:basho]])))))
 
 (t/deftest gql-test
   (t/is (= "{foo}\nquery {bar}\nmutation {qux}\nsubscription {baz}\nfragment foo on Foo{bar}\n{foo2}\nquery {bar2}\nmutation {qux2}\nsubscription {baz2}\nfragment foo2 on Foo2{bar2}"