Support directives on directive definitions in GraphQL (#19171)

changelog_unreleased/graphql/19171.md

@@ -0,0 +1,17 @@
+#### Support directives on directive definitions (#19171 by @YBJ0000)
+
+[Directives on directive definitions](https://github.com/graphql/graphql-js/pull/4521) (and `extend directive` extensions) are now supported.
+
+<!-- prettier-ignore -->
+```gql
+# Input
+directive @a @b on QUERY
+extend directive @a @b
+
+# Prettier stable
+Error: Syntax Error: Expected "on", found "@".
+
+# Prettier main
+directive @a @b on QUERY
+extend directive @a @b
+```

src/language-graphql/parser-graphql.js

@@ -17,6 +17,7 @@ function parseComments(ast) {
 
 const parseOptions = {
   allowLegacyFragmentVariables: true,
+  experimentalDirectivesOnDirectiveDefinitions: true,
 };
 
 function createParseError(error) {

src/language-graphql/printer-graphql.js

@@ -290,11 +290,19 @@ function genericPrint(path, options, print) {
               ")",
             ])
           : "",
+        printDirectives(path, print),
         node.repeatable ? " repeatable" : "",
         " on ",
         ...join(" | ", path.map(print, "locations")),
       ];
 
+    case "DirectiveExtension":
+      return [
+        "extend directive @",
+        print("name"),
+        printDirectives(path, print),
+      ];
+
     case "EnumTypeExtension":
     case "EnumTypeDefinition":
       return [

src/language-graphql/visitor-keys.js

@@ -13,10 +13,4 @@ for (const kind of [
   delete visitorKeys[kind];
 }
 
-// Not supported yet
-visitorKeys.DirectiveDefinition = visitorKeys.DirectiveDefinition.filter(
-  (key) => key !== "directives",
-);
-delete visitorKeys.DirectiveExtension;
-
 export default visitorKeys;

tests/format/graphql/directive-decl/__snapshots__/format.test.js.snap

@@ -42,3 +42,30 @@ directive @a(as: String = 1) on QUERY
 
 ================================================================================
 `;
+
+exports[`directives-on-directive-definitions.graphql format 1`] = `
+====================================options=====================================
+parsers: ["graphql"]
+                                                      printWidth: 80 (default) |
+=====================================input======================================
+directive @a @b on QUERY
+directive @a(x: Int)   @b @c on QUERY
+directive @a @b repeatable on QUERY
+directive @a(x: Int) @b repeatable on QUERY | MUTATION
+directive @a @b(reason: "deprecated") on QUERY
+
+extend directive @a @b
+extend directive @a @b @c
+
+=====================================output=====================================
+directive @a @b on QUERY
+directive @a(x: Int) @b @c on QUERY
+directive @a @b repeatable on QUERY
+directive @a(x: Int) @b repeatable on QUERY | MUTATION
+directive @a @b(reason: "deprecated") on QUERY
+
+extend directive @a @b
+extend directive @a @b @c
+
+================================================================================
+`;

tests/format/graphql/directive-decl/directives-on-directive-definitions.graphql

@@ -0,0 +1,8 @@
+directive @a @b on QUERY
+directive @a(x: Int)   @b @c on QUERY
+directive @a @b repeatable on QUERY
+directive @a(x: Int) @b repeatable on QUERY | MUTATION
+directive @a @b(reason: "deprecated") on QUERY
+
+extend directive @a @b
+extend directive @a @b @c

tests/unit/__snapshots__/visitor-keys.js.snap

@@ -1294,9 +1294,14 @@ exports[`visitor keys graphql 1`] = `
   "DirectiveDefinition": [
     "arguments",
     "description",
+    "directives",
     "locations",
     "name",
   ],
+  "DirectiveExtension": [
+    "directives",
+    "name",
+  ],
   "Document": [
     "definitions",
   ],