try to make test coverage pass

Author: martinbonnin

src/language/__tests__/printer-test.ts

@@ -124,11 +124,16 @@ describe('Printer: Query document', () => {
 
     it('Experimental: prints directives on directives', () => {
     const queryASTWithVariableDirective = parse(
-      'directive @foo @bar on FIELD_DEFINITION',
+      `
+      directive @foo @bar on FIELD_DEFINITION
+      extend directive @foo @baz
+      `,
       { experimentalDirectivesOnDirectiveDefinitions: true },
     );
     expect(print(queryASTWithVariableDirective)).to.equal(dedent`
       directive @foo @bar on FIELD_DEFINITION
+      
+      extend directive @foo @baz
     `);
   });