Preserve directives on fragments when merging AST

.changeset/tidy-comics-roll.md

@@ -0,0 +1,5 @@
+---
+'@graphiql/toolkit': minor
+---
+
+Preserve directives on fragment during merge

packages/graphiql-toolkit/src/graphql-helpers/__tests__/merge-ast.spec.ts

@@ -202,6 +202,34 @@ describe('MergeAst', () => {
     expect(removeParametersCommas(parseMergeAndPrint(query))).toBe(mergedQuery);
     expect(parseMergeAndPrint(query, sorareSchema)).toBe(mergedQueryWithSchema);
   });
+
+  it('preserve directives on fragments', () => {
+    const query = /* GraphQL */ `
+      query Test($param: Boolean!) {
+        ...Fragment1 @include(if: $param)
+      }
+
+      fragment Fragment1 on Test {
+        id
+      }
+    `;
+    const mergedQuery = stripWhitespace(/* GraphQL */ `
+      query Test($param: Boolean!) {
+        ... on Test @include(if: $param) {
+          id
+        }
+      }
+    `);
+    const mergedQueryWithSchema = stripWhitespace(/* GraphQL */ `
+      query Test($param: Boolean!) {
+        ... on Test @include(if: $param) {
+          id
+        }
+      }
+    `);
+    expect(parseMergeAndPrint(query)).toBe(mergedQuery);
+    expect(parseMergeAndPrint(query, schema)).toBe(mergedQueryWithSchema);
+  });
 });
 
 function parseMergeAndPrint(query: string, maybeSchema?: GraphQLSchema) {

packages/graphiql-toolkit/src/graphql-helpers/merge-ast.ts

@@ -70,11 +70,11 @@ function inlineRelevantFragmentSpreads(
       }
       const fragmentDefinition = fragmentDefinitions[selection.name.value];
       if (fragmentDefinition) {
-        const { typeCondition, directives, selectionSet } = fragmentDefinition;
+        const { typeCondition, selectionSet } = fragmentDefinition;
         selection = {
           kind: Kind.INLINE_FRAGMENT,
           typeCondition,
-          directives,
+          directives: selection.directives,
           selectionSet,
         };
       }