fix __typename not selected if already selected with alias (#5963)

* fix __typename not selected if already selected with alias * changeset * fix unit tests
ardatan · Mar 11, 2024 · 8199416 · 8199416
1 parent 4468fb8
commit 8199416
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Showing 3 changed files with 32 additions and 21 deletions.
diff --git a/.changeset/twelve-buckets-bow.md b/.changeset/twelve-buckets-bow.md
@@ -0,0 +1,5 @@
+---
+"@graphql-tools/wrap": patch
+---
+
+Fix missing `__typename` field when it is already present but aliased.
diff --git a/packages/wrap/src/transforms/TransformCompositeFields.ts b/packages/wrap/src/transforms/TransformCompositeFields.ts
@@ -150,34 +150,25 @@ export default class TransformCompositeFields<TContext = Record<string, any>>
 
     const parentTypeName = parentType.name;
     let newSelections: Array<SelectionNode> = [];
-    let typeNameExists = node.selections.some(
-      selection => selection.kind === Kind.FIELD && selection.name.value === '__typename',
-    );
+    let isTypenameSelected = false;
 
     for (const selection of node.selections) {
-      if (selection.kind !== Kind.FIELD || selection.name.value === '__typename') {
+      if (selection.kind !== Kind.FIELD) {
         newSelections.push(selection);
         continue;
       }
 
-      const newName = selection.name.value;
-
-      // See https://github.com/ardatan/graphql-tools/issues/2282
+      // The `__typename` selection should not be aliased
+      // to be accessible with this name
       if (
-        !typeNameExists &&
-        (this.dataTransformer != null || this.errorsTransformer != null) &&
-        (this.subscriptionTypeName == null || parentTypeName !== this.subscriptionTypeName)
+        selection.name.value === '__typename' &&
+        (!selection.alias || selection.alias.value === '__typename')
       ) {
-        newSelections.push({
-          kind: Kind.FIELD,
-          name: {
-            kind: Kind.NAME,
-            value: '__typename',
-          },
-        });
-        typeNameExists = true;
+        isTypenameSelected = true;
       }
 
+      const newName = selection.name.value;
+
       let transformedSelection: Maybe<SelectionNode | Array<SelectionNode>>;
       if (this.fieldNodeTransformer == null) {
         transformedSelection = selection;
@@ -228,6 +219,21 @@ export default class TransformCompositeFields<TContext = Record<string, any>>
       });
     }
 
+    // See https://github.com/ardatan/graphql-tools/issues/2282
+    if (
+      !isTypenameSelected &&
+      (this.dataTransformer != null || this.errorsTransformer != null) &&
+      (this.subscriptionTypeName == null || parentTypeName !== this.subscriptionTypeName)
+    ) {
+      newSelections.push({
+        kind: Kind.FIELD,
+        name: {
+          kind: Kind.NAME,
+          value: '__typename',
+        },
+      });
+    }
+
     return {
       ...node,
       selections: newSelections,

diff --git a/packages/wrap/tests/transformTransformCompositeFields.test.ts b/packages/wrap/tests/transformTransformCompositeFields.test.ts
@@ -125,9 +125,6 @@ describe('TransformCompositeFields', () => {
       2,
       expect.objectContaining({
         selections: [
-          expect.objectContaining({
-            name: expect.objectContaining({ kind: 'Name', value: '__typename' }),
-          }),
           expect.objectContaining({
             name: expect.objectContaining({ kind: 'Name', value: 'product' }),
             selectionSet: expect.objectContaining({
@@ -141,6 +138,9 @@ describe('TransformCompositeFields', () => {
               ],
             }),
           }),
+          expect.objectContaining({
+            name: expect.objectContaining({ kind: 'Name', value: '__typename' }),
+          }),
         ],
       }),
     );