fix(core): Correctly parse fragments defined before operations

Fixes #459

packages/core/e2e/asset.e2e-spec.ts

@@ -6,7 +6,7 @@ import gql from 'graphql-tag';
 import path from 'path';
 
 import { initialData } from '../../../e2e-common/e2e-initial-data';
-import { testConfig, TEST_SETUP_TIMEOUT_MS } from '../../../e2e-common/test-config';
+import { TEST_SETUP_TIMEOUT_MS, testConfig } from '../../../e2e-common/test-config';
 
 import { ASSET_FRAGMENT } from './graphql/fragments';
 import {
@@ -14,6 +14,7 @@ import {
     DeleteAsset,
     DeletionResult,
     GetAsset,
+    GetAssetFragmentFirst,
     GetAssetList,
     GetProductWithVariants,
     SortOrder,
@@ -121,6 +122,20 @@ describe('Asset resolver', () => {
         });
     });
 
+    /**
+     * https://github.com/vendure-ecommerce/vendure/issues/459
+     */
+    it('transforms URL when fragment defined before query (GH issue #459)', async () => {
+        const { asset } = await adminClient.query<
+            GetAssetFragmentFirst.Query,
+            GetAssetFragmentFirst.Variables
+        >(GET_ASSET_FRAGMENT_FIRST, {
+            id: firstAssetId,
+        });
+
+        expect(asset?.preview).toBe('test-url/test-assets/alexandru-acea-686569-unsplash__preview.jpg');
+    });
+
     describe('createAssets', () => {
         it('permitted types by mime type', async () => {
             const filesToUpload = [
@@ -343,6 +358,19 @@ export const GET_ASSET = gql`
     ${ASSET_FRAGMENT}
 `;
 
+export const GET_ASSET_FRAGMENT_FIRST = gql`
+    fragment AssetFragFirst on Asset {
+        id
+        preview
+    }
+
+    query GetAssetFragmentFirst($id: ID!) {
+        asset(id: $id) {
+            ...AssetFragFirst
+        }
+    }
+`;
+
 export const CREATE_ASSETS = gql`
     mutation CreateAssets($input: [CreateAssetInput!]!) {
         createAssets(input: $input) {

packages/core/e2e/graphql/generated-e2e-admin-types.ts

@@ -3744,6 +3744,16 @@ export type GetAssetQuery = { __typename?: 'Query' } & {
     asset?: Maybe<{ __typename?: 'Asset' } & Pick<Asset, 'width' | 'height'> & AssetFragment>;
 };
 
+export type AssetFragFirstFragment = { __typename?: 'Asset' } & Pick<Asset, 'id' | 'preview'>;
+
+export type GetAssetFragmentFirstQueryVariables = {
+    id: Scalars['ID'];
+};
+
+export type GetAssetFragmentFirstQuery = { __typename?: 'Query' } & {
+    asset?: Maybe<{ __typename?: 'Asset' } & AssetFragFirstFragment>;
+};
+
 export type CreateAssetsMutationVariables = {
     input: Array<CreateAssetInput>;
 };
@@ -5881,6 +5891,16 @@ export namespace GetAsset {
     export type Asset = AssetFragment;
 }
 
+export namespace AssetFragFirst {
+    export type Fragment = AssetFragFirstFragment;
+}
+
+export namespace GetAssetFragmentFirst {
+    export type Variables = GetAssetFragmentFirstQueryVariables;
+    export type Query = GetAssetFragmentFirstQuery;
+    export type Asset = AssetFragFirstFragment;
+}
+
 export namespace CreateAssets {
     export type Variables = CreateAssetsMutationVariables;
     export type Mutation = CreateAssetsMutation;

packages/core/src/api/common/graphql-value-transformer.ts

@@ -114,6 +114,9 @@ export class GraphqlValueTransformer {
                         currentNode = currentNode.parent;
                     }
                 }
+                if (node.kind === 'FragmentDefinition') {
+                    currentNode = rootNode;
+                }
             },
         };
         for (const operation of document.definitions) {