test(stitch): add a reproduction for issue #1571

packages/stitch/tests/repro1571.test.ts

@@ -0,0 +1,105 @@
+import { linkToExecutor } from '@graphql-tools/links';
+import { makeExecutableSchema } from '@graphql-tools/schema';
+import { wrapSchema } from '@graphql-tools/wrap';
+import { ApolloLink, Observable } from 'apollo-link';
+import gql from 'graphql-tag';
+
+import { stitchSchemas } from '../src/stitchSchemas';
+import { ExecutionResult, GraphQLError, graphql } from 'graphql';
+
+export const typeDefs = gql`
+  input LoginInput {
+    username: String
+    password: String
+  }
+
+  type LoginPayload {
+    accessToken: String!
+  }
+
+  type Query {
+    meh: Boolean
+  }
+
+  type Mutation {
+    login(input: LoginInput!): LoginPayload!
+  }
+`;
+
+const link = new ApolloLink(operation => {
+  return new Observable(observer => {
+    const responses: Record<string, ExecutionResult> = {
+      'whatever@goodpass': {
+        data: {
+          login: {
+            accessToken: 'at',
+          },
+        },
+      },
+      'whatever@wrongpass': {
+        errors: [
+          ({
+            message: 'INVALID_CREDENTIALS',
+            path: ['login'],
+          } as unknown) as GraphQLError,
+        ],
+        data: null,
+      },
+    };
+
+    const response = responses[`${operation.variables.username}@${operation.variables.password}`];
+    if (response) {
+      observer.next(response);
+      observer.complete();
+    } else {
+      observer.error(new Error('UNEXPECTED_ERROR'));
+    }
+  });
+});
+
+const authSchema = wrapSchema({
+  executor: linkToExecutor(link),
+  schema: makeExecutableSchema({ typeDefs }),
+});
+
+const stitchedSchema = stitchSchemas({
+  subschemas: [{ schema: authSchema }],
+});
+
+describe('Repro for issue #1571', () => {
+  it.each`
+    username      | password      | response
+    ${'whatever'} | ${'goodpass'} | ${{
+      data: {
+        login: {
+          accessToken: 'at',
+        },
+      },
+    }}
+    ${'whatever'} | ${'wrongpass'} | ${{
+      errors: [{
+        message: 'INVALID_CREDENTIALS',
+        path: ['login'],
+      }],
+      data: null,
+    }}
+  `(
+    'should return the expected response for $username@$password',
+    async ({ username, password, response }: { username: string; password: string; response: string }) => {
+      const stitchedResult = await graphql(
+        stitchedSchema,
+        `
+          mutation Login($username: String!, $password: String!) {
+            login(input: { username: $username, password: $password }) {
+              accessToken
+            }
+          }
+        `,
+        undefined,
+        undefined,
+        { username, password },
+      );
+      expect(stitchedResult).toEqual(response);
+    },
+  );
+});