Branch/Environment/Version
- Branch/Version: v5.1.2
- Environment: On-prem
Describe the bug
GraphQL unexpected null results. When using a Supergraph with subgraphs (2 or more) that target GraphQL services we have observed issues where a single invalid ID can result in all instances of that object type in the result set being returned as null.
Reproduction steps
This repo contains a complete reproduction of the error
https://gitlab.com/vee-engineering-public/dependencies/tyk-5x-null-reference-bug/-/blob/master/README.md?ref_type=heads
Actual behaviour
Any invalid (does not exist) object ID causes all objects of that type to be null
{
"data": {
"posts": {
"getPosts": [
{
"id": "1",
"title": "post-1",
"authorId": 9999,
"user": null <- Should be null
},
{
"id": "2",
"title": "post-2",
"authorId": 2,
"user": null <- Should *not* be null
},
{
"id": "3",
"title": "post-3",
"authorId": 3,
"user": null <- Should *not* be null
},
{
"id": "4",
"title": "post-4",
"authorId": 4,
"user": null <- Should *not* be null
}
]
}
}
}
Expected behaviour
Only objects with invalid IDs should show as null. Other instances should return normally
{
"data": {
"posts": {
"getPosts": [
{
"id": "1",
"title": "post-1",
"authorId": null,
"user": null <- This value is correctly returned as null
},
{
"id": "2",
"title": "post-2",
"authorId": 2,
"user": { <- returned correctly (not affected by post ID 1 being null)
"id": "2",
"name": "user-2"
}
},
{
"id": "3",
"title": "post-3",
"authorId": 3,
"user": {
"id": "3",
"name": "user-3"
}
},
{
"id": "4",
"title": "post-4",
"authorId": 4,
"user": {
"id": "4",
"name": "user-4"
}
}
]
}
}
}
Screenshots/Video
N/A
Logs (debug mode or log file):
time="Oct 10 10:30:26" level=debug msg="/data (beforeFetchHook): {\"method\":\"POST\",\"url\":\"http://users:3000/graphql\",\"header\":{},\"body\":{\"query\":\"query($representations: [_Any!]!){_entities(representations: $representations){__typename ... on User {name}}}\",\"variables\":{\"representations\":[{\"id\":\"9999\",\"__typename\":\"User\"},{\"id\":\"2\",\"__typename\":\"User\"},{\"id\":\"3\",\"__typename\":\"User\"},{\"id\":\"4\",\"__typename\":\"User\"}]}}}" api_id=subgraph-users api_name=subgraph-users mw=GraphQLMiddleware org_id=default origin= path="[47 100 97 116 97]"
2023-10-10T10:30:27.017937006Z time="Oct 10 10:30:27" level=debug msg="/data (afterFetchHook.OnData): {\"_entities\":[null,{\"__typename\":\"User\",\"name\":\"user-2\"},{\"__typename\":\"User\",\"name\":\"user-3\"},{\"__typename\":\"User\",\"name\":\"user-4\"}]}" api_id=subgraph-users api_name=subgraph-users mw=GraphQLMiddleware org_id=default origin= path="[47 100 97 116 97]" single_flight=false
2023-10-10T10:30:27.019007048Z time="Oct 10 10:30:27" level=error msg="http: proxy error: Key path not found" api_id=subgraph-users api_name=subgraph-users mw=ReverseProxy org_id=default prefix=proxy server_name="users:3000" user_id=-- user_ip= user_name=
2023-10-10T10:30:27.019548673Z
Configuration (tyk config file):
https://gitlab.com/vee-engineering-public/dependencies/tyk-5x-null-reference-bug/-/blob/master/tyk-v5-1-2/tyk-standalone.conf?ref_type=heads
Additional context
This behaviour was not present in Tyk v4.3.1. There was a different bug on that version that would cause a sort/match/join error if any object id in a result set was returned as null. As per this open issue
Requesting list of records with null foreign key relationship mix up the response and makes data integrity issue · Issue #4353 · TykTechnologies/tyk · GitHub . The workaournd to that was to return dummy IDs (so not null) that did not resolve.
