[Feature] Disable a graphql filter if the variable is not set

首先跟踪 graph-node 对省略变量的 GraphQL 过滤器处理，并将其与两个 curl 示例中展示的公共 API 行为进行比较。当省略变量会禁用其过滤器，而不是生成与 null 相等的条件，并且示例查询的行为有测试覆盖时，即视为完成。

Description

Hi, I was running a graph-node of the latest stable version (v0.33.0), and an example-subgraph. After that, I was trying to request entities with GraphQL query like:

curl 'http://127.0.0.1:9000/subgraphs/name/example' \
  -H 'Accept-Language: zh-CN,zh;q=0.9,en;q=0.8' \
  -H 'Connection: keep-alive' \
  -H 'Origin: http://127.0.0.1:9000' \
  -H 'Referer: http://127.0.0.1:9000/subgraphs/name/example/graphql' \
  -H 'Sec-Fetch-Dest: empty' \
  -H 'Sec-Fetch-Mode: cors' \
  -H 'Sec-Fetch-Site: same-origin' \
  -H 'User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/117.0.0.0 Safari/537.36' \
  -H 'accept: application/json, multipart/mixed' \
  -H 'content-type: application/json' \
  -H 'sec-ch-ua: "Google Chrome";v="117", "Not;A=Brand";v="8", "Chromium";v="117"' \
  -H 'sec-ch-ua-mobile: ?0' \
  -H 'sec-ch-ua-platform: "macOS"' \
  --data-raw '{"query":"query MyQuery($id: ID) {\n  gravatars(first: 10, where: {id: $id}) {\n    id\n  }\n}","variables":{},"operationName":"MyQuery","extensions":{"headers":null}}' \
  --compressed

For more clarity, we define a filter variable id but leave it alone without setting any value.

query MyQuery($id: ID) {
  gravatars(first: 10, where: {id: $id}) {
    id
  }
}

In this case, the graph-node returns me nothing, looking like it takes the variable id as null, and queries the Postgres with the filter condition to check if id is equal to null.

Interestingly, while I was trying to simulate a similar action in our thegraph endpoint api.thegraph.com, even I didn't set any variables for id or symbol, the server would still response all entries regarding these filter variables as disabled.

curl 'https://api.thegraph.com/subgraphs/name/graphprotocol/compound-v2' \
  -H 'authority: api.thegraph.com' \
  -H 'accept: */*' \
  -H 'accept-language: zh-CN,zh;q=0.9,en;q=0.8' \
  -H 'content-type: application/json' \
  -H 'origin: https://api.thegraph.com' \
  -H 'referer: https://api.thegraph.com/subgraphs/name/graphprotocol/compound-v2' \
  -H 'sec-ch-ua: "Google Chrome";v="117", "Not;A=Brand";v="8", "Chromium";v="117"' \
  -H 'sec-ch-ua-mobile: ?0' \
  -H 'sec-ch-ua-platform: "macOS"' \
  -H 'sec-fetch-dest: empty' \
  -H 'sec-fetch-mode: cors' \
  -H 'sec-fetch-site: same-origin' \
  -H 'user-agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/117.0.0.0 Safari/537.36' \
  --data-raw '{"operationName":"markets","variables":{},"query":"query markets($id: ID, $symbol: String) {\n  markets(first: 7, where: {id: $id, symbol: $symbol}) {\n    id\n    symbol\n  }\n}\n"}' \
  --compressed

So, what is the main cause for this difference of GraphQL filter behavior between graph-node binary and our public api endpoint? Is it possible for graph-node to conform with the same behavior (disable a graphql filter if the variable is not set)?

This issue may also be relevant to #4112

Are you aware of any blockers that must be resolved before implementing this feature? If so, which? Link to any relevant GitHub issues.

No response

Some information to help us out

• Tick this box if you plan on implementing this feature yourself.
• I have searched the issue tracker to make sure this issue is not a duplicate.