Handle resolving a null field with @http

[amitksingh1490]

Discussed in #2466

^{Originally posted by angristan July 19, 2024}
With this example:

schema @server(port: 8000) @upstream(baseURL: "http://jsonplaceholder.typicode.com") {
  query: Query
}

type Query {
  users: [User] @http(path: "/users")
}

type User {
  id: Int!
  name: String!
  username: String!
  email: String!
  authorID: String

  posts: [Post]
    @http(
      path: "/posts"
      query: [{ key: "author_ids[]", value: "{{.value.authorID}}" }]
      batchKey: ["author_ids[]"]
    )
}

type Post {
  id: Int!
  title: String!
  body: String!
}

If authorID is not nil, it works as expected, however if it is nil, it calls /posts without any query param, thus returning unrelated posts.

Expected url
https://jsonplaceholder.typicode.com/posts?userId=
Actual url
https://jsonplaceholder.typicode.com/posts

By default this should be the behaviour

[tusharmath]

@angristan

Do we need the = in the end? Can we drop that like below?

- https://jsonplaceholder.typicode.com/posts?userId=
+ https://jsonplaceholder.typicode.com/posts?userId

[tusharmath]

/bounty 100$

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Attempt	Started (GMT+0)	Solution
🟢 @ssddOnTop	Jul 19, 2024, 11:31:18 AM	#2470

[ssddOnTop]

/attempt #2467

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[angristan]

Looks like we can drop the equal sign: https://stackoverflow.com/questions/4557387/is-a-url-query-parameter-valid-if-it-has-no-value

In the API I'm querying, providing posts?userId or posts?userId= yields the same result (nothing). I feel like posts?userId= might be safer, but that's just a gut feeling

[angristan]

Btw I don't know the codebase, but I got this working:

diff --git a/src/core/http/query_encoder.rs b/src/core/http/query_encoder.rs
index c978988f..c68d3356 100644
--- a/src/core/http/query_encoder.rs
+++ b/src/core/http/query_encoder.rs
@@ -51,7 +51,7 @@ pub fn convert_value(value: &async_graphql::Value) -> Option<String> {
         async_graphql::Value::String(s) => Some(s.to_string()),
         async_graphql::Value::Number(n) => Some(n.to_string()),
         async_graphql::Value::Boolean(b) => Some(b.to_string()),
-        _ => None,
+        _ => Some("".to_string()),
     }
 }
 
@@ -95,6 +95,18 @@ mod tests {
         assert_eq!(actual, expected);
     }
 
+    #[test]
+    fn test_encode_key_with_null_value() {
+        let encoder = QueryEncoder::RepeatedKey;
+        let values = Value::List(vec![]);
+        let arg_raw_value = Some(ValueString::Value(Cow::Borrowed(&values)));
+
+        let actual = encoder.encode("key", arg_raw_value);
+        let expected = Some("key=".to_string());
+
+        assert_eq!(actual, expected);
+    }
+
     #[test]
     fn test_encode_env_var() {
         let encoder = QueryEncoder::default();

[ssddOnTop]

Btw I don't know the codebase, but I got this working:

ye that's the problem I think (a bit different)

[algora-pbc]

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[algora-pbc]

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