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fix(schema): preserve explicit additionalProperties semantics #113

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Merged
sara-dini merged 2 commits into from
May 16, 2026
Merged

fix(schema): preserve explicit additionalProperties semantics #113

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897e338
fix(schema): preserve additionalProperties for explicit arg schemas
May 16, 2026
fdc418d
refactor(schema): use Entry API for object schema normalization
May 16, 2026
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56 changes: 47 additions & 9 deletions src/main.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -5,6 +5,7 @@ use reqwest::{
Client as HttpClient,
};
use serde::{Deserialize, Serialize};
use serde_json::map::Entry;
use serde_json::{json, Value};
use std::cmp::Ordering;
use std::collections::HashSet;
Expand Down Expand Up @@ -4579,15 +4580,23 @@ fn rewrite_tools_list(body: &str, creds: Option<&Credentials>) -> String {
// Normalize no-arg object schemas so OpenAI-style function conversion
// always gets an explicit `properties` object.
if schema.get("type").and_then(|t| t.as_str()) == Some("object") {
schema
.entry("properties".to_string())
.or_insert_with(|| json!({}));
schema
.entry("required".to_string())
.or_insert_with(|| json!([]));
schema
.entry("additionalProperties".to_string())
.or_insert_with(|| json!(false));
let had_properties = match schema.entry("properties".to_string()) {
Entry::Occupied(_) => true,
Entry::Vacant(v) => {
v.insert(json!({}));
false
}
};
if let Entry::Vacant(v) = schema.entry("required".to_string()) {
v.insert(json!([]));
}
if !had_properties {
if let Entry::Vacant(v) =
schema.entry("additionalProperties".to_string())
{
v.insert(json!(false));
}
}
}
Comment on lines +4582 to +4600
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@gemini-code-assist gemini-code-assist Bot May 16, 2026

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medium

The normalization logic for inputSchema is correctly implemented to ensure OpenAI compatibility while preserving existing additionalProperties semantics. However, the current implementation performs multiple redundant lookups on the schema map (e.g., get, entry, entry, entry). While not a critical performance bottleneck in this context, combining these into a single entry-based match would be more efficient and idiomatic Rust.

References
  1. Prefer efficient map access patterns in Rust to avoid redundant lookups and allocations. (link)


// Add proxy-only confirmation flags / validation hints
Expand Down Expand Up @@ -7624,6 +7633,35 @@ mod tests {
);
}

#[test]
fn test_rewrite_tools_list_does_not_force_additional_properties_on_arg_schema() {
let body = serde_json::to_string(&json!({
"jsonrpc": "2.0",
"id": 1,
"result": {
"tools": [{
"name": "help",
"description": "Help",
"inputSchema": {
"type": "object",
"properties": {"query": {"type": "string"}}
}
}]
}
}))
.unwrap();

let result = rewrite_tools_list(&body, None);
let parsed: Value = serde_json::from_str(&result).unwrap();
let schema = parsed["result"]["tools"][0]["inputSchema"]
.as_object()
.expect("inputSchema must be object");
assert!(
!schema.contains_key("additionalProperties"),
"arg schema should keep JSON Schema default additionalProperties behavior"
);
}

// --- MCP annotations tests ---

#[test]
Expand Down
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