[query] regression test for filter & limit (#23773)

make sure we don't accidentally mix up the application of Limit and Filter in query pipelines by adding a regression test.

GitOrigin-RevId: fb9ee928779e4c77cf39a930125cd82cabd16220

crates/isolate/src/tests/query.rs

@@ -22,6 +22,7 @@ use must_let::must_let;
 use pretty_assertions::assert_eq;
 use runtime::testing::TestRuntime;
 use value::{
+    assert_val,
     id_v6::DocumentIdV6,
     ConvexObject,
 };
@@ -59,6 +60,27 @@ async fn test_full_table_scan(rt: TestRuntime) -> anyhow::Result<()> {
     Ok(())
 }
 
+#[convex_macro::test_runtime]
+async fn test_filter_first(rt: TestRuntime) -> anyhow::Result<()> {
+    let t = UdfTest::default(rt).await?;
+    add_index(&t).await?;
+    // Create two documents with different numbers, and filter for them.
+    // This tests that Limit and Filter are applied in the correct order,
+    // because if Limit is applied before Filter, `query().filter().first()`
+    // would run as `query().first().filter()` and get no results.
+    t.mutation("query:insert", assert_obj!( "number" => 1))
+        .await?;
+    t.mutation("query:insert", assert_obj!( "number" => 2))
+        .await?;
+
+    must_let!(let ConvexValue::Object(r) = t.query("query:filterFirst", assert_obj!( "number" => 1)).await?);
+    assert_eq!(r.get("hello"), Some(&assert_val!(1)));
+
+    must_let!(let ConvexValue::Object(r) = t.query("query:filterFirst", assert_obj!( "number" => 2)).await?);
+    assert_eq!(r.get("hello"), Some(&assert_val!(2)));
+    Ok(())
+}
+
 #[convex_macro::test_runtime]
 async fn test_boolean_value_filters(rt: TestRuntime) -> anyhow::Result<()> {
     let t = UdfTest::default(rt).await?;

npm-packages/udf-tests/convex/query.ts

@@ -27,6 +27,13 @@ export const filterScan = query(({ db }, { number }: { number: number }) =>
     .collect(),
 );
 
+export const filterFirst = query(({ db }, { number }: { number: number }) =>
+  db
+    .query("test")
+    .filter((q) => q.eq(q.field("hello"), number))
+    .first(),
+);
+
 export const explicitScan = query(({ db }, { number }: { number: number }) => {
   return db
     .query("test")