From 03b52e587788d4c57a8379b52408646c785b33e5 Mon Sep 17 00:00:00 2001
From: "lancedb-gatefixer[bot]"
 <313497061+lancedb-gatefixer[bot]@users.noreply.github.com>
Date: Thu, 6 Aug 2026 16:43:59 +0800
Subject: [PATCH] test(node): cover fixed-size list schemas with typed arrays
 (#3866)

## Summary

- cover explicit FixedSizeList schemas populated from Float32Array
values
- verify the original vector.0 failure stays fixed across Arrow 15, 16,
17, and 18

## Root cause and fix

In v0.16, schema subset inference treated typed-array vectors as nested
objects and looked up numeric paths such as vector.0, which do not exist
in a FixedSizeList schema. Current typed-array handling correctly
recognizes ArrayBuffer views as vector values instead of traversing
their elements. This change adds the missing regression coverage for the
reported explicit-schema path so that behavior cannot regress unnoticed.

## Validation

- pnpm test __test__/arrow.test.ts --runInBand
- pnpm lint
- pnpm build
- pnpm run docs
- pnpm test --runInBand (681 passed, 5 skipped)

Fixes #2134

<!-- lance-gatekeeper-fix:v1 agent=1d548cb70f6df110ce0a5b119395b52a
generation=1 -->

Co-authored-by: Gatefixer <313497061+lancedb-gatefixer[bot]@users.noreply.github.com>
---
 nodejs/__test__/arrow.test.ts | 29 +++++++++++++++++++++++++++++
 1 file changed, 29 insertions(+)

diff --git a/nodejs/__test__/arrow.test.ts b/nodejs/__test__/arrow.test.ts
index 9e20e3c04..c05849cb9 100644
--- a/nodejs/__test__/arrow.test.ts
+++ b/nodejs/__test__/arrow.test.ts
@@ -197,6 +197,35 @@ describe.each([arrow15, arrow16, arrow17, arrow18])(
         expect(table.getChild("d")?.toJSON()).toEqual([9n, 10n, null]);
       });
 
+      it("will use a provided FixedSizeList schema with typed array values", function () {
+        const schema = new Schema([
+          new Field("text", new Utf8(), false),
+          new Field(
+            "vector",
+            new FixedSizeList(3, new Field("item", new Float32(), false)),
+            false,
+          ),
+        ]);
+
+        const table = makeArrowTable(
+          [
+            {
+              text: "foo",
+              vector: new Float32Array([1, 2, 3]),
+            },
+          ],
+          { schema },
+        );
+
+        expect(table.getChild("text")?.toJSON()).toEqual(["foo"]);
+        expect(
+          table
+            .getChild("vector")
+            ?.toJSON()
+            .map((value) => value.toJSON()),
+        ).toEqual([[1, 2, 3]]);
+      });
+
       it("will assume the column `vector` is FixedSizeList<Float32> by default", async function () {
         const schema = new Schema([
           new Field("a", new Float(Precision.DOUBLE), true),