From 58d072f0a16794e96e07302cac8169c74017c14c Mon Sep 17 00:00:00 2001
From: Tomas Dvorak <toomas2d@gmail.com>
Date: Tue, 15 Oct 2024 15:39:54 +0200
Subject: [PATCH] fix(serialization): handle bounded functions

Ref: #92
Signed-off-by: Tomas Dvorak <toomas2d@gmail.com>
---
 src/serializer/serializer.test.ts | 26 ++++++++++++++++++++++++++
 src/serializer/serializer.ts      |  4 +++-
 2 files changed, 29 insertions(+), 1 deletion(-)

diff --git a/src/serializer/serializer.test.ts b/src/serializer/serializer.test.ts
index 16c831bd..40098620 100644
--- a/src/serializer/serializer.test.ts
+++ b/src/serializer/serializer.test.ts
@@ -25,6 +25,7 @@ import { BAMLLM } from "@/adapters/bam/llm.js";
 import { BAMChatLLM } from "@/adapters/bam/chat.js";
 import { SerializerError } from "@/serializer/error.js";
 import { ValueOf } from "@/internals/types.js";
+import { toBoundedFunction } from "@/serializer/utils.js";
 
 describe("Serializer", () => {
   it.each([
@@ -265,6 +266,31 @@ describe("Serializer", () => {
       expect(() => Serializer.deserialize(json, [BaseMessage])).not.toThrowError();
     });
 
+    it("Handles bounded functions", () => {
+      const a = 1;
+      const b = 2;
+
+      let fn = toBoundedFunction(
+        (...args: any[]) => [a, b, ...args].reduce((a, b) => a + b, 0),
+        [
+          {
+            name: "a",
+            value: a,
+          },
+          {
+            name: "b",
+            value: b,
+          },
+        ],
+      );
+
+      for (let i = 0; i < 5; ++i) {
+        const serialized = Serializer.serialize(fn);
+        fn = Serializer.deserialize(serialized);
+        expect(fn(3)).toBe(6);
+      }
+    });
+
     it("Handles nested functions", () => {
       vi.stubEnv("GENAI_API_KEY", "123");
       const { data } = JSON.parse(
diff --git a/src/serializer/serializer.ts b/src/serializer/serializer.ts
index 109c2890..3482b095 100644
--- a/src/serializer/serializer.ts
+++ b/src/serializer/serializer.ts
@@ -31,6 +31,7 @@ import {
   RootNode,
   SerializerNode,
   SerializerRefIdentifier,
+  toBoundedFunction,
   traverseObject,
   traverseWithUpdate,
 } from "@/serializer/utils.js";
@@ -43,6 +44,7 @@ import { SerializerError } from "@/serializer/error.js";
 import { ZodType } from "zod";
 import { toJsonSchema } from "@/internals/helpers/schema.js";
 import { createAbortController } from "@/internals/helpers/cancellation.js";
+import { hasMinLength } from "@/internals/helpers/array.js";
 
 export interface SerializeFactory<A = unknown, B = unknown> {
   ref: ClassConstructor<A> | NamedFunction<A>;
@@ -530,7 +532,7 @@ Serializer.register(Function, {
         value: () => value.fn,
       }),
     );
-    return fn;
+    return hasMinLength(binds, 1) ? toBoundedFunction(fn, binds) : fn;
   },
 });