From 23ddfbc51352c8fcc5623d7a7dfb544e9f32aa32 Mon Sep 17 00:00:00 2001
From: ankit25bcs10610 <ankit25bcs10610@users.noreply.github.com>
Date: Fri, 3 Jul 2026 02:30:34 +0530
Subject: [PATCH] fix(reka-ai): guard first-message access in chat transform

The conversation_history transform dereferenced `messages[0]` before any
element was pushed to the local array:

- `if (media_url && messages[0].media_url)` throws when the first message
  is an image (messages is still empty at that point).
- `if (messages[0].type !== 'human')` throws when the message list is
  empty (or fully filtered).

Use optional chaining so an image-first or empty message list no longer
crashes the transform. Add regression tests.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
---
 src/providers/reka-ai/chatComplete.test.ts | 33 ++++++++++++++++++++++
 src/providers/reka-ai/chatComplete.ts      |  4 +--
 2 files changed, 35 insertions(+), 2 deletions(-)
 create mode 100644 src/providers/reka-ai/chatComplete.test.ts

diff --git a/src/providers/reka-ai/chatComplete.test.ts b/src/providers/reka-ai/chatComplete.test.ts
new file mode 100644
index 000000000..7faf4e493
--- /dev/null
+++ b/src/providers/reka-ai/chatComplete.test.ts
@@ -0,0 +1,33 @@
+import { Params } from '../../types/requestBody';
+import { ParameterConfig, ProviderConfig } from '../types';
+import { RekaAIChatCompleteConfig } from './chatComplete';
+
+const transformMessages = (config: ProviderConfig) => {
+  const messagesConfig = config.messages as ParameterConfig;
+  return (params: Params) => messagesConfig.transform!(params, {} as any);
+};
+
+describe('RekaAIChatCompleteConfig messages transform', () => {
+  const transform = transformMessages(RekaAIChatCompleteConfig);
+
+  it('does not throw when the first message is an image', () => {
+    expect(() =>
+      transform({
+        messages: [
+          {
+            role: 'user',
+            content: [
+              { type: 'image_url', image_url: { url: 'https://x/y.png' } },
+            ],
+          },
+        ],
+      } as Params)
+    ).not.toThrow();
+  });
+
+  it('does not throw when there are no messages', () => {
+    expect(() =>
+      transform({ messages: [] } as unknown as Params)
+    ).not.toThrow();
+  });
+});
diff --git a/src/providers/reka-ai/chatComplete.ts b/src/providers/reka-ai/chatComplete.ts
index 8b217b9f5..2c054c2cc 100644
--- a/src/providers/reka-ai/chatComplete.ts
+++ b/src/providers/reka-ai/chatComplete.ts
@@ -38,7 +38,7 @@ export const RekaAIChatCompleteConfig: ProviderConfig = {
         media_url?: string;
       }) => {
         // NOTE: can't have more than one image in conversation history
-        if (media_url && messages[0].media_url) {
+        if (media_url && messages[0]?.media_url) {
           return;
         }
 
@@ -76,7 +76,7 @@ export const RekaAIChatCompleteConfig: ProviderConfig = {
         }
       });
 
-      if (messages[0].type !== 'human') {
+      if (messages[0]?.type !== 'human') {
         messages.unshift({
           type: 'human',
           text: 'Placeholder for alternation',