From 655718768b22bbec7d72e801b9f88679ab61ae53 Mon Sep 17 00:00:00 2001
From: dancode-188 <danbitengo@gmail.com>
Date: Sun, 28 Dec 2025 01:45:56 +0300
Subject: [PATCH] fix: add validation to importChain to prevent crashes, fixes
 #12

importChain would crash when given invalid JSON or when required fields
were missing. No try-catch on JSON.parse() and no validation before
accessing chain.steps would cause TypeErrors.

Added validation for:
- JSON parsing errors (wrapped in try-catch)
- Required fields: name must be a string
- steps must be an array (not undefined/null)

Now throws clear errors instead of cryptic TypeErrors when import fails.
---
 src/lib/chain-service.ts | 23 +++++++++++++++++++++--
 1 file changed, 21 insertions(+), 2 deletions(-)

diff --git a/src/lib/chain-service.ts b/src/lib/chain-service.ts
index b6666c2..67aae96 100644
--- a/src/lib/chain-service.ts
+++ b/src/lib/chain-service.ts
@@ -379,8 +379,27 @@ class ChainService {
    * Import chain from JSON
    */
   async importChain(json: string): Promise<Chain> {
-    const chain = JSON.parse(json) as Chain;
-    
+    let parsed: any;
+
+    try {
+      parsed = JSON.parse(json);
+    } catch (error) {
+      throw new Error('Invalid JSON format');
+    }
+
+    // Validate required fields
+    if (!parsed || typeof parsed !== 'object') {
+      throw new Error('Invalid chain data: expected object');
+    }
+    if (!parsed.name || typeof parsed.name !== 'string') {
+      throw new Error('Invalid chain data: name is required');
+    }
+    if (!Array.isArray(parsed.steps)) {
+      throw new Error('Invalid chain data: steps must be an array');
+    }
+
+    const chain = parsed as Chain;
+
     // Generate new IDs
     chain.id = `chain-${Date.now()}`;
     chain.createdAt = new Date();