Catch json errors a little better (#3437)

Co-authored-by: Douwe Osinga <douwe@squareup.com>

ui/desktop/src/utils/askAI.ts

@@ -1,4 +1,5 @@
 import { getApiUrl, getSecretKey } from '../config';
+import { safeJsonParse } from './jsonUtils';
 
 const getQuestionClassifierPrompt = (messageContent: string): string => `
 You are a simple classifier that takes content and decides if it is asking for input 
@@ -167,7 +168,7 @@ export async function ask(prompt: string): Promise<string> {
     throw new Error('Failed to get response');
   }
 
-  const data = await response.json();
+  const data = await safeJsonParse<{ response: string }>(response, 'Failed to get AI response');
   return data.response;
 }
 

ui/desktop/src/utils/costDatabase.ts

@@ -1,5 +1,6 @@
 // Import the proper type from ConfigContext
 import { getApiUrl, getSecretKey } from '../config';
+import { safeJsonParse } from './jsonUtils';
 
 export interface ModelCostInfo {
   input_token_cost: number; // Cost per token for input (in USD)
@@ -47,7 +48,15 @@ async function fetchPricingForModel(
     throw new Error(`API request failed with status ${response.status}`);
   }
 
-  const data = await response.json();
+  const data = await safeJsonParse<{
+    pricing: Array<{
+      provider: string;
+      model: string;
+      input_token_cost: number;
+      output_token_cost: number;
+      currency: string;
+    }>;
+  }>(response, 'Failed to parse pricing data');
 
   // Find the specific model pricing using the lookup provider/model
   const pricing = data.pricing?.find(

ui/desktop/src/utils/githubUpdater.ts

@@ -4,6 +4,7 @@ import * as fs from 'fs/promises';
 import * as path from 'path';
 import * as os from 'os';
 import log from './logger';
+import { safeJsonParse } from './jsonUtils';
 
 interface GitHubRelease {
   tag_name: string;
@@ -53,7 +54,10 @@ export class GitHubUpdater {
         throw new Error(`GitHub API returned ${response.status}: ${response.statusText}`);
       }
 
-      const release: GitHubRelease = await response.json();
+      const release: GitHubRelease = await safeJsonParse<GitHubRelease>(
+        response,
+        'Failed to get GitHub release information'
+      );
       log.info(`GitHubUpdater: Found release: ${release.tag_name} (${release.name})`);
       log.info(`GitHubUpdater: Release published at: ${release.published_at}`);
       log.info(`GitHubUpdater: Release assets count: ${release.assets.length}`);

ui/desktop/src/utils/jsonUtils.ts

@@ -0,0 +1,13 @@
+export async function safeJsonParse<T>(
+  response: Response,
+  errorMessage: string = 'Failed to parse server response'
+): Promise<T> {
+  try {
+    return (await response.json()) as T;
+  } catch (error) {
+    if (error instanceof SyntaxError) {
+      throw new Error(errorMessage);
+    }
+    throw error;
+  }
+}