Merge pull request 'fix: limit the prompt template to 1,000 characters' (#12) from fix/template-length-limit into develop

Reviewed-on: https://git.zavage.net/Zavage-Software/search-with-chatgpt-powered-by-openai-extension/pulls/12

lib/defaults.js

@@ -3,6 +3,12 @@
 
 export const OPEN_IN_VALUES = ["new-tab", "background-tab", "new-window"];
 
+// In UTF-16 units, as maxlength counts. Keeps the template far inside
+// storage.sync's 8192-byte item quota even when every character is a pasted
+// control character (six bytes once JSON-escaped), and far beyond any template
+// the 8,000-character URL budget could send.
+export const MAX_TEMPLATE_CHARS = 1000;
+
 export const DEFAULT_SETTINGS = {
   contextMenuMode: "simple",
   showTranslate: false,

lib/settings.js

@@ -1,4 +1,4 @@
-import { DEFAULT_SETTINGS, OPEN_IN_VALUES } from "./defaults.js";
+import { DEFAULT_SETTINGS, MAX_TEMPLATE_CHARS, OPEN_IN_VALUES } from "./defaults.js";
 
 export function normalizeLanguage(value) {
   if (typeof value !== "string") return "";
@@ -28,7 +28,7 @@ export function mergeSettings(stored) {
   if (OPEN_IN_VALUES.includes(stored.openIn)) {
     merged.openIn = stored.openIn;
   }
-  if (typeof stored.promptTemplate === "string") {
+  if (typeof stored.promptTemplate === "string" && stored.promptTemplate.length <= MAX_TEMPLATE_CHARS) {
     merged.promptTemplate = stored.promptTemplate;
   }
   return merged;