feat: add settings defaults and validation with unit tests

lib/defaults.js

@@ -0,0 +1,13 @@
+// Single source of truth for the settings shape and their defaults.
+// Defaults reproduce the extension's pre-1.1 behaviour exactly: an empty model
+// and both toggles off mean the only URL parameter sent is `q`.
+
+export const OPEN_IN_VALUES = ["new-tab", "background-tab", "new-window"];
+
+export const DEFAULT_SETTINGS = {
+  model: "",
+  temporaryChat: false,
+  webSearch: false,
+  openIn: "new-tab",
+  promptTemplate: "{query}",
+};

lib/settings.js

@@ -0,0 +1,45 @@
+import { DEFAULT_SETTINGS, OPEN_IN_VALUES } from "./defaults.js";
+
+// Pure. Layers stored values over the defaults, dropping unknown keys and
+// falling back on wrong types or out-of-range values. A fresh or signed-out
+// profile returns {} from storage, which yields the defaults.
+export function mergeSettings(stored) {
+  const merged = { ...DEFAULT_SETTINGS };
+  if (stored === null || typeof stored !== "object") {
+    return merged;
+  }
+  if (typeof stored.model === "string") {
+    merged.model = stored.model;
+  }
+  if (typeof stored.temporaryChat === "boolean") {
+    merged.temporaryChat = stored.temporaryChat;
+  }
+  if (typeof stored.webSearch === "boolean") {
+    merged.webSearch = stored.webSearch;
+  }
+  if (OPEN_IN_VALUES.includes(stored.openIn)) {
+    merged.openIn = stored.openIn;
+  }
+  if (typeof stored.promptTemplate === "string") {
+    merged.promptTemplate = stored.promptTemplate;
+  }
+  return merged;
+}
+
+// storage.sync works with no Mozilla account (it behaves as local storage and
+// syncs later if the user signs in), so no capability probe is needed. Any
+// rejection falls back to defaults rather than blocking the user's action.
+// Firefox sanitises all non-quota backend errors to a single generic string, so
+// there is nothing useful to branch on.
+export async function load() {
+  try {
+    const stored = await browser.storage.sync.get(Object.keys(DEFAULT_SETTINGS));
+    return mergeSettings(stored);
+  } catch {
+    return mergeSettings(null);
+  }
+}
+
+export async function save(partial) {
+  await browser.storage.sync.set(partial);
+}

package.json

@@ -1,7 +1,8 @@
 {
   "name": "search-with-chatgpt-powered-by-openai-extension",
-  "version": "1.0.0",
+  "version": "1.1.0",
   "private": true,
+  "type": "module",
   "description": "Development tooling for the Search with ChatGPT Firefox extension.",
   "engines": {
     "node": ">=22"
@@ -9,8 +10,9 @@
   "scripts": {
     "dev": "web-ext run",
     "lint": "web-ext lint",
+    "test:unit": "node --test",
     "build": "web-ext build",
-    "test": "npm run lint && npm run build"
+    "test": "npm run lint && npm run test:unit && npm run build"
   },
   "devDependencies": {
     "web-ext": "10.5.0"

test/settings.test.js

@@ -0,0 +1,80 @@
+import test from "node:test";
+import assert from "node:assert/strict";
+
+import { DEFAULT_SETTINGS } from "../lib/defaults.js";
+import { mergeSettings } from "../lib/settings.js";
+
+test("empty object yields the defaults", () => {
+  assert.deepEqual(mergeSettings({}), DEFAULT_SETTINGS);
+});
+
+test("null and undefined yield the defaults", () => {
+  assert.deepEqual(mergeSettings(null), DEFAULT_SETTINGS);
+  assert.deepEqual(mergeSettings(undefined), DEFAULT_SETTINGS);
+});
+
+test("a non-object yields the defaults", () => {
+  assert.deepEqual(mergeSettings("nonsense"), DEFAULT_SETTINGS);
+  assert.deepEqual(mergeSettings(42), DEFAULT_SETTINGS);
+});
+
+test("valid stored values are preserved", () => {
+  assert.deepEqual(
+    mergeSettings({
+      model: "auto",
+      temporaryChat: true,
+      webSearch: true,
+      openIn: "new-window",
+      promptTemplate: "Explain: {query}",
+    }),
+    {
+      model: "auto",
+      temporaryChat: true,
+      webSearch: true,
+      openIn: "new-window",
+      promptTemplate: "Explain: {query}",
+    },
+  );
+});
+
+test("missing keys fall back individually", () => {
+  const merged = mergeSettings({ model: "auto" });
+  assert.equal(merged.model, "auto");
+  assert.equal(merged.temporaryChat, DEFAULT_SETTINGS.temporaryChat);
+  assert.equal(merged.promptTemplate, DEFAULT_SETTINGS.promptTemplate);
+});
+
+test("unknown keys are dropped", () => {
+  const merged = mergeSettings({ model: "auto", nope: "gone", openInn: "typo" });
+  assert.deepEqual(Object.keys(merged).sort(), Object.keys(DEFAULT_SETTINGS).sort());
+  assert.equal("nope" in merged, false);
+});
+
+test("wrong types fall back to the default", () => {
+  const merged = mergeSettings({
+    model: 123,
+    temporaryChat: "yes",
+    webSearch: 1,
+    promptTemplate: [],
+  });
+  assert.equal(merged.model, DEFAULT_SETTINGS.model);
+  assert.equal(merged.temporaryChat, DEFAULT_SETTINGS.temporaryChat);
+  assert.equal(merged.webSearch, DEFAULT_SETTINGS.webSearch);
+  assert.equal(merged.promptTemplate, DEFAULT_SETTINGS.promptTemplate);
+});
+
+test("an out-of-range openIn falls back to the default", () => {
+  assert.equal(mergeSettings({ openIn: "teleport" }).openIn, DEFAULT_SETTINGS.openIn);
+  assert.equal(mergeSettings({ openIn: "" }).openIn, DEFAULT_SETTINGS.openIn);
+});
+
+test("each documented openIn value is accepted", () => {
+  for (const value of ["new-tab", "background-tab", "new-window"]) {
+    assert.equal(mergeSettings({ openIn: value }).openIn, value);
+  }
+});
+
+test("mergeSettings does not mutate DEFAULT_SETTINGS", () => {
+  mergeSettings({ model: "mutated" });
+  assert.equal(DEFAULT_SETTINGS.model, "");
+});