refactor: declarative context-menu registry; named selection threshold

CONTEXT_MENU_ENTRIES maps every menu id to {action, style, parentId,
title}, replacing the split('-') id parsing that only worked because no
name contained a hyphen. Foreign menu ids are now ignored explicitly.
Parity pinned by tests enumerating all 30 previous ids. The 10-char
toolbar trigger threshold is now the named MIN_SELECTION_LENGTH.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

entrypoints/background.ts

@@ -1,6 +1,6 @@
 import { defineBackground } from 'wxt/utils/define-background';
 import type { AnalyzePayload, LexAIConfig, LexAIResponse } from '@lib/types';
-import { ACTIONS, ACTION_LABELS, CONTEXT_MENU_STYLES } from '@lib/actions';
+import { CONTEXT_MENU_ENTRIES, findContextMenuEntry } from '@lib/actions';
 import { decryptApiKey } from '@lib/crypto';
 import { callProvider, getSystemPrompt, listModels } from '@lib/providers';
 
@@ -40,35 +40,26 @@ export default defineBackground(() => {
   // ─── Context menus ───────────────────────────────────────────────────────
   chrome.runtime.onInstalled.addListener(() => {
     chrome.contextMenus.removeAll(() => {
-      ACTIONS.forEach(action => {
+      CONTEXT_MENU_ENTRIES.forEach((entry) => {
         chrome.contextMenus.create({
-          id: `lexai-${action}`,
-          title: `⚡ LexAI: ${ACTION_LABELS[action]}`,
+          id: entry.id,
+          parentId: entry.parentId,
+          title: entry.title,
           contexts: ['selection'],
         });
-        CONTEXT_MENU_STYLES.forEach(style => {
-          chrome.contextMenus.create({
-            id: `lexai-${action}-${style.toLowerCase()}`,
-            parentId: `lexai-${action}`,
-            title: style,
-            contexts: ['selection'],
-          });
-        });
       });
     });
   });
 
   chrome.contextMenus.onClicked.addListener((info, tab) => {
     if (!info.selectionText || !tab?.id) return;
-    // Parse action and style from menuItemId e.g. "lexai-fix-formal"
-    const parts = info.menuItemId.toString().replace('lexai-', '').split('-');
-    const action = parts[0];
-    const style = parts[1] ? parts[1].charAt(0).toUpperCase() + parts[1].slice(1) : 'Default';
+    const entry = findContextMenuEntry(info.menuItemId.toString());
+    if (!entry) return;
     chrome.tabs.sendMessage(tab.id, {
       type: 'lexai-context-menu',
-      action,
+      action: entry.action,
       text: info.selectionText,
-      style,
+      style: entry.style,
     });
   });
 

entrypoints/content.ts

@@ -1,6 +1,6 @@
 import { defineContentScript } from 'wxt/utils/define-content-script';
 import { isExtensionValid, safeSendMessage } from '@lib/messaging';
-import { WRITING_STYLES } from '@lib/actions';
+import { MIN_SELECTION_LENGTH, WRITING_STYLES } from '@lib/actions';
 
 export default defineContentScript({
   matches: ['<all_urls>'],
@@ -48,7 +48,7 @@ export default defineContentScript({
         const end = el.selectionEnd ?? -1;
         if (end - start >= 2) {
           const text = el.value.substring(start, end).trim();
-          if (text.length > 10) {
+          if (text.length >= MIN_SELECTION_LENGTH) {
             selectedText   = text;
             storedStart    = start;
             storedEnd      = end;
@@ -64,7 +64,7 @@ export default defineContentScript({
       const sel = window.getSelection();
       if (sel && sel.rangeCount > 0) {
         const text = sel.toString().trim();
-        if (text.length > 10) {
+        if (text.length >= MIN_SELECTION_LENGTH) {
           selectedText  = text;
           storedRange   = sel.getRangeAt(0).cloneRange(); // CLONE — selection will be lost later
           storedElement = null;

src/lib/actions.ts

@@ -21,3 +21,43 @@ export type WritingStyle = (typeof WRITING_STYLES)[number];
 
 // Context menus omit 'Default' — the parent action item already covers it.
 export const CONTEXT_MENU_STYLES = WRITING_STYLES.filter((s) => s !== 'Default');
+
+// Minimum selection length (chars, after trim) before the floating toolbar
+// appears. Kept deliberately above 1-2 chars so accidental double-click
+// selections don't trigger the UI.
+export const MIN_SELECTION_LENGTH = 10;
+
+// ─── Context-menu registry ────────────────────────────────────────────────────
+// Declarative id -> {action, style} mapping. Replaces the old split('-')
+// parsing of menuItemId, which only worked because no action or style name
+// contained a hyphen. Order matters: each parent precedes its children so
+// chrome.contextMenus.create never sees an unknown parentId.
+
+export interface ContextMenuEntry {
+  id: string;
+  action: ActionId;
+  style: WritingStyle;
+  // 'Default' entries are top-level parents; styled entries nest under them.
+  parentId?: string;
+  title: string;
+}
+
+export const CONTEXT_MENU_ENTRIES: ContextMenuEntry[] = ACTIONS.flatMap((action) => [
+  {
+    id: `lexai-${action}`,
+    action,
+    style: 'Default' as WritingStyle,
+    title: `⚡ LexAI: ${ACTION_LABELS[action]}`,
+  },
+  ...CONTEXT_MENU_STYLES.map((style) => ({
+    id: `lexai-${action}-${style.toLowerCase()}`,
+    action,
+    style,
+    parentId: `lexai-${action}`,
+    title: style as string,
+  })),
+]);
+
+export function findContextMenuEntry(menuItemId: string): ContextMenuEntry | undefined {
+  return CONTEXT_MENU_ENTRIES.find((e) => e.id === menuItemId);
+}

tests/unit/actions.test.ts

@@ -0,0 +1,48 @@
+import { describe, it, expect } from 'vitest';
+import {
+  ACTIONS,
+  ACTION_LABELS,
+  WRITING_STYLES,
+  CONTEXT_MENU_STYLES,
+  CONTEXT_MENU_ENTRIES,
+  findContextMenuEntry,
+} from '@lib/actions';
+
+describe('context-menu registry', () => {
+  it('contains 5 parents + 5x5 style children = 30 entries (parity with old loops)', () => {
+    expect(CONTEXT_MENU_ENTRIES).toHaveLength(30);
+    expect(CONTEXT_MENU_ENTRIES.filter((e) => !e.parentId)).toHaveLength(ACTIONS.length);
+  });
+
+  it('every parent precedes its children (contextMenus.create ordering)', () => {
+    CONTEXT_MENU_ENTRIES.forEach((entry, i) => {
+      if (entry.parentId) {
+        const parentIndex = CONTEXT_MENU_ENTRIES.findIndex((e) => e.id === entry.parentId);
+        expect(parentIndex).toBeGreaterThanOrEqual(0);
+        expect(parentIndex).toBeLessThan(i);
+      }
+    });
+  });
+
+  it('maps every previous menu id to the same action/style as the old split("-") parser', () => {
+    // The old parser: strip 'lexai-', split on '-', capitalize the style part.
+    for (const action of ACTIONS) {
+      const parent = findContextMenuEntry(`lexai-${action}`);
+      expect(parent).toMatchObject({ action, style: 'Default' });
+      expect(parent!.title).toBe(`⚡ LexAI: ${ACTION_LABELS[action]}`);
+
+      for (const style of CONTEXT_MENU_STYLES) {
+        const child = findContextMenuEntry(`lexai-${action}-${style.toLowerCase()}`);
+        expect(child).toMatchObject({ action, style, parentId: `lexai-${action}`, title: style });
+      }
+    }
+  });
+
+  it('returns undefined for foreign menu ids', () => {
+    expect(findContextMenuEntry('some-other-extension-item')).toBeUndefined();
+  });
+
+  it('style lists stay consistent', () => {
+    expect(CONTEXT_MENU_STYLES).toEqual(WRITING_STYLES.filter((s) => s !== 'Default'));
+  });
+});