refactor(email): move emailLibrary.js into static/js/emailLibrary/

The email library was 11,375 lines in one file, the second-largest JS
module in the repo. `static/js/emailLibrary/` already held four extracted
helpers, so the package existed; the bulk of the code just was not in it.

The implementation moves to `emailLibrary/index.js` and the old path
becomes a re-export wrapper. Five call sites import that path, four of
them dynamically with a `?v=` string, and `sw.js` caches URLs verbatim,
so a wrapper is what makes the move need no coordinated edit to any of
them.

The test side is the part worth reviewing. 58 tests read
`static/js/emailLibrary.js` as text. Pointing them at
`emailLibrary/index.js` would buy one move and break again on the next
one, which is exactly what happened to the stylesheet tests (they now go
through `tests/helpers/stylesheets.py`). So the same shape:
`tests/helpers/js_modules.py` reads the whole package, and assertions
stop caring which module a function sits in.

`tests/test_email_library_module_graph_js.py` is new. This frontend has
no module-graph validation, and a package fails in ways a single file
cannot: a wrapper that drops an export is `undefined` at call time rather
than an error at load time, and a module that reads a `const` across an
import cycle throws only when that module is entered first. It pins the
wrapper's surface against the entry module's, evaluates every module on
its own in a browser, and requires both import paths to hand out one
instance.

It also caught a live gap while being written:
`emailLibrary/replyRecipients.js` is imported by `emailInbox.js`, an app
shell module, and was never in the `sw.js` precache.

static/sw.js

@@ -7,7 +7,7 @@
 //   - Other static assets (images/fonts/libs): cache-first with bg refresh.
 //   - API / non-GET: never cached.
 // Bump CACHE_NAME whenever the precache list or SW logic changes.
-const CACHE_NAME = 'odysseus-v654-css-split-3';
+const CACHE_NAME = 'odysseus-v655-email-library-split';
 
 // KaTeX resolves these from its own stylesheet, so caching the CSS without them
 // gives offline math fallback glyphs instead of proper typesetting.
@@ -84,9 +84,12 @@ const PRECACHE = [
   '/static/js/slashCommands.js?v=20260921chatgptusage1',
   '/static/js/research/jobs.js?v=20260910researcherrorpersist1',
   '/static/js/emailInbox.js?v=20260914aireply4',
+  '/static/js/emailLibrary/index.js',
   '/static/js/emailLibrary/utils.js',
   '/static/js/emailLibrary/signatureFold.js',
   '/static/js/emailLibrary/state.js',
+  // emailInbox.js has always imported this one; it was never precached.
+  '/static/js/emailLibrary/replyRecipients.js',
   '/static/js/notes.js?v=20260911notesselectioncancel1',
   '/static/js/tasks.js?v=20260914taskmodel1',
   '/static/js/calendar.js?v=20260914emailsource11',

tests/helpers/js_modules.py

@@ -0,0 +1,50 @@
+"""Read a split JS subpackage the way the module graph does.
+
+``static/js/emailLibrary.js`` is a re-export wrapper; the implementation lives
+in ``static/js/emailLibrary/``. A test that asserts on email-library behaviour
+has to look at every module in that package, because reading one file ties the
+test to whichever module a function happens to sit in today — it goes red the
+next time something moves without any behaviour changing.
+
+That is the mistake the stylesheet split made, which is why
+``tests/helpers/stylesheets.py`` exists. This is the same helper for JS.
+
+Order is deterministic: the entry module first, then the rest alphabetically.
+Tests that assert "A appears before B" are asserting about one module's source,
+not about the package, so the concatenation order only has to be stable.
+"""
+
+from __future__ import annotations
+
+from pathlib import Path
+
+_STATIC_JS = Path(__file__).resolve().parents[2] / "static" / "js"
+
+EMAIL_LIBRARY_WRAPPER = _STATIC_JS / "emailLibrary.js"
+EMAIL_LIBRARY_PACKAGE = _STATIC_JS / "emailLibrary"
+EMAIL_LIBRARY_ENTRY = EMAIL_LIBRARY_PACKAGE / "index.js"
+
+
+def _package_paths(package: Path, entry: Path) -> list[Path]:
+    if not entry.is_file():
+        raise AssertionError(f"missing package entry module: {entry}")
+    rest = sorted(p for p in package.glob("*.js") if p != entry)
+    return [entry, *rest]
+
+
+def email_library_paths(include_wrapper: bool = False) -> list[Path]:
+    """Every module of the email-library package, entry module first.
+
+    ``include_wrapper`` adds the compatibility file at the old top-level path.
+    Leave it off for assertions about implementation code: the wrapper holds
+    only an ``export … from`` list.
+    """
+    paths = _package_paths(EMAIL_LIBRARY_PACKAGE, EMAIL_LIBRARY_ENTRY)
+    return [EMAIL_LIBRARY_WRAPPER, *paths] if include_wrapper else paths
+
+
+def email_library_source(include_wrapper: bool = False) -> str:
+    """The whole email-library package as one string."""
+    return "\n".join(
+        p.read_text(encoding="utf-8") for p in email_library_paths(include_wrapper)
+    )

tests/test_action_menu_order.py

@@ -2,6 +2,7 @@ from pathlib import Path
 import subprocess
 
 from tests.helpers.stylesheets import app_css
+from tests.helpers.js_modules import email_library_source
 
 
 ROOT = Path(__file__).resolve().parents[1]
@@ -13,13 +14,17 @@ def test_shared_action_menu_order_is_used_by_item_menus() -> None:
         "static/js/tasks.js": "orderActionMenuItems",
         "static/js/sessions.js": "orderActionMenuItems",
         "static/js/research/panel.js": "orderActionMenuItems",
-        "static/js/emailLibrary.js": "orderActionMenuItems",
         "static/js/memory.js": "orderActionMenuItems",
     }
     for relative_path, helper in expected_imports.items():
         source = (ROOT / relative_path).read_text(encoding="utf-8")
         assert "actionMenuOrder.js" in source
         assert helper in source
+    # The email library is a package, so the import and the call can sit in
+    # different modules of it.
+    email = email_library_source()
+    assert "actionMenuOrder.js" in email
+    assert "orderActionMenuItems" in email
 
 
 def test_common_action_order_matches_product_convention() -> None:
@@ -68,20 +73,20 @@ def test_dropdown_select_actions_use_the_canonical_icon() -> None:
         "static/js/sessions.js",
         "static/js/skills.js",
         "static/js/tasks.js",
-        "static/js/emailLibrary.js",
         "static/js/research/panel.js",
     ):
         module = (ROOT / relative_path).read_text(encoding="utf-8")
         assert "SELECT_MENU_ICON" in module
+    assert "SELECT_MENU_ICON" in email_library_source()
 
 
 def test_email_filter_menu_has_context_title() -> None:
-    source = (ROOT / "static/js/emailLibrary.js").read_text(encoding="utf-8")
+    source = email_library_source()
     assert 'email-filter-menu-title">Filter by...</div>' in source
 
 
 def test_email_setting_toggles_render_neutral_disabled_state() -> None:
-    source = (ROOT / "static/js/emailLibrary.js").read_text(encoding="utf-8")
+    source = email_library_source()
     style = app_css()
     assert 'email-settings-auto-reply-section' in source
     assert 'email-settings-display-enabled-state' in source
@@ -90,14 +95,14 @@ def test_email_setting_toggles_render_neutral_disabled_state() -> None:
 
 
 def test_email_search_options_menu_has_context_title() -> None:
-    source = (ROOT / "static/js/emailLibrary.js").read_text(encoding="utf-8")
+    source = email_library_source()
     menu_start = source.index('id="email-search-options-menu"')
     menu_end = source.index("</div>", menu_start) + len("</div>")
     assert 'email-search-options-title">Filter by...</div>' in source[menu_start:menu_end]
 
 
 def test_email_date_headers_mark_unexpected_timeline_gaps() -> None:
-    source = (ROOT / "static/js/emailLibrary.js").read_text(encoding="utf-8")
+    source = email_library_source()
     assert "function _emailTimelineGapThreshold(items)" in source
     assert "email-date-gap-break" in source
     assert "gapDays > 90 && gapDays > timelineGapThreshold" in source
@@ -107,7 +112,7 @@ def test_email_date_headers_mark_unexpected_timeline_gaps() -> None:
 
 
 def test_email_filters_and_card_favorite_toggle_are_wired() -> None:
-    source = (ROOT / "static/js/emailLibrary.js").read_text(encoding="utf-8")
+    source = email_library_source()
     assert '<option value="tag:action-needed">' not in source
     assert "filter:tag:action-needed" not in source
     assert "email-card-favorite" in source
@@ -132,7 +137,7 @@ def test_email_filters_and_card_favorite_toggle_are_wired() -> None:
 
 
 def test_email_auto_reply_start_date_seeds_today_when_picker_opens() -> None:
-    source = (ROOT / "static/js/emailLibrary.js").read_text(encoding="utf-8")
+    source = email_library_source()
     assert "function _todayDateInputValue()" in source
     assert "if (autoReplyStart && !autoReplyStart.value) autoReplyStart.value = _todayDateInputValue();" in source
     assert "autoReplyStart?.addEventListener('pointerdown', seedAutoReplyStartDate);" in source
@@ -140,7 +145,7 @@ def test_email_auto_reply_start_date_seeds_today_when_picker_opens() -> None:
 
 
 def test_email_auto_reply_syncs_one_calendar_event_per_account() -> None:
-    source = (ROOT / "static/js/emailLibrary.js").read_text(encoding="utf-8")
+    source = email_library_source()
     assert "function _syncAutoReplyCalendarEvent(cfg)" in source
     assert "summary: 'Email Auto Reply (away)'" in source
     assert "function _findAutoReplyCalendarEventUids(cfg, accountId)" in source
@@ -155,7 +160,7 @@ def test_email_auto_reply_syncs_one_calendar_event_per_account() -> None:
 
 
 def test_email_settings_show_away_account_and_compact_display_controls() -> None:
-    source = (ROOT / "static/js/emailLibrary.js").read_text(encoding="utf-8")
+    source = email_library_source()
     style = app_css()
     assert 'email-account-away-label">(AWAY)</span>' in source
     assert 'id="email-lib-auto-reply-badge"' in source
@@ -175,14 +180,14 @@ def test_email_settings_show_away_account_and_compact_display_controls() -> None
 
 
 def test_email_cleanup_uses_the_memory_tidy_star_icon() -> None:
-    source = (ROOT / "static/js/emailLibrary.js").read_text(encoding="utf-8")
+    source = email_library_source()
     cleanup = source[source.index("function _emailCleanupSettingsHtml"):source.index("function _emailDisplaySettingsHtml")]
     assert "email-settings-clean-btn" in cleanup
     assert "M12 0L14.59 8.41L23 12L14.59 15.59L12 24L9.41 15.59L1 12L9.41 8.41Z" in cleanup
 
 
 def test_email_settings_escape_returns_to_email_list() -> None:
-    source = (ROOT / "static/js/emailLibrary.js").read_text(encoding="utf-8")
+    source = email_library_source()
     settings_guard = "if (modal.classList.contains('email-settings-mode'))"
     assert settings_guard in source
     assert source.index(settings_guard) < source.index("closeEmailLibrary();", source.index(settings_guard))
@@ -190,7 +195,7 @@ def test_email_settings_escape_returns_to_email_list() -> None:
 
 
 def test_email_select_escape_cancels_selection_without_closing_library() -> None:
-    source = (ROOT / "static/js/emailLibrary.js").read_text(encoding="utf-8")
+    source = email_library_source()
     select_guard = "if (state._selectMode) {"
     select_start = source.index(select_guard, source.index("if (e.key === 'Escape')"))
     assert "_setSelectBtnState(false);" in source[select_start:select_start + 260]
@@ -206,7 +211,7 @@ def test_chat_delete_actions_use_the_shared_trash_bin_icon() -> None:
 
 
 def test_agent_unsubscribe_uses_the_reviewed_target_without_rescanning() -> None:
-    source = (ROOT / "static/js/emailLibrary.js").read_text(encoding="utf-8")
+    source = email_library_source()
     start = source.index("function _askAgentToUnsubscribe")
     end = source.index("function _unsubscribeCandidateUids", start)
     prompt = source[start:end]
@@ -219,7 +224,7 @@ def test_agent_unsubscribe_uses_the_reviewed_target_without_rescanning() -> None
 
 
 def test_email_clean_always_forces_a_fresh_unsubscribe_scan() -> None:
-    source = (ROOT / "static/js/emailLibrary.js").read_text(encoding="utf-8")
+    source = email_library_source()
     start = source.index("function _bindEmailSettingsPageControls")
     end = source.index("function _setUnsubButtonBusy", start)
     controls = source[start:end]
@@ -228,7 +233,7 @@ def test_email_clean_always_forces_a_fresh_unsubscribe_scan() -> None:
 
 
 def test_unsubscribe_duplicate_badge_is_lowered() -> None:
-    frontend = (ROOT / "static/js/emailLibrary.js").read_text(encoding="utf-8")
+    frontend = email_library_source()
     stylesheet = app_css()
     assert "email-unsub-duplicate-badge" in frontend
     start = stylesheet.index(".email-unsub-duplicate-badge {")
@@ -236,7 +241,7 @@ def test_unsubscribe_duplicate_badge_is_lowered() -> None:
 
 
 def test_unsubscribe_scan_status_sits_before_clean_action() -> None:
-    frontend = (ROOT / "static/js/emailLibrary.js").read_text(encoding="utf-8")
+    frontend = email_library_source()
     stylesheet = app_css()
     start = frontend.index("function _emailCleanupSettingsHtml")
     end = frontend.index("function _emailDisplaySettingsHtml", start)
@@ -257,7 +262,7 @@ def test_unsubscribe_scan_status_sits_before_clean_action() -> None:
 
 
 def test_unsubscribe_success_removes_messages_before_the_next_scan() -> None:
-    frontend = (ROOT / "static/js/emailLibrary.js").read_text(encoding="utf-8")
+    frontend = email_library_source()
     backend = (ROOT / "routes/email_routes.py").read_text(encoding="utf-8")
     mcp = (ROOT / "mcp_servers/email_server.py").read_text(encoding="utf-8")
     assert "async function _deleteAfterUnsubscribe" in frontend
@@ -271,7 +276,7 @@ def test_unsubscribe_success_removes_messages_before_the_next_scan() -> None:
 
 
 def test_agent_email_mutations_reconcile_bulk_single_and_mailto_results() -> None:
-    source = (ROOT / "static/js/emailLibrary.js").read_text(encoding="utf-8")
+    source = email_library_source()
     start = source.index("function _agentDeletedEmailUids")
     end = source.index("function _handleAgentEmailToolOutput", start)
     resolver = source[start:end]
@@ -282,7 +287,7 @@ def test_agent_email_mutations_reconcile_bulk_single_and_mailto_results() -> Non
 
 
 def test_browser_agent_unsubscribe_cleans_sender_after_positive_confirmation() -> None:
-    source = (ROOT / "static/js/emailLibrary.js").read_text(encoding="utf-8")
+    source = email_library_source()
     start = source.index("function _agentBrowserUnsubscribeSucceeded")
     end = source.index("function _agentDeletedEmailUids", start)
     browser_flow = source[start:end]
@@ -321,7 +326,7 @@ def test_unsubscribe_cleanup_can_remove_same_sender_unsubscribe_messages() -> No
 
 
 def test_unsubscribe_review_marks_handled_cards_and_offers_scan_further() -> None:
-    source = (ROOT / "static" / "js" / "emailLibrary.js").read_text()
+    source = email_library_source()
     start = source.index("function _markUnsubscribeCardDone")
     end = source.index("async function _runUnsubscribeCleanup", start)
     card = source[start:end]
@@ -331,7 +336,7 @@ def test_unsubscribe_review_marks_handled_cards_and_offers_scan_further() -> Non
 
 
 def test_unsubscribe_review_can_ignore_a_candidate_without_deleting_it() -> None:
-    source = (ROOT / "static" / "js" / "emailLibrary.js").read_text()
+    source = email_library_source()
     styles = app_css()
     assert "email-unsub-ignore-btn" in source
     assert "_rememberUnsubscribeIgnored(c)" in source
@@ -340,7 +345,7 @@ def test_unsubscribe_review_can_ignore_a_candidate_without_deleting_it() -> None
 
 
 def test_email_settings_sections_use_static_headers() -> None:
-    source = (ROOT / "static" / "js" / "emailLibrary.js").read_text()
+    source = email_library_source()
     styles = app_css()
     assert 'class="email-unsub-accent-icon"' in source
     assert 'M12 0L14.59 8.41' in source

tests/test_active_document_visibility_contract.py

@@ -1,5 +1,6 @@
 from pathlib import Path
 import re
+from tests.helpers.js_modules import email_library_paths
 
 
 ROOT = Path(__file__).resolve().parents[1]
@@ -42,8 +43,8 @@ def test_all_runtime_document_imports_share_one_module_url():
         ROOT / "static/js/chat.js",
         ROOT / "static/js/chatStream.js",
         ROOT / "static/js/chatRenderer.js",
-        ROOT / "static/js/emailLibrary.js",
         ROOT / "static/js/slashCommands.js",
+        *email_library_paths(include_wrapper=True),
     ]
     versions = {
         match

tests/test_calendar_tool_card_static.py

@@ -2,6 +2,7 @@ from pathlib import Path
 import re
 
 from tests.helpers.stylesheets import app_css
+from tests.helpers.js_modules import email_library_source
 
 
 ROOT = Path(__file__).resolve().parents[1]
@@ -32,7 +33,7 @@ def test_calendar_chat_event_links_fetch_uid_and_show_title_time():
     app_src = (ROOT / "static/app.js").read_text()
     renderer_src = (ROOT / "static/js/chatRenderer.js").read_text()
     inbox_src = (ROOT / "static/js/emailInbox.js").read_text()
-    library_src = (ROOT / "static/js/emailLibrary.js").read_text()
+    library_src = email_library_source()
 
     assert '@router.get("/events/{uid}")' in routes_src
     assert "async function _fetchEventByUid" in calendar_src

tests/test_calendar_visual_static.py

@@ -2,6 +2,7 @@ from pathlib import Path
 import re
 
 from tests.helpers.stylesheets import app_css
+from tests.helpers.js_modules import email_library_source
 
 
 ROOT = Path(__file__).resolve().parents[1]
@@ -285,13 +286,10 @@ def test_calendar_tool_guidance_preserves_manual_tags_on_unrelated_updates():
 
 def test_calendar_visual_asset_versions_are_bumped():
     versions = []
-    for rel in (
-        "static/app.js",
-        "static/js/chatRenderer.js",
-        "static/js/emailInbox.js",
-        "static/js/emailLibrary.js",
-    ):
-        src = (ROOT / rel).read_text()
+    for src in [
+        (ROOT / rel).read_text()
+        for rel in ("static/app.js", "static/js/chatRenderer.js", "static/js/emailInbox.js")
+    ] + [email_library_source()]:
         match = re.search(r"calendar\.js\?v=([A-Za-z0-9_-]+)", src)
         assert match
         versions.append(match.group(1))

tests/test_card_menu_style_contract.py

@@ -1,4 +1,5 @@
 from pathlib import Path
+from tests.helpers.js_modules import email_library_paths
 
 
 ROOT = Path(__file__).resolve().parents[1]
@@ -31,14 +32,17 @@ def test_library_chat_card_menu_uses_standard_anchor_gap():
 
 
 def test_card_menus_use_the_same_anchor_gap():
-    for relative_path in (
-        "static/js/sessions.js",
-        "static/js/documentLibrary.js",
-        "static/js/emailLibrary.js",
-        "static/js/memory.js",
-        "static/js/tasks.js",
-        "static/js/skills.js",
-    ):
-        source = (ROOT / relative_path).read_text(encoding="utf-8")
-        assert "rect.bottom + 2" not in source, relative_path
-        assert "r.bottom + 2" not in source, relative_path
+    modules = [
+        ROOT / relative_path
+        for relative_path in (
+            "static/js/sessions.js",
+            "static/js/documentLibrary.js",
+            "static/js/memory.js",
+            "static/js/tasks.js",
+            "static/js/skills.js",
+        )
+    ] + email_library_paths(include_wrapper=True)
+    for module in modules:
+        source = module.read_text(encoding="utf-8")
+        assert "rect.bottom + 2" not in source, module
+        assert "r.bottom + 2" not in source, module

tests/test_email_ai_reply_context_draft_static.py

@@ -1,11 +1,12 @@
 from pathlib import Path
+from tests.helpers.js_modules import email_library_source
 
 
 ROOT = Path(__file__).resolve().parent.parent
 
 
 def test_email_ai_reply_context_is_saved_and_restored_per_message():
-    source = (ROOT / "static/js/emailLibrary.js").read_text(encoding="utf-8")
+    source = email_library_source()
 
     assert "_AI_REPLY_CONTEXT_DRAFT_PREFIX" in source
     assert "data?.account_id || em?.account_id || state._libAccountId" in source
@@ -17,7 +18,7 @@ def test_email_ai_reply_context_is_saved_and_restored_per_message():
 
 
 def test_email_ai_reply_context_only_clears_after_draft_opens():
-    library = (ROOT / "static/js/emailLibrary.js").read_text(encoding="utf-8")
+    library = email_library_source()
     inbox = (ROOT / "static/js/emailInbox.js").read_text(encoding="utf-8")
 
     assert "const draftOpened = await _runAiReplyFromButton" in library

tests/test_email_attachment_search.py

@@ -1,5 +1,6 @@
 import sqlite3
 from email.message import EmailMessage
+from tests.helpers.js_modules import email_library_source
 
 
 def test_attachment_filename_is_part_of_ui_index_search(tmp_path, monkeypatch):
@@ -89,7 +90,7 @@ def test_forwarding_filters_signature_assets_and_mobile_export_stops_bubbling():
 
 
 def test_attachment_open_spins_icon_only():
-    library = open("static/js/emailLibrary.js", encoding="utf-8").read()
+    library = email_library_source()
     start = library.index("reader.querySelectorAll('.email-attachment-open')")
     end = library.index("reader.querySelectorAll('.email-attachment-download')", start)
     handler = library[start:end]
@@ -109,7 +110,7 @@ def test_move_document_creates_destination_before_adopting_it():
 
 
 def test_deferred_attachment_check_shows_feedback_and_repairs_stale_card_icon():
-    library = open("static/js/emailLibrary.js", encoding="utf-8").read()
+    library = email_library_source()
     start = library.index("function _loadDeferredAttachmentsIntoReader")
     end = library.index('\n// "Open in new tab"', start)
     loader = library[start:end]
@@ -159,7 +160,7 @@ def test_attachment_cache_backfill_preserves_message_id(tmp_path, monkeypatch):
 
 
 def test_single_email_tag_has_no_more_control():
-    library = open("static/js/emailLibrary.js", encoding="utf-8").read()
+    library = email_library_source()
     group = library[library.index("function _emailTagGroupHtml("):library.index("function _fitEmailCardTags(")]
     assert "if (visible.length === 1) return visible[0];" in group
     assert "if (visible.length === 2) return visible.join('');" in group
@@ -167,7 +168,7 @@ def test_single_email_tag_has_no_more_control():
 
 
 def test_email_folder_and_filter_pickers_treat_their_buttons_as_inside_clicks():
-    library = open("static/js/emailLibrary.js", encoding="utf-8").read()
+    library = email_library_source()
 
     assert library.count(
         "bindMenuDismiss(menu, finishClose, e => !picker.contains(e.target))"
@@ -177,7 +178,7 @@ def test_email_folder_and_filter_pickers_treat_their_buttons_as_inside_clicks():
 
 def test_empty_reply_has_two_editable_rows_and_reply_survives_compact_toolbar():
     inbox = open("static/js/emailInbox.js", encoding="utf-8").read()
-    library = open("static/js/emailLibrary.js", encoding="utf-8").read()
+    library = email_library_source()
 
     assert "<p><br></p><p><br></p>\\n" in inbox
     fit_start = library.index("function _fitReaderActions")

tests/test_email_folder_chip_static.py

@@ -1,11 +1,12 @@
 from pathlib import Path
+from tests.helpers.js_modules import email_library_source
 
 
 ROOT = Path(__file__).resolve().parents[1]
 
 
 def test_folder_chip_stays_with_date_and_moves_down():
-    source = (ROOT / "static" / "js" / "emailLibrary.js").read_text()
+    source = email_library_source()
     css = (ROOT / "static" / "style.css").read_text()
 
     assert 'class="email-meta-date-group"' in source

tests/test_email_library_bulk_actions.py

@@ -1,22 +1,22 @@
 from pathlib import Path
+from tests.helpers.js_modules import email_library_source
 
 
 _REPO = Path(__file__).resolve().parents[1]
-_EMAIL_LIBRARY = _REPO / "static" / "js" / "emailLibrary.js"
 _EMAIL_ROUTES = _REPO / "routes" / "email_routes.py"
 _EMAIL_MCP_SERVER = _REPO / "mcp_servers" / "email_server.py"
 _EMAIL_FIXTURE_HELPER = _REPO / "scripts" / "ody_eval_email_fixture.py"
 
 
 def _bulk_action_source() -> str:
-    text = _EMAIL_LIBRARY.read_text(encoding="utf-8")
+    text = email_library_source()
     start = text.index("async function _bulkAction(action)")
     end = text.index("\n}\n\n// _extractName", start) + 3
     return text[start:end]
 
 
 def _function_source(name: str) -> str:
-    text = _EMAIL_LIBRARY.read_text(encoding="utf-8")
+    text = email_library_source()
     start = text.index(f"function {name}")
     next_function = text.find("\nfunction ", start + 1)
     next_async = text.find("\nasync function ", start + 1)
@@ -50,7 +50,7 @@ def test_email_bulk_read_unread_checks_backend_success_before_syncing_cache():
 
 
 def test_email_bulk_export_attachments_is_ui_only_selected_context():
-    frontend = _EMAIL_LIBRARY.read_text(encoding="utf-8")
+    frontend = email_library_source()
     backend = _EMAIL_ROUTES.read_text(encoding="utf-8")
     export_src = frontend[
         frontend.index("async function _exportSelectedAttachments()"):
@@ -86,7 +86,7 @@ def test_email_context_changes_clear_bulk_selection_state():
     Folder, account, filter, quick-filter, attachment, and search basis changes
     must exit select mode before the next list/search view can run bulk actions.
     """
-    text = _EMAIL_LIBRARY.read_text(encoding="utf-8")
+    text = email_library_source()
     reset_src = _function_source("_resetBulkSelectionForContextChange")
     fresh_src = _function_source("_resetEmailListForFreshLoad")
     add_pill_src = _function_source("_addSearchPill")
@@ -118,7 +118,7 @@ def test_email_refresh_uses_explicit_server_refresh_contract():
     refresh button should keep the old rows visible while asking the server to
     evict those fast paths and refetch the visible mailbox slice.
     """
-    frontend = _EMAIL_LIBRARY.read_text(encoding="utf-8")
+    frontend = email_library_source()
     backend = _EMAIL_ROUTES.read_text(encoding="utf-8")
 
     assert "refresh=1&_=${Date.now()}" in frontend
@@ -150,7 +150,7 @@ def test_fixture_email_requires_explicit_eval_flag():
 
 def test_email_client_cache_drops_fixture_rows():
     """Old fixture rows in browser storage must not keep rendering."""
-    frontend = _EMAIL_LIBRARY.read_text(encoding="utf-8")
+    frontend = email_library_source()
 
     assert "function _looksLikeFixtureEmailRow(row)" in frontend
     assert "function _libCacheHasFixtureRows(value)" in frontend

tests/test_email_library_module_graph_js.py

@@ -0,0 +1,187 @@
+"""Module-graph coverage for the split email library.
+
+``specs/frontend.md`` records that this frontend has "no build-time type
+checking, module graph validation, or script-order validation". That is
+tolerable for a single 11k-line file and not tolerable for a package: splitting
+``emailLibrary.js`` into modules that import each other adds three failure modes
+nothing else here would catch.
+
+1. The compatibility wrapper at ``static/js/emailLibrary.js`` drops an export.
+   Five call sites import that path; a missing name is ``undefined`` at call
+   time, not an error at load time, so the panel just stops responding.
+2. A module in the package fails to evaluate — a stale relative specifier after
+   a move, or a temporal-dead-zone read across an import cycle. The package has
+   cycles by construction: extracted modules call back into ``index.js`` from
+   event handlers. That is safe for hoisted function declarations and *not* safe
+   for a ``const`` read while the graph is still evaluating, and which one you
+   wrote is invisible in a diff.
+3. A new module is missing from the ``sw.js`` precache, so the panel that works
+   online cannot open offline.
+
+The first and third are read off the source. The second needs a real module
+loader, so it runs in a browser: each module is imported *on its own*, in a
+fresh page, because entering the cycle at a submodule rather than at the entry
+module is the order that exposes a dead-zone read.
+"""
+
+import json
+import re
+import subprocess
+from pathlib import Path
+
+from tests.helpers.js_modules import (
+    EMAIL_LIBRARY_ENTRY,
+    EMAIL_LIBRARY_WRAPPER,
+    email_library_paths,
+)
+
+ROOT = Path(__file__).resolve().parents[1]
+_SW = ROOT / "static" / "sw.js"
+
+# `export function foo`, `export async function foo`, `export const foo`.
+_EXPORT_DECL = re.compile(
+    r"^export\s+(?:async\s+)?(?:function|const|let|class)\s+([A-Za-z_$][\w$]*)",
+    re.M,
+)
+# `export { a, b } from '...'` and `export { a, b }`.
+_EXPORT_LIST = re.compile(r"export\s*\{([^}]*)\}", re.S)
+
+
+def _declared_exports(path: Path) -> set[str]:
+    return set(_EXPORT_DECL.findall(path.read_text(encoding="utf-8")))
+
+
+def _listed_exports(path: Path) -> set[str]:
+    names: set[str] = set()
+    for block in _EXPORT_LIST.findall(path.read_text(encoding="utf-8")):
+        for raw in block.split(","):
+            name = raw.strip().split(" as ")[-1].strip()
+            if name:
+                names.add(name)
+    return names
+
+
+def test_wrapper_re_exports_the_entry_module_surface_exactly():
+    """The old path must expose the same names as the package entry module.
+
+    Not a subset and not a superset: a missing name breaks a caller silently,
+    and a name the entry module no longer exports is a load-time error.
+    """
+    entry = _declared_exports(EMAIL_LIBRARY_ENTRY) | _listed_exports(EMAIL_LIBRARY_ENTRY)
+    wrapper = _listed_exports(EMAIL_LIBRARY_WRAPPER)
+    assert wrapper, f"{EMAIL_LIBRARY_WRAPPER} re-exports nothing"
+    assert wrapper == entry, (
+        "static/js/emailLibrary.js and static/js/emailLibrary/index.js disagree "
+        f"on the public surface; only in the wrapper: {sorted(wrapper - entry)}; "
+        f"only in the entry module: {sorted(entry - wrapper)}"
+    )
+
+
+def test_every_package_module_is_precached():
+    sw = _SW.read_text(encoding="utf-8")
+    for path in email_library_paths():
+        url = "/static/js/emailLibrary/" + path.name
+        assert f"'{url}'" in sw, (
+            f"{url} is not in the static/sw.js precache, so a panel that works "
+            "online will not open offline"
+        )
+
+
+def test_every_package_module_evaluates_on_its_own_in_a_browser():
+    """Import each module first, alone, and require it to evaluate.
+
+    Entering the package at a submodule is what turns an import cycle from
+    harmless into a `ReferenceError: cannot access '…' before initialization`.
+    Importing the entry module first would hide exactly that.
+    """
+    urls = ["/static/js/emailLibrary.js"] + [
+        "/static/js/emailLibrary/" + p.name for p in email_library_paths()
+    ]
+    script = r'''
+      import { chromium } from 'playwright';
+      const origin = process.env.ODYSSEUS_TEST_STATIC_ORIGIN;
+      const urls = JSON.parse(process.env.ODYSSEUS_EMAIL_MODULE_URLS);
+      const browser = await chromium.launch({ headless: true });
+      const results = {};
+      for (const url of urls) {
+        const page = await browser.newPage();
+        // Same synthetic shell the other email browser tests use: these
+        // modules touch #toast and #sidebar while evaluating.
+        await page.goto(`${origin}/static/js/documentStats.js`);
+        await page.setContent('<div id="toast"></div><div id="chat-container"></div><div id="sidebar"></div>');
+        results[url] = await page.evaluate(async (target) => {
+          try {
+            const mod = await import(target);
+            return { ok: true, exports: Object.keys(mod).sort() };
+          } catch (err) {
+            return { ok: false, error: String(err && err.message || err) };
+          }
+        }, url);
+        await page.close();
+      }
+      console.log(JSON.stringify(results));
+      await browser.close();
+    '''
+    result = subprocess.run(
+        ["node", "--input-type=module", "-e", script],
+        cwd=ROOT,
+        check=False,
+        capture_output=True,
+        text=True,
+        env={
+            **__import__("os").environ,
+            "ODYSSEUS_EMAIL_MODULE_URLS": json.dumps(urls),
+        },
+    )
+    assert result.returncode == 0, result.stderr
+    data = json.loads(result.stdout)
+    broken = {url: info["error"] for url, info in data.items() if not info["ok"]}
+    assert not broken, f"modules that failed to evaluate on their own: {broken}"
+    assert set(data) == set(urls)
+
+
+def test_wrapper_and_entry_module_hand_out_the_same_functions():
+    """Importing either path must give one live module instance.
+
+    Two instances would mean two copies of the panel's module state, and the
+    panel is a singleton keyed on DOM ids — the second copy would fight the
+    first over `#email-lib-modal`.
+    """
+    script = r'''
+      import { chromium } from 'playwright';
+      const origin = process.env.ODYSSEUS_TEST_STATIC_ORIGIN;
+      const browser = await chromium.launch({ headless: true });
+      const page = await browser.newPage();
+      await page.goto(`${origin}/static/js/documentStats.js`);
+      await page.setContent('<div id="toast"></div><div id="chat-container"></div><div id="sidebar"></div>');
+      const out = await page.evaluate(async () => {
+        const wrapper = await import('/static/js/emailLibrary.js');
+        const entry = await import('/static/js/emailLibrary/index.js');
+        const names = Object.keys(wrapper).sort();
+        return {
+          names,
+          identical: names.filter((n) => wrapper[n] === entry[n]),
+          callable: names.filter((n) => typeof wrapper[n] === 'function'),
+        };
+      });
+      console.log(JSON.stringify(out));
+      await browser.close();
+    '''
+    result = subprocess.run(
+        ["node", "--input-type=module", "-e", script],
+        cwd=ROOT,
+        check=False,
+        capture_output=True,
+        text=True,
+    )
+    assert result.returncode == 0, result.stderr
+    data = json.loads(result.stdout)
+    assert data["names"], "the wrapper exported nothing at runtime"
+    assert data["identical"] == data["names"], (
+        "the wrapper and the entry module handed out different objects for "
+        f"{sorted(set(data['names']) - set(data['identical']))}"
+    )
+    assert data["callable"] == data["names"], (
+        "not every export is callable: "
+        f"{sorted(set(data['names']) - set(data['callable']))}"
+    )

tests/test_email_library_prewarm.py

@@ -4,14 +4,13 @@ import shutil
 import subprocess
 
 import pytest
+from tests.helpers.js_modules import email_library_source
 
 
 _REPO = Path(__file__).resolve().parents[1]
-_EMAIL_LIBRARY = _REPO / "static" / "js" / "emailLibrary.js"
-
 
 def _source() -> str:
-    return _EMAIL_LIBRARY.read_text(encoding="utf-8")
+    return email_library_source()
 
 
 def _function_source(name: str) -> str:

tests/test_email_open_dedup_js.py

@@ -6,11 +6,11 @@ import subprocess
 from pathlib import Path
 
 import pytest
+from tests.helpers.js_modules import email_library_source
 
 
 _REPO = Path(__file__).resolve().parent.parent
 _INBOX_JS = _REPO / "static" / "js" / "emailInbox.js"
-_LIBRARY_JS = _REPO / "static" / "js" / "emailLibrary.js"
 _HAS_NODE = shutil.which("node") is not None
 
 
@@ -21,7 +21,7 @@ def _extract_between(source: str, signature: str, next_marker: str) -> str:
 
 
 def test_library_unread_preview_has_one_authoritative_request_and_rollback():
-    source = _LIBRARY_JS.read_text(encoding="utf-8")
+    source = email_library_source()
     function = _extract_between(source, "async function _toggleCardPreview", "\n/**\n * Wrap a probable signature block")
 
     assert function.count("/api/email/read/") == 1
@@ -38,7 +38,7 @@ def test_library_unread_preview_has_one_authoritative_request_and_rollback():
 
 @pytest.mark.skipif(not _HAS_NODE, reason="node binary not on PATH")
 def test_library_authoritative_success_defeats_newer_rollback_in_either_order():
-    source = _LIBRARY_JS.read_text(encoding="utf-8")
+    source = email_library_source()
     function = _extract_between(source, "async function _toggleCardPreview", "\n/**\n * Wrap a probable signature block")
     settlements = _extract_between(
         function,
@@ -101,7 +101,7 @@ console.log(JSON.stringify({{
 
 
 def test_library_reply_open_carries_immutable_mailbox_context():
-    library_source = _LIBRARY_JS.read_text(encoding="utf-8")
+    library_source = email_library_source()
     inbox_source = _INBOX_JS.read_text(encoding="utf-8")
 
     assert "const mailboxGeneration = _emailMailboxGeneration;" in library_source

tests/test_email_picker_exclusivity_static.py

@@ -1,12 +1,13 @@
 from pathlib import Path
 import re
+from tests.helpers.js_modules import email_library_source
 
 
 ROOT = Path(__file__).resolve().parent.parent
 
 
 def test_email_folder_and_filter_pickers_are_exclusive_and_escape_safe():
-    source = (ROOT / "static/js/emailLibrary.js").read_text(encoding="utf-8")
+    source = email_library_source()
 
     assert source.count("const filterMenu = document.getElementById('email-filter-menu');") == 1
     assert source.count("const folderMenu = document.getElementById('email-folder-menu');") == 1

tests/test_email_ui_async_identity.py

@@ -1,11 +1,12 @@
 from pathlib import Path
+from tests.helpers.js_modules import email_library_source
 
 
 ROOT = Path(__file__).resolve().parents[1]
 
 
 def test_card_delete_waits_for_durable_success_and_uses_email_identity():
-    source = (ROOT / "static/js/emailLibrary.js").read_text()
+    source = email_library_source()
     assert "function _emailMutationQuery(em" in source
     assert "em?.folder || fallbackFolder" in source
     assert "em?.account_id || state._libAccountId" in source

tests/test_external_context_tool_gate.py

@@ -8,6 +8,7 @@ from pathlib import Path
 
 import pytest
 
+from tests.helpers.js_modules import email_library_paths
 import src.tool_capabilities as tool_capabilities
 from src.tool_capabilities import (
     KNOWN_CAPABILITY_TOOLS,
@@ -1405,11 +1406,10 @@ def test_frontend_tool_approval_uses_opaque_id_and_fixed_decisions():
             "static/js/chatStream.js",
             "static/js/document.js",
             "static/js/emailInbox.js",
-            "static/js/emailLibrary.js",
             "static/js/settings.js",
             "static/js/slashCommands.js",
         )
-    ]
+    ] + [p.read_text() for p in email_library_paths(include_wrapper=True)]
     assert all(
         "20260722emailfastindex1" not in source
         for source in approval_module_sources

tests/test_notes_mobile_checklist_toggle_static.py

@@ -2,6 +2,7 @@ from pathlib import Path
 import re
 
 from tests.helpers.stylesheets import app_css
+from tests.helpers.js_modules import email_library_source
 
 
 ROOT = Path(__file__).resolve().parent.parent
@@ -72,7 +73,7 @@ def test_drawing_edits_mark_notes_dirty_and_keep_one_gallery_image():
 
 
 def test_calendar_email_attachments_have_a_calendar_import_action():
-    email = (ROOT / "static" / "js" / "emailLibrary.js").read_text(encoding="utf-8")
+    email = email_library_source()
     calendar = (ROOT / "static" / "js" / "calendar.js").read_text(encoding="utf-8")
 
     assert "email-attachment-calendar-open" in email

tests/test_security_regressions.py

@@ -18,6 +18,7 @@ import importlib
 from pathlib import Path
 
 import pytest
+from tests.helpers.js_modules import email_library_source
 
 
 # ── prompt-injection context wrapper ────────────────────────────
@@ -1009,8 +1010,7 @@ def test_diagnostics_routes_are_admin_gated():
 def test_email_thread_rendering_sanitizes_body_html():
     """Both threaded render paths must run server-parsed body_html through the
     allowlist sanitizer (the flat path already did)."""
-    src = Path(__file__).resolve().parents[1] / "static" / "js" / "emailLibrary.js"
-    text = src.read_text()
+    text = email_library_source()
     # every `t.body_html` reference is wrapped by _sanitizeHtml(...)
     assert text.count("t.body_html") == text.count("_sanitizeHtml(t.body_html")
     assert "t.body_html" in text  # guard against the file being refactored away