Six of the seven modules call `spinnerModule.createWhirlpool(...)` and none
of them imported it. Everything still parsed, every module still loaded, and
the Email Settings page threw `ReferenceError: spinnerModule is not defined`
the moment `settings.js` mounted it — the panel rendered its loading spinner
and stopped there.
The cause is worth writing down because it is the same shape as the bug: the
import statements were collected with a pattern that was not anchored to the
start of a line, and the header comment says "the old import path keeps
resolving". That prose matched first and swallowed the real
`import spinnerModule from '../spinner.js';` that followed it.
`test_no_module_uses_a_package_name_it_never_bound` closes the class. Nothing
else here can: `node --check` parses without resolving scope, and loading a
module does not run the function body where the throw lives. It checks the
package's own vocabulary — every name any module in it binds — rather than
trying to model the browser's globals, so it has no false positives and still
catches the one mistake a split actually makes: the declaration stays behind
and the use moves.
`emailLibrary/index.js` goes from 11,375 lines to 6,187. What came out:
- `settingsPage.js` (879) — the Email Settings view, its form and controls,
away/auto-reply including the calendar-event sync, and the display
preferences. The inline-image preference lives here rather than with the
renderer because the settings form owns writing it.
- `unsubscribe.js` (1,224) — the bulk-unsubscribe review flow. One exported
entry point, its own localStorage keys, its own agent-tool-output listeners.
- `reader.js` (676) — opening an email as a docked tab or a floating window,
plus the AI summary panel both of them share.
- `menus.js` (855) — the reader More menu, the card kebab menu, the bulk
Actions menu and `_bulkAction`.
- `bodyRender.js` (871) — plain and threaded body rendering, inline MIME
images, quote folding.
- `attachments.js` (491) — attachment chips and the deferred load for messages
whose attachment list was not in the list response.
- `aiReply.js` (449) — AI-reply entry points, the per-message context draft,
the translate and remind submenus.
The extracted modules import back from `index.js`, so the graph has cycles.
That is safe for hoisted function declarations and unsafe for a value read
during evaluation, so nothing crosses a module boundary except functions:
`API_BASE` is re-declared per module, the way `emailInbox.js` and
`emailShared.js` already do it, and `_autoReplyRefreshSeq` moves into
`state.js` because the settings page and the unread-badge refresh both write
it and an imported binding is read-only. The module-graph test enters the
package at each module in turn, which is the order that would expose a
dead-zone read.
Two test helpers grew while doing this. `js_function_source` replaces three
marker-pair slices ("from this signature down to that comment") whose end
marker had moved into another module — the slice ran past the function and
kept passing against the wrong text. Its first implementation balanced braces
by walking characters and ended `_toggleCardPreview` 18 lines early, because
the apostrophe in `// that's a scroll, not a nav` opened a string that ate the
braces after it. It now keys on the invariant the file actually holds: a
top-level declaration starts at column 0, so its closing brace is the next
lone `}` at column 0.
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.
Alexandre Teixeira