Direct property assignment and Object.defineProperty both fail
silently on CI when jsdom marks URL.createObjectURL as non-writable
and non-configurable. vi.stubGlobal('URL', ...) replaces globalThis.URL
entirely — which always succeeds — while extending the real URL class
so all URL parsing behaviour is preserved. vi.unstubAllGlobals() is
called at the start of beforeEach to reset cleanly between tests.
Two root causes:
1. authUrl.test.ts (007, 011, 012): Object.defineProperty in setup.ts
fails silently on CI when jsdom's URL.createObjectURL is
non-configurable. vi.restoreAllMocks() in beforeEach then restores
the property to jsdom's native implementation (returns '').
Fix: assign URL.createObjectURL = vi.fn(() => 'blob:mock') directly
in authUrl.test.ts's beforeEach, after restoreAllMocks(), so every
test in the file gets a fresh, reliable mock. Remove the now-
unnecessary mockClear() from test 012.
2. client.test.ts (013): MSW patches the global Response constructor and
calls blob.stream() on the body — a method not implemented by jsdom's
Blob. Fix: replace new Response(blob) with a plain-object duck-type
({ ok: true, blob: () => Promise.resolve(blob) }) to bypass the
patched constructor entirely.
Three interrelated issues caused 4 tests to pass locally but fail on CI:
1. setup.ts only applied the URL.createObjectURL stub when it was
undefined, but jsdom already defines it (returning ''). Changed to
always override with configurable:true so the predictable 'blob:mock'
value is set in every environment.
2. FE-API-013 used Object.defineProperty (non-configurable in jsdom) and
MSW to handle a native fetch call. Replaced with vi.spyOn for both
URL.createObjectURL/revokeObjectURL and a direct fetch mock, which is
more reliable across environments.
3. FE-COMP-AUTHURL-012's vi.spyOn(URL, 'createObjectURL') returned the
same vi.fn() instance set in setup.ts, accumulating calls from all
prior tests in the file (1+8+7+6=22 instead of 6). Added mockClear()
immediately after the spy setup to reset the count.
jubnl