deno

d5cd0de2 - test(upgrade): run channel flow tests against the mock server offline

test(upgrade): run channel flow tests against the mock server offline The `stable`, `canary`, `specific_stable` and `specific_canary` upgrade spec tests each copied the binary and ran a real `deno upgrade`, hitting GitHub / dl.deno.land and downloading a full ~40MB release on every CI run. That wastes bandwidth and couples PR CI to the live release state (a freshly published version could break the output match on unrelated PRs). Point these four at the existing test-server mock instead, the same way `delta` and `checksum` already do, via DENO_TESTING_UPGRADE and DENO_DONT_USE_INTERNAL_BASE_UPGRADE_URL. The version lookup and download now resolve to localhost:4545, so the tests are fully offline, deterministic (fixed sentinel versions), and run in tens of milliseconds instead of ~13s. The mock serves a placeholder, non-executable binary, so each upgrade runs through version resolution and the download and then fails validation; the tests assert the resolved version and the mocked download URL rather than a completed install. Canary downloads previously had no test hook, so extend the DENO_TESTING_UPGRADE redirect to the canary download URL in get_download_url and teach the test server to serve zips under /deno-upgrade/canary/, mirroring the existing /deno-upgrade/download/ handling. The end-to-end tests that need a real runnable binary (space_in_tmp, out) are intentionally left on the real network for now.