CheckAsync built its own HttpClient inline, so nothing beyond tag
parsing was testable without hitting the real GitHub API. Added an
internal CheckAsync(currentVersion, HttpMessageHandler, ct) overload
(the public method now delegates to it) as a seam for a stub handler,
and tests for the full best-effort matrix: newer/equal/older/unparseable
tag, missing html_url, HTTP error status, malformed JSON, a thrown
HttpRequestException, and an unparseable local version — all of which
must resolve to null or the correct LatestRelease, never throw.
ElectrumClient, WalletSynchronizer, TransactionInspector, CertificatePinStore
and peer discovery went from 0% coverage to close to full coverage, all
against the fake ElectrumX server:
- ElectrumClient: request/response correlation under load, server errors,
notifications, disconnection, cancellation, SSL handshake with TOFU pinning.
- WalletSynchronizer: gap-limit scanning, UTXO/history reconstruction,
unconfirmed/immature balances, busy-retry, disk-cache reuse, and the
security-critical path where a lying server fails Merkle verification and
the sync must abort.
- TransactionInspector: fee calculation from resolved inputs, mine/theirs
attribution, RBF flag, coinbase handling, degraded paths when a previous
transaction can't be resolved.
- CertificatePinStore: TOFU pin/match/mismatch/reset, corrupted-file fallback.
- ServerRegistry: peer discovery and persistence via DiscoverAsync.
- UpdateChecker: release-tag parsing and semver comparison.
davide