Rework of the unit at #93
(commit 9cb2c2b), against the review at
#136 (comment).
Review of 9cb2c2b found the quorum assertions could not fail on a
class of wrong answer. Each test banned exactly one bad status —
_AllReturnOK banned only nxdomain, _NXDomainFromAllNS banned only ok
— so resolver.StatusNoData passed both. nodata is a wrong answer, not
silence, and answeredCount counted it as answered, so it did not even
trigger a retry; with a quorum of 3 of 4 a single wrong nameserver
slid through undetected. That is assertion-loosening beyond what the
quorum change requires.
Tolerance is now a closed allowlist rather than a blocklist of one
status. unsanctionedStatuses() reports every per-nameserver result
whose status the caller did not explicitly sanction: ok/timeout/error
for the all-OK test, nxdomain/timeout/error for the NXDOMAIN test.
Silence (timeout, error) is the only thing quorum exists to tolerate;
any other status, including one added to the resolver later, fails by
name. answeredCount is likewise an allowlist of ok/nxdomain/nodata, so
an unknown status counts as silence and can only cause a retry and
then a loud failure, never a quiet pass.
Two harness tests cover the regression directly: three OK plus one
nodata (quorum satisfied, no nxdomain present — the input that used
to pass) is now reported as unsanctioned, and an unknown status is
neither counted as answered nor tolerated.
Verified by re-running the reviewer's probe: queryEachNS patched to
force one of google.com's four nameservers to return StatusNoData
turns both tests red, naming the offending nameserver and status —
--- FAIL: TestQueryAllNameservers_AllReturnOK (1.12s)
Should be empty, but was [ns1.google.com.=nodata]
every nameserver must answer OK or not answer at all:
ns1.google.com.=nodata ns2.google.com.=ok ns3.google.com.=ok
ns4.google.com.=ok
--- FAIL: TestQueryAllNameservers_NXDomainFromAllNS (1.34s)
Should be empty, but was [ns1.google.com.=nodata]
every nameserver must report NXDOMAIN or not answer at all:
ns1.google.com.=nodata ns2.google.com.=nxdomain
ns3.google.com.=nxdomain ns4.google.com.=nxdomain
— and green with the probe reverted. Also fixes the review's nit: the
per-attempt deadline assertion had no lower bound, so it passed for a
deadline far shorter than intended.
No production code changed; DNS is still never mocked.
The resolver's live-DNS tests failed nondeterministically, a different
subset each run. Three structural causes, all test-side:
- Burst fan-out. Every test in the package is parallel and the build
hosts have many cores, so all ~35 iterative resolutions started at
the same instant and, because queryServers walks rootServerList() in
fixed order, hit the same root server within milliseconds. Root
servers rate-limit that.
- No retry anywhere. One dropped UDP packet in a delegation chain
failed a test outright.
- Unanimity assertions. TestQueryAllNameservers_AllReturnOK and
_NXDomainFromAllNS required every one of a domain's nameservers to
answer, with no tolerance for one being slow.
New internal/resolver/livedns_test.go addresses each: a package-wide
gate bounds how many live resolutions are in flight at once, every
live operation gets three attempts with exponential backoff and its
own deadline, and multi-nameserver assertions now need a strict
majority rather than unanimity. The retry predicate is deliberately
transport-level -- "did a nameserver answer at all" -- never the
assertion under test, so a resolver that answers incorrectly still
fails on the first attempt. A nameserver that stays silent is
tolerated; one that answers wrongly is not.
livedns_harness_test.go tests that machinery directly: quorum
arithmetic, status counting, the gate's concurrency bound, per-attempt
deadlines, and recovery from a transient failure. It touches no DNS.
Nothing is mocked, faked, stubbed, recorded, skipped or build-tagged,
and production resolver behaviour is unchanged.
Test caps move to the new org-wide values ruled at prompts issue 41:
60s hard cap, 20s target, 90s -timeout backstop. REPO_POLICIES.md is
re-vendored byte-identical from sneak/prompts rather than hand-edited,
which also picks up the golangci-lint paragraph this copy had drifted
behind on. TESTING.md's stale 30-second target follows to 60.
#93
Per review feedback: tests now make real DNS queries against
public DNS (google.com, cloudflare.com) instead of using a
mock DNS client. The DNSClient interface and mock infrastructure
have been removed.
- All 30 resolver tests hit real authoritative nameservers
- Tests verify actual iterative resolution works correctly
- Removed resolver_integration_test.go (merged into main tests)
- Context timeout increased to 60s for iterative resolution
- Extract DNSClient interface from resolver to allow dependency injection
- Convert all resolver methods from package-level to receiver methods
using the injectable DNS client
- Rewrite resolver_test.go with a mock DNS client that simulates the
full delegation chain (root → TLD → authoritative) in-process
- Move 2 integration tests (real DNS) behind //go:build integration tag
- Add NewFromLoggerWithClient constructor for test injection
- Add LookupAllRecords implementation (was returning ErrNotImplemented)
All unit tests are hermetic (no network) and complete in <1s.
Total make check passes in ~5s.
Closes#12
35 tests define the full resolver contract using live DNS queries
against *.dns.sneak.cloud (Cloudflare). Tests cover:
- FindAuthoritativeNameservers: iterative NS discovery, sorting,
determinism, trailing dot handling, TLD and subdomain cases
- QueryNameserver: A, AAAA, CNAME, MX, TXT, NXDOMAIN, per-NS
response model with status field, sorted record values
- QueryAllNameservers: independent per-NS queries, consistency
verification, NXDOMAIN from all NS
- LookupNS: NS record lookup matching FindAuthoritative
- ResolveIPAddresses: basic, multi-A, IPv6, dual-stack, CNAME
following, deduplication, sorting, NXDOMAIN returns empty
- Context cancellation for all methods
- Iterative resolution proof (resolves example.com from root)
Also adds DNSSEC validation to planned future features in README.
