test: make live DNS tests robust instead of gated (closes #93)

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

REPO_POLICIES.md

@@ -1,6 +1,6 @@
 ---
 title: Repository Policies
-last_modified: 2026-07-06
+last_modified: 2026-08-07
 ---
 
 This document covers repository structure, tooling, and workflow standards. Code
@@ -189,8 +189,13 @@ style conventions are in separate documents:
   module under test to verify it compiles/parses. There is no excuse for
   `make test` to be a no-op.
 
-- `make test` must complete in under 20 seconds. Add a 30-second timeout in the
-  Makefile.
+- `make test` must complete in under 60 seconds. That is the hard cap, and a
+  suite that exceeds it fails. Under 20 seconds is the target. A suite between
+  20 and 60 seconds is still green, but the overage must be filed as an
+  improvement bug against that repo. Add a 90-second timeout to the test
+  invocation in the Makefile (`go test -timeout 90s`). The backstop deliberately
+  sits above the hard cap so that it catches a genuinely hung test rather than a
+  merely slow one.
 
 - **`make test` should use the conditional verbose rerun pattern.** Run tests
   without `-v` (verbose) first. If tests fail, automatically rerun with `-v` to
@@ -209,9 +214,9 @@ style conventions are in separate documents:
 
     ```makefile
     test:
-    	@go test -timeout 30s -race -cover ./... || \
+    	@go test -timeout 90s -race -cover ./... || \
     		{ echo "--- Rerunning with -v for details ---"; \
-    		  go test -timeout 30s -race -v ./...; exit 1; }
+    		  go test -timeout 90s -race -v ./...; exit 1; }
     ```
 
     Python example:
@@ -260,7 +265,10 @@ style conventions are in separate documents:
 
 - `.golangci.yml` is standardized and must _NEVER_ be modified by an agent, only
   manually by the user. Fetch from
-  `https://git.eeqj.de/sneak/prompts/raw/branch/main/.golangci.yml`.
+  `https://git.eeqj.de/sneak/prompts/raw/branch/main/.golangci.yml`. The
+  canonical golangci-lint version is v2.12.2 (released 2026-05-06), installed
+  commit-pinned via
+  `go install github.com/golangci/golangci-lint/v2/cmd/golangci-lint@c0d3ddc9cf3faa61a4e378e879ece580256d76e5`.
 
 - When pinning images or packages by hash, add a comment above the reference
   with the version and date (YYYY-MM-DD).

TESTING.md

@@ -17,7 +17,7 @@ real servers ensures the resolver works correctly in production.
 
 - Tests hit real DNS infrastructure and require network access
 - Test duration depends on network conditions; timeout tuning keeps
-  the suite within the 30-second target
+  the suite within the 60-second target
 - Query timeout is calibrated to 3× maximum antipodal RTT (~300ms)
   plus processing margin
 - Root server fan-out is limited to reduce parallel query load

TODO.md

@@ -25,6 +25,16 @@ confirm make check still passes.
 
 # Completed Steps
 
+- 2026-08-10: live-DNS test flakiness addressed by robustness rather
+  than gating, per the owner's ruling on #93: new
+  `internal/resolver/livedns_test.go` adds a package-wide concurrency
+  gate (so parallel tests stop bursting at the first root server),
+  retry with exponential backoff on transport failures only, and
+  quorum instead of unanimity for multi-nameserver assertions. The
+  `make test` cap moved to the new org-wide 60s hard cap / 20s target
+  with a 90s `-timeout` backstop; `REPO_POLICIES.md` re-vendored
+  byte-identical from `sneak/prompts`. No mocks, no `-short`, no build
+  tags, no skips, and no change to production resolver behaviour
 - 2026-08-10: all linting moved into Docker: new root `Dockerfile.lint`
   on the digest-pinned `golangci/golangci-lint:v2.12.2` image,
   `script/lint` reduced to a thin wrapper that builds it with

internal/resolver/livedns_harness_test.go

@@ -0,0 +1,162 @@
+package resolver_test
+
+import (
+	"context"
+	"sync"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+
+	"sneak.berlin/go/dnswatcher/internal/resolver"
+)
+
+// Tests for the live-DNS harness in livedns_test.go itself. These
+// exercise pure logic and the retry/concurrency plumbing; they
+// perform no DNS resolution of any kind, so they neither mock DNS
+// nor depend on it.
+
+func TestLiveQuorumIsStrictMajority(t *testing.T) {
+	t.Parallel()
+
+	cases := map[int]int{
+		0:  1,
+		1:  1,
+		2:  2,
+		3:  2,
+		4:  3,
+		5:  3,
+		13: 7,
+	}
+
+	for total, want := range cases {
+		assert.Equal(
+			t, want, liveQuorum(total),
+			"liveQuorum(%d)", total,
+		)
+	}
+}
+
+func TestStatusCountingIgnoresSilentNameservers(t *testing.T) {
+	t.Parallel()
+
+	results := map[string]*resolver.NameserverResponse{
+		"ns1.example.": {
+			Nameserver: "ns1.example.",
+			Status:     resolver.StatusOK,
+		},
+		"ns2.example.": {
+			Nameserver: "ns2.example.",
+			Status:     resolver.StatusOK,
+		},
+		"ns3.example.": {
+			Nameserver: "ns3.example.",
+			Status:     resolver.StatusTimeout,
+		},
+		"ns4.example.": {
+			Nameserver: "ns4.example.",
+			Status:     resolver.StatusError,
+		},
+	}
+
+	assert.Equal(
+		t, 2, countStatus(results, resolver.StatusOK),
+	)
+	assert.Equal(
+		t, 0, countStatus(results, resolver.StatusNXDomain),
+	)
+
+	// Two of four answered, which is short of the quorum of
+	// three: this is the state that triggers a retry rather
+	// than an assertion failure.
+	assert.Equal(t, 2, answeredCount(results))
+	assert.Less(t, answeredCount(results), liveQuorum(len(results)))
+
+	assert.Equal(
+		t,
+		"ns1.example.=ok ns2.example.=ok "+
+			"ns3.example.=timeout ns4.example.=error",
+		describeStatuses(results),
+	)
+}
+
+func TestRetryLiveRecoversFromTransientFailure(t *testing.T) {
+	t.Parallel()
+
+	const wantAttempts = 2
+
+	attempts := 0
+
+	retryLive(t, "transient", func(_ context.Context) error {
+		attempts++
+
+		if attempts < wantAttempts {
+			return errLiveNoAnswer
+		}
+
+		return nil
+	})
+
+	assert.Equal(t, wantAttempts, attempts)
+}
+
+func TestRetryLiveGivesEachAttemptADeadline(t *testing.T) {
+	t.Parallel()
+
+	retryLive(t, "deadline", func(ctx context.Context) error {
+		deadline, ok := ctx.Deadline()
+		assert.True(t, ok, "attempt should carry a deadline")
+		assert.LessOrEqual(
+			t, time.Until(deadline), liveAttemptTimeout,
+		)
+
+		return nil
+	})
+}
+
+func TestRunLiveBoundsConcurrency(t *testing.T) {
+	t.Parallel()
+
+	const workers = 24
+
+	var (
+		mu       sync.Mutex
+		wg       sync.WaitGroup
+		inFlight int
+		maxSeen  int
+	)
+
+	wg.Add(workers)
+
+	for range workers {
+		go func() {
+			defer wg.Done()
+
+			_ = runLive(func(_ context.Context) error {
+				mu.Lock()
+				inFlight++
+
+				if inFlight > maxSeen {
+					maxSeen = inFlight
+				}
+				mu.Unlock()
+
+				time.Sleep(time.Millisecond)
+
+				mu.Lock()
+				inFlight--
+				mu.Unlock()
+
+				return nil
+			})
+		}()
+	}
+
+	wg.Wait()
+
+	assert.Positive(t, maxSeen)
+	assert.LessOrEqual(
+		t, maxSeen, liveConcurrency,
+		"live queries must stay under the package-wide gate",
+	)
+}

internal/resolver/livedns_test.go

@@ -0,0 +1,437 @@
+package resolver_test
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"sort"
+	"strings"
+	"testing"
+	"time"
+
+	"sneak.berlin/go/dnswatcher/internal/resolver"
+)
+
+// ----------------------------------------------------------------
+// Live DNS test support
+// ----------------------------------------------------------------
+//
+// Every test in this package resolves against the real, live DNS —
+// see TESTING.md. Nothing here mocks, fakes, stubs, records or
+// replays DNS, and nothing here skips or gates a test: the helpers
+// below only change *how* the live queries are issued, so that a
+// single dropped UDP packet or one slow authoritative server does
+// not turn a correct resolver into a red build.
+//
+// Three mechanisms, all test-side:
+//
+//  1. Bounded concurrency. The package's tests are parallel and the
+//     build hosts have many cores, so without a limit every test
+//     starts its own iterative resolution at the same instant and
+//     they all hit the first root server in rootServerList() within
+//     a few milliseconds of each other. Root servers rate-limit
+//     that, which shows up as a different arbitrary subset of tests
+//     failing on each run. liveGate caps how many resolutions are
+//     in flight at once.
+//
+//  2. Retry with exponential backoff. Each live operation gets
+//     several attempts with its own timeout. The retry predicate is
+//     strictly transport-level — "did a nameserver answer at all" —
+//     never the assertion the test is making. A resolver that
+//     answers incorrectly still fails on the first attempt.
+//
+//  3. Quorum. Where an assertion spans several independent
+//     nameservers, a strict majority answering as expected is
+//     enough; a server that fails to answer is tolerated, while a
+//     server that answers *wrongly* still fails the test.
+
+const (
+	// liveAttempts is how many times a live DNS operation is
+	// attempted before the test fails.
+	liveAttempts = 3
+
+	// liveAttemptTimeout bounds one attempt. Worst case for an
+	// operation is liveAttempts * liveAttemptTimeout plus the
+	// backoff — about 26 seconds, well inside the 90-second
+	// `go test -timeout` backstop even when several operations
+	// exhaust their attempts.
+	liveAttemptTimeout = 8 * time.Second
+
+	// liveBackoffBase is the delay after the first failed
+	// attempt; it is multiplied by liveBackoffFactor each time.
+	liveBackoffBase = 500 * time.Millisecond
+
+	// liveBackoffFactor is the exponential backoff multiplier.
+	liveBackoffFactor = 2
+
+	// liveConcurrency caps how many live resolutions may be in
+	// flight across the whole package at once.
+	liveConcurrency = 6
+
+	// minNameservers is the smallest nameserver count a
+	// well-run zone is expected to publish.
+	minNameservers = 2
+)
+
+// liveGate bounds concurrent live resolutions package-wide. It has
+// to be package scoped: the whole point is that it is shared by
+// every parallel test in the package.
+//
+//nolint:gochecknoglobals // package-wide live query rate limit
+var liveGate = make(chan struct{}, liveConcurrency)
+
+var (
+	// errLiveNoAnswer reports that a live operation produced no
+	// usable answer, which is retried rather than asserted on.
+	errLiveNoAnswer = errors.New("no answer from live DNS")
+
+	// errLiveNoQuorum reports that too few of a domain's
+	// nameservers answered for a quorum assertion to be made.
+	errLiveNoQuorum = errors.New("no nameserver quorum")
+)
+
+// runLive executes one attempt of a live operation, holding a slot
+// in liveGate for its duration and bounding it with its own
+// timeout.
+func runLive(op func(ctx context.Context) error) error {
+	liveGate <- struct{}{}
+	defer func() { <-liveGate }()
+
+	ctx, cancel := context.WithTimeout(
+		context.Background(), liveAttemptTimeout,
+	)
+	defer cancel()
+
+	return op(ctx)
+}
+
+// retryLive runs op until it reports success, retrying transport
+// failures with exponential backoff, and fails the test if every
+// attempt fails. op returns an error only for a failure to obtain
+// an answer — never for an answer the test disagrees with, which
+// belongs in an assertion so that it fails immediately. op stores
+// whatever it obtained where its caller can find it.
+func retryLive(
+	t *testing.T,
+	what string,
+	op func(ctx context.Context) error,
+) {
+	t.Helper()
+
+	var last error
+
+	backoff := liveBackoffBase
+
+	for attempt := range liveAttempts {
+		if attempt > 0 {
+			t.Logf(
+				"%s: attempt %d of %d failed (%v), "+
+					"retrying in %s",
+				what, attempt, liveAttempts, last, backoff,
+			)
+			time.Sleep(backoff)
+
+			backoff *= liveBackoffFactor
+		}
+
+		last = runLive(op)
+		if last == nil {
+			return
+		}
+	}
+
+	t.Fatalf(
+		"%s: no answer after %d live attempts: %v",
+		what, liveAttempts, last,
+	)
+}
+
+// liveQuorum is how many of total nameservers must agree for a
+// multi-nameserver assertion to hold: a strict majority.
+func liveQuorum(total int) int {
+	if total < 1 {
+		return 1
+	}
+
+	return total/2 + 1
+}
+
+// countStatus counts the responses carrying the given status.
+func countStatus(
+	results map[string]*resolver.NameserverResponse,
+	status string,
+) int {
+	n := 0
+
+	for _, resp := range results {
+		if resp.Status == status {
+			n++
+		}
+	}
+
+	return n
+}
+
+// answeredCount counts the nameservers that produced an answer of
+// any kind, as opposed to failing or timing out.
+func answeredCount(
+	results map[string]*resolver.NameserverResponse,
+) int {
+	return len(results) -
+		countStatus(results, resolver.StatusError) -
+		countStatus(results, resolver.StatusTimeout)
+}
+
+// describeStatuses renders per-nameserver statuses for use in
+// assertion failure messages.
+func describeStatuses(
+	results map[string]*resolver.NameserverResponse,
+) string {
+	parts := make([]string, 0, len(results))
+	for ns, resp := range results {
+		parts = append(
+			parts, fmt.Sprintf("%s=%s", ns, resp.Status),
+		)
+	}
+
+	sort.Strings(parts)
+
+	return strings.Join(parts, " ")
+}
+
+// ----------------------------------------------------------------
+// Live operation wrappers
+// ----------------------------------------------------------------
+
+// liveFindAuthoritative resolves a domain's authoritative
+// nameservers, retrying until the delegation chain can be walked.
+func liveFindAuthoritative(
+	t *testing.T,
+	r *resolver.Resolver,
+	domain string,
+) []string {
+	t.Helper()
+
+	var out []string
+
+	retryLive(
+		t,
+		"FindAuthoritativeNameservers("+domain+")",
+		func(ctx context.Context) error {
+			ns, err := r.FindAuthoritativeNameservers(ctx, domain)
+			if err != nil {
+				return err
+			}
+
+			if len(ns) == 0 {
+				return fmt.Errorf(
+					"%w: %s has no nameservers",
+					errLiveNoAnswer, domain,
+				)
+			}
+
+			out = ns
+
+			return nil
+		},
+	)
+
+	return out
+}
+
+// liveLookupNS is liveFindAuthoritative through the LookupNS entry
+// point, so that both entry points stay independently exercised.
+func liveLookupNS(
+	t *testing.T,
+	r *resolver.Resolver,
+	domain string,
+) []string {
+	t.Helper()
+
+	var out []string
+
+	retryLive(
+		t,
+		"LookupNS("+domain+")",
+		func(ctx context.Context) error {
+			ns, err := r.LookupNS(ctx, domain)
+			if err != nil {
+				return err
+			}
+
+			if len(ns) == 0 {
+				return fmt.Errorf(
+					"%w: %s has no nameservers",
+					errLiveNoAnswer, domain,
+				)
+			}
+
+			out = ns
+
+			return nil
+		},
+	)
+
+	return out
+}
+
+// liveQueryNameserver queries one nameserver, retrying while that
+// nameserver fails to answer. NXDOMAIN and NODATA are answers and
+// are returned to the caller to assert on.
+func liveQueryNameserver(
+	t *testing.T,
+	r *resolver.Resolver,
+	nameserver string,
+	hostname string,
+) *resolver.NameserverResponse {
+	t.Helper()
+
+	what := fmt.Sprintf(
+		"QueryNameserver(%s, %s)", nameserver, hostname,
+	)
+
+	var out *resolver.NameserverResponse
+
+	retryLive(
+		t,
+		what,
+		func(ctx context.Context) error {
+			resp, err := r.QueryNameserver(
+				ctx, nameserver, hostname,
+			)
+			if err != nil {
+				return err
+			}
+
+			if resp.Status == resolver.StatusTimeout ||
+				resp.Status == resolver.StatusError {
+				return fmt.Errorf(
+					"%w: %s returned %s: %s",
+					errLiveNoAnswer, nameserver,
+					resp.Status, resp.Error,
+				)
+			}
+
+			out = resp
+
+			return nil
+		},
+	)
+
+	return out
+}
+
+// liveQueryAllNameservers queries every authoritative nameserver
+// for a hostname, retrying until a quorum of them has answered.
+// Individual nameservers that stay silent are left in the result
+// for the caller to account for.
+func liveQueryAllNameservers(
+	t *testing.T,
+	r *resolver.Resolver,
+	hostname string,
+) map[string]*resolver.NameserverResponse {
+	t.Helper()
+
+	var out map[string]*resolver.NameserverResponse
+
+	retryLive(
+		t,
+		"QueryAllNameservers("+hostname+")",
+		func(ctx context.Context) error {
+			results, err := r.QueryAllNameservers(ctx, hostname)
+			if err != nil {
+				return err
+			}
+
+			if len(results) == 0 {
+				return fmt.Errorf(
+					"%w: no nameservers queried for %s",
+					errLiveNoAnswer, hostname,
+				)
+			}
+
+			answered := answeredCount(results)
+			if answered < liveQuorum(len(results)) {
+				return fmt.Errorf(
+					"%w: %d of %d answered: %s",
+					errLiveNoQuorum, answered,
+					len(results), describeStatuses(results),
+				)
+			}
+
+			out = results
+
+			return nil
+		},
+	)
+
+	return out
+}
+
+// liveResolveIPs resolves a hostname that is expected to have
+// addresses, retrying until at least one is returned.
+func liveResolveIPs(
+	t *testing.T,
+	r *resolver.Resolver,
+	hostname string,
+) []string {
+	t.Helper()
+
+	var out []string
+
+	retryLive(
+		t,
+		"ResolveIPAddresses("+hostname+")",
+		func(ctx context.Context) error {
+			ips, err := r.ResolveIPAddresses(ctx, hostname)
+			if err != nil {
+				return err
+			}
+
+			if len(ips) == 0 {
+				return fmt.Errorf(
+					"%w: no addresses for %s",
+					errLiveNoAnswer, hostname,
+				)
+			}
+
+			out = ips
+
+			return nil
+		},
+	)
+
+	return out
+}
+
+// liveResolveIPsAllowingEmpty resolves a hostname that may legitimately
+// have no addresses, so the empty result is returned rather than
+// retried. Used for names that must not exist; the corresponding
+// QueryAllNameservers test is what proves the nameservers actively
+// said NXDOMAIN rather than merely staying silent.
+func liveResolveIPsAllowingEmpty(
+	t *testing.T,
+	r *resolver.Resolver,
+	hostname string,
+) []string {
+	t.Helper()
+
+	var out []string
+
+	retryLive(
+		t,
+		"ResolveIPAddresses("+hostname+")",
+		func(ctx context.Context) error {
+			ips, err := r.ResolveIPAddresses(ctx, hostname)
+			if err != nil {
+				return err
+			}
+
+			out = ips
+
+			return nil
+		},
+	)
+
+	return out
+}

internal/resolver/resolver_test.go

@@ -32,32 +32,17 @@ func newTestResolver(t *testing.T) *resolver.Resolver {
 	return resolver.NewFromLogger(log)
 }
 
-func testContext(t *testing.T) context.Context {
-	t.Helper()
-
-	ctx, cancel := context.WithTimeout(
-		context.Background(), 60*time.Second,
-	)
-	t.Cleanup(cancel)
-
-	return ctx
-}
-
+// findOneNSForDomain picks one authoritative nameserver to aim a
+// test at. Live-DNS retry, concurrency and quorum handling live in
+// livedns_test.go.
 func findOneNSForDomain(
 	t *testing.T,
 	r *resolver.Resolver,
-	ctx context.Context, //nolint:revive // test helper
 	domain string,
 ) string {
 	t.Helper()
 
-	nameservers, err := r.FindAuthoritativeNameservers(
-		ctx, domain,
-	)
-	require.NoError(t, err)
-	require.NotEmpty(t, nameservers)
-
-	return nameservers[0]
+	return liveFindAuthoritative(t, r, domain)[0]
 }
 
 // ----------------------------------------------------------------
@@ -70,13 +55,7 @@ func TestFindAuthoritativeNameservers_ValidDomain(
 	t.Parallel()
 
 	r := newTestResolver(t)
-	ctx := testContext(t)
-
-	nameservers, err := r.FindAuthoritativeNameservers(
-		ctx, "google.com",
-	)
-	require.NoError(t, err)
-	require.NotEmpty(t, nameservers)
+	nameservers := liveFindAuthoritative(t, r, "google.com")
 
 	hasGoogleNS := false
 
@@ -99,13 +78,9 @@ func TestFindAuthoritativeNameservers_Subdomain(
 	t.Parallel()
 
 	r := newTestResolver(t)
-	ctx := testContext(t)
+	nameservers := liveFindAuthoritative(t, r, "www.google.com")
 
-	nameservers, err := r.FindAuthoritativeNameservers(
-		ctx, "www.google.com",
-	)
-	require.NoError(t, err)
-	require.NotEmpty(t, nameservers)
+	assert.NotEmpty(t, nameservers)
 }
 
 func TestFindAuthoritativeNameservers_ReturnsSorted(
@@ -114,12 +89,7 @@ func TestFindAuthoritativeNameservers_ReturnsSorted(
 	t.Parallel()
 
 	r := newTestResolver(t)
-	ctx := testContext(t)
-
-	nameservers, err := r.FindAuthoritativeNameservers(
-		ctx, "google.com",
-	)
-	require.NoError(t, err)
+	nameservers := liveFindAuthoritative(t, r, "google.com")
 
 	assert.True(
 		t,
@@ -134,17 +104,8 @@ func TestFindAuthoritativeNameservers_Deterministic(
 	t.Parallel()
 
 	r := newTestResolver(t)
-	ctx := testContext(t)
-
-	first, err := r.FindAuthoritativeNameservers(
-		ctx, "google.com",
-	)
-	require.NoError(t, err)
-
-	second, err := r.FindAuthoritativeNameservers(
-		ctx, "google.com",
-	)
-	require.NoError(t, err)
+	first := liveFindAuthoritative(t, r, "google.com")
+	second := liveFindAuthoritative(t, r, "google.com")
 
 	assert.Equal(t, first, second)
 }
@@ -155,17 +116,8 @@ func TestFindAuthoritativeNameservers_TrailingDot(
 	t.Parallel()
 
 	r := newTestResolver(t)
-	ctx := testContext(t)
-
-	ns1, err := r.FindAuthoritativeNameservers(
-		ctx, "google.com",
-	)
-	require.NoError(t, err)
-
-	ns2, err := r.FindAuthoritativeNameservers(
-		ctx, "google.com.",
-	)
-	require.NoError(t, err)
+	ns1 := liveFindAuthoritative(t, r, "google.com")
+	ns2 := liveFindAuthoritative(t, r, "google.com.")
 
 	assert.Equal(t, ns1, ns2)
 }
@@ -176,13 +128,7 @@ func TestFindAuthoritativeNameservers_CloudflareDomain(
 	t.Parallel()
 
 	r := newTestResolver(t)
-	ctx := testContext(t)
-
-	nameservers, err := r.FindAuthoritativeNameservers(
-		ctx, "cloudflare.com",
-	)
-	require.NoError(t, err)
-	require.NotEmpty(t, nameservers)
+	nameservers := liveFindAuthoritative(t, r, "cloudflare.com")
 
 	for _, ns := range nameservers {
 		assert.True(t, strings.HasSuffix(ns, "."),
@@ -199,13 +145,9 @@ func TestQueryNameserver_BasicA(t *testing.T) {
 	t.Parallel()
 
 	r := newTestResolver(t)
-	ctx := testContext(t)
-	ns := findOneNSForDomain(t, r, ctx, "google.com")
+	ns := findOneNSForDomain(t, r, "google.com")
+	resp := liveQueryNameserver(t, r, ns, "www.google.com")
 
-	resp, err := r.QueryNameserver(
-		ctx, ns, "www.google.com",
-	)
-	require.NoError(t, err)
 	require.NotNil(t, resp)
 
 	assert.Equal(t, resolver.StatusOK, resp.Status)
@@ -222,13 +164,8 @@ func TestQueryNameserver_AAAA(t *testing.T) {
 	t.Parallel()
 
 	r := newTestResolver(t)
-	ctx := testContext(t)
-	ns := findOneNSForDomain(t, r, ctx, "cloudflare.com")
-
-	resp, err := r.QueryNameserver(
-		ctx, ns, "cloudflare.com",
-	)
-	require.NoError(t, err)
+	ns := findOneNSForDomain(t, r, "cloudflare.com")
+	resp := liveQueryNameserver(t, r, ns, "cloudflare.com")
 
 	aaaaRecords := resp.Records["AAAA"]
 	require.NotEmpty(t, aaaaRecords,
@@ -247,13 +184,8 @@ func TestQueryNameserver_MX(t *testing.T) {
 	t.Parallel()
 
 	r := newTestResolver(t)
-	ctx := testContext(t)
-	ns := findOneNSForDomain(t, r, ctx, "google.com")
-
-	resp, err := r.QueryNameserver(
-		ctx, ns, "google.com",
-	)
-	require.NoError(t, err)
+	ns := findOneNSForDomain(t, r, "google.com")
+	resp := liveQueryNameserver(t, r, ns, "google.com")
 
 	mxRecords := resp.Records["MX"]
 	require.NotEmpty(t, mxRecords,
@@ -265,13 +197,8 @@ func TestQueryNameserver_TXT(t *testing.T) {
 	t.Parallel()
 
 	r := newTestResolver(t)
-	ctx := testContext(t)
-	ns := findOneNSForDomain(t, r, ctx, "google.com")
-
-	resp, err := r.QueryNameserver(
-		ctx, ns, "google.com",
-	)
-	require.NoError(t, err)
+	ns := findOneNSForDomain(t, r, "google.com")
+	resp := liveQueryNameserver(t, r, ns, "google.com")
 
 	txtRecords := resp.Records["TXT"]
 	require.NotEmpty(t, txtRecords,
@@ -297,14 +224,10 @@ func TestQueryNameserver_NXDomain(t *testing.T) {
 	t.Parallel()
 
 	r := newTestResolver(t)
-	ctx := testContext(t)
-	ns := findOneNSForDomain(t, r, ctx, "google.com")
-
-	resp, err := r.QueryNameserver(
-		ctx, ns,
-		"this-surely-does-not-exist-xyz.google.com",
+	ns := findOneNSForDomain(t, r, "google.com")
+	resp := liveQueryNameserver(
+		t, r, ns, "this-surely-does-not-exist-xyz.google.com",
 	)
-	require.NoError(t, err)
 
 	assert.Equal(t, resolver.StatusNXDomain, resp.Status)
 }
@@ -313,13 +236,8 @@ func TestQueryNameserver_RecordsSorted(t *testing.T) {
 	t.Parallel()
 
 	r := newTestResolver(t)
-	ctx := testContext(t)
-	ns := findOneNSForDomain(t, r, ctx, "google.com")
-
-	resp, err := r.QueryNameserver(
-		ctx, ns, "google.com",
-	)
-	require.NoError(t, err)
+	ns := findOneNSForDomain(t, r, "google.com")
+	resp := liveQueryNameserver(t, r, ns, "google.com")
 
 	for recordType, values := range resp.Records {
 		assert.True(
@@ -336,13 +254,8 @@ func TestQueryNameserver_ResponseIncludesNameserver(
 	t.Parallel()
 
 	r := newTestResolver(t)
-	ctx := testContext(t)
-	ns := findOneNSForDomain(t, r, ctx, "cloudflare.com")
-
-	resp, err := r.QueryNameserver(
-		ctx, ns, "cloudflare.com",
-	)
-	require.NoError(t, err)
+	ns := findOneNSForDomain(t, r, "cloudflare.com")
+	resp := liveQueryNameserver(t, r, ns, "cloudflare.com")
 
 	assert.Equal(t, ns, resp.Nameserver)
 }
@@ -353,14 +266,10 @@ func TestQueryNameserver_EmptyRecordsOnNXDomain(
 	t.Parallel()
 
 	r := newTestResolver(t)
-	ctx := testContext(t)
-	ns := findOneNSForDomain(t, r, ctx, "google.com")
-
-	resp, err := r.QueryNameserver(
-		ctx, ns,
-		"this-surely-does-not-exist-xyz.google.com",
+	ns := findOneNSForDomain(t, r, "google.com")
+	resp := liveQueryNameserver(
+		t, r, ns, "this-surely-does-not-exist-xyz.google.com",
 	)
-	require.NoError(t, err)
 
 	totalRecords := 0
 	for _, values := range resp.Records {
@@ -374,18 +283,9 @@ func TestQueryNameserver_TrailingDotHandling(t *testing.T) {
 	t.Parallel()
 
 	r := newTestResolver(t)
-	ctx := testContext(t)
-	ns := findOneNSForDomain(t, r, ctx, "google.com")
-
-	resp1, err := r.QueryNameserver(
-		ctx, ns, "google.com",
-	)
-	require.NoError(t, err)
-
-	resp2, err := r.QueryNameserver(
-		ctx, ns, "google.com.",
-	)
-	require.NoError(t, err)
+	ns := findOneNSForDomain(t, r, "google.com")
+	resp1 := liveQueryNameserver(t, r, ns, "google.com")
+	resp2 := liveQueryNameserver(t, r, ns, "google.com.")
 
 	assert.Equal(t, resp1.Status, resp2.Status)
 }
@@ -398,15 +298,9 @@ func TestQueryAllNameservers_ReturnsAllNS(t *testing.T) {
 	t.Parallel()
 
 	r := newTestResolver(t)
-	ctx := testContext(t)
+	results := liveQueryAllNameservers(t, r, "google.com")
 
-	results, err := r.QueryAllNameservers(
-		ctx, "google.com",
-	)
-	require.NoError(t, err)
-	require.NotEmpty(t, results)
-
-	assert.GreaterOrEqual(t, len(results), 2)
+	assert.GreaterOrEqual(t, len(results), minNameservers)
 
 	for ns, resp := range results {
 		assert.Equal(t, ns, resp.Nameserver)
@@ -417,19 +311,27 @@ func TestQueryAllNameservers_AllReturnOK(t *testing.T) {
 	t.Parallel()
 
 	r := newTestResolver(t)
-	ctx := testContext(t)
+	results := liveQueryAllNameservers(t, r, "google.com")
 
-	results, err := r.QueryAllNameservers(
-		ctx, "google.com",
+	// A quorum, not unanimity: one authoritative server being
+	// slow or rate-limiting us is a property of the live
+	// internet, not a resolver defect.
+	assert.GreaterOrEqual(
+		t,
+		countStatus(results, resolver.StatusOK),
+		liveQuorum(len(results)),
+		"a quorum of nameservers should answer OK: %s",
+		describeStatuses(results),
 	)
-	require.NoError(t, err)
 
-	for ns, resp := range results {
-		assert.Equal(
-			t, resolver.StatusOK, resp.Status,
-			"NS %s should return OK", ns,
+	// Any nameserver claiming google.com does not exist is a
+	// real failure and is never tolerated.
+	assert.Zero(
+		t,
+		countStatus(results, resolver.StatusNXDomain),
+		"no nameserver should report NXDOMAIN: %s",
+		describeStatuses(results),
 	)
-	}
 }
 
 func TestQueryAllNameservers_NXDomainFromAllNS(
@@ -438,20 +340,26 @@ func TestQueryAllNameservers_NXDomainFromAllNS(
 	t.Parallel()
 
 	r := newTestResolver(t)
-	ctx := testContext(t)
-
-	results, err := r.QueryAllNameservers(
-		ctx,
-		"this-surely-does-not-exist-xyz.google.com",
+	results := liveQueryAllNameservers(
+		t, r, "this-surely-does-not-exist-xyz.google.com",
 	)
-	require.NoError(t, err)
 
-	for ns, resp := range results {
-		assert.Equal(
-			t, resolver.StatusNXDomain, resp.Status,
-			"NS %s should return nxdomain", ns,
+	assert.GreaterOrEqual(
+		t,
+		countStatus(results, resolver.StatusNXDomain),
+		liveQuorum(len(results)),
+		"a quorum of nameservers should report NXDOMAIN: %s",
+		describeStatuses(results),
+	)
+
+	// Silence is tolerated; a positive answer for a name that
+	// does not exist is not.
+	assert.Zero(
+		t,
+		countStatus(results, resolver.StatusOK),
+		"no nameserver should answer OK: %s",
+		describeStatuses(results),
 	)
-	}
 }
 
 // ----------------------------------------------------------------
@@ -462,11 +370,7 @@ func TestLookupNS_ValidDomain(t *testing.T) {
 	t.Parallel()
 
 	r := newTestResolver(t)
-	ctx := testContext(t)
-
-	nameservers, err := r.LookupNS(ctx, "google.com")
-	require.NoError(t, err)
-	require.NotEmpty(t, nameservers)
+	nameservers := liveLookupNS(t, r, "google.com")
 
 	for _, ns := range nameservers {
 		assert.True(t, strings.HasSuffix(ns, "."),
@@ -479,10 +383,7 @@ func TestLookupNS_Sorted(t *testing.T) {
 	t.Parallel()
 
 	r := newTestResolver(t)
-	ctx := testContext(t)
-
-	nameservers, err := r.LookupNS(ctx, "google.com")
-	require.NoError(t, err)
+	nameservers := liveLookupNS(t, r, "google.com")
 
 	assert.True(t, sort.StringsAreSorted(nameservers))
 }
@@ -491,15 +392,8 @@ func TestLookupNS_MatchesFindAuthoritative(t *testing.T) {
 	t.Parallel()
 
 	r := newTestResolver(t)
-	ctx := testContext(t)
-
-	fromLookup, err := r.LookupNS(ctx, "google.com")
-	require.NoError(t, err)
-
-	fromFind, err := r.FindAuthoritativeNameservers(
-		ctx, "google.com",
-	)
-	require.NoError(t, err)
+	fromLookup := liveLookupNS(t, r, "google.com")
+	fromFind := liveFindAuthoritative(t, r, "google.com")
 
 	assert.Equal(t, fromFind, fromLookup)
 }
@@ -512,11 +406,7 @@ func TestResolveIPAddresses_ReturnsIPs(t *testing.T) {
 	t.Parallel()
 
 	r := newTestResolver(t)
-	ctx := testContext(t)
-
-	ips, err := r.ResolveIPAddresses(ctx, "google.com")
-	require.NoError(t, err)
-	require.NotEmpty(t, ips)
+	ips := liveResolveIPs(t, r, "google.com")
 
 	for _, ip := range ips {
 		parsed := net.ParseIP(ip)
@@ -530,10 +420,7 @@ func TestResolveIPAddresses_Deduplicated(t *testing.T) {
 	t.Parallel()
 
 	r := newTestResolver(t)
-	ctx := testContext(t)
-
-	ips, err := r.ResolveIPAddresses(ctx, "google.com")
-	require.NoError(t, err)
+	ips := liveResolveIPs(t, r, "google.com")
 
 	seen := make(map[string]bool)
 
@@ -547,10 +434,7 @@ func TestResolveIPAddresses_Sorted(t *testing.T) {
 	t.Parallel()
 
 	r := newTestResolver(t)
-	ctx := testContext(t)
-
-	ips, err := r.ResolveIPAddresses(ctx, "google.com")
-	require.NoError(t, err)
+	ips := liveResolveIPs(t, r, "google.com")
 
 	assert.True(t, sort.StringsAreSorted(ips))
 }
@@ -561,13 +445,10 @@ func TestResolveIPAddresses_NXDomainReturnsEmpty(
 	t.Parallel()
 
 	r := newTestResolver(t)
-	ctx := testContext(t)
-
-	ips, err := r.ResolveIPAddresses(
-		ctx,
-		"this-surely-does-not-exist-xyz.google.com",
+	ips := liveResolveIPsAllowingEmpty(
+		t, r, "this-surely-does-not-exist-xyz.google.com",
 	)
-	require.NoError(t, err)
+
 	assert.Empty(t, ips)
 }
 
@@ -575,11 +456,9 @@ func TestResolveIPAddresses_CloudflareDomain(t *testing.T) {
 	t.Parallel()
 
 	r := newTestResolver(t)
-	ctx := testContext(t)
+	ips := liveResolveIPs(t, r, "cloudflare.com")
 
-	ips, err := r.ResolveIPAddresses(ctx, "cloudflare.com")
-	require.NoError(t, err)
-	require.NotEmpty(t, ips)
+	assert.NotEmpty(t, ips)
 }
 
 // ----------------------------------------------------------------

script/test

@@ -6,7 +6,7 @@ ROOT="$(cd "$(dirname "$0")/.." && pwd -P)"
 
 main() {
     cd "$ROOT"
-    go test -v -race -timeout 30s -cover ./...
+    go test -v -race -timeout 90s -cover ./...
 }
 
 main "$@"