PerryTS · proggeramlug · Jul 30, 2026 · Jul 26, 2026 · Jul 26, 2026 · Jul 26, 2026
diff --git a/changelog.d/6862-dns-parity-expansion.md b/changelog.d/6862-dns-parity-expansion.md
@@ -0,0 +1 @@
+Expanded deterministic `node:dns` parity coverage from 6 to 43 fixtures and strengthened the node-suite regression floor to protect both pass counts and fixture counts.
diff --git a/crates/perry-codegen/src/loop_purity.rs b/crates/perry-codegen/src/loop_purity.rs
@@ -121,9 +121,7 @@ fn expr_alloc_free(e: &Expr) -> bool {
         // Element READS never allocate — they return an existing element / a
         // number. Recurse so the object and index are themselves alloc-free.
         Expr::IndexGet { object, index } => expr_alloc_free(object) && expr_alloc_free(index),
-        Expr::BufferIndexGet { buffer, index } => {
-            expr_alloc_free(buffer) && expr_alloc_free(index)
-        }
+        Expr::BufferIndexGet { buffer, index } => expr_alloc_free(buffer) && expr_alloc_free(index),
         Expr::Uint8ArrayGet { array, index } => expr_alloc_free(array) && expr_alloc_free(index),
         // `arr[i]++` / `--`: read-modify-write of an existing numeric slot, no
         // growth, no allocation.

diff --git a/scripts/node_suite_regression_check.py b/scripts/node_suite_regression_check.py
@@ -52,15 +52,23 @@ def main():
         print(f"ERROR: runner exited {proc.returncode}", file=sys.stderr)
         return 2
 
-    # Parse "module  pass  total  %" rows from the runner table.
+    # Parse "module  pass  total  %  outcome=count ..." rows from the runner table.
     # The header row ("module  pass  total  %") can't match because pass/total
     # are not digits, so no name-based exclusion is needed — and excluding the
     # name "module" would wrongly drop the real node:module module.
     current = {}
     for line in proc.stdout.splitlines():
-        m = re.match(r"^(\S+)\s+(\d+)\s+(\d+)\s+[\d.]+", line)
+        m = re.match(r"^(\S+)\s+(\d+)\s+(\d+)\s+[\d.]+(?:\s+(.*))?$", line)
         if m:
-            current[m.group(1)] = {"pass": int(m.group(2)), "total": int(m.group(3))}
+            outcomes = {
+                name: int(count)
+                for name, count in re.findall(r"(\w+)=(\d+)", m.group(4) or "")
+            }
+            current[m.group(1)] = {
+                "pass": int(m.group(2)),
+                "total": int(m.group(3)),
+                "outcomes": outcomes,
+            }
 
     regressions, improvements = [], []
     for mod, floor in baseline.items():
@@ -71,8 +79,20 @@ def main():
         if cur["pass"] < floor["pass"]:
             regressions.append(
                 f"{mod}: {cur['pass']}/{cur['total']} < floor {floor['pass']}/{floor['total']}  (-{floor['pass'] - cur['pass']})")
-        elif cur["pass"] > floor["pass"]:
-            improvements.append(f"{mod}: {cur['pass']}/{cur['total']}  (+{cur['pass'] - floor['pass']})")
+        if cur["total"] < floor["total"]:
+            regressions.append(
+                f"{mod}: {cur['total']} fixtures < floor {floor['total']}  (-{floor['total'] - cur['total']})")
+        for outcome, ceiling in floor.get("outcomes", {}).items():
+            count = cur["outcomes"].get(outcome, 0)
+            if count > ceiling:
+                regressions.append(
+                    f"{mod}: {outcome}={count} > ceiling {ceiling}  (+{count - ceiling})")
+        pass_delta = cur["pass"] - floor["pass"]
+        fixture_delta = cur["total"] - floor["total"]
+        if pass_delta > 0 or fixture_delta > 0:
+            improvements.append(
+                f"{mod}: {cur['pass']}/{cur['total']} "
+                f"({pass_delta:+d} passes, {fixture_delta:+d} fixtures)")
 
     # Overall is derived, not stored (avoids cross-PR merge conflicts on a
     # shared aggregate). Compute it from the per-module floors at report time.

diff --git a/scripts/node_suite_run.py b/scripts/node_suite_run.py
@@ -103,7 +103,7 @@ def run_one(args):
     try:
         n = subprocess.run([NODE, path], capture_output=True, text=True, timeout=30)
     except Exception:
-        return (mod, "node_err")
+        return (mod, "node_err", path)
     # A non-zero node exit can be intentional (the test exercises an error path),
     # so we don't bucket it as node_err; we require Perry to match BOTH stdout and
     # the exit code below, which keeps genuine error-path parity counted as pass.
@@ -112,15 +112,15 @@ def run_one(args):
         try:
             c = subprocess.run([PERRY, path, "-o", out], capture_output=True, text=True, timeout=120)
             if c.returncode != 0:
-                return (mod, "compile_fail")
+                return (mod, "compile_fail", path)
             p = subprocess.run([out], capture_output=True, text=True, timeout=30)
         except Exception:
-            return (mod, "perry_err")
+            return (mod, "perry_err", path)
     # Match stdout byte-for-byte (ignore only trailing-newline noise, not leading
     # whitespace) AND exit code — so a Perry crash that happened to print matching
     # output before dying is a diff, not a false pass.
     ok = (normalize(n.stdout.rstrip("\n")) == normalize(p.stdout.rstrip("\n"))) and (n.returncode == p.returncode)
-    return (mod, "pass" if ok else "diff")
+    return (mod, "pass" if ok else "diff", path)
 
 
 # --- pre-warm one test per module serially ---
@@ -144,11 +144,15 @@ def run_one(args):
 sys.stderr.write(f"fast lane: {len(fast)} tests @6, slow lane: {len(slow)} tests @1\n")
 sys.stderr.flush()
 with ThreadPoolExecutor(max_workers=6) as ex:
-    for mod, outcome in ex.map(run_one, fast):
+    for mod, outcome, path in ex.map(run_one, fast):
         res[mod][outcome] += 1
+        if outcome not in {"pass", "diff"}:
+            sys.stderr.write(f"{outcome}: {os.path.relpath(path, ROOT)}\n")
 for t in slow:
-    mod, outcome = run_one(t)
+    mod, outcome, path = run_one(t)
     res[mod][outcome] += 1
+    if outcome not in {"pass", "diff"}:
+        sys.stderr.write(f"{outcome}: {os.path.relpath(path, ROOT)}\n")
 
 # --- report ---
 tot_p = tot = 0

diff --git a/test-parity/node-suite/dns/README.md b/test-parity/node-suite/dns/README.md
@@ -0,0 +1,218 @@
+# `node:dns` granular parity suite
+
+This directory compares deterministic public `node:dns` and `node:dns/promises`
+behavior with Node 26.5.0. Each TypeScript file has one contract or one small
+record family. The differential runner executes this module sequentially.
+
+## Audited starting point
+
+The six starting fixtures were reviewed before expansion:
+
+- `constants/error-aliases.ts` already covered the full public error-code table.
+- `imports/default-export.ts` mixed import identity with a live `resolve4()`
+  request. The request was removed because it queried the host nameserver and
+  changed between `ECONNREFUSED`, `ENOTFOUND`, and `EBADRESP`.
+- `lookup/loopback.ts` uses only the system hosts path and loopback addresses.
+  It remains as the broad callback/promise smoke case.
+- `resolve/localhost.ts` queried the configured nameserver rather than the hosts
+  file. It was removed and replaced with local authoritative-server fixtures.
+- `settings/default-result-order.ts` used host-dependent localhost ordering. It
+  now tests only shared state, valid values, and invalid-value preservation.
+- `settings/servers.ts` only parses and stores server addresses. It remains and
+  now reports missing alternate-runtime methods without aborting.
+
+The audit also traced Perry's DNS manifest, native dispatch table,
+`crates/perry-runtime/src/dns.rs`, and
+`crates/perry-runtime/src/dns_resolver.rs`. Perry implements real wire queries,
+but several `Resolver` object, validation, callback-request, TTL, cancellation,
+and descriptor contracts still differ from Node.
+
+## Fixed upstream sources
+
+The selection was reviewed on 2026-07-26 against these primary snapshots:
+
+- Node 26.5.0 commit
+  [`bebd1b8d92bf4cc917844d6335ed1ecf9c2a75fb`](https://github.com/nodejs/node/tree/bebd1b8d92bf4cc917844d6335ed1ecf9c2a75fb),
+  especially
+  [`lib/dns.js`](https://github.com/nodejs/node/blob/bebd1b8d92bf4cc917844d6335ed1ecf9c2a75fb/lib/dns.js),
+  [`internal/dns/utils.js`](https://github.com/nodejs/node/blob/bebd1b8d92bf4cc917844d6335ed1ecf9c2a75fb/lib/internal/dns/utils.js),
+  [`callback_resolver.js`](https://github.com/nodejs/node/blob/bebd1b8d92bf4cc917844d6335ed1ecf9c2a75fb/lib/internal/dns/callback_resolver.js),
+  [`promises.js`](https://github.com/nodejs/node/blob/bebd1b8d92bf4cc917844d6335ed1ecf9c2a75fb/lib/internal/dns/promises.js),
+  and the
+  [`test-dns*` parallel tests](https://github.com/nodejs/node/tree/bebd1b8d92bf4cc917844d6335ed1ecf9c2a75fb/test/parallel).
+- Deno main commit
+  [`34c46613cbe20450b74c0e8d4f0fd8f6f781d807`](https://github.com/denoland/deno/tree/34c46613cbe20450b74c0e8d4f0fd8f6f781d807),
+  especially
+  [`dns_test.ts`](https://github.com/denoland/deno/blob/34c46613cbe20450b74c0e8d4f0fd8f6f781d807/tests/unit_node/dns_test.ts)
+  and its
+  [`node:dns` polyfill](https://github.com/denoland/deno/blob/34c46613cbe20450b74c0e8d4f0fd8f6f781d807/ext/node/polyfills/dns.ts).
+- Bun main commit
+  [`44f6469e0d4ae93467aa65c7e3bc9001000c7b31`](https://github.com/oven-sh/bun/tree/44f6469e0d4ae93467aa65c7e3bc9001000c7b31),
+  especially
+  [`node-dns.test.js`](https://github.com/oven-sh/bun/blob/44f6469e0d4ae93467aa65c7e3bc9001000c7b31/test/js/node/dns/node-dns.test.js),
+  its selected
+  [Node DNS tests](https://github.com/oven-sh/bun/tree/44f6469e0d4ae93467aa65c7e3bc9001000c7b31/test/js/node/test/parallel),
+  and
+  [`dns.ts`](https://github.com/oven-sh/bun/blob/44f6469e0d4ae93467aa65c7e3bc9001000c7b31/src/js/node/dns.ts).
+
+Node 26.5.0 is the oracle. Deno and Bun results show whether another runtime
+made the same choice; they do not weaken the Node contract.
+
+## Covered contracts
+
+- export inventory, default/namespace identity, callback/promise aliases,
+  descriptors, function names, and arity;
+- literal IPv4/IPv6 lookup, localhost loopback, callback request objects, family
+  forms, option accessor order, option validation, falsy hostnames, and
+  `util.promisify()` behavior;
+- IPv4/IPv6 loopback `lookupService`, port coercion, and argument validation;
+- shared default result order, module resolver rebinding, server parsing,
+  sparse/accessor arrays, invalid-update preservation, and resolver-local server
+  state;
+- `Resolver` prototype layout, constructor option access and validation,
+  receiver checks, `setLocalAddress`, `setServers`, method validation, active
+  cancellation, and idempotent cancellation;
+- callback and promise A/AAAA with TTL, ANY, CAA, CNAME, MX, NAPTR, NS, PTR,
+  SOA, SRV, TXT, IDNA, rrtype aliases, reverse validation, and DNS error shape.
+
+Record fixtures use `fixtures/local-dns-server.mjs`. The `.mjs` extension keeps
+the helper out of the runner's recursive `*.ts` fixture discovery and makes its
+ES module mode explicit. It starts the same child Node server for every runtime,
+binds an ephemeral UDP loopback port, returns fixed TEST-NET/documentation
+records, and closes in `finally`. No fixture sends a query to an internet
+nameserver.
+
+## Environment and result
+
+- Oracle: Node 26.5.0, commit `bebd1b8d92bf4cc917844d6335ed1ecf9c2a75fb`.
+- Perry runtime: commit `563c35951b347aabac3e093efd9c8b2af8ecd5d9`, built with
+  `rustc 1.95.0 (59807616e 2026-04-14)` and `cargo build --release --bin perry`.
+- Alternate execution: Deno 2.9.3 and Bun 1.2.18.
+- Alternate source review: Deno `34c46613cbe20450b74c0e8d4f0fd8f6f781d807` and
+  Bun `44f6469e0d4ae93467aa65c7e3bc9001000c7b31`.
+
+Three complete Node rounds ran all 43 fixtures with zero errors, crashes, or
+timeouts and byte-identical aggregate SHA-256
+`e18b3a7e82b9309c1f8db862d25a5ee1ec2210a61a4f0ad09582ebff948a2f2d`. Three
+complete focused Perry runs produced the same **17 pass / 26 diff / 0 compile
+failure / 0 crash / 0 timeout** result after active cancellation idempotence was
+added. The baseline records `17/43`.
+
+One complete alternate-runtime pass produced:
+
+- Deno: 21 exact matches and 22 diffs; no error, crash, or timeout.
+- Bun: 13 exact matches and 30 diffs; no error, crash, or timeout.
+
+## Stable Perry differences
+
+- Module surface: the `promises` property is a data property rather than Node's
+  lazy getter; public functions use different names and arities.
+- Lookup: callback requests return `undefined`; callback checks, falsy-host
+  errors, string families, option getter order, validation, and promisification
+  differ.
+- Lookup service: numeric-string promise coercion and argument checks differ.
+- Resolution: TTL objects, typed record fields, callback request objects, and
+  enumerable DNS error fields differ. A/AAAA values, ANY values after key
+  canonicalization, IDNA, name records, and TXT records match.
+- Resolver: active `cancel()` reports `ETIMEOUT` instead of `ECANCELLED`;
+  constructor checks, prototype layout, method metadata, resolve validation, and
+  local-address validation differ.
+- Settings: default-resolver method rebinding, sparse/accessor server arrays,
+  and one bracketed IPv6 normalization case differ.
+
+## Per-fixture classification
+
+`pass` and `match` mean exact stdout and exit-code parity with Node 26.5.0.
+`diff` means the fixture completed but exposed a stable contract difference.
+
+| Fixture                                  | Perry | Deno  | Bun   |
+| ---------------------------------------- | ----- | ----- | ----- |
+| `constants/error-aliases.ts`             | pass  | diff  | match |
+| `imports/aliases.ts`                     | pass  | diff  | diff  |
+| `imports/default-export.ts`              | pass  | match | match |
+| `imports/descriptors.ts`                 | diff  | diff  | diff  |
+| `imports/export-inventory.ts`            | pass  | diff  | diff  |
+| `imports/function-metadata.ts`           | diff  | diff  | diff  |
+| `lookup-service/ipv6-loopback.ts`        | pass  | match | diff  |
+| `lookup-service/port-coercion.ts`        | diff  | diff  | diff  |
+| `lookup-service/validation.ts`           | diff  | match | match |
+| `lookup/callback-validation.ts`          | diff  | match | match |
+| `lookup/falsy-hostname.ts`               | diff  | diff  | diff  |
+| `lookup/family-forms.ts`                 | diff  | diff  | diff  |
+| `lookup/ip-literals-callback.ts`         | diff  | match | diff  |
+| `lookup/ip-literals-promises.ts`         | pass  | match | match |
+| `lookup/loopback.ts`                     | pass  | match | match |
+| `lookup/options-accessors.ts`            | diff  | diff  | diff  |
+| `lookup/options-validation.ts`           | diff  | match | match |
+| `lookup/promisify.ts`                    | diff  | diff  | diff  |
+| `resolve/address-records.ts`             | diff  | match | diff  |
+| `resolve/any-records.ts`                 | pass  | match | match |
+| `resolve/errors.ts`                      | diff  | diff  | diff  |
+| `resolve/idna.ts`                        | pass  | match | diff  |
+| `resolve/name-records.ts`                | pass  | diff  | match |
+| `resolve/reverse-validation.ts`          | diff  | diff  | diff  |
+| `resolve/rrtype-aliases.ts`              | diff  | match | diff  |
+| `resolve/structured-records.ts`          | diff  | diff  | diff  |
+| `resolve/txt-record.ts`                  | pass  | match | diff  |
+| `resolver/cancel-active.ts`              | diff  | match | diff  |
+| `resolver/cancel-idempotent.ts`          | pass  | match | match |
+| `resolver/constructor-validation.ts`     | diff  | match | diff  |
+| `resolver/method-metadata.ts`            | diff  | diff  | diff  |
+| `resolver/options-accessors.ts`          | pass  | diff  | diff  |
+| `resolver/prototype.ts`                  | diff  | diff  | diff  |
+| `resolver/receiver-validation.ts`        | pass  | match | diff  |
+| `resolver/resolve-receiver.ts`           | pass  | match | diff  |
+| `resolver/resolve-validation.ts`         | diff  | match | diff  |
+| `resolver/set-local-address.ts`          | diff  | diff  | diff  |
+| `resolver/set-servers-validation.ts`     | pass  | match | match |
+| `settings/default-resolver-rebinding.ts` | diff  | diff  | diff  |
+| `settings/default-result-order.ts`       | pass  | diff  | diff  |
+| `settings/servers-array-semantics.ts`    | diff  | match | match |
+| `settings/servers-normalization.ts`      | diff  | diff  | match |
+| `settings/servers.ts`                    | pass  | diff  | diff  |
+
+## Commands
+
+```sh
+cargo build --release --bin perry
+NODE_BIN="$HOME/.nvm/versions/node/v26.5.0/bin/node" \
+  python3 scripts/node_suite_run.py target/release/perry "$PWD" dns
+python3 -m json.tool test-parity/node_suite_baseline.json >/dev/null
+```
+
+Local authoritative-server cases need permission to bind ephemeral loopback UDP
+ports and spawn the helper Node process.
+
+## Stopping boundary
+
+The suite stops at 43 fixtures. A fresh review of the fixed Node, Deno, and Bun
+trees found no other public contract that was both deterministic, portable,
+non-redundant, and reachable through this print-and-diff harness.
+
+Excluded on purpose:
+
+- Node's `test/internet/test-dns-*` files and Bun's public-domain fixtures:
+  answers, TTLs, delegation, and availability can change.
+- Successful `reverse()` was prototyped against the local server. Perry did not
+  settle within 70 seconds, so retaining it would leave cleanup to the harness
+  timeout and would not isolate a useful result. Input validation remains.
+- The valid callback `Resolver.resolve(hostname, callback)` default-rrtype
+  overload was prototyped against the local server. Node and Deno settled, but
+  Perry did not invoke the callback. Retaining it would require an arbitrary
+  timeout or fire-and-forget cleanup; argument validation remains covered.
+- Node's two-channel query test was prototyped with two local sockets. Perry did
+  not pass the auxiliary-server ready barrier within 30 seconds. Server-state
+  independence remains covered without keeping a timeout that mixes child
+  process behavior into the DNS result.
+- Resolver timeout/retry timing, set-servers-during-query, worker termination,
+  perf hooks, snapshots, memory faults, malformed packet counts, TCP fallback,
+  and stress cases depend on timers, scheduler order, internals, workers, or
+  crash-only harnesses.
+- `resolveTlsa()` remains covered by export and method metadata only. It was not
+  in the requested record-method set or the selected Deno/Bun suites; adding a
+  value-shape case would not supply cross-runtime evidence.
+- Exact host `getServers()` defaults, localhost address order, reverse
+  hostnames, service names, and non-loopback `lookup()` results depend on OS
+  configuration.
+- DNS-over-TLS/HTTPS, DNSSEC, cache policy, and transport internals are not
+  public `node:dns` contracts in the selected Node suite.
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1 @@
		Expanded deterministic `node:dns` parity coverage from 6 to 43 fixtures and strengthened the node-suite regression floor to protect both pass counts and fixture counts.