fuzz-target-every-parse: the §3.2 differential target — three parsers + skip_forward through the doc-hidden surfaces via shared invariants, 66 committed seeds + gitignore negation + README row; two real skip_forward findings fixed inline (division-by-zero/negative-interval wrap on sqlite+mem, i64 gap subtraction overflow on all three engines incl. pg) and registered as PROVENANCE D-38

2026-10-10 22:01:13 +00:00
1 parent 1f6cc0970a
commit f7c1bd79b0
@@ -252,8 +252,8 @@ fn fire_due(sched: &mut ScheduleState, queues: &mut QueueState, state: &State, n
 /// in the future, grid-aligned (the schedule row's advance makes the
 /// gap inspectable).
 pub fn skip_forward(next_fire_at: i64, now: i64, interval: i64) -> i64 {
-    let gap = (now - next_fire_at) as i128;
-    let interval = interval as i128;
+    let gap = now as i128 - next_fire_at as i128;
+    let interval = interval.max(1) as i128;
    let next = (next_fire_at as i128) + (gap / interval + 1) * interval;
    if next > i64::MAX as i128 {
        i64::MAX
@@ -262,7 +262,7 @@ fn next_every_boundary(spec: &str, after: i64) -> Result<i64> {
 /// (the skipped boundaries never enqueue). 128-bit intermediates keep
 /// the arithmetic saturation-safe; the result clamps at `i64::MAX`.
 pub fn skip_forward(next_fire_at: i64, now: i64, interval: i64) -> i64 {
-    let gap = (now - next_fire_at) as i128;
+    let gap = now as i128 - next_fire_at as i128;
    let interval = interval.max(1) as i128;
    let next = (next_fire_at as i128) + (gap / interval + 1) * interval;
    if next > i64::MAX as i128 {
@@ -130,6 +130,7 @@ Cherry-picks: empty at scaffold, append-only forever.
 | D-35 | drop | `Writer::try_acquire` cut (the non-blocking writer-slot try): upstream's embedding harness used it for try-shaped entry points its surface exposed; this engine's seam always blocks (`acquire`) — the writer-slot lease is a *parks-the-writer* lease by design (ADR-007's honest model), so a try-shaped acquire would contradict the posture rather than extend it. The probe tests driving it re-express their properties through `acquire`/`release`/`close` (the engine-reachable surface); the engine-level lease tests (`tx_tests`' lease/parking suite) pin the observable posture end-to-end | `schema.rs` (`Writer::try_acquire` + the three `writer_reader_tests` call sites) | ADR-007 (the caller-held-lease seam: `begin_tx` parks a concurrent writer — no try-shaped begin exists on the contract surface); ADR-012 §2 (nothing on the engine side reaches a try-acquire); wave-3 lint-removal obligation — cut, not suppressed | ours |
 | D-36 | drop | `UpdateWatcher::spawn` and `SharedUpdateWatcher::new` cut (the default-cadence convenience constructors): upstream's embedding harnesses opened watchers without explicit config; this engine's single open path always constructs a `WatcherConfig` — from `SqliteOpts` (ADR-023 §4's `poll_interval` knob, `None` = the 1 ms default) — and passes it through `*_with_config`; a config-less twin would re-create two open postures (the mixed-flag inconsistency D-29 resolved at the URI layer). `WatcherConfig::default()` remains the default's single owner; the tests driving the cut constructors now build the config explicitly, pinning the same behavior | `watcher.rs` (both constructors + five watcher-test call sites) | ADR-023 §4 (the cadence knob rides the engine's opts — one open posture carries config); ADR-012 §2 (one construction path the engine reviews); wave-3 lint-removal obligation — cut, not suppressed | ours |
 | D-37 | re-derivation | visibility-only widening on the re-derived `@every` surface: `parse_every_interval` (`pub(crate)` → `pub`) and `skip_forward` (module-private → `pub`) in `queue_ops.rs`, plus this subtree's facade re-export (`mod.rs`: `pub use queue_ops::{parse_every_interval, skip_forward}`), so the engine crate root can `#[doc(hidden)] pub use` both as the wave-7 fuzzing differential target's drive surface (`fuzz-parser-exposure`, target `every_parse`). Zero logic change, zero signature change, zero name change; `mod substrate` stays private, so containment holds — nothing leaves the crate except the doc-hidden root re-exports. A `pub use` re-export mechanically requires item-level `pub` (E0364/E0603), which is why the facade line is in `mod.rs`; the module doc's "nothing re-exported" boundary sentence was amended in the same commit to name this sole exception | `queue_ops.rs` (two visibility keywords); `mod.rs` (facade re-export line + boundary-doc exception sentence) | ADR-012 §3 (fidelity governs the ported honker body — `watcher.rs`/`schema.rs`/`ops.rs` untouched; `queue_ops.rs` is the re-derived half, owned contract-v1 code, so a visibility-only delta is legitimate); docs/research/fuzzing.md §3.2 (option (b): the `#[doc(hidden)]` narrow exposure); ADR-017 §3 (doc-hidden test surface, no stability guarantee — the `Job::from_row` precedent) | ours |
+| D-38 | port delta | degenerate/adversarial-triple hardening on `skip_forward` (two legs, both aligning to the pg engine's committed clamp shape where it existed and extending pg itself): (1) the `interval` is clamped (`interval.max(1) as i128`) — pre-fix, `interval == 0` panicked on i128 division-by-zero, reachable only through degenerate/non-grammar callers (the parsers reject `n <= 0`, so every engine-internal call site passes `interval >= 1`); (2) the gap is computed in i128 (`now as i128 - next_fire_at as i128`) — pre-fix, `now - next_fire_at` was an **i64 subtraction** that panics in debug (overflow) / silently wraps in release when `(next_fire_at, now)` straddle the full domain (`now=i64::MIN`-adjacent, `next_fire_at=i64::MAX`-adjacent), feeding a wrapped gap to the 128-bit arithmetic and breaking the saturation guarantee. Found by the `every_parse` differential target (wave 7, tasks/fuzz-target-every-parse) driving the adversarial `(next_fire_at, now, interval)` space; pg needed leg (2) as well. Observable behavior unaffected in the reachable domain (|gap| < i64 range), saturation posture now holds over the whole domain. Zero signature change; lineage body untouched (`skip_forward` is the re-derived scheduler half, D-12's own) | `queue_ops.rs` (`skip_forward`, two lines) | docs/research/fuzzing.md §3.2 (the overflow-posture invariant: reject-or-saturate, never wrap or panic, over the whole domain); wave-6's register-overflow alignment (tasks/review-wave-6); alkstore-postgres/src/scheduler.rs `skip_forward` (the pinned clamp shape) | ours |

 ### Cherry-picks

@@ -525,8 +525,8 @@ fn next_every_boundary(spec: &str, after: i64) -> Result<i64, String> {
 }

 pub fn skip_forward(next_fire_at: i64, now: i64, interval: i64) -> i64 {
-    let gap = (now - next_fire_at) as i128;
-    let interval = interval as i128;
+    let gap = now as i128 - next_fire_at as i128;
+    let interval = interval.max(1) as i128;
    let next = (next_fire_at as i128) + (gap / interval + 1) * interval;
    if next > i64::MAX as i128 {
        i64::MAX
@@ -1,5 +1,6 @@
 target
 corpus/*
 !corpus/payload_codec
+!corpus/every_parse
 artifacts
 coverage
@@ -21,4 +21,11 @@ test = false
 doc = false
 bench = false

+[[bin]]
+name = "every_parse"
+path = "fuzz_targets/every_parse.rs"
+test = false
+doc = false
+bench = false
+
 [workspace]
@@ -28,7 +28,7 @@ libFuzzer targets for alkstore's parse/codec surfaces (see
 | Target | Drives | Invariants |
 |---|---|---|
 | `payload_codec` | `encode_payload` / `payload_as::<T>` (`alkstore/src/payload.rs`) | no-panic on any byte sequence; every decode failure typed `Error::Codec`; deep nesting loud at serde_json's recursion limit; `Value` round-trip (serde_json canonicalization pinned); typed round-trip for a representative payload set |
-| `every_parse` | the three `parse_every_interval` implementations (differential) | filled by its target task |
+| `every_parse` | the three `parse_every_interval` implementations (differential, through the engines' `#[doc(hidden)]` re-exports) + each engine's `skip_forward` boundary arithmetic | no-panic on any UTF-8-lossy string (each parser, each boundary path); typed rejection (`Error::InvalidSpec` on pg/mem, the substrate's error under its mapping on SQLite); three-way agreement on the Ok/Err partition and the `Ok` interval value (error identity not pinned — the SQLite `Result<i64, String>` vs `InvalidSpec` asymmetry is known); overflow posture: `skip_forward` over adversarial `(next_fire_at, now, interval)` triples rejects-or-saturates, never wraps or panics; the `n <= 0` and giant-`n` arms (leading zeros, digit overflow at exactly `i64::MAX/86400`, positive-zero rejection) |
 | `name_validation` | `validate_name` / `validate_shared_name` / `validate_local_name` (`alkstore/src/validation.rs`) | filled by its target task |

 ## Commands
@@ -0,0 +1 @@
+@every 1s
@@ -0,0 +1 @@
+@every 5s
@@ -0,0 +1 @@
+@every 9s
@@ -0,0 +1 @@
+@every 17s
@@ -0,0 +1 @@
+@every 42m
@@ -0,0 +1 @@
+@every 1m
@@ -0,0 +1 @@
+@every 90m
@@ -0,0 +1 @@
+@every 2h
@@ -0,0 +1 @@
+@every 24h
@@ -0,0 +1 @@
+@every 1d
@@ -0,0 +1 @@
+@every 7d
@@ -0,0 +1 @@
+@every 365d
@@ -0,0 +1 @@
+@every 007s
@@ -0,0 +1 @@
+@every 007m
@@ -0,0 +1 @@
+@every 000000042h
@@ -0,0 +1 @@
+@every 007d
@@ -0,0 +1 @@
+@every 0s
@@ -0,0 +1 @@
+@every 00m
@@ -0,0 +1 @@
+@every 0000d
@@ -0,0 +1 @@
+@every -5s
@@ -0,0 +1 @@
+@every -0s
@@ -0,0 +1 @@
+@every 9223372036854775807s
@@ -0,0 +1 @@
+@every 9223372036854775806s
@@ -0,0 +1 @@
+@every 9223372036854775808s
@@ -0,0 +1 @@
+@every 9223372036854775807m
@@ -0,0 +1 @@
+@every 9223372036854775807h
@@ -0,0 +1 @@
+@every 9223372036854775807d
@@ -0,0 +1 @@
+@every 18446744073709551616s
@@ -0,0 +1 @@
+@every 18446744073709551616000000m
@@ -0,0 +1 @@
+@every 106751991167300d
@@ -0,0 +1 @@
+@every 106751991167301d
@@ -0,0 +1 @@
+@every 106751991167299d
@@ -0,0 +1 @@
+@every 2147483647d
@@ -0,0 +1 @@
+@every 4294967295d
@@ -0,0 +1 @@
+@every 100000000000d
@@ -0,0 +1 @@
+@every
@@ -0,0 +1 @@
+@every 
@@ -0,0 +1 @@
+@every   5s
@@ -0,0 +1 @@
+@every 5s 
@@ -0,0 +1 @@
+@every	5s
@@ -0,0 +1 @@
+@every 5 s
@@ -0,0 +1 @@
+@every 5sx
@@ -0,0 +1 @@
+@every 5S
@@ -0,0 +1 @@
+@every +5s
@@ -0,0 +1 @@
+@every .5s
@@ -0,0 +1 @@
+@every 3.5s
@@ -0,0 +1 @@
+@every 5.0s
@@ -0,0 +1 @@
+@every 5	s
@@ -0,0 +1 @@
+@every és
@@ -0,0 +1 @@
+ÿ @every ÿ 5s þ
@@ -0,0 +1 @@
+@every 5sÿ
@@ -0,0 +1 @@
+@once
@@ -0,0 +1 @@
+@hourly
@@ -0,0 +1 @@
+@daily
@@ -0,0 +1 @@
+@weekly
@@ -0,0 +1 @@
+*/5 * * * *
@@ -0,0 +1 @@
+0 0 * * *
@@ -0,0 +1 @@
+every 5s
@@ -0,0 +1 @@
+5s
@@ -0,0 +1 @@
+@every 5
@@ -0,0 +1 @@
+@every s
@@ -0,0 +1 @@
+@every 9223372036854775807s skip-forward-triple payload XXXXX
@@ -0,0 +1 @@
+������������������������
@@ -0,0 +1,11 @@
+//! The §3.2 target: the three per-engine `@every` parsers driven
+//! differentially through the `fuzz-parser-exposure` doc-hidden
+//! surfaces, plus each engine's `skip_forward` boundary arithmetic.
+
+#![no_main]
+
+use libfuzzer_sys::fuzz_target;
+
+fuzz_target!(|data: &[u8]| {
+    alkstore_fuzz_shared::every_parse::fuzz_every_parse(data);
+});
@@ -124,8 +124,130 @@ def payload_codec_seeds():
        i += 1


+def every_parse_seeds():
+    i = 0
+
+    # Every grammar-valid unit form (s|m|h|d), single and multi-digit.
+    for spec in [
+        "@every 1s",
+        "@every 5s",
+        "@every 9s",
+        "@every 17s",
+        "@every 42m",
+        "@every 1m",
+        "@every 90m",
+        "@every 2h",
+        "@every 24h",
+        "@every 1d",
+        "@every 7d",
+        "@every 365d",
+    ]:
+        write_seed("every_parse", i, spec.encode())
+        i += 1
+
+    # Leading-zero forms (parsed through, value = the digits).
+    for spec in ["@every 007s", "@every 007m", "@every 000000042h", "@every 007d"]:
+        write_seed("every_parse", i, spec.encode())
+        i += 1
+
+    # The n <= 0 arms: positive zero (with and without leading zeros)
+    # and the negative shapes (digits == 0 inside the grammar).
+    for spec in ["@every 0s", "@every 00m", "@every 0000d", "@every -5s", "@every -0s"]:
+        write_seed("every_parse", i, spec.encode())
+        i += 1
+
+    # The i64::MAX neighborhood: giant-n accept at scale-1, digit
+    # overflow past i64, and unit-multiplier overflow above it.
+    for spec in [
+        "@every 9223372036854775807s",
+        "@every 9223372036854775806s",
+        "@every 9223372036854775808s",
+        "@every 9223372036854775807m",
+        "@every 9223372036854775807h",
+        "@every 9223372036854775807d",
+        "@every 18446744073709551616s",
+        "@every 18446744073709551616000000m",
+    ]:
+        write_seed("every_parse", i, spec.encode())
+        i += 1
+
+    # The digit-overflow boundary at exactly i64::MAX/86400 (and ±1).
+    for spec in [
+        "@every 106751991167300d",
+        "@every 106751991167301d",
+        "@every 106751991167299d",
+    ]:
+        write_seed("every_parse", i, spec.encode())
+        i += 1
+
+    # d-unit multiplier blowups.
+    for spec in ["@every 2147483647d", "@every 4294967295d", "@every 100000000000d"]:
+        write_seed("every_parse", i, spec.encode())
+        i += 1
+
+    # Whitespace / garbage / truncation shapes.
+    for raw in [
+        b"@every",
+        b"@every ",
+        b"@every   5s",
+        b"@every 5s ",
+        b"@every\t5s",
+        b"@every 5 s",
+        b"@every 5sx",
+        b"@every 5S",
+        b"@every +5s",
+        b"@every .5s",
+        b"@every 3.5s",
+        b"@every 5.0s",
+        b"@every 5\ts",
+        b"@every \xc3\xa9s",
+        b"\xff @every \xff 5s \xfe",
+        b"@every 5s\xff",
+    ]:
+        write_seed("every_parse", i, raw)
+        i += 1
+
+    # Non-grammar prefixes and shapes (cron / @once adjacency).
+    for raw in [
+        b"@once",
+        b"@hourly",
+        b"@daily",
+        b"@weekly",
+        b"*/5 * * * *",
+        b"0 0 * * *",
+        b"every 5s",
+        b"5s",
+        b"@every 5",
+        b"@every s",
+    ]:
+        write_seed("every_parse", i, raw)
+        i += 1
+
+    # Byte payloads ≥ 24 bytes: the boundary-arithmetic leg folds
+    # adversarial (next_fire_at, now, interval) triples straight out of
+    # the bytes — the i64::MAX neighborhood, negative shapes, d-blowups.
+    for raw in [
+        b"@every 9223372036854775807s skip-forward-triple payload XXXXX",
+        b"\x00" * 24,
+        b"\xff" * 24,
+        bytes([
+            0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x7F,  # next = i64::MAX
+            0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x40,  # now = 2^62
+            0x80, 0xC8, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00,  # interval = 250000
+        ]),
+        bytes([
+            0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x80,  # next = i64::MIN + 1
+            0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x7F,  # now = i64::MAX
+            0x80, 0x92, 0xFC, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,  # interval = negative
+        ]),
+    ]:
+        write_seed("every_parse", i, raw)
+        i += 1
+
+
 def main():
    payload_codec_seeds()
+    every_parse_seeds()


 if __name__ == "__main__":
@@ -6,6 +6,9 @@ edition = "2021"

 [dependencies]
 alkstore = { path = "../../alkstore" }
+alkstore-sqlite = { path = "../../alkstore-sqlite" }
+alkstore-postgres = { path = "../../alkstore-postgres" }
+alkstore-mem = { path = "../../alkstore-mem" }
 serde = { version = "1", features = ["derive"] }
 serde_json = "1"

@@ -0,0 +1,276 @@
+//! Invariant logic for the `every_parse` target (docs/research/
+//! fuzzing.md §3.2): the three one-owner `@every` parsers (ADR-009 §2's
+//! grammar, ADR-012 §2's one-owner rule) driven **differentially**
+//! through the engines' `#[doc(hidden)]` re-exports — no-panic on any
+//! string, typed rejection, three-way agreement (the Ok/Err partition
+//! and the `Ok` value; error *identity* is deliberately not pinned —
+//! the SQLite surface's `Result<i64, String>` vs pg/mem's
+//! `Result<i64>`/`InvalidSpec` is a known, typed asymmetry), the
+//! overflow posture, and the `n <= 0` / giant-`n` arms.
+
+use alkstore::Error;
+use alkstore_mem as mem_engine;
+use alkstore_postgres as pg_engine;
+use alkstore_sqlite as sqlite_engine;
+
+pub fn fuzz_every_parse(data: &[u8]) {
+    let spec = String::from_utf8_lossy(data);
+    assert_parse_agreement(spec.as_ref());
+    assert_parse_battery();
+    assert_skip_battery();
+    assert_skip_triples(data);
+}
+
+/// pg and mem reject grammar-violating shapes with their own typed
+/// error, `Error::InvalidSpec` — never a panic, never a silent `Ok`
+/// on a shape the authored tests reject.
+fn assert_typed_rejection(spec: &str, engine: &str) {
+    let result = match engine {
+        "pg" => pg_engine::parse_every_interval(spec),
+        _ => mem_engine::parse_every_interval(spec),
+    };
+    match result {
+        Ok(_) | Err(Error::InvalidSpec { .. }) => {}
+        Err(other) => panic!("{engine} rejects must be `InvalidSpec`, got {other:?} for {spec:?}"),
+    }
+}
+
+/// One invocation of the three parsers over a lossy-decoded spec:
+/// three-way agreement on the Ok/Err partition and the `Ok` value
+/// (SQLite's `Err` payloads are `String`s — the accepted asymmetry — so
+/// the SQLite comparison is partition-and-value only).
+fn assert_parse_agreement(spec: &str) {
+    assert_typed_rejection(spec, "pg");
+    assert_typed_rejection(spec, "mem");
+    let sqlite_result = sqlite_engine::parse_every_interval(spec).map_err(|_| ());
+    let pg_result = pg_engine::parse_every_interval(spec).map_err(|_| ());
+    let mem_result = mem_engine::parse_every_interval(spec).map_err(|_| ());
+    assert_eq!(
+        pg_result, mem_result,
+        "pg and mem must agree on the Ok/Err partition for {spec:?}"
+    );
+    match pg_result {
+        Ok(interval) => {
+            assert_eq!(
+                sqlite_result,
+                Ok(interval),
+                "sqlite must accept {spec:?} with pg/mem's interval"
+            );
+        }
+        Err(()) => {
+            assert_eq!(
+                sqlite_result,
+                Err(()),
+                "sqlite must reject what pg/mem reject for {spec:?}"
+            );
+        }
+    }
+}
+
+type Engine = (&'static str, fn(&str) -> Result<i64, ()>);
+
+fn engines() -> Vec<Engine> {
+    vec![
+        ("sqlite", |s: &str| {
+            sqlite_engine::parse_every_interval(s).map_err(|_| ())
+        }),
+        ("pg", |s: &str| {
+            pg_engine::parse_every_interval(s).map_err(|_| ())
+        }),
+        ("mem", |s: &str| {
+            mem_engine::parse_every_interval(s).map_err(|_| ())
+        }),
+    ]
+}
+
+/// The grammar battery: shapes the authored tests already reject/accept
+/// — pinned on every invocation so neither the fuzz path nor a corpus
+/// replay ever observes drift (a silent `Ok` on a known-bad shape, a
+/// changed interval value, a lost reject). Giant-`n` arms: the
+/// `9223372036854775807` neighborhood and digit overflow at exactly
+/// `i64::MAX/86400`.
+fn assert_parse_battery() {
+    for (spec, want) in accept_battery() {
+        for (engine_name, engine) in engines() {
+            assert_eq!(
+                engine(spec),
+                Ok(want),
+                "{engine_name} must accept the grammar-valid {spec:?}"
+            );
+        }
+    }
+    for spec in reject_battery() {
+        for (engine_name, engine) in engines() {
+            assert!(
+                engine(spec).is_err(),
+                "{engine_name} must reject the grammar-violating {spec:?}"
+            );
+        }
+    }
+}
+
+fn accept_battery() -> Vec<(&'static str, i64)> {
+    vec![
+        ("@every 1s", 1),
+        ("@every 5s", 5),
+        ("@every 9s", 9),
+        ("@every 17s", 17),
+        ("@every 42m", 2520),
+        ("@every 1m", 60),
+        ("@every 90m", 5400),
+        ("@every 2h", 7200),
+        ("@every 24h", 86_400),
+        ("@every 1d", 86_400),
+        ("@every 7d", 604_800),
+        ("@every 007s", 7),
+        ("@every 007m", 420),
+        ("@every 000000042h", 151_200),
+        ("@every 106751991167300d", 9_223_372_036_854_720_000),
+        ("@every 9223372036854775807s", i64::MAX),
+        ("@every 9223372036854775806s", i64::MAX - 1),
+    ]
+}
+
+fn reject_battery() -> Vec<&'static str> {
+    vec![
+        "",
+        "@every",
+        "@every ",
+        "@every 0s",
+        "@every -5s",
+        "@every +5s",
+        "@every 5",
+        "@every s",
+        "@every 5sx",
+        "@every 5S",
+        "@every  5s",
+        "@every 5s ",
+        "@every 3.5s",
+        "@every 9223372036854775808s",
+        "@every 9223372036854775807m",
+        "@every 106751991167301d",
+        "@every 18446744073709551616s",
+        "@every 00m",
+        "every 5s",
+        "5s",
+        "*/5 * * * *",
+        "0 0 * * *",
+        "@once",
+        "@hourly",
+        "@daily",
+        "@weekly",
+        "@minute",
+    ]
+}
+
+/// The overflow-posture battery for the next-boundary arithmetic:
+/// adversarial `(next_fire_at, now, interval)` triples (the `i64::MAX`
+/// neighborhood, negative shapes, `d`-unit multiplier blowups) —
+/// reject-or-saturate semantics, never wrapping or panicking. The
+/// three implementations are asserted equal over the whole domain
+/// (post-clamp they carry pg's pinned shape identically).
+fn assert_skip_battery() {
+    for &(next_fire_at, now, interval) in TRIPLES {
+        assert_skip_posture(next_fire_at, now, interval);
+    }
+}
+
+const TRIPLES: &[(i64, i64, i64)] = &[
+    (0, 0, 0),
+    (0, 0, 1),
+    (0, 1, 1),
+    (5, 4, 60),
+    (5, 3, 60),
+    (i64::MAX, i64::MAX, 1),
+    (i64::MAX - 5, i64::MAX, 1),
+    (i64::MAX - 100, i64::MAX, 86_400),
+    (i64::MAX - 100, i64::MAX, 86_400 * 30),
+    (i64::MAX / 2, i64::MAX, i64::MAX / 2),
+    (i64::MAX / 2, i64::MAX, i64::MAX),
+    (i64::MAX, i64::MAX, i64::MAX),
+    (i64::MIN, i64::MIN, 1),
+    (i64::MIN, i64::MIN, 86_400),
+    (i64::MIN, i64::MAX, 1),
+    (i64::MIN, i64::MAX, 86_400 * 30),
+    (i64::MIN, 0, 86_400),
+    (0, i64::MAX, 86_400 * 365),
+    (5, 4, 0),
+    (5, 4, -60),
+    (i64::MAX, i64::MIN, -1),
+    (i64::MIN, i64::MAX, i64::MIN),
+    (0, i64::MAX, i64::MIN),
+    (86_400, 86_399, 86_400 * u32::MAX as i64),
+];
+
+fn assert_skip_posture(next_fire_at: i64, now: i64, interval: i64) {
+    let a = sqlite_engine::skip_forward(next_fire_at, now, interval);
+    let b = pg_engine::skip_forward(next_fire_at, now, interval);
+    let c = mem_engine::skip_forward(next_fire_at, now, interval);
+    assert_eq!(
+        a, b,
+        "sqlite and pg skip-forward must agree for ({next_fire_at}, {now}, {interval})"
+    );
+    assert_eq!(
+        b, c,
+        "pg and mem skip-forward must agree for ({next_fire_at}, {now}, {interval})"
+    );
+
+    // Saturation: the result is either the `i64::MAX` clamp or a value
+    // strictly beyond `now` — no wrap into the past, ever.
+    assert!(
+        a == i64::MAX || a > now,
+        "skip-forward must land strictly beyond `now` or saturate: got {a} for ({next_fire_at}, {now}, {interval})"
+    );
+}
+
+/// Adversarial triples folded straight out of the input bytes — the
+/// whole `(next_fire_at, now, interval)` domain through the fuzz path
+/// and every ≥24-byte corpus seed.
+fn assert_skip_triples(data: &[u8]) {
+    let (chunks, remainder) = data.as_chunks::<24>();
+    for chunk in chunks {
+        assert_skip_triple(chunk);
+    }
+    let mut tail = [0u8; 24];
+    tail[..remainder.len()].copy_from_slice(remainder);
+    assert_skip_triple(&tail);
+}
+
+fn assert_skip_triple(chunk: &[u8]) {
+    let next_fire_at = i64::from_le_bytes(chunk[..8].try_into().expect("slice is 8 bytes"));
+    let now = i64::from_le_bytes(chunk[8..16].try_into().expect("slice is 8 bytes"));
+    let interval = i64::from_le_bytes(chunk[16..24].try_into().expect("slice is 8 bytes"));
+    assert_skip_posture(next_fire_at, now, interval);
+}
+
+#[cfg(test)]
+mod corpus_replay {
+    use super::*;
+    use std::path::PathBuf;
+
+    #[test]
+    fn committed_corpus_replays_through_the_invariants() {
+        let corpus = PathBuf::from(env!("CARGO_MANIFEST_DIR")).join("../corpus/every_parse");
+        let mut count = 0usize;
+        for entry in std::fs::read_dir(&corpus).expect("corpus directory is committed") {
+            let path = entry.expect("corpus entry readable").path();
+            let data = std::fs::read(&path).expect("corpus entry readable");
+            fuzz_every_parse(&data);
+            count += 1;
+        }
+        assert!(
+            count >= 48,
+            "committed seed corpus is present, found {count}"
+        );
+    }
+
+    #[test]
+    fn invariants_hold_without_corpus() {
+        fuzz_every_parse(b"");
+        fuzz_every_parse(b"@every 5s");
+        fuzz_every_parse(b"@every 106751991167301d");
+        fuzz_every_parse(b"\xff @every \xff 5s \xfe");
+        fuzz_every_parse(&[0u8; 24]);
+        fuzz_every_parse(&(i64::MIN as i128).to_le_bytes());
+    }
+}
@@ -4,4 +4,5 @@
 //! CI pattern) without a nightly toolchain.

 pub mod arbitrary_value;
+pub mod every_parse;
 pub mod payload_codec;
@@ -1,7 +1,7 @@
 ---
 id: fuzz-target-every-parse
 name: Fuzz target — `every_parse` (the three `@every` parsers, differential)
-status: pending
+status: completed
 depends_on: [fuzz-scaffold, fuzz-parser-exposure]
 scope: moderate
 risk: medium
@@ -73,17 +73,23 @@ escalate), not a task failure.

 ## Acceptance Criteria

- [ ] `fuzz_targets/every_parse.rs` + `shared/src/every_parse.rs`
+- [x] `fuzz_targets/every_parse.rs` + `shared/src/every_parse.rs`
      exist; `cargo fuzz build` builds the target
- [ ] All five §3.2 invariant classes implemented and exercised by both
+- [x] All five §3.2 invariant classes implemented and exercised by both
      the fuzz path and the replay module; the three-way agreement
      asserted on every input (fuzz) and every seed (replay)
- [ ] Seed corpus committed, deterministic-generated, gitignore
+- [x] Seed corpus committed, deterministic-generated, gitignore
      negation in place
- [ ] `cargo test --manifest-path fuzz/shared/Cargo.toml` green;
+- [x] `cargo test --manifest-path fuzz/shared/Cargo.toml` green;
      `shared` clippy/fmt gates green
- [ ] Root workspace gates still green; substrate diff still empty
- [ ] Any three-way divergence found during target development is
+- [x] Root workspace gates still green; substrate diff still empty
+      *(amended at implementation, 2026-10-10 — see Notes: the target
+      found a real no-panic/overflow-posture finding in `skip_forward`,
+      dispositioned inline per the task's own finding posture; the
+      substrate delta is two keyword-free lines in the re-derived
+      `queue_ops.rs`, registered as PROVENANCE D-38; lineage body
+      untouched)*
+- [x] Any three-way divergence found during target development is
      recorded in Notes with its disposition (fixed / escalated), not
      silently absorbed

@@ -101,8 +107,106 @@ escalate), not a task failure.

 ## Notes

-> To be filled by implementation agent
+Decisions of record the implementation made that the description didn't
+pin:
+
+- **Two real findings, both in `skip_forward` (the boundary leg),
+  dispositioned fixed inline** (per this task's risk note, the
+  campaign task's posture — small crate-side fixes ride the task that
+  finds them):
+  1. **Division-by-zero panic + negative-`interval` under-wrap** —
+     SQLite and mem's `skip_forward` cast `interval` straight into
+     `i128` (pg had `interval.max(1)`); `interval == 0` panicked on
+     i128 division, and a negative `interval` skipped the high-side
+     guard so `next < i64::MIN` wrapped silently. Fix: the clamp, pg's
+     committed shape. With `interval >= 1` the under-flow path is
+     unreachable, so the fix is exactly pg's body — no extra guard was
+     added beyond it.
+  2. **i64 gap subtraction before the i128 cast (all three engines,
+     including pg)** — `(now - next_fire_at) as i128` computed the
+     difference in i64: panics (debug overflow) / wraps silently
+     (release) when `(next_fire_at, now)` straddle the full domain
+     (`now = i64::MIN`-adjacent, `next_fire_at = i64::MAX`-adjacent).
+     The 128-bit intermediates story had a hole at its first line. Fix:
+     `now as i128 - next_fire_at as i128` — same one line, all three.
+  Observable reachability: both pre-fix paths are reachable only
+  outside the parsers' grammar domain (`n <= 0` rejected ⇒ callers
+  pass `interval >= 1`; `|gap| < i64` range in every clock-domain
+  call) — no engine-internal behavior change; the invariant now holds
+  over the whole domain. SQLite's delta registered as
+  `substrate/PROVENANCE.md` **D-38** (queue_ops.rs is the re-derived
+  half, D-12's own — D-31/D-37's precedent for owned-code deltas in
+  the register); mem needs no provenance entry (engine-owned
+  `scheduler.rs`), and pg's one-line delta is engine-owned likewise.
+- **(a)-companion leg not built.** The optional `schedule()`-driven
+  register-posture leg stayed unbuilt: the register-path posture (parse
+  → first-boundary `checked_add` → reject `InvalidSpec`) is suite-pinned
+  already, and driving the mem factory from `shared` would pull a
+  tokio runtime into the stable gate crate for one redundant leg.
+- **`skip_forward` three-way equality asserted, not just no-panic.**
+  Post-fix the three bodies are lexically identical, so the target
+  goes further than the task text required: three-way output
+  equality on *every* `(next_fire_at, now, interval)` triple (fixed
+  adversarial battery + triples folded out of the input bytes at
+  24-byte stride), plus the saturation pin
+  (`i64::MAX` clamp or strictly-beyond-`now`, never a past value).
+- **Error identity left unpinned as specified**: SQLite's
+  `Result<i64, String>` vs pg/mem's `InvalidSpec` — the differential
+  pins partition-and-value; the typed-rejection check (pg/mem must
+  reject with `Error::InvalidSpec`, never another variant) runs ahead
+  of the agreement assert.
+- **Corpus growth noise after the smoke campaign**: a 180 s detached
+  smoke (`run-detached.sh every_parse -max_len=4096
+  -use_value_profile=1`, ~737k execs, 0 crash/oom/timeout — the
+  campaign task re-runs the full budget) grew `corpus/every_parse` to
+  686 files; the grown additions were pruned back to the 66 committed
+  generator seeds since corpus-policy reconciliation
+  (grown-corpus disposition, the seed-promotion posture) is the
+  campaign task's named AC. The `!corpus/every_parse` negation does
+  un-ignore grown additions in that dir — the same shape alksocks
+  shipped, so the tension is the campaign task's to resolve, noted
+  here for context.

 ## Summary

-> To be filled on completion
+Landed the `every_parse` differential target (2026-10-10): the §3.2
+surface — all three one-owner `parse_every_interval` implementations
+driven through the `fuzz-parser-exposure` `#[doc(hidden)]` re-exports,
+plus all three `skip_forward` boundary postures.
+
+- **`fuzz/shared/src/every_parse.rs`** — the invariant logic (stable
+  toolchain, replayable): typed-rejection pin (pg/mem rejects are
+  `Error::InvalidSpec` only), three-way agreement on partition +
+  `Ok` value for arbitrary lossy-decoded strings, a fixed grammar
+  battery (17 accept shapes with pinned interval values incl.
+  leading-zero and the `i64::MAX`/`i64::MAX/86400`-neighborhood
+  giant-`n` arms; 27 reject shapes incl. positive-zero, negative,
+  whitespace/truncation, cron/`@once` adjacency and unknown units),
+  and the overflow-posture battery over `skip_forward` (24 fixed
+  adversarial triples + 24-byte-stride triples folded from the raw
+  input; three-way equality + saturate-or-strictly-future pin).
+  `#[cfg(test)]` corpus replay over the committed dir (≥48 seeds).
+- **`fuzz/fuzz_targets/every_parse.rs`** + `[[bin]]` entry (the
+  payload_codec shape); engine path deps added to `shared`'s manifest;
+  lib.rs module registered.
+- **66 committed seeds** from `gen_fuzz_seeds.py`'s new
+  `every_parse()` (registry wired); `!corpus/every_parse` gitignore
+  negation; `fuzz/README.md` targets-table row filled.
+- **Two findings found and fixed inline** (details in Notes):
+  `skip_forward` division-by-zero/negative-`interval` wrap (sqlite +
+  mem), and the i64 gap subtraction before the i128 cast (all three
+  engines incl. pg). PROVENANCE D-38 records the substrate delta.
+- **Smoke verdict**: 180 s detached campaign, ~737k execs, 0
+  crash/oom/timeout — the fixes closed out the deterministic finding
+  space; grown corpus pruned to the committed seeds.
+
+Verified: `cargo build` clean; `cargo test` workspace green (15 ok
+result groups, 0 failures); `cargo clippy --all-targets -- -D
+warnings` clean; `cargo fmt --check` clean; the shared gate
+`cargo test --manifest-path fuzz/shared/Cargo.toml` green;
+shared clippy `-D warnings` + fmt --check green;
+`cargo fuzz build` green from `fuzz/` (nightly pin; all three engines
+compile under ASAN through the new bin);
+`cargo check -p alkstore-mem --target wasm32-unknown-unknown` clean.
+Lineage body untouched; the substrate delta is the two-line
+`skip_forward` fix in the re-derived half, registered as D-38.
				`@@ -0,0 +1 @@`
				`@every 9223372036854775807s skip-forward-triple payload XXXXX`