Merge pull request 'A shrink is read against the item's own path: a moved directory starts its size history again (hq issue 368)' (#204) from fix/368-data-shrank-path-change into main

cmd/mesh-controller/data_test.go

@@ -169,6 +169,44 @@ func TestAShrinkOfMoreThanHalfIsUrgent(t *testing.T) {
 	}
 }
 
+// THE FALSE ALARM (issue 368), replayed through the store D13 reads: an agent's home moved from the
+// operator's own home (94.7 MB) to the agent account's fresh one (490 B), and `data-shrank` was raised
+// for data that was never lost. A moved item is read against its new path only, so nothing is raised —
+// and a genuine shrink at the new path, a week of history later, still is.
+func TestAMovedPathIsNoShrinkAndAShrinkThereStillIs(t *testing.T) {
+	inv := inventory.ForTest(t)
+	ctx := t.Context()
+	shelf := shelfFor(t, houseManifest)
+	declared := []inventory.DeclaredData{{Module: "house", Item: "config", Class: "irreplaceable", Owned: true}}
+	start := time.Now().Add(-6 * time.Hour)
+	measure := func(at time.Time, path string, size int64) []conditions.Observation {
+		t.Helper()
+		if _, err := inv.RecordData(ctx, "home", declared, map[string]map[string]inventory.Measurement{"house": {
+			"config": {Path: path, Size: bytesOf(size), MeasuredAt: when(at), LastWrite: when(at),
+				LastBackup: when(at)}}}, "", at); err != nil {
+			t.Fatal(err)
+		}
+		records, err := inv.Data(ctx)
+		if err != nil {
+			t.Fatal(err)
+		}
+		peaks, err := inv.DataPeaks(ctx, at.Add(-shrinkWindow))
+		if err != nil {
+			t.Fatal(err)
+		}
+		return dataFindings(records, peaks, shelf, nil, nil, at)
+	}
+	measure(start, "/home/operator/.claude", 94_700_000)
+	if got := findingsByKind(measure(start.Add(10*time.Minute), "/home/agent/.claude", 490)); got[kindDataShrank].Kind != "" {
+		t.Fatalf("a moved path raised a shrink: %+v", got[kindDataShrank])
+	}
+	measure(start.Add(2*time.Hour), "/home/agent/.claude", 300<<20)
+	got := findingsByKind(measure(start.Add(4*time.Hour), "/home/agent/.claude", 1<<20))[kindDataShrank]
+	if got.Severity != conditions.Urgent || !strings.Contains(got.Summary, "shrank") {
+		t.Fatalf("a genuine shrink at the new path was not raised: %+v", got)
+	}
+}
+
 // Data said to be written all the time and not written; data with no backup or an old one — urgent when
 // irreplaceable, a warning when valuable; and a new item given its bound before it is said.
 func TestQuietDataAndMissingBackupsAreSaidByClass(t *testing.T) {

internal/inventory/data.go

@@ -94,7 +94,9 @@ type DataChange struct {
 }
 
 // readingEvery is how often a measurement is kept as a reading: the shrink is read over days, and a
-// row every five minutes would say the same thing sixty times an hour.
+// row every five minutes would say the same thing sixty times an hour. A reading keeps the item's path
+// as it stands after the measurement — the holder's, or the last one known when it named none — and an
+// item at a path with no recent reading is read at once (novox/hq issue 368).
 const readingEvery = 55 * time.Minute
 
 // readingsKept is how long readings are kept.
@@ -187,10 +189,14 @@ func (i *Inventory) RecordData(ctx context.Context, machine string, declared []D
 		}
 		if m.Size != nil && m.MeasuredAt != nil && Comparable(m.Precision) {
 			if _, err := tx.Exec(ctx, `
-				insert into data_reading (machine, module, item, at, size_bytes, last_write)
-				select $1, $2, $3, $4, $5, $6
-				 where not exists (select 1 from data_reading
-				                    where machine = $1 and module = $2 and item = $3 and at > $4::timestamptz - $7::interval)`,
+				insert into data_reading (machine, module, item, at, size_bytes, last_write, path)
+				select $1, $2, $3, $4, $5, $6, d.path
+				  from data_item d
+				 where d.machine = $1 and d.module = $2 and d.item = $3
+				   and not exists (select 1 from data_reading
+				                    where machine = $1 and module = $2 and item = $3 and path = d.path
+				                      and at > $4::timestamptz - $7::interval)
+				on conflict (machine, module, item, at) do nothing`,
 				machine, d.Module, d.Item, *m.MeasuredAt, *m.Size, m.LastWrite,
 				fmt.Sprintf("%d seconds", int(readingEvery.Seconds()))); err != nil {
 				return change, err
@@ -281,10 +287,14 @@ func (i *Inventory) DataOf(ctx context.Context, machine, module, item string) (D
 	return r, err
 }
 
-// DataPeaks is each item's largest reading since a moment, keyed by DataRecord.Key.
+// DataPeaks is each item's largest reading since a moment, keyed by DataRecord.Key — read only from
+// readings at the item's path now (novox/hq issue 368): a directory is never compared with another one
+// that once held the same item, so a moved item starts its size history again at its new path.
 func (i *Inventory) DataPeaks(ctx context.Context, since time.Time) (map[string]int64, error) {
-	rows, err := i.store.Pool().Query(ctx, `select machine, module, item, max(size_bytes) from data_reading
-		where at >= $1 group by machine, module, item`, since)
+	rows, err := i.store.Pool().Query(ctx, `select r.machine, r.module, r.item, max(r.size_bytes)
+		from data_reading r
+		join data_item d on d.machine = r.machine and d.module = r.module and d.item = r.item and d.path = r.path
+		where r.at >= $1 group by r.machine, r.module, r.item`, since)
 	if err != nil {
 		return nil, err
 	}

internal/inventory/data_test.go

@@ -128,3 +128,66 @@ func TestAPartialMeasurementIsNeverAReading(t *testing.T) {
 		t.Fatalf("%+v, %v", r, err)
 	}
 }
+
+// A shrink is read against what the same directory held (novox/hq issue 368): an item whose path moved
+// — an agent's home moved to its own account — starts its size history again at the new path, and a
+// genuine shrink at the new path is still read against what that path held.
+func TestThePeakIsReadAtTheItemsPathOnly(t *testing.T) {
+	inv := fresh(t)
+	ctx := t.Context()
+	now := time.Date(2026, 10, 10, 0, 0, 0, 0, time.UTC)
+	declared := []DeclaredData{{Module: "claude-code", Item: "agent-home", Class: "valuable", Owned: true}}
+	measure := func(when time.Time, path string, s int64) {
+		t.Helper()
+		if _, err := inv.RecordData(ctx, "novox", declared, map[string]map[string]Measurement{"claude-code": {
+			"agent-home": {Path: path, Size: size(s), MeasuredAt: at(when)}}}, "", when); err != nil {
+			t.Fatal(err)
+		}
+	}
+	measure(now, "/home/operator/.claude", 94_700_000)
+	// The path moves ten minutes later: the new directory is measured at once, not an hour on.
+	measure(now.Add(10*time.Minute), "/home/agent/.claude", 490)
+	peaks, err := inv.DataPeaks(ctx, now.Add(-time.Hour))
+	if err != nil || peaks["novox/claude-code/agent-home"] != 490 {
+		t.Fatalf("after the path moved the peak is %v (%v), want 490: the old directory's size is no shrink "+
+			"of the new one", peaks, err)
+	}
+	// The new directory grows, then genuinely loses most of it: that is read against the new path's peak.
+	measure(now.Add(2*time.Hour), "/home/agent/.claude", 80_000_000)
+	measure(now.Add(4*time.Hour), "/home/agent/.claude", 1_000)
+	peaks, err = inv.DataPeaks(ctx, now.Add(-time.Hour))
+	if err != nil || peaks["novox/claude-code/agent-home"] != 80_000_000 {
+		t.Fatalf("a shrink at the new path is read against %v (%v), want 80000000", peaks, err)
+	}
+	// A measurement that names no path is the item's last known path's, not a new history.
+	measure(now.Add(6*time.Hour), "", 2_000)
+	peaks, err = inv.DataPeaks(ctx, now.Add(-time.Hour))
+	if err != nil || peaks["novox/claude-code/agent-home"] != 80_000_000 {
+		t.Fatalf("a measurement with no path started a new history: peak %v (%v)", peaks, err)
+	}
+	// Moving back to a directory measured before reads it against what it held then.
+	measure(now.Add(8*time.Hour), "/home/operator/.claude", 94_000_000)
+	peaks, err = inv.DataPeaks(ctx, now.Add(-time.Hour))
+	if err != nil || peaks["novox/claude-code/agent-home"] != 94_700_000 {
+		t.Fatalf("back at the first path the peak is %v (%v), want 94700000", peaks, err)
+	}
+}
+
+// Two measurements at the same moment at two paths keep one reading and fail nothing: the second
+// would otherwise break the reading's key and lose the machine's whole record (issue 368 review).
+func TestTwoPathsAtOneMomentFailNothing(t *testing.T) {
+	inv := fresh(t)
+	ctx := t.Context()
+	now := time.Date(2026, 10, 10, 0, 0, 0, 0, time.UTC)
+	declared := []DeclaredData{{Module: "claude-code", Item: "agent-home", Class: "valuable", Owned: true}}
+	for _, path := range []string{"/home/operator/.claude", "/home/agent/.claude"} {
+		if _, err := inv.RecordData(ctx, "novox", declared, map[string]map[string]Measurement{"claude-code": {
+			"agent-home": {Path: path, Size: size(100), MeasuredAt: at(now)}}}, "", now); err != nil {
+			t.Fatalf("a measurement at %s failed: %v", path, err)
+		}
+	}
+	r, err := inv.DataOf(ctx, "novox", "claude-code", "agent-home")
+	if err != nil || r.Path != "/home/agent/.claude" {
+		t.Fatalf("%+v, %v", r, err)
+	}
+}

internal/inventory/migrations/0092-a-reading-says-the-path-it-was-measured-at.sql

@@ -0,0 +1,21 @@
+-- A reading says the path it was measured at (novox/hq issue 368).
+--
+-- A shrink is read against the largest reading of the last seven days. Readings were kept by machine,
+-- module and item only, so when an item's path moved — on 2026-10-10 an agent's home moved from the
+-- operator's own home to the agent account's (ADR 0266) — the new, fresh directory was read against
+-- the old one's size, and `data-shrank` was raised for data that was never lost. A reading now keeps
+-- its path, and the peak is read only from readings at the item's path now: a moved item starts its
+-- size history again, and moving back to a path reads it against what that path held.
+--
+-- **Every reading kept so far is taken to be at its item's path now.** Where it was really measured
+-- is not on record; taking the path now keeps every item's history, so a shrink that is real stays
+-- raised. An item whose path moved before this migration stays compared with its old directory until
+-- those readings leave the seven-day window. Readings of an item no longer kept keep no path, and are
+-- read for nothing.
+--
+-- Numbered 0092, past 0091, the highest on main or any open branch when this was written.
+alter table data_reading add column path text;
+
+update data_reading r set path = d.path
+  from data_item d
+ where d.machine = r.machine and d.module = r.module and d.item = r.item;