Files
lanework/KanbanTests/BoardStoreTests.swift
rzen 988a7245a3 Memoize the reload parse and short-circuit value-equal snapshots
The loader gains a ParseMemo — the previous walk's parsed documents keyed
by root-relative path, trusted on the git-index heuristic (mtime + size,
no hashing) and passed as an input so the loader stays stateless. A hit
skips exactly one file read; schema, order, coercions, dedupe, and every
directory listing run fresh, so memoized and cold walks are output-
identical (golden-corpus equivalence suite). Entries record only past the
schema gate, so a defect can never be answered from the memo.

The store skips the snapshot assignment wholesale when the fresh model is
value-equal — no @Observable churn, no render pass, no snapshotGeneration
bump — and a new landedReloads counter carries walk-completion for the
three consumers whose subject is the walk, not the snapshot: the card
window's comment thread, the comment search index, and the auto-committer's
covering gate (which now counts a completed walk as covering even when
nothing changed). Warnings and defects move on their own equality; failed
reloads bump neither counter. An injectable ParseCounter makes the
single-file-echo claim a test.

Claude-Session: https://claude.ai/code/session_01CqjXB7ASoWtbyoGod68k97
2026-08-01 11:38:25 -04:00

835 lines
37 KiB
Swift

import Foundation
import Testing
@testable import Kanban
/// `BoardStore`'s correctness is almost entirely about *what survives what*: a failed reload must
/// not eat a good snapshot, a selection must not survive a liveness flip, a wholesale operation's
/// expectation must not be consumed by a walk that predates it. So these tests drive the store
/// through its one inbound door — `handleWatcherEvent(_:)` — against real boards in real temp
/// directories, and never through a `FolderWatcher` (which has its own suite, and whose FSEvents
/// timing would turn every assertion here into a race).
///
/// **No sleeps stand in for ordering.** `awaitQuiescence()` is how a test waits for the pipeline,
/// and the one test that needs a load pinned *open* mid-flight uses `BoardStore.loadBarrier` to pin
/// it rather than guessing at a duration. The single polling helper (`waitUntil`) waits for an
/// actor to report that a load has arrived at that barrier — a fact, not an elapsed time.
// MARK: - Fixtures
/// `WriterFixture`, `Ident` and `Item` live in `WriterTestSupport.swift`; a board store needs
/// exactly what the writer suites needed — hand-written `index.md` files in a temp tree — so this
/// file borrows them rather than growing a third copy.
/// Frontmatter that opens and closes correctly but does not parse: an unclosed flow sequence. The
/// shape a non-atomic external write leaves behind when a reload catches it mid-flight, which is the
/// case 02-architecture.md § Live-reload resilience is written about.
private let brokenIndex = "---\nschema: 1\norder: 1024\nlabels: [a, b\n---\nbody\n"
/// A card whose `deleted:` key is present — the tombstone an agent or a hand-edit adds to a file the
/// user currently has selected.
private func tombstoned(order: String, title: String) -> String {
"""
---
schema: 1
title: \(title)
order: \(order)
deleted: 2026-03-03T09:00:00Z
---
\(title) body.
"""
}
/// The board every test starts from: two lanes, two cards in the first, and one stray folder so
/// `loadWarnings` has something real to carry.
@MainActor
private func makeBoard() throws -> WriterFixture {
let fixture = try WriterFixture()
try fixture.item("", Item.board)
try fixture.item(Ident.lane1, Item.rich(order: "1024", title: "Todo"))
try fixture.item("\(Ident.lane1)/\(Ident.card1)", Item.rich(order: "1024", title: "First"))
try fixture.item("\(Ident.lane1)/\(Ident.card2)", Item.rich(order: "2048", title: "Second"))
try fixture.item(Ident.lane2, Item.rich(order: "2048", title: "Doing"))
try fixture.item("notes", "not a board item at all\n")
return fixture
}
private func lane(_ id: String, in snapshot: BoardModel) -> Lane? {
snapshot.lanes.first { $0.id.rawValue == id }
}
private func cardTitles(inLane id: String, of snapshot: BoardModel) -> [String] {
(lane(id, in: snapshot)?.cards ?? []).compactMap(\.title.value)
}
/// Relative paths as `BoardLoadError` reports them — root-relative, `/`-joined.
private func indexPath(_ components: String...) -> String {
(components + ["index.md"]).joined(separator: "/")
}
// MARK: - Assertion helpers
/// The refusal-side twin of `WriterTestSupport.writeFailure`: runs `operation` expecting the store
/// to turn it away, and hands back the refusal for inspection.
@MainActor
@discardableResult
private func refusal(_ operation: () throws -> Void) -> BoardStoreWriteRefusal? {
do {
try operation()
Issue.record("expected the store to refuse the write, but it ran")
return nil
} catch let error as BoardStoreWriteRefusal {
return error
} catch {
Issue.record("expected a BoardStoreWriteRefusal, got \(error)")
return nil
}
}
/// Counts the bracket calls a store makes, standing in for the watcher the registry will wire up.
@MainActor
private final class BracketLog {
private(set) var begins = 0
private(set) var ends = 0
/// Wired into a store the way the registry will wire its watcher.
func attach(to store: BoardStore) {
store.watcherBrackets = (begin: { self.begins += 1 }, end: { self.ends += 1 })
}
}
/// Holds a finished tree walk open until a test says otherwise, and reports when one has arrived.
///
/// This is what makes the "an in-flight walk never consumes the wholesale expectation" test a proof
/// rather than a coin flip: without it, whether the walk in question had already applied would
/// depend on how fast the disk was.
private actor LoadGate {
private(set) var arrivals = 0
private var isOpen = false
private var waiters: [CheckedContinuation<Void, Never>] = []
func arrive() async {
arrivals += 1
guard !isOpen else { return }
await withCheckedContinuation { waiters.append($0) }
}
func open() {
isOpen = true
let pending = waiters
waiters.removeAll()
for waiter in pending {
waiter.resume()
}
}
}
/// Polls until `condition` holds or the deadline passes. Used only to notice that a load has reached
/// the gate — the ordering itself is enforced by the gate, never by the interval.
private func waitUntil(_ deadline: Duration = .seconds(5), _ condition: @Sendable () async -> Bool) async {
let start = ContinuousClock.now
while ContinuousClock.now - start < deadline {
if await condition() { return }
try? await Task.sleep(for: .milliseconds(5))
}
}
// MARK: - Tests
@MainActor
@Suite("BoardStore")
struct BoardStoreTests {
// MARK: Opening
@Test("A valid board loads its snapshot and its warnings at init")
func initialLoadSucceeds() async throws {
let fixture = try makeBoard()
defer { fixture.tearDown() }
let store = try BoardStore(rootURL: fixture.root)
#expect(store.rootURL == fixture.root)
#expect(store.snapshot.lanes.count == 2)
#expect(cardTitles(inLane: Ident.lane1, of: store.snapshot) == ["First", "Second"])
#expect(store.loadWarnings.contains(.nonUUIDFolderIgnored(path: "notes")))
#expect(store.reloadFailure == nil)
#expect(store.readOnlyLock == nil)
#expect(!store.isReadOnly)
#expect(store.selection == .empty)
}
@Test("A broken board throws at init rather than constructing a store — fail-fast")
func initialLoadFailsFast() async throws {
let fixture = try makeBoard()
defer { fixture.tearDown() }
try fixture.item(Ident.lane1, brokenIndex)
// There is nothing to fall back on before the first load, so every later rule — the banner,
// the lock, "a failed reload never replaces a good snapshot" — has no meaning here.
do throws(BoardLoadFailure) {
_ = try BoardStore(rootURL: fixture.root)
Issue.record("expected the initial load to fail")
} catch {
#expect(error.primary.path == indexPath(Ident.lane1))
if case .unparseableYAML = error.primary.reason {} else {
Issue.record("expected unparseable YAML, got \(error.primary.reason)")
}
}
}
@Test("A store built from a pre-walked result is the store the walking init would have built")
func prewalkedInitMatchesTheWalkingInit() async throws {
let fixture = try makeBoard()
defer { fixture.tearDown() }
// The two inits the board window's loading state put side by side: the walk on this actor,
// and the same walk run somewhere else and handed over (`BoardStoreRegistry.acquireOffMain`
// runs it on a detached task). If these ever disagreed, an open would show a different board
// depending on which actor walked it.
let walkedHere = try BoardStore(rootURL: fixture.root)
let result = try BoardLoader.load(boardRoot: fixture.root)
let walkedElsewhere = BoardStore(rootURL: fixture.root, loaded: result)
#expect(walkedElsewhere.rootURL == walkedHere.rootURL)
#expect(walkedElsewhere.snapshot == walkedHere.snapshot)
#expect(walkedElsewhere.loadWarnings == walkedHere.loadWarnings)
#expect(walkedElsewhere.defects.count == walkedHere.defects.count)
// The rest of the opening posture, which is what a second init could quietly get wrong.
#expect(walkedElsewhere.reloadFailure == nil)
#expect(walkedElsewhere.readOnlyLock == nil)
#expect(!walkedElsewhere.isReadOnly)
#expect(walkedElsewhere.selection == .empty)
#expect(walkedElsewhere.reloadGeneration == 0)
}
// MARK: Reloading
@Test("A foreign tree change reloads and the snapshot shows the external edit")
func foreignChangeReloads() async throws {
let fixture = try makeBoard()
defer { fixture.tearDown() }
let store = try BoardStore(rootURL: fixture.root)
// Exactly what an agent or an editor does: a card folder appears, with no Writer and no
// bracket anywhere near it.
try fixture.item("\(Ident.lane1)/\(Ident.card3)", Item.rich(order: "3072", title: "Third"))
store.handleWatcherEvent(.treeChanged(.foreign))
await store.awaitQuiescence()
#expect(cardTitles(inLane: Ident.lane1, of: store.snapshot) == ["First", "Second", "Third"])
#expect(store.reloadFailure == nil)
}
@Test("A failed reload keeps the last good snapshot, and the next success heals it")
func failedReloadKeepsTheSnapshot() async throws {
let fixture = try makeBoard()
defer { fixture.tearDown() }
let store = try BoardStore(rootURL: fixture.root)
let lastGood = store.snapshot
try fixture.item("\(Ident.lane1)/\(Ident.card1)", brokenIndex)
store.handleWatcherEvent(.treeChanged(.foreign))
await store.awaitQuiescence()
#expect(store.snapshot == lastGood, "a failed reload never replaces a good snapshot")
#expect(store.reloadFailure?.primary.path == indexPath(Ident.lane1, Ident.card1))
#expect(store.loadWarnings.contains(.nonUUIDFolderIgnored(path: "notes")), "warnings describe the snapshot on screen, so they stay with it")
// Transient breakage self-heals: the watcher kept watching and the fix arrives as an
// ordinary reload.
try fixture.item("\(Ident.lane1)/\(Ident.card1)", Item.rich(order: "1024", title: "Fixed"))
store.handleWatcherEvent(.treeChanged(.foreign))
await store.awaitQuiescence()
#expect(store.reloadFailure == nil)
#expect(cardTitles(inLane: Ident.lane1, of: store.snapshot) == ["Fixed", "Second"])
}
@Test("An ordinary failed reload does not lock the board — editing continues around the breakage")
func ordinaryFailureDoesNotLock() async throws {
let fixture = try makeBoard()
defer { fixture.tearDown() }
let store = try BoardStore(rootURL: fixture.root)
try fixture.item("\(Ident.lane1)/\(Ident.card1)", brokenIndex)
store.handleWatcherEvent(.treeChanged(.foreign))
await store.awaitQuiescence()
#expect(store.reloadFailure != nil)
#expect(store.readOnlyLock == nil)
#expect(!store.isReadOnly)
// Per-file breakage: the snapshot still describes the tree, so a real write through the
// Writer is safe and must go through.
// The explicit closure signature is `performWrite`'s one ergonomic wart: with a non-`Void`
// result, `T` and the closure's thrown type cannot both be inferred, and the thrown type
// widens to `any Error`. See `performWrite`'s doc comment.
let created = try store.performWrite { () throws(BoardWriteError) -> ItemID in
try BoardWriter.createCard(inLane: fixture.url(Ident.lane2), title: "Filed anyway")
}
#expect(fixture.exists("\(Ident.lane2)/\(created.rawValue)/index.md"))
}
// MARK: Display-state write-through
@Test("A successful reload calls the display-state delegate, whether or not anything actually changed")
func successfulReloadCallsDisplayStateDelegate() async throws {
let fixture = try makeBoard()
defer { fixture.tearDown() }
let store = try BoardStore(rootURL: fixture.root)
var calls = 0
store.displayStateDelegate = { calls += 1 }
// An ordinary foreign change with no board-level field touched at all — the "did title,
// icon, or iconColor actually change" comparison is the registry's own no-op guard
// (`BoardRegistry.syncDisplayState`), not something this store decides by diffing itself.
try fixture.item("\(Ident.lane1)/\(Ident.card3)", Item.rich(order: "3072", title: "Third"))
store.handleWatcherEvent(.treeChanged(.foreign))
await store.awaitQuiescence()
#expect(calls == 1)
}
@Test("A failed reload does not call the display-state delegate — there is no new snapshot to report")
func failedReloadDoesNotCallDisplayStateDelegate() async throws {
let fixture = try makeBoard()
defer { fixture.tearDown() }
let store = try BoardStore(rootURL: fixture.root)
var calls = 0
store.displayStateDelegate = { calls += 1 }
try fixture.item("\(Ident.lane1)/\(Ident.card1)", brokenIndex)
store.handleWatcherEvent(.treeChanged(.foreign))
await store.awaitQuiescence()
#expect(calls == 0)
}
@Test("A reload with no display-state delegate wired is harmless")
func reloadWithoutADisplayStateDelegateIsANoOp() async throws {
let fixture = try makeBoard()
defer { fixture.tearDown() }
let store = try BoardStore(rootURL: fixture.root)
try fixture.item("\(Ident.lane1)/\(Ident.card3)", Item.rich(order: "3072", title: "Third"))
store.handleWatcherEvent(.treeChanged(.foreign))
await store.awaitQuiescence()
#expect(cardTitles(inLane: Ident.lane1, of: store.snapshot) == ["First", "Second", "Third"])
}
// MARK: Wholesale operations
@Test("A wholesale operation whose reload succeeds leaves no lock and no leaked expectation")
func wholesaleSuccessConsumesTheExpectation() async throws {
let fixture = try makeBoard()
defer { fixture.tearDown() }
let store = try BoardStore(rootURL: fixture.root)
let brackets = BracketLog()
brackets.attach(to: store)
try store.performWholesale {
try fixture.item(Ident.lane3, Item.rich(order: "3072", title: "Done"))
}
#expect(brackets.begins == 1)
#expect(brackets.ends == 1)
store.handleWatcherEvent(.treeChanged(.appMediated))
await store.awaitQuiescence()
#expect(store.readOnlyLock == nil)
#expect(store.reloadFailure == nil)
#expect(store.snapshot.lanes.count == 3)
// The expectation was consumed by that reload rather than left armed: an ordinary failure
// afterwards is per-file breakage again, and must not lock.
try fixture.item("\(Ident.lane1)/\(Ident.card1)", brokenIndex)
store.handleWatcherEvent(.treeChanged(.foreign))
await store.awaitQuiescence()
#expect(store.reloadFailure != nil)
#expect(store.readOnlyLock == nil, "the wholesale expectation must not outlive the reload that consumed it")
}
@Test("A failed reload after a wholesale operation locks the board, refuses writes, and clears on the next success")
func wholesaleFailureLocksAndHeals() async throws {
let fixture = try makeBoard()
defer { fixture.tearDown() }
let store = try BoardStore(rootURL: fixture.root)
let brackets = BracketLog()
brackets.attach(to: store)
let lastGood = store.snapshot
// The shape of a branch switch that lands a tree this app cannot read: the snapshot on
// screen now describes something that is not there any more.
try store.performWholesale {
try fixture.item("\(Ident.lane1)/\(Ident.card1)", brokenIndex)
}
store.handleWatcherEvent(.treeChanged(.appMediated))
await store.awaitQuiescence()
#expect(store.readOnlyLock == .bracketedReloadFailed)
#expect(store.isReadOnly)
#expect(store.reloadFailure?.primary.path == indexPath(Ident.lane1, Ident.card1))
#expect(store.snapshot == lastGood)
// Writes are refused, and refused *before* the bracket opens — a refusal must not leave the
// watcher suspended.
var ran = false
let refused = refusal { try store.performWrite { ran = true } }
#expect(refused == .readOnlyLocked(.bracketedReloadFailed))
#expect(!ran)
#expect(brackets.begins == 1, "the refusal opened no bracket")
#expect(brackets.ends == 1)
// A locked board refuses to *start* wholesale work too.
refusal { try store.performWholesale { ran = true } }
#expect(!ran)
// Reading stays live throughout — keeping the last-good snapshot is the point of the lock.
store.select([ItemID(rawValue: Ident.card2)], in: .board)
#expect(store.selection.ids.count == 1)
try fixture.item("\(Ident.lane1)/\(Ident.card1)", Item.rich(order: "1024", title: "Repaired"))
store.handleWatcherEvent(.treeChanged(.foreign))
await store.awaitQuiescence()
#expect(store.readOnlyLock == nil, "the next successful reload clears both the banner and the lock")
#expect(store.reloadFailure == nil)
#expect(cardTitles(inLane: Ident.lane1, of: store.snapshot) == ["Repaired", "Second"])
try store.performWrite { ran = true }
#expect(ran)
}
@Test("The wholesale expectation binds to the walk started after it, never to one already in flight")
func wholesaleExpectationSurvivesAnInFlightLoad() async throws {
let fixture = try makeBoard()
defer { fixture.tearDown() }
let store = try BoardStore(rootURL: fixture.root)
let gate = LoadGate()
store.loadBarrier = { await gate.arrive() }
// Walk 1 reads the tree while it is still valid, then parks before applying.
store.handleWatcherEvent(.treeChanged(.foreign))
await waitUntil { await gate.arrivals >= 1 }
// Broken only now — walk 1 is past its read, walk 2 is not.
try fixture.item("\(Ident.lane1)/\(Ident.card1)", brokenIndex)
// Armed while walk 1 is demonstrably still in flight. A boolean flag would be consumed by
// walk 1's *successful* application and would leave walk 2's failure unlocked.
try store.performWholesale {}
store.handleWatcherEvent(.treeChanged(.appMediated))
await gate.open()
await store.awaitQuiescence()
#expect(store.reloadGeneration == 2, "two walks: the one in flight, then the one the operation owed")
#expect(store.reloadFailure?.primary.path == indexPath(Ident.lane1, Ident.card1))
#expect(store.readOnlyLock == .bracketedReloadFailed)
}
// MARK: Selection across reloads
/// The rules themselves belong to `ItemReferenceSet`/`TransientBoardState` and are proved in
/// `TransientBoardStateTests` across all three referencing sets. These stay because what they
/// pin here is the *store's* half: that `land(_:generation:origin:)` re-resolves on success and
/// only on success, read through the `selection`/`select`/`clearSelection` conveniences the
/// command sites use.
@Test("A selected item that vanished from the tree leaves the selection; the survivor stays")
func selectionDropsVanishedMembers() async throws {
let fixture = try makeBoard()
defer { fixture.tearDown() }
let store = try BoardStore(rootURL: fixture.root)
store.select([ItemID(rawValue: Ident.card1), ItemID(rawValue: Ident.card2)], in: .board)
try FileManager.default.removeItem(at: fixture.url("\(Ident.lane1)/\(Ident.card1)"))
store.handleWatcherEvent(.treeChanged(.foreign))
await store.awaitQuiescence()
#expect(store.selection.ids == [ItemID(rawValue: Ident.card2)])
#expect(store.selection.container == .board)
}
@Test("A container crossing is a vanish: a selected card trashed externally leaves the selection")
func selectionEjectsAContainerCrossing() async throws {
let fixture = try makeBoard()
defer { fixture.tearDown() }
let store = try BoardStore(rootURL: fixture.root)
store.select([ItemID(rawValue: Ident.card1), ItemID(rawValue: Ident.card2)], in: .board)
try fixture.move("\(Ident.lane1)/\(Ident.card1)", toTrash: Ident.card1)
store.handleWatcherEvent(.treeChanged(.foreign))
await store.awaitQuiescence()
// Still in the snapshot — the trash renders it — but no longer in the selection's container,
// so 04's one-container invariant survives a foreign edit (02-architecture.md's reload rule,
// resettled 2026-07-28: "re-resolution matches UUID *and* container side").
#expect(store.snapshot.trash.map(\.id.rawValue) == [Ident.card1])
#expect(store.selection.ids == [ItemID(rawValue: Ident.card2)])
}
@Test("Deleting a lane externally takes its cards out of the selection with it")
func selectionEjectsCardsUnderARemovedLane() async throws {
let fixture = try makeBoard()
defer { fixture.tearDown() }
let store = try BoardStore(rootURL: fixture.root)
store.select([ItemID(rawValue: Ident.card1), ItemID(rawValue: Ident.card2)], in: .board)
// A lane delete is physical now (03-board-ui.md § Trash), so the cards genuinely go with it
// — no ancestor walk needed, and none left to do: presence is the whole test.
try FileManager.default.removeItem(at: fixture.url(Ident.lane1))
store.handleWatcherEvent(.treeChanged(.foreign))
await store.awaitQuiescence()
#expect(store.snapshot.lanes.first { $0.id.rawValue == Ident.lane1 } == nil)
#expect(store.selection.ids.isEmpty)
}
@Test("A selection can resolve to nothing, and nothing is invented to replace it")
func selectionCanResolveToNothing() async throws {
let fixture = try makeBoard()
defer { fixture.tearDown() }
let store = try BoardStore(rootURL: fixture.root)
store.select([ItemID(rawValue: Ident.card1), ItemID(rawValue: Ident.card2)], in: .board)
try FileManager.default.removeItem(at: fixture.url("\(Ident.lane1)/\(Ident.card1)"))
try FileManager.default.removeItem(at: fixture.url("\(Ident.lane1)/\(Ident.card2)"))
store.handleWatcherEvent(.treeChanged(.foreign))
await store.awaitQuiescence()
#expect(store.selection.ids.isEmpty)
#expect(store.selection.container == .board, "the container survives even when the membership does not")
store.select([ItemID(rawValue: Ident.lane1)], in: .board)
store.clearSelection()
#expect(store.selection == .empty)
}
// MARK: Coalescing
@Test("A burst of signals during one walk coalesces into exactly one follow-up")
func signalBurstCoalescesIntoOneFollowUp() async throws {
let fixture = try makeBoard()
defer { fixture.tearDown() }
let store = try BoardStore(rootURL: fixture.root)
try fixture.item("\(Ident.lane1)/\(Ident.card3)", Item.rich(order: "3072", title: "Third"))
// No `await` between them, so the main actor never yields and no result can land in the
// middle: the first signal starts a walk, the other four fold into one pending reload.
for _ in 0..<5 {
store.handleWatcherEvent(.treeChanged(.foreign))
}
await store.awaitQuiescence()
#expect(store.reloadGeneration == 2, "five signals, one walk plus one follow-up")
#expect(cardTitles(inLane: Ident.lane1, of: store.snapshot) == ["First", "Second", "Third"])
#expect(store.reloadFailure == nil)
}
// MARK: Brackets
@Test("performWrite brackets exactly once, whether the operation returns or throws")
func performWriteBracketsExactlyOnce() async throws {
let fixture = try makeBoard()
defer { fixture.tearDown() }
let store = try BoardStore(rootURL: fixture.root)
let brackets = BracketLog()
brackets.attach(to: store)
var ran = false
try store.performWrite { ran = true }
#expect(ran)
#expect(brackets.begins == 1)
#expect(brackets.ends == 1)
// A Writer operation that fails partway has still touched disk, so the bracket has to close
// on the throwing path too — an unbalanced one would suspend the watcher for the session.
let boom = BoardWriteError(operation: .style(title: nil), path: "/nowhere", reason: .io(message: "disk full"))
do {
try store.performWrite { () throws(BoardWriteError) -> Void in throw boom }
Issue.record("expected the operation's own error to propagate")
} catch let error as BoardWriteError {
#expect(error == boom, "the store rethrows the Writer's error untouched")
} catch {
Issue.record("expected a BoardWriteError, got \(error)")
}
#expect(brackets.begins == 2)
#expect(brackets.ends == 2)
}
// MARK: Root changes
@Test("A root change with no delegate wired leaves the last good snapshot alone")
func rootChangeWithoutADelegateIsANoOp() async throws {
let fixture = try makeBoard()
defer { fixture.tearDown() }
let store = try BoardStore(rootURL: fixture.root)
let lastGood = store.snapshot
// Re-resolve-or-lock needs a bookmark this store does not own, so the response is
// delegated (the registry wires it — `RootRecoveryTests` drives the real thing). With no
// delegate, the honest answer is the same one every failure path gives: keep the last good
// snapshot. Guessing here would lock a board that had merely moved.
store.handleWatcherEvent(.rootChanged)
await store.awaitQuiescence()
#expect(store.snapshot == lastGood)
#expect(store.reloadFailure == nil)
#expect(store.readOnlyLock == nil)
#expect(store.reloadGeneration == 0, "a root change schedules no reload of its own")
}
@Test("A root change with a delegate hands over and starts no reload of its own")
func rootChangeIsDelegated() async throws {
let fixture = try makeBoard()
defer { fixture.tearDown() }
let store = try BoardStore(rootURL: fixture.root)
var calls = 0
store.rootChangeDelegate = { calls += 1 }
store.handleWatcherEvent(.rootChanged)
await store.awaitQuiescence()
#expect(calls == 1)
// The delegate's two outcomes both end in a reload — at the re-resolved root, or on the
// root's return. One fired from here would walk a path that just stopped being the board.
#expect(store.reloadGeneration == 0)
}
}
// MARK: - The parse memo and the value-equal skip
/// **"The walk memoizes its parse, never its result"** and **"the store skips the assignment entirely
/// when the fresh snapshot equals the current one"** (02-architecture.md § Live-reload resilience,
/// both blessed 2026-07-31).
///
/// The loader's half is pinned in `BoardLoaderParseMemoTests` and over the golden corpus in
/// `FixtureMemoEquivalenceTests`; what only this suite can state is the *wiring* — that the store
/// hands each walk the one before it (`BoardStore.parseCounter` is the seam that makes "re-parsed
/// nothing" observable at all), and that the skip is a skip of the observable assignment and of
/// nothing else the landing owes.
@MainActor
@Suite("BoardStore ▸ the parse memo and the value-equal skip")
struct BoardStoreReloadMemoTests {
/// Every `index.md` `makeBoard()` puts in the walk's way: the root, two lanes, two cards. The
/// stray `notes/` folder holds one too and is deliberately not counted — a non-UUID-shaped folder
/// is never descended into, so the loader never opens it, memo or no memo.
static let indexCount = 5
/// One reload through the store's one inbound door, with a counter attached.
private func reload(_ store: BoardStore, _ origin: WatchOrigin = .foreign) async -> BoardLoader.ParseCounter.Counts {
let counter = BoardLoader.ParseCounter()
store.parseCounter = counter
store.handleWatcherEvent(.treeChanged(origin))
await store.awaitQuiescence()
store.parseCounter = nil
return counter.counts
}
@Test("A reload of an untouched tree opens no index.md and assigns no snapshot")
func anUnchangedTreeCostsNothing() async throws {
let fixture = try makeBoard()
defer { fixture.tearDown() }
let store = try BoardStore(rootURL: fixture.root)
let before = store.snapshot
let counts = await reload(store)
#expect(counts == .init(parsed: 0, reused: Self.indexCount))
// The skip proper: no assignment, so no `@Observable` churn and no render pass.
#expect(store.snapshotGeneration == 0)
#expect(store.snapshot == before)
// And the landing still happened — the bookkeeping the skip must never cover.
#expect(store.landedReloads == 1)
#expect(store.reloadFailure == nil)
}
@Test("A single-file echo re-parses exactly that file, and does assign")
func oneEditedFileIsTheOnlyOneReParsed() async throws {
let fixture = try makeBoard()
defer { fixture.tearDown() }
let store = try BoardStore(rootURL: fixture.root)
try fixture.item("\(Ident.lane1)/\(Ident.card1)", Item.rich(order: "1024", title: "Renamed"))
let counts = await reload(store)
#expect(counts == .init(parsed: 1, reused: Self.indexCount - 1))
#expect(cardTitles(inLane: Ident.lane1, of: store.snapshot) == ["Renamed", "Second"])
#expect(store.snapshotGeneration == 1)
#expect(store.landedReloads == 1)
}
@Test("The memo carries from reload to reload rather than going cold every other walk")
func theMemoChains() async throws {
let fixture = try makeBoard()
defer { fixture.tearDown() }
let store = try BoardStore(rootURL: fixture.root)
// Three landings: one value-equal (which skips the assignment), one that changes a file, and
// one value-equal again. If the skipped landing dropped its memo, the walk after it would go
// cold — which is exactly the bug this pins.
#expect(await reload(store) == .init(parsed: 0, reused: Self.indexCount))
try fixture.item("\(Ident.lane1)/\(Ident.card2)", Item.rich(order: "2048", title: "Edited"))
#expect(await reload(store) == .init(parsed: 1, reused: Self.indexCount - 1))
#expect(await reload(store) == .init(parsed: 0, reused: Self.indexCount))
#expect(cardTitles(inLane: Ident.lane1, of: store.snapshot) == ["First", "Edited"])
#expect(store.snapshotGeneration == 1, "only the middle reload had anything to assign")
#expect(store.landedReloads == 3)
#expect(store.parseMemo.count == Self.indexCount)
}
@Test("A failed reload keeps the snapshot and bumps neither counter")
func aFailedReloadBumpsNothing() async throws {
let fixture = try makeBoard()
defer { fixture.tearDown() }
let store = try BoardStore(rootURL: fixture.root)
let before = store.snapshot
try fixture.item(Ident.lane1, brokenIndex)
_ = await reload(store)
#expect(store.snapshot == before, "a failed reload never replaces a good snapshot")
#expect(store.snapshotGeneration == 0)
#expect(store.landedReloads == 0, "there is no snapshot in hand, so nothing was covered")
#expect(store.reloadFailure?.primary.path == indexPath(Ident.lane1))
}
@Test("A failed reload's breakage clears on the next success, which is value-equal")
func breakageClearsOnAValueEqualSuccess() async throws {
let fixture = try makeBoard()
defer { fixture.tearDown() }
let store = try BoardStore(rootURL: fixture.root)
try fixture.item(Ident.lane1, brokenIndex)
_ = await reload(store)
#expect(store.reloadFailure != nil)
// Repaired to exactly what it was: the model comes back value-equal, the assignment is
// skipped — and the standing breakage condition must still heal, because it is not board
// structure and is not what the skip covers.
try fixture.item(Ident.lane1, Item.rich(order: "1024", title: "Todo"))
_ = await reload(store)
#expect(store.reloadFailure == nil)
#expect(store.snapshotGeneration == 0, "the repaired tree is the tree that was already on screen")
#expect(store.landedReloads == 1)
}
// MARK: What the skip must never cover
@Test("Warnings follow the tree even when the model does not move")
func warningsFollowTheTree() async throws {
let fixture = try makeBoard()
defer { fixture.tearDown() }
let store = try BoardStore(rootURL: fixture.root)
// A second non-UUID-shaped folder: a stray is not in the model, so this changes `loadWarnings`
// and nothing else. It is also never descended into, so the walk still opens no file.
try fixture.item("scratch", "not a board item at all\n")
let counts = await reload(store)
#expect(counts == .init(parsed: 0, reused: Self.indexCount))
#expect(store.snapshotGeneration == 0)
#expect(store.landedReloads == 1)
#expect(store.loadWarnings.contains(.nonUUIDFolderIgnored(path: "scratch")))
#expect(store.loadWarnings.contains(.nonUUIDFolderIgnored(path: "notes")))
}
@Test("Defects follow the tree even when the model does not move")
func defectsFollowTheTree() async throws {
let fixture = try makeBoard()
defer { fixture.tearDown() }
let store = try BoardStore(rootURL: fixture.root)
#expect(store.looseCardFiles.isEmpty)
// A loose file beside an untouched `index.md`: pending work the walk found, with the snapshot
// value-equal on either side of it. Defects are what `runScheduledHeals` reads, so a skip
// that swallowed them would silently retire the heal engine on quiet boards.
try "loose".write(
to: fixture.url("\(Ident.lane1)/\(Ident.card1)").appendingPathComponent("notes.txt"),
atomically: true,
encoding: .utf8
)
_ = await reload(store)
#expect(store.snapshotGeneration == 0)
#expect(store.landedReloads == 1)
#expect(store.looseCardFiles.map(\.fileNames) == [["notes.txt"]])
}
@Test("An attachment arriving moves the snapshot, because the snapshot carries the listing")
func attachmentsAreNotMemoized() async throws {
let fixture = try makeBoard()
defer { fixture.tearDown() }
let store = try BoardStore(rootURL: fixture.root)
let attachments = fixture.url("\(Ident.lane1)/\(Ident.card1)")
.appendingPathComponent("attachments", isDirectory: true)
try FileManager.default.createDirectory(at: attachments, withIntermediateDirectories: true)
try "png".write(to: attachments.appendingPathComponent("shot.png"), atomically: true, encoding: .utf8)
let counts = await reload(store)
// Not one file opened, and the card's paperclip is still current: directory enumeration is
// outside the memo's scope by design, because an attachment never touches `index.md`.
#expect(counts == .init(parsed: 0, reused: Self.indexCount))
#expect(lane(Ident.lane1, in: store.snapshot)?.cards.first?.attachments == ["shot.png"])
#expect(store.snapshotGeneration == 1)
#expect(store.landedReloads == 1)
}
@Test("A no-change reload announces nothing and leaves no state behind")
func aNoChangeReloadIsSilent() async throws {
let fixture = try makeBoard()
defer { fixture.tearDown() }
let store = try BoardStore(rootURL: fixture.root)
var spoken: [String?] = []
store.announce = { spoken.append($0) }
_ = await reload(store)
_ = await reload(store, .reconciling)
#expect(spoken == [nil, nil])
#expect(store.readOnlyLock == nil)
#expect(store.snapshotGeneration == 0)
#expect(store.landedReloads == 2)
}
@Test("A value-equal reload still lands for the auto-commit seam and the covering gate")
func aValueEqualReloadStillLands() async throws {
let fixture = try makeBoard()
defer { fixture.tearDown() }
let store = try BoardStore(rootURL: fixture.root)
let landings = LandingCount()
store.commitSeam = HistoryCommitSeam(
willWrite: {},
writeBracketDidClose: {},
reloadDidLand: { _ in landings.value += 1 }
)
_ = await reload(store)
// The covering gate counts landings, not assignments (`GitAutoCommitter.landedReloads`), and
// the commit seam is armed by every landing whether or not the snapshot moved — "a landing
// that finds nothing to commit is the silent no-op, not a wasted trip".
#expect(landings.value == 1)
#expect(store.landedReloads == 1)
#expect(store.snapshotGeneration == 0)
}
}
/// What the reload path told the history seam — a box, because `HistoryCommitSeam` is a struct of
/// closures and a captured `var` cannot be read back after the reload has landed.
@MainActor
private final class LandingCount {
var value = 0
}