Adds tests and fix for race condition in sales preparing state.

codex/sales/states/preparing.nim

@@ -15,6 +15,8 @@ import ./errored
 
 type
   SalePreparing* = ref object of ErrorHandlingState
+    # I really don't want to keep this. Someone, please help.
+    doThing*: proc(): Future[void] {.async, gcsafe.}
 
 logScope:
   topics = "marketplace sales preparing"
@@ -31,7 +33,7 @@ method onSlotFilled*(state: SalePreparing, requestId: RequestId,
                      slotIndex: UInt256): ?State =
   return some State(SaleFilled())
 
-method run*(state: SalePreparing, machine: Machine): Future[?State] {.async.} =
+method run*(prepareState: SalePreparing, machine: Machine): Future[?State] {.async.} =
   let agent = SalesAgent(machine)
   let data = agent.data
   let context = agent.context
@@ -67,17 +69,25 @@ method run*(state: SalePreparing, machine: Machine): Future[?State] {.async.} =
       request.ask.pricePerSlot,
       request.ask.collateral):
     debug "no availability found for request, ignoring"
-
     return some State(SaleIgnored())
 
   info "availability found for request, creating reservation"
 
+  # I need a hook to mess with the reservations AFTER the availability is found.
+  if not isNil(prepareState.doThing):
+    await prepareState.doThing()
+
   without reservation =? await reservations.createReservation(
     availability.id,
     request.ask.slotSize,
     request.id,
     data.slotIndex
   ), error:
+    # Race condition:
+    # reservations.findAvailability (line 65) is no guarantee. You can never know for certain that the reservation can be created until after you have it.
+    # Should createReservation fail because there's no space, we proceed to SaleIgnored.
+    if error of BytesOutOfBoundsError:
+      return some State(SaleIgnored())
     return some State(SaleErrored(error: error))
 
   data.reservation = some reservation

tests/codex/sales/states/testpreparing.nim

@@ -1,21 +1,62 @@
-import std/unittest
+import pkg/chronos
 import pkg/questionable
+import pkg/datastore
+import pkg/stew/byteutils
 import pkg/codex/contracts/requests
 import pkg/codex/sales/states/preparing
 import pkg/codex/sales/states/downloading
 import pkg/codex/sales/states/cancelled
 import pkg/codex/sales/states/failed
 import pkg/codex/sales/states/filled
+import pkg/codex/sales/states/ignored
+import pkg/codex/sales/states/errored
+import pkg/codex/sales/salesagent
+import pkg/codex/sales/salescontext
+import pkg/codex/sales/reservations
+import pkg/codex/stores/repostore
+import ../../../asynctest
+import ../../helpers
 import ../../examples
+import ../../helpers/mockmarket
+import ../../helpers/mockclock
 
-suite "sales state 'preparing'":
-
+asyncchecksuite "sales state 'preparing'":
   let request = StorageRequest.example
   let slotIndex = (request.ask.slots div 2).u256
+  let market = MockMarket.new()
+  let clock = MockClock.new()
+  var agent: SalesAgent
   var state: SalePreparing
+  var repo: RepoStore
+  var availability: Availability
+  var context: SalesContext
 
   setup:    
+    availability = Availability(
+      totalSize: request.ask.slotSize + 100.u256,
+      freeSize: request.ask.slotSize + 100.u256,
+      duration: request.ask.duration + 60.u256,
+      minPrice: request.ask.pricePerSlot - 10.u256,
+      maxCollateral: request.ask.collateral + 400.u256
+    )
+    let repoDs = SQLiteDatastore.new(Memory).tryGet()
+    let metaDs = SQLiteDatastore.new(Memory).tryGet()
+    repo = RepoStore.new(repoDs, metaDs)
+    await repo.start()
+
     state = SalePreparing.new()
+    context = SalesContext(
+      market: market,
+      clock: clock
+    )
+    context.reservations = Reservations.new(repo)
+    agent = newSalesAgent(context,
+                          request.id,
+                          slotIndex,
+                          request.some)
+
+  teardown:
+    await repo.stop()
 
   test "switches to cancelled state when request expires":
     let next = state.onCancelled(request)
@@ -28,3 +69,40 @@ suite "sales state 'preparing'":
   test "switches to filled state when slot is filled":
     let next = state.onSlotFilled(request.id, slotIndex)
     check !next of SaleFilled
+
+  proc createAvailability() =
+    let a = waitFor context.reservations.createAvailability(
+      availability.totalSize,
+      availability.duration,
+      availability.minPrice,
+      availability.maxCollateral
+    )
+    availability = a.get
+
+  test "run switches to ignored when no availability":
+    let next = await state.run(agent)
+    check !next of SaleIgnored
+  
+  test "run switches to downloading when reserved":
+    createAvailability()
+    let next = await state.run(agent)
+    check !next of SaleDownloading
+
+  test "run switches to errored when reserve failed":
+    createAvailability()
+    state.doThing = proc(): Future[void] {.async, gcsafe.} =
+      # Mess up availability, causes createReservation to fail:
+      (await repo.metaDs.put(availability.id.key.tryGet(), "A!".toBytes())).tryGet()
+
+    let next = await state.run(agent)
+    check !next of SaleErrored
+
+  test "run switches to ignored when reserve fails with BytesOutOfBounds":
+    createAvailability()
+    state.doThing = proc(): Future[void] {.async, gcsafe.} =
+      # Oops we don't have any free bytes after all.
+      availability.freeSize = 0.u256
+      (await repo.metaDs.put(availability.id.key.tryGet(), availability.toJson.toBytes)).tryGet()
+
+    let next = await state.run(agent)
+    check !next of SaleIgnored