Adding a test to ensure that tx commit order is properly tested

Tracers can expect that that `OnTxCommit` is called in proper transaction order so that it have the certitude that the current `OnTxCommit` is that correct one to happen relative to all other transaction.

This is already the case, this test case only add a certain confidence that this assertion is going to be respected if any refactor happen in the future.

tasks/scheduler_test.go

@@ -100,6 +100,8 @@ func TestProcessAll(t *testing.T) {
 		http.ListenAndServe("localhost:6060", nil)
 	}()
 
+	var testTxTracerCommitIndexes = new([]int)
+
 	tests := []struct {
 		name          string
 		workers       int
@@ -400,7 +402,7 @@ func TestProcessAll(t *testing.T) {
 			workers:   10,
 			runs:      1,
 			addStores: true,
-			requests:  addTxTracerToTxEntries(requestList(250)),
+			requests:  addTxTracerToTxEntries(requestList(250), newTestResetTxTracer),
 			deliverTxFunc: func(ctx sdk.Context, req types.RequestDeliverTx, tx sdk.Tx, checksum [32]byte) (res types.ResponseDeliverTx) {
 				defer abortRecoveryFunc(&res)
 				wait := rand.Intn(10)
@@ -413,7 +415,7 @@ func TestProcessAll(t *testing.T) {
 				newVal := val + fmt.Sprintf("%d", ctx.TxIndex())
 				kv.Set(itemKey, []byte(newVal))
 
-				if v, ok := ctx.Context().Value("test_tracer").(*testTxTracer); ok {
+				if v, ok := ctx.Context().Value("test_tracer").(*testResetTxTracer); ok {
 					v.OnTxExecute()
 				}
 
@@ -434,6 +436,39 @@ func TestProcessAll(t *testing.T) {
 			},
 			expectedErr: nil,
 		},
+		{
+			name:      "Test tx Commit done in requests order",
+			workers:   10,
+			runs:      1,
+			addStores: true,
+			requests:  addTxTracerToTxEntries(requestList(250), func(txIndex int) sdk.TxTracer { return newTestCommitTxTracer(txIndex, testTxTracerCommitIndexes) }),
+			deliverTxFunc: func(ctx sdk.Context, req types.RequestDeliverTx, tx sdk.Tx, checksum [32]byte) (res types.ResponseDeliverTx) {
+				defer abortRecoveryFunc(&res)
+				wait := rand.Intn(10)
+				time.Sleep(time.Duration(wait) * time.Millisecond)
+				// all txs read and write to the same key to maximize conflicts
+				kv := ctx.MultiStore().GetKVStore(testStoreKey)
+				val := string(kv.Get(itemKey))
+				time.Sleep(time.Duration(wait) * time.Millisecond)
+				// write to the store with this tx's index
+				newVal := val + fmt.Sprintf("%d", ctx.TxIndex())
+				kv.Set(itemKey, []byte(newVal))
+
+				// return what was read from the store (final attempt should be index-1)
+				return types.ResponseDeliverTx{
+					Info: newVal,
+				}
+			},
+			assertions: func(t *testing.T, ctx sdk.Context, res []types.ResponseDeliverTx) {
+				expectedCommitTxIndexes := make([]int, 250)
+				for i := 0; i < 250; i++ {
+					expectedCommitTxIndexes[i] = i
+				}
+
+				require.Equal(t, expectedCommitTxIndexes, *testTxTracerCommitIndexes)
+			},
+			expectedErr: nil,
+		},
 	}
 
 	for _, tt := range tests {
@@ -468,41 +503,79 @@ func TestProcessAll(t *testing.T) {
 	}
 }
 
-func addTxTracerToTxEntries(txEntries []*sdk.DeliverTxEntry) []*sdk.DeliverTxEntry {
+func addTxTracerToTxEntries(txEntries []*sdk.DeliverTxEntry, factory func(txIndex int) sdk.TxTracer) []*sdk.DeliverTxEntry {
 	for _, txEntry := range txEntries {
-		txEntry.TxTracer = newTestTxTracer(txEntry.AbsoluteIndex)
+		txEntry.TxTracer = factory(txEntry.AbsoluteIndex)
 	}
 
 	return txEntries
 }
 
-var _ sdk.TxTracer = &testTxTracer{}
-
-func newTestTxTracer(txIndex int) *testTxTracer {
-	return &testTxTracer{txIndex: txIndex, canExecute: true}
-}
+var _ sdk.TxTracer = testTxTracer{}
 
 type testTxTracer struct {
-	txIndex    int
-	canExecute bool
+	onCommit          func()
+	onInjectInContext func(ctx sdk.Context) sdk.Context
+	onReset           func()
 }
 
-func (t *testTxTracer) Commit() {
-	t.canExecute = false
+func (t testTxTracer) Commit() {
+	if t.onCommit != nil {
+		t.onCommit()
+	}
 }
 
-func (t *testTxTracer) InjectInContext(ctx sdk.Context) sdk.Context {
+func (t testTxTracer) InjectInContext(ctx sdk.Context) sdk.Context {
+	if t.onInjectInContext != nil {
+		return t.onInjectInContext(ctx)
+	}
+
 	return ctx.WithContext(context.WithValue(ctx.Context(), "test_tracer", t))
 }
 
-func (t *testTxTracer) Reset() {
-	t.canExecute = true
+func (t testTxTracer) Reset() {
+	if t.onReset != nil {
+		t.onReset()
+	}
+}
+
+func newTestResetTxTracer(txIndex int) sdk.TxTracer {
+	var tracer *testResetTxTracer
+	tracer = &testResetTxTracer{
+		testTxTracer: testTxTracer{
+			onCommit: func() {
+				tracer.canExecute = false
+			},
+			onReset: func() {
+				tracer.canExecute = true
+			},
+		},
+
+		txIndex:    txIndex,
+		canExecute: true,
+	}
+	return tracer
+}
+
+type testResetTxTracer struct {
+	testTxTracer
+
+	txIndex    int
+	canExecute bool
 }
 
-func (t *testTxTracer) OnTxExecute() {
+func (t *testResetTxTracer) OnTxExecute() {
 	if !t.canExecute {
 		panic(fmt.Errorf("task #%d was asked to execute but the tracer is not in the correct state, most probably due to missing Reset call or over execution", t.txIndex))
 	}
 
 	t.canExecute = false
 }
+
+func newTestCommitTxTracer(txIndex int, committedTxIndexes *[]int) sdk.TxTracer {
+	return &testTxTracer{
+		onCommit: func() {
+			*committedTxIndexes = append(*committedTxIndexes, txIndex)
+		},
+	}
+}