Tests validateDifficulty ( ValidatePruningPointViolationAndProofOfWorkAndDifficulty) (#1532)

* Adds tests for validateDifficulty

* fixes according to the review notes: adding the test's goal and fix an unmatch test name on the NewTestConsensus.

* Fixes according to the review notes:delete the function genesisBits - No usages.

* Fix according to review - fix comments.

Co-authored-by: tal <tal@daglabs.com>
Co-authored-by: Ori Newman <orinewman1@gmail.com>

domain/consensus/constructors.go

@@ -1,6 +1,17 @@
 package consensus
 
-import "github.com/kaspanet/kaspad/domain/consensus/model"
+import (
+	"github.com/kaspanet/kaspad/domain/consensus/model"
+	"github.com/kaspanet/kaspad/domain/consensus/model/externalapi"
+	"math/big"
+	"time"
+)
 
 // GHOSTDAGManagerConstructor is the function signature for a constructor of a type implementing model.GHOSTDAGManager
-type GHOSTDAGManagerConstructor func(model.DBReader, model.DAGTopologyManager, model.GHOSTDAGDataStore, model.BlockHeaderStore, model.KType) model.GHOSTDAGManager
+type GHOSTDAGManagerConstructor func(model.DBReader, model.DAGTopologyManager,
+	model.GHOSTDAGDataStore, model.BlockHeaderStore, model.KType) model.GHOSTDAGManager
+
+// DifficultyManagerConstructor is the function signature for a constructor of a type implementing model.DifficultyManager
+type DifficultyManagerConstructor func(model.DBReader, model.GHOSTDAGManager, model.GHOSTDAGDataStore,
+	model.BlockHeaderStore, model.DAGTopologyManager, model.DAGTraversalManager, *big.Int, int, bool, time.Duration,
+	*externalapi.DomainHash) model.DifficultyManager

domain/consensus/factory.go

@@ -63,19 +63,22 @@ type Factory interface {
 	SetTestGHOSTDAGManager(ghostdagConstructor GHOSTDAGManagerConstructor)
 	SetTestLevelDBCacheSize(cacheSizeMiB int)
 	SetTestPreAllocateCache(preallocateCaches bool)
+	SetTestDifficultyManager(difficultyConstructor DifficultyManagerConstructor)
 }
 
 type factory struct {
-	dataDir             string
-	ghostdagConstructor GHOSTDAGManagerConstructor
-	cacheSizeMiB        *int
-	preallocateCaches   *bool
+	dataDir               string
+	ghostdagConstructor   GHOSTDAGManagerConstructor
+	difficultyConstructor DifficultyManagerConstructor
+	cacheSizeMiB          *int
+	preallocateCaches     *bool
 }
 
 // NewFactory creates a new Consensus factory
 func NewFactory() Factory {
 	return &factory{
-		ghostdagConstructor: ghostdagmanager.New,
+		ghostdagConstructor:   ghostdagmanager.New,
+		difficultyConstructor: difficultymanager.New,
 	}
 }
 
@@ -159,7 +162,7 @@ func (f *factory) NewConsensus(dagParams *dagconfig.Params, db infrastructuredat
 		dbManager,
 		pastMedianTimeManager,
 		ghostdagDataStore)
-	difficultyManager := difficultymanager.New(
+	difficultyManager := f.difficultyConstructor(
 		dbManager,
 		ghostdagManager,
 		ghostdagDataStore,
@@ -466,6 +469,11 @@ func (f *factory) SetTestGHOSTDAGManager(ghostdagConstructor GHOSTDAGManagerCons
 	f.ghostdagConstructor = ghostdagConstructor
 }
 
+// SetTestDifficultyManager is a setter for the difficultyManager field on the factory.
+func (f *factory) SetTestDifficultyManager(difficultyConstructor DifficultyManagerConstructor) {
+	f.difficultyConstructor = difficultyConstructor
+}
+
 func (f *factory) SetTestLevelDBCacheSize(cacheSizeMiB int) {
 	f.cacheSizeMiB = &cacheSizeMiB
 }

domain/consensus/processes/blockvalidator/pruning_violation_proof_of_work_and_difficulty_test.go

@@ -1,6 +1,7 @@
 package blockvalidator_test
 
 import (
+	"github.com/kaspanet/kaspad/domain/consensus/model"
 	"github.com/kaspanet/kaspad/domain/consensus/model/pow"
 	"github.com/kaspanet/kaspad/domain/consensus/ruleerrors"
 	"github.com/kaspanet/kaspad/domain/consensus/utils/blockheader"
@@ -12,8 +13,8 @@ import (
 	"math"
 	"math/big"
 	"math/rand"
-
 	"testing"
+	"time"
 
 	"github.com/kaspanet/kaspad/domain/consensus"
 	"github.com/kaspanet/kaspad/domain/consensus/model/externalapi"
@@ -241,3 +242,60 @@ func TestCheckPruningPointViolation(t *testing.T) {
 		}
 	})
 }
+
+// TestValidateDifficulty verifies that in case of a block with an unexpected difficulty,
+// an appropriate error message (ErrUnexpectedDifficulty) will be returned on the
+// function ValidatePruningPointViolationAndProofOfWorkAndDifficulty. The required difficulty is
+// "calculated" by the function (dm *mocDifficultyManager) RequiredDifficulty ,
+// where mocDifficultyManager is special implementation of the type DifficultyManager for this test (defined below).
+func TestValidateDifficulty(t *testing.T) {
+	testutils.ForAllNets(t, true, func(t *testing.T, params *dagconfig.Params) {
+
+		factory := consensus.NewFactory()
+		mocDifficulty := &mocDifficultyManager{}
+		factory.SetTestDifficultyManager(func(model.DBReader, model.GHOSTDAGManager, model.GHOSTDAGDataStore,
+			model.BlockHeaderStore, model.DAGTopologyManager, model.DAGTraversalManager, *big.Int, int, bool, time.Duration,
+			*externalapi.DomainHash) model.DifficultyManager {
+			return mocDifficulty
+		})
+		genesisDifficulty := params.GenesisBlock.Header.Bits()
+		mocDifficulty.testDifficulty = genesisDifficulty
+		mocDifficulty.testGenesisBits = genesisDifficulty
+		tc, teardown, err := factory.NewTestConsensus(params, false, "TestValidateDifficulty")
+		if err != nil {
+			t.Fatalf("Error setting up consensus: %+v", err)
+		}
+		defer teardown(false)
+
+		emptyCoinbase := externalapi.DomainCoinbaseData{
+			ScriptPublicKey: &externalapi.ScriptPublicKey{
+				Script:  nil,
+				Version: 0,
+			},
+		}
+		block, _, err := tc.BuildBlockWithParents([]*externalapi.DomainHash{params.GenesisHash}, &emptyCoinbase, nil)
+		if err != nil {
+			t.Fatalf("TestValidateDifficulty: Failed build block with parents: %v.", err)
+		}
+		blockHash := consensushashing.BlockHash(block)
+		tc.BlockStore().Stage(blockHash, block)
+		tc.BlockHeaderStore().Stage(blockHash, block.Header)
+		wrongTestDifficulty := mocDifficulty.testDifficulty + uint32(5)
+		mocDifficulty.testDifficulty = wrongTestDifficulty
+
+		err = tc.BlockValidator().ValidatePruningPointViolationAndProofOfWorkAndDifficulty(blockHash)
+		if err == nil || !errors.Is(err, ruleerrors.ErrUnexpectedDifficulty) {
+			t.Fatalf("Expected block to be invalid with err: %v, instead found: %v", ruleerrors.ErrUnexpectedDifficulty, err)
+		}
+	})
+}
+
+type mocDifficultyManager struct {
+	testDifficulty  uint32
+	testGenesisBits uint32
+}
+
+// RequiredDifficulty returns the difficulty required for the test
+func (dm *mocDifficultyManager) RequiredDifficulty(*externalapi.DomainHash) (uint32, error) {
+	return dm.testDifficulty, nil
+}