op-challenger: Remove dead code from game.go

This code to determine which claim is the pre-state claim & which claim
is the post state claim is no longer needed because it is done in the
contracts.

op-challenger/fault/game.go

@@ -26,14 +26,6 @@ type Game interface {
 	// IsDuplicate returns true if the provided [Claim] already exists in the game state.
 	IsDuplicate(claim Claim) bool
 
-	// PreStateClaim gets the claim which commits to the pre-state of this specific claim.
-	// This will return an error if it is called with a non-leaf claim.
-	PreStateClaim(claim Claim) (Claim, error)
-
-	// PostStateClaim gets the claim which commits to the post-state of this specific claim.
-	// This will return an error if it is called with a non-leaf claim.
-	PostStateClaim(claim Claim) (Claim, error)
-
 	// AgreeWithLevel returns if the game state agrees with the provided claim level.
 	AgreeWithClaimLevel(claim Claim) bool
 }
@@ -140,45 +132,3 @@ func (g *gameState) getParent(claim Claim) (Claim, error) {
 		return parent.self, nil
 	}
 }
-
-func (g *gameState) PreStateClaim(claim Claim) (Claim, error) {
-	// Do checks in PreStateClaim because these do not hold while walking the tree
-	if claim.Depth() != int(g.depth) {
-		return Claim{}, errors.New("Only leaf claims have pre or post state")
-	}
-	// If the claim is the far left most claim, the pre-state is pulled from the contracts & we can supply at contract index.
-	if claim.IndexAtDepth() == 0 {
-		return Claim{
-			ContractIndex: -1,
-		}, nil
-	}
-	return g.preStateClaim(claim)
-}
-
-// preStateClaim is the internal tree walker which does not do error handling
-func (g *gameState) preStateClaim(claim Claim) (Claim, error) {
-	parent, _ := g.getParent(claim)
-	if claim.DefendsParent() {
-		return parent, nil
-	} else {
-		return g.preStateClaim(parent)
-	}
-}
-
-func (g *gameState) PostStateClaim(claim Claim) (Claim, error) {
-	// Do checks in PostStateClaim because these do not hold while walking the tree
-	if claim.Depth() != int(g.depth) {
-		return Claim{}, errors.New("Only leaf claims have pre or post state")
-	}
-	return g.postStateClaim(claim)
-}
-
-// postStateClaim is the internal tree walker which does not do error handling
-func (g *gameState) postStateClaim(claim Claim) (Claim, error) {
-	parent, _ := g.getParent(claim)
-	if claim.DefendsParent() {
-		return g.postStateClaim(parent)
-	} else {
-		return parent, nil
-	}
-}

op-challenger/fault/game_test.go

@@ -195,46 +195,6 @@ func TestGame_ClaimPairs(t *testing.T) {
 	require.ElementsMatch(t, expected, claims)
 }
 
-// TestPrePostStateOnlyOnLeafClaim tests that if PreStateClaim or PostStateClaim is called with an non-leaf claim
-// those functions return an error.
-func TestPrePostStateOnlyOnLeafClaim(t *testing.T) {
-	root, top, middle, bottom := createTestClaims()
-	g := NewGameState(false, root, testMaxDepth)
-	require.NoError(t, g.PutAll([]Claim{top, middle, bottom}))
-
-	_, err := g.PreStateClaim(middle)
-	require.Error(t, err)
-	_, err = g.PostStateClaim(middle)
-	require.Error(t, err)
-}
-
-func TestPreStateClaim(t *testing.T) {
-	root, top, middle, bottom := createTestClaims()
-	g := NewGameState(false, root, testMaxDepth)
-	require.NoError(t, g.Put(top))
-	require.NoError(t, g.Put(middle))
-	require.NoError(t, g.Put(bottom))
-
-	// Bottom trace index is 4. Pre trace index is then 3
-	pre, err := g.PreStateClaim(bottom)
-	require.NoError(t, err)
-	require.Equal(t, top, pre)
-
-}
-
-func TestPostStateClaim(t *testing.T) {
-	root, top, middle, bottom := createTestClaims()
-	g := NewGameState(false, root, testMaxDepth)
-	require.NoError(t, g.Put(top))
-	require.NoError(t, g.Put(middle))
-	require.NoError(t, g.Put(bottom))
-
-	// Bottom trace index is 4. Post trace index is then 5
-	post, err := g.PostStateClaim(bottom)
-	require.NoError(t, err)
-	require.Equal(t, middle, post)
-}
-
 func TestAgreeWithClaimLevelDisagreeWithOutput(t *testing.T) {
 	// Setup the game state.
 	root, top, middle, bottom := createTestClaims()