problem: same check coded in different places

Author: splix

src/main/kotlin/io/emeraldpay/dshackle/ChainOptions.kt

@@ -0,0 +1,44 @@
+/**
+ * Copyright (c) 2025 EmeraldPay Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package io.emeraldpay.dshackle
+
+import io.emeraldpay.api.Chain
+
+class ChainOptions {
+    companion object {
+        fun supportsEIP1559(chain: Chain): Boolean =
+            when (chain) {
+                Chain.ETHEREUM,
+                Chain.TESTNET_GOERLI,
+                Chain.TESTNET_HOLESKY,
+                Chain.TESTNET_SEPOLIA,
+                Chain.TESTNET_HOODI,
+                -> true
+                else -> false
+            }
+
+        fun isPos(chain: Chain): Boolean =
+            when (chain) {
+                Chain.ETHEREUM,
+                Chain.TESTNET_GOERLI,
+                Chain.TESTNET_HOLESKY,
+                Chain.TESTNET_HOODI,
+                Chain.TESTNET_SEPOLIA,
+                -> true
+                else -> false
+            }
+    }
+}

src/main/kotlin/io/emeraldpay/dshackle/upstream/ForkWatchFactory.kt

@@ -16,6 +16,7 @@
 package io.emeraldpay.dshackle.upstream
 
 import io.emeraldpay.api.Chain
+import io.emeraldpay.dshackle.ChainOptions
 import org.slf4j.LoggerFactory
 import org.springframework.beans.factory.annotation.Autowired
 import org.springframework.stereotype.Service
@@ -34,22 +35,11 @@ class ForkWatchFactory(
     private val initialized = EnumMap<Chain, ForkWatch>(Chain::class.java)
     private val initializeLock = ReentrantLock()
 
-    private val posChains =
-        listOf(
-            // at this moment (Aug 2022) it's still a PoW, but upgrade is coming in weeks, so it's better to configure everything in advance
-            Chain.ETHEREUM,
-            // those are upgraded to Merge
-            Chain.TESTNET_GOERLI,
-            Chain.TESTNET_ROPSTEN,
-            Chain.TESTNET_HOLESKY,
-            Chain.TESTNET_SEPOLIA,
-        )
-
     fun create(chain: Chain): ForkWatch =
         initializeLock.withLock {
             initialized.getOrPut(chain) {
                 val forkChoice =
-                    if (posChains.contains(chain)) {
+                    if (ChainOptions.isPos(chain)) {
                         PriorityForkChoice().also {
                             it.followUpstreams(
                                 currentMultistreamHolder

src/main/kotlin/io/emeraldpay/dshackle/upstream/ethereum/EthereumMultistream.kt

@@ -17,6 +17,7 @@
 package io.emeraldpay.dshackle.upstream.ethereum
 
 import io.emeraldpay.api.Chain
+import io.emeraldpay.dshackle.ChainOptions
 import io.emeraldpay.dshackle.cache.Caches
 import io.emeraldpay.dshackle.reader.CompoundReader
 import io.emeraldpay.dshackle.reader.MultistreamReader
@@ -68,32 +69,8 @@ open class EthereumMultistream(
 
     private var subscribe = EthereumEgressSubscription(this, NoPendingTxes())
 
-    private val supportsEIP1559 =
-        when (chain) {
-            Chain.ETHEREUM,
-            Chain.TESTNET_ROPSTEN,
-            Chain.TESTNET_GOERLI,
-            Chain.TESTNET_HOLESKY,
-            Chain.TESTNET_SEPOLIA,
-            Chain.TESTNET_HOODI,
-            Chain.TESTNET_RINKEBY,
-            -> true
-            else -> false
-        }
-
-    private val isPos =
-        when (chain) {
-            Chain.ETHEREUM,
-            Chain.TESTNET_GOERLI,
-            Chain.TESTNET_HOLESKY,
-            Chain.TESTNET_HOODI,
-            Chain.TESTNET_SEPOLIA,
-            -> true
-            else -> false
-        }
-
     private val feeEstimation =
-        if (supportsEIP1559) {
+        if (ChainOptions.supportsEIP1559(chain)) {
             EthereumPriorityFees(this, dataReaders, 256)
         } else {
             EthereumLegacyFees(this, dataReaders, 256)
@@ -153,7 +130,7 @@ open class EthereumMultistream(
                 }
             } else {
                 val newHead =
-                    if (isPos) {
+                    if (ChainOptions.isPos(chain)) {
                         val heads = upstreams.map { Pair(it.getOptions().priority, it.getHead()) }
                         MergedPosHead(heads)
                     } else {