problem: routing doesn't consider block ref in request (i.e. "latest")

src/test/groovy/io/emeraldpay/dshackle/upstream/SelectorSpec.groovy

@@ -292,4 +292,61 @@ class SelectorSpec extends Specification {
                 [test: "foo"],
         ]
     }
+
+    def "Match by height when equal"() {
+        setup:
+        def matcher = new Selector.HeightMatcher(1000)
+        def up = Mock(Upstream) {
+            1 * getHead() >> Mock(Head) {
+                1 * getCurrentHeight() >> 1000
+            }
+        }
+        when:
+        def act = matcher.matches(up)
+        then:
+        act
+    }
+
+    def "Match by height when higher"() {
+        setup:
+        def matcher = new Selector.HeightMatcher(1000)
+        def up = Mock(Upstream) {
+            1 * getHead() >> Mock(Head) {
+                1 * getCurrentHeight() >> 1001
+            }
+        }
+        when:
+        def act = matcher.matches(up)
+        then:
+        act
+    }
+
+    def "No match by height when less"() {
+        setup:
+        def matcher = new Selector.HeightMatcher(1000)
+        def up = Mock(Upstream) {
+            1 * getHead() >> Mock(Head) {
+                1 * getCurrentHeight() >> 999
+            }
+        }
+        when:
+        def act = matcher.matches(up)
+        then:
+        !act
+    }
+
+    def "No match by height when none"() {
+        setup:
+        def matcher = new Selector.HeightMatcher(1000)
+        def up = Mock(Upstream) {
+            1 * getHead() >> Mock(Head) {
+                1 * getCurrentHeight() >> null
+            }
+        }
+        when:
+        def act = matcher.matches(up)
+        then:
+        !act
+    }
+
 }

src/test/groovy/io/emeraldpay/dshackle/upstream/calls/EthereumCallSelectorSpec.groovy

@@ -0,0 +1,81 @@
+/**
+ * Copyright (c) 2020 EmeraldPay, Inc
+ *
+ * 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.upstream.calls
+
+import io.emeraldpay.dshackle.upstream.Head
+import io.emeraldpay.dshackle.upstream.Selector
+import spock.lang.Specification
+
+class EthereumCallSelectorSpec extends Specification {
+
+    EthereumCallSelector callSelector = new EthereumCallSelector()
+
+    def "Get height matcher for latest balance"() {
+        setup:
+        def head = Mock(Head) {
+            1 * getCurrentHeight() >> 100
+        }
+        when:
+        def act = callSelector.getMatcher("eth_getBalance", '["0x0000", "latest"]', head)
+        then:
+        act == new Selector.HeightMatcher(100)
+    }
+
+    def "Get height matcher for latest call"() {
+        setup:
+        def head = Mock(Head) {
+            1 * getCurrentHeight() >> 100
+        }
+        when:
+        def act = callSelector.getMatcher("eth_call", '["0x0000", "latest"]', head)
+        then:
+        act == new Selector.HeightMatcher(100)
+    }
+
+    def "Get height matcher for latest storageAt"() {
+        setup:
+        def head = Mock(Head) {
+            1 * getCurrentHeight() >> 100
+        }
+        when:
+        def act = callSelector.getMatcher("eth_getStorageAt", '["0x295a70b2de5e3953354a6a8344e616ed314d7251", "0x0", "latest"]', head)
+        then:
+        act == new Selector.HeightMatcher(100)
+    }
+
+    def "Get height matcher for balance on block"() {
+        setup:
+        def head = Mock(Head) {
+            _ * getCurrentHeight() >> 100
+        }
+        when:
+        def act = callSelector.getMatcher("eth_getBalance", '["0x0000", "0x40"]', head)
+        then:
+        act == new Selector.HeightMatcher(0x40)
+    }
+
+    def "No matcher for pending balance"() {
+        setup:
+        def head = Mock(Head) {
+            _ * getCurrentHeight() >> 100
+        }
+        when:
+        def act = callSelector.getMatcher("eth_getBalance", '["0x0000", "pending"]', head)
+        then:
+        act == null
+    }
+
+}