[FABCJ-288] fix: simple key end of range

As per Node and Go, permit "" to be used to
indicate the end of the range.

Only for simple keys

(mistake in the checkstyle rules picked up by vscode checkstyle plugin)

Signed-off-by: Matthew B White <whitemat@uk.ibm.com>

Author: mbwhite

ci/checkstyle/checkstyle.xml

@@ -10,7 +10,6 @@
 -->
 <module name="Checker">
   <property name="severity" value="error"/>
-  <property name="basedir" value="${basedir}"/>
   <property name="fileExtensions" value="java, properties, xml"/>
   <module name="TreeWalker">
     <module name="SuppressWithNearbyCommentFilter">

fabric-chaincode-shim/src/main/java/org/hyperledger/fabric/shim/impl/InvocationStubImpl.java

@@ -248,10 +248,10 @@ public QueryResultsIterator<KeyValue> getStateByRange(final String startKey, fin
         String start = startKey;
         String end = endKey;
 
-        if (startKey == null || startKey.isEmpty()) {
+        if (startKey == null) {
             start = UNSPECIFIED_KEY;
         }
-        if (endKey == null || endKey.isEmpty()) {
+        if (endKey == null) {
             end = UNSPECIFIED_KEY;
         }
         CompositeKey.validateSimpleKeys(start, end);
@@ -293,10 +293,10 @@ public QueryResultsIteratorWithMetadata<KeyValue> getStateByRangeWithPagination(
         String start = startKey;
         String end = endKey;
 
-        if (startKey == null || startKey.isEmpty()) {
+        if (startKey == null) {
             start = UNSPECIFIED_KEY;
         }
-        if (endKey == null || endKey.isEmpty()) {
+        if (endKey == null) {
             end = UNSPECIFIED_KEY;
         }
 
@@ -520,10 +520,10 @@ public QueryResultsIterator<KeyValue> getPrivateDataByRange(final String collect
         String end = endKey;
 
         validateCollection(collection);
-        if (startKey == null || startKey.isEmpty()) {
+        if (startKey == null) {
             start = UNSPECIFIED_KEY;
         }
-        if (endKey == null || endKey.isEmpty()) {
+        if (endKey == null) {
             end = UNSPECIFIED_KEY;
         }
         CompositeKey.validateSimpleKeys(start, end);

fabric-chaincode-shim/src/test/java/org/hyperledger/fabric/shim/impl/InvocationStubImplTest.java

@@ -0,0 +1,116 @@
+/*
+ * Copyright 2019 IBM All Rights Reserved.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+package org.hyperledger.fabric.shim.impl;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+import static org.hyperledger.fabric.protos.peer.ChaincodeShim.ChaincodeMessage.Type.GET_STATE_BY_RANGE;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+import com.google.protobuf.ByteString;
+import com.google.protobuf.InvalidProtocolBufferException;
+
+import org.hyperledger.fabric.protos.peer.ChaincodeShim.ChaincodeMessage;
+import org.hyperledger.fabric.protos.peer.ChaincodeShim.GetStateByRange;
+import org.hyperledger.fabric.protos.peer.ChaincodeShim.QueryResponse;
+import org.hyperledger.fabric.shim.ledger.KeyValue;
+import org.hyperledger.fabric.shim.ledger.QueryResultsIterator;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Nested;
+import org.junit.jupiter.api.Test;
+import org.mockito.ArgumentCaptor;
+
+public class InvocationStubImplTest {
+
+    private final String channelId = "mychannel";
+    private final String txId = "0xCAFEBABE";
+
+    @Nested
+    class GetStateByRangeTests {
+
+        private InvocationStubImpl stubImpl;
+        private ArgumentCaptor<ChaincodeMessage> chaincodeMessageCaptor;
+        private ChaincodeInvocationTask mockHandler;
+
+        @BeforeEach
+        public void beforeEach() throws Exception {
+            final ChaincodeMessage mockMessage = ChaincodeMessageFactory.newGetStateEventMessage(channelId, txId, "",
+                    "key");
+            mockHandler = mock(ChaincodeInvocationTask.class);
+            final ByteString mockString = QueryResponse.newBuilder().build().toByteString();
+
+            chaincodeMessageCaptor = ArgumentCaptor.forClass(ChaincodeMessage.class);
+
+            when(mockHandler.invoke(any())).thenReturn(mockString);
+            stubImpl = new InvocationStubImpl(mockMessage, mockHandler);
+        }
+
+        @Test
+        public void regular() throws InvalidProtocolBufferException {
+            final QueryResultsIterator<KeyValue> qri = stubImpl.getStateByRange("Aardvark", "Zebra");
+
+            verify(mockHandler).invoke(chaincodeMessageCaptor.capture());
+            assertThat(qri).isNotNull();
+
+            final ChaincodeMessage msg = chaincodeMessageCaptor.getValue();
+            assertThat(msg.getTxid()).isEqualTo("0xCAFEBABE");
+            assertThat(msg.getType()).isEqualTo(GET_STATE_BY_RANGE);
+
+            final GetStateByRange range = GetStateByRange.parseFrom(msg.getPayload());
+            assertThat(range.getStartKey()).isEqualTo("Aardvark");
+            assertThat(range.getEndKey()).isEqualTo("Zebra");
+        }
+
+        @Test
+        public void nullvalues() throws InvalidProtocolBufferException {
+            final QueryResultsIterator<KeyValue> qri = stubImpl.getStateByRange(null, null);
+
+            verify(mockHandler).invoke(chaincodeMessageCaptor.capture());
+            assertThat(qri).isNotNull();
+
+            final ChaincodeMessage msg = chaincodeMessageCaptor.getValue();
+            assertThat(msg.getTxid()).isEqualTo("0xCAFEBABE");
+            assertThat(msg.getType()).isEqualTo(GET_STATE_BY_RANGE);
+
+            final GetStateByRange range = GetStateByRange.parseFrom(msg.getPayload());
+
+            final String unspecifiedKey = new String(Character.toChars(0x000001));
+            assertThat(range.getStartKey()).isEqualTo(unspecifiedKey);
+            assertThat(range.getEndKey()).isEqualTo(unspecifiedKey);
+        }
+
+        @Test
+        public void unbounded() throws InvalidProtocolBufferException {
+            final QueryResultsIterator<KeyValue> qri = stubImpl.getStateByRange("", "");
+
+            verify(mockHandler).invoke(chaincodeMessageCaptor.capture());
+            assertThat(qri).isNotNull();
+
+            final ChaincodeMessage msg = chaincodeMessageCaptor.getValue();
+            assertThat(msg.getTxid()).isEqualTo("0xCAFEBABE");
+            assertThat(msg.getType()).isEqualTo(GET_STATE_BY_RANGE);
+
+            final GetStateByRange range = GetStateByRange.parseFrom(msg.getPayload());
+
+            assertThat(range.getStartKey()).isEqualTo("");
+            assertThat(range.getEndKey()).isEqualTo("");
+        }
+
+        @Test
+        public void simplekeys() {
+            assertThatThrownBy(() -> {
+                final QueryResultsIterator<KeyValue> qri = stubImpl
+                        .getStateByRange(new String(Character.toChars(Character.MIN_CODE_POINT)), "");
+            }).hasMessageContaining("not allowed");
+
+        }
+
+    }
+
+}