Fix IOOBE when converting empty bytes to a UTF8 String (#32)

Signed-off-by: Richard Bair <[email protected]>
hashgraph · Apr 11, 2023 · fe97298 · fe97298
1 parent dcb0e74
commit fe97298
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Showing 3 changed files with 33 additions and 10 deletions.
diff --git a/pbj-core/pbj-runtime/src/main/java/com/hedera/pbj/runtime/io/buffer/RandomAccessData.java b/pbj-core/pbj-runtime/src/main/java/com/hedera/pbj/runtime/io/buffer/RandomAccessData.java
@@ -461,7 +461,7 @@ default String asUtf8String(final long offset, final long len) {
             throw new BufferUnderflowException();
         }
 
-        if (offset < 0 || offset >= length()) {
+        if (offset < 0 || offset + len > length()) {
             throw new IndexOutOfBoundsException();
         }
 

diff --git a/pbj-core/pbj-runtime/src/test/java/com/hedera/pbj/runtime/io/buffer/BytesTest.java b/pbj-core/pbj-runtime/src/test/java/com/hedera/pbj/runtime/io/buffer/BytesTest.java
@@ -3,6 +3,10 @@
 import com.hedera.pbj.runtime.io.ReadableSequentialData;
 import com.hedera.pbj.runtime.io.ReadableTestBase;
 import edu.umd.cs.findbugs.annotations.NonNull;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.ValueSource;
+import java.nio.charset.StandardCharsets;
+import static org.assertj.core.api.Assertions.assertThat;
 
 public class BytesTest extends ReadableTestBase {
 
@@ -25,4 +29,11 @@ protected ReadableSequentialData fullyUsedSequence() {
     protected ReadableSequentialData sequence(@NonNull final byte[] arr) {
         return Bytes.wrap(arr).toReadableSequentialData();
     }
+
+    @ParameterizedTest
+    @ValueSource(strings = { "", "a", "ab", "abc", "✅" })
+    void utf8Strings(final String s) {
+        final var buf = Bytes.wrap(s.getBytes(StandardCharsets.UTF_8));
+        assertThat(buf.asUtf8String()).isEqualTo(s);
+    }
 }
diff --git a/...core/pbj-runtime/src/test/java/com/hedera/pbj/runtime/io/buffer/RandomAccessDataTest.java b/...core/pbj-runtime/src/test/java/com/hedera/pbj/runtime/io/buffer/RandomAccessDataTest.java
@@ -3,6 +3,11 @@
 import com.hedera.pbj.runtime.io.ReadableSequentialData;
 import com.hedera.pbj.runtime.io.ReadableTestBase;
 import edu.umd.cs.findbugs.annotations.NonNull;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.ValueSource;
+import java.nio.charset.StandardCharsets;
+import static org.assertj.core.api.Assertions.assertThat;
 
 public class RandomAccessDataTest extends ReadableTestBase {
 
@@ -26,15 +31,22 @@ protected ReadableSequentialData sequence(@NonNull final byte[] arr) {
         return new RandomAccessSequenceAdapter(new StubbedRandomAccessData(arr));
     }
 
+    @ParameterizedTest
+    @ValueSource(strings = { "", "a", "ab", "abc", "✅" })
+    void utf8Strings(final String s) {
+        final var buf = new StubbedRandomAccessData(s.getBytes(StandardCharsets.UTF_8));
+        assertThat(buf.asUtf8String()).isEqualTo(s);
+    }
+
     private record StubbedRandomAccessData(@NonNull byte[] bytes) implements RandomAccessData {
-            @Override
-            public long length() {
-                return bytes.length;
-            }
-
-            @Override
-            public byte getByte(long offset) {
-                return bytes[Math.toIntExact(offset)];
-            }
+        @Override
+        public long length() {
+            return bytes.length;
         }
+
+        @Override
+        public byte getByte(long offset) {
+            return bytes[Math.toIntExact(offset)];
+        }
+    }
 }