added test

Author: raydac

jbbp/src/test/java/com/igormaznitsa/jbbp/io/JBBPBitInputStreamTest.java

@@ -40,6 +40,7 @@
 import java.io.EOFException;
 import java.io.IOException;
 import java.util.Random;
+import java.util.function.Supplier;
 import org.apache.commons.lang3.tuple.Pair;
 import org.junit.jupiter.api.Test;
 
@@ -70,6 +71,38 @@ private static JBBPBitInputStream asInputStreamMSB0(final int... array) {
         JBBPBitOrder.MSB0);
   }
 
+  @Test
+  public void testIsDetectedPartlyReadBitField() throws Exception {
+    final Supplier<JBBPBitInputStream> oneByteStream =
+        () -> new JBBPBitInputStream(new ByteArrayInputStream(new byte[] {1}));
+    final Supplier<JBBPBitInputStream> oneByteStreamNoAccumulated =
+        () -> new JBBPBitInputStream(new ByteArrayInputStream(new byte[] {1}), false);
+
+    JBBPBitInputStream in = oneByteStream.get();
+    assertFalse(in.isDetectedPartlyReadBitField());
+    in.read();
+    assertFalse(in.isDetectedPartlyReadBitField());
+
+    in = oneByteStream.get();
+    assertFalse(in.isDetectedPartlyReadBitField());
+    in.readBits(BITS_1);
+    assertFalse(in.isDetectedPartlyReadBitField());
+    in.read();
+    assertTrue(in.isDetectedPartlyReadBitField());
+
+    in = oneByteStreamNoAccumulated.get();
+    assertFalse(in.isDetectedPartlyReadBitField());
+    in.read();
+    assertFalse(in.isDetectedPartlyReadBitField());
+
+    in = oneByteStreamNoAccumulated.get();
+    assertFalse(in.isDetectedPartlyReadBitField());
+    in.readBits(BITS_1);
+    assertFalse(in.isDetectedPartlyReadBitField());
+    in.read();
+    assertTrue(in.isDetectedPartlyReadBitField());
+  }
+
   @Test
   public void testReadMsb0Direct() throws Exception {
     byte[] data = str2bin("00000001_101_00001000_00000_01_00_1011_00000");