fix: Types.BOOLEAN and Types.BIT should have identical behaviour for nullability (#920)

* Types.BOOLEAN and Types.BIT should have identical behaviour for nullability. In master, BOOLEAN is nullable but BIT will throw IllegalArgumentException if an attempt is made to set a null value. * fix: Types.BOOLEAN and Types.BIT should have identical behaviour for nullability. In master, BOOLEAN is nullable but BIT will throw IllegalArgumentException if an attempt is made to set a null value.

Author: Clamatius

src/main/java/com/google/cloud/spanner/jdbc/JdbcParameterStore.java

@@ -858,6 +858,7 @@ private Builder setNullValue(ValueBinder<Builder> binder, Integer sqlType) {
  return binder.to((ByteArray) null);
  case Types.BLOB:
  return binder.to((ByteArray) null);
+ case Types.BIT:
  case Types.BOOLEAN:
  return binder.to((Boolean) null);
  case Types.CHAR:

src/test/java/com/google/cloud/spanner/jdbc/JdbcParameterStoreTest.java

@@ -18,6 +18,7 @@
 
 import static org.junit.Assert.assertArrayEquals;
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
 import static org.junit.Assume.assumeTrue;
@@ -379,6 +380,9 @@ public void testSetParameterWithType() throws SQLException, IOException {
  params.setParameter(1, BigDecimal.ZERO, type);
  assertEquals(BigDecimal.ZERO, params.getParameter(1));
  verifyParameter(params, Value.bool(false));
+ params.setParameter(1, null, type);
+ assertNull(params.getParameter(1));
+ verifyParameter(params, Value.bool(null));
  }
 
  // types that should lead to numeric