Fix default value of targeting.hb_pb

Author: AntoxaAntoxic

src/main/java/org/prebid/server/auction/CpmRange.java

@@ -1,7 +1,6 @@
 package org.prebid.server.auction;
 
 import org.apache.commons.lang3.ObjectUtils;
-import org.apache.commons.lang3.StringUtils;
 import org.prebid.server.proto.openrtb.ext.request.ExtGranularityRange;
 import org.prebid.server.settings.model.Account;
 import org.prebid.server.settings.model.AccountAuctionConfig;
@@ -19,6 +18,8 @@
  */
 public class CpmRange {
 
+    public static final String DEFAULT_CPM = "0.0";
+
     private static final Locale LOCALE = Locale.US;
     private static final int DEFAULT_PRECISION = 2;
 
@@ -30,7 +31,7 @@ private CpmRange() {
      */
     public static String fromCpm(BigDecimal cpm, PriceGranularity priceGranularity, Account account) {
         final BigDecimal value = fromCpmAsNumber(cpm, priceGranularity, account);
-        return value != null ? format(value, priceGranularity.getPrecision()) : StringUtils.EMPTY;
+        return value != null ? format(value, priceGranularity.getPrecision()) : DEFAULT_CPM;
     }
 
     /**

src/main/java/org/prebid/server/auction/TargetingKeywordsCreator.java

@@ -77,8 +77,6 @@ public class TargetingKeywordsCreator {
      */
     private static final String FORMAT_KEY = "_format";
 
-    private static final String DEFAULT_CPM = "0.0";
-
     private final PriceGranularity priceGranularity;
     private final boolean includeWinners;
     private final boolean includeBidderKeys;
@@ -204,7 +202,7 @@ private Map<String, String> makeFor(String bidder,
 
         final String roundedCpm = isPriceGranularityValid()
                 ? CpmRange.fromCpm(price, priceGranularity, account)
-                : DEFAULT_CPM;
+                : CpmRange.DEFAULT_CPM;
 
         keywordMap.put(this.keyPrefix + PB_KEY, roundedCpm);
 

src/test/java/org/prebid/server/auction/CpmRangeTest.java

@@ -21,6 +21,20 @@
 
 public class CpmRangeTest {
 
+    @Test
+    public void fromCpmShouldReturnZeroValueIfPriceDoesNotFitToRange() {
+        // given
+        final PriceGranularity priceGranularity = createFromExtPriceGranularity(
+                ExtPriceGranularity.of(null, singletonList(ExtGranularityRange.of(BigDecimal.valueOf(3),
+                        BigDecimal.valueOf(0.01)))));
+
+        // when
+        final String result = CpmRange.fromCpm(BigDecimal.valueOf(-2.0), priceGranularity, givenAccount());
+
+        // then
+        assertThat(result).isEqualTo("0.0");
+    }
+
     @Test
     public void fromCpmShouldReturnMaxRangeIfCpmExceedsIt() {
         assertThat(CpmRange.fromCpm(BigDecimal.valueOf(21), createFromString("auto"), givenAccount()))