[JENKINS-59220] - Updated EnvVars to add a method that extends putAll functionality (#4194)

* Updated EnvVars to add a method that extends putAll functionality

* Updated method name

* Added test coverage

core/src/main/java/hudson/EnvVars.java

@@ -388,6 +388,15 @@ public class EnvVars extends TreeMap<String,String> {
         if (value!=null)
             put(key,value);
     }
+
+    /**
+     * Add entire map but filter null values out.
+     * @since TODO
+     */
+    public void putAllNonNull(Map<String, String> map) {
+        map.forEach(this::putIfNotNull);
+    }
+
     
     /**
      * Takes a string that looks like "a=b" and adds that to this map.

core/src/test/java/hudson/EnvVarsTest.java

@@ -23,19 +23,15 @@
  */
 package hudson;
 
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertTrue;
-
 import hudson.EnvVars.OverrideOrderCalculator;
 
-import java.util.Arrays;
-import java.util.Collections;
-import java.util.HashSet;
-import java.util.List;
+import java.util.*;
 
 import com.google.common.collect.Sets;
 import org.junit.Test;
 
+import static org.junit.Assert.*;
+
 /**
  * @author Kohsuke Kawaguchi
  */
@@ -140,4 +136,25 @@ public class EnvVarsTest {
         assertEquals(Arrays.asList("B", "A", "C"), order.subList(0, 3));
         assertEquals(Sets.newHashSet("E", "D"), new HashSet<>(order.subList(3, order.size())));
     }
+
+    @Test
+    public void putIfNotNull() {
+        EnvVars env = new EnvVars();
+        env.putIfNotNull("foo", null);
+        assertTrue(env.isEmpty());
+        env.putIfNotNull("foo", "bar");
+        assertFalse(env.isEmpty());
+    }
+
+    @Test
+    public void putAllNonNull() {
+        EnvVars env = new EnvVars();
+        TreeMap<String, String> map = new TreeMap<>();
+        map.put("A", "a");
+        map.put("B", null);
+        TreeMap<String, String> filteredMap = new TreeMap<>();
+        filteredMap.put("A", "a");
+        env.putAllNonNull(map);
+        assertEquals(filteredMap, env);
+    }
 }