use Optional for null safety and add a test for null versions coming from API

Author: rantoniuk

src/main/java/hudson/plugins/jira/JiraSession.java

@@ -1,5 +1,19 @@
 package hudson.plugins.jira;
 
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.Optional;
+import java.util.Set;
+import java.util.concurrent.TimeoutException;
+import java.util.logging.Logger;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+import org.apache.commons.lang.StringUtils;
 import static org.apache.commons.lang.StringUtils.isNotEmpty;
 
 import com.atlassian.jira.rest.client.api.domain.BasicIssue;
@@ -11,23 +25,11 @@
 import com.atlassian.jira.rest.client.api.domain.Status;
 import com.atlassian.jira.rest.client.api.domain.Transition;
 import com.atlassian.jira.rest.client.api.domain.Version;
+
 import edu.umd.cs.findbugs.annotations.NonNull;
 import edu.umd.cs.findbugs.annotations.Nullable;
 import hudson.plugins.jira.extension.ExtendedVersion;
 import hudson.plugins.jira.model.JiraIssueField;
-import java.util.ArrayList;
-import java.util.Collections;
-import java.util.HashMap;
-import java.util.HashSet;
-import java.util.List;
-import java.util.Map;
-import java.util.Optional;
-import java.util.Set;
-import java.util.concurrent.TimeoutException;
-import java.util.logging.Logger;
-import java.util.regex.Matcher;
-import java.util.regex.Pattern;
-import org.apache.commons.lang.StringUtils;
 
 /**
  * Connection to Jira.
@@ -268,7 +270,7 @@ public void replaceFixVersion(String projectKey, String fromVersion, String toVe
             newVersions.add(newVersion);
 
             Iterable<Version> issueVersions =
-                    Optional.of(issue.getFixVersions()).orElse(Collections.emptyList());
+                    Optional.ofNullable(issue.getFixVersions()).orElse(Collections.emptyList());
             LOGGER.fine(String.format("[%s] current versions: %s", issue.getKey(), issueVersions));
 
             if (StringUtils.startsWith(fromVersion, "/") && StringUtils.endsWith(fromVersion, "/")) {
@@ -323,7 +325,7 @@ public void addFixVersion(String projectKey, String version, String query) throw
             LOGGER.fine("Adding version: " + newVersion.getName() + " to issue: " + issue.getKey());
             List<Version> fixVersions = new ArrayList<>();
 
-            Optional.of(issue.getFixVersions()).orElse(Collections.emptyList()).forEach(fixVersions::add);
+            Optional.ofNullable(issue.getFixVersions()).orElse(Collections.emptyList()).forEach(fixVersions::add);
 
             fixVersions.add(newVersion);
             service.updateIssue(issue.getKey(), fixVersions);

src/test/java/hudson/plugins/jira/JiraSessionTest.java

@@ -1,17 +1,5 @@
 package hudson.plugins.jira;
 
-import static org.hamcrest.MatcherAssert.assertThat;
-import static org.hamcrest.Matchers.equalTo;
-import static org.hamcrest.Matchers.hasItem;
-import static org.hamcrest.Matchers.hasProperty;
-import static org.mockito.Mockito.spy;
-import static org.mockito.Mockito.times;
-import static org.mockito.Mockito.verify;
-import static org.mockito.Mockito.when;
-
-import com.atlassian.jira.rest.client.api.domain.Issue;
-import com.atlassian.jira.rest.client.api.domain.Version;
-import hudson.plugins.jira.extension.ExtendedVersion;
 import java.io.IOException;
 import java.net.URI;
 import java.net.URISyntaxException;
@@ -20,13 +8,27 @@
 import java.util.List;
 import java.util.concurrent.ThreadLocalRandom;
 import java.util.concurrent.TimeoutException;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.equalTo;
+import static org.hamcrest.Matchers.hasItem;
+import static org.hamcrest.Matchers.hasProperty;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.extension.ExtendWith;
 import org.mockito.ArgumentCaptor;
 import org.mockito.Mock;
+import static org.mockito.Mockito.spy;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
 import org.mockito.junit.jupiter.MockitoExtension;
 
+import com.atlassian.jira.rest.client.api.domain.Issue;
+import com.atlassian.jira.rest.client.api.domain.Version;
+
+import hudson.plugins.jira.extension.ExtendedVersion;
+
 @ExtendWith(MockitoExtension.class)
 class JiraSessionTest {
 
@@ -63,7 +65,7 @@ void replaceWithFixVersionByRegex() throws URISyntaxException, TimeoutException
 
         ArgumentCaptor<String> issueKeys = ArgumentCaptor.forClass(String.class);
         ArgumentCaptor<List> versionList = ArgumentCaptor.forClass(List.class);
-        verify(service, times(2)).updateIssue(issueKeys.capture(), versionList.capture());
+        verify(service, times(issues.size())).updateIssue(issueKeys.capture(), versionList.capture());
 
         // First Issue, current FixVersion replaced by new one
         assertThat(issueKeys.getAllValues().get(0), equalTo(issues.get(0).getKey()));
@@ -95,13 +97,14 @@ void replaceFixVersion() throws URISyntaxException, TimeoutException {
         ArrayList<Issue> issues = new ArrayList<>();
         issues.add(getIssue(Arrays.asList("v1.0"), 1L));
         issues.add(getIssue(Arrays.asList("v1.0", "v1.0.0", "v2.0.0"), 2L));
+        issues.add(getIssue(null, 3L));
         when(service.getIssuesFromJqlSearch(QUERY, JiraSession.MAX_ISSUES)).thenReturn(issues);
 
         jiraSession.replaceFixVersion(PROJECT_KEY, "v1.0", newVersion.getName(), QUERY);
 
         ArgumentCaptor<String> issueKeys = ArgumentCaptor.forClass(String.class);
         ArgumentCaptor<List> versionList = ArgumentCaptor.forClass(List.class);
-        verify(service, times(2)).updateIssue(issueKeys.capture(), versionList.capture());
+        verify(service, times(issues.size())).updateIssue(issueKeys.capture(), versionList.capture());
 
         // First Issue, current FixVersion replaced by new one
         assertThat(issueKeys.getAllValues().get(0), equalTo(issues.get(0).getKey()));
@@ -116,16 +119,23 @@ void replaceFixVersion() throws URISyntaxException, TimeoutException {
         assertThat(secondIssueUpdatedFixVersions, hasItem(hasProperty("name", equalTo(newVersion.getName()))));
         assertThat(secondIssueUpdatedFixVersions, hasItem(hasProperty("name", equalTo("v1.0.0"))));
         assertThat(secondIssueUpdatedFixVersions, hasItem(hasProperty("name", equalTo("v2.0.0"))));
+
+        // Third Issue, no FixVersion, new fixVersion added.
+        List<Version> thirdIssueVersions = versionList.getAllValues().get(2);
+        assertThat(thirdIssueVersions.size(), equalTo(1));
+        assertThat(thirdIssueVersions.get(0), equalTo(newVersion));
+
     }
 
     private Issue getIssue(List<String> versions, long id) throws URISyntaxException {
-        List<Version> fixVersions = new ArrayList<>();
+        List<Version> fixVersions = null;
         if (versions != null) {
+            fixVersions = new ArrayList<>();
             for (String fixVersion : versions) {
                 fixVersions.add(new Version(
                         new URI("self"), ThreadLocalRandom.current().nextLong(), fixVersion, null, false, false, null));
             }
-        }
+        } 
 
         return new Issue(
                 "",