Iss. #65 - Fix error caused by no project match in validation req

src/main/java/org/eclipsefoundation/git/eca/helper/CommitHelper.java

@@ -15,6 +15,7 @@ import java.util.stream.Collectors;
 import javax.ws.rs.core.MultivaluedMap;
 
 import org.eclipsefoundation.git.eca.model.Commit;
+import org.eclipsefoundation.git.eca.model.Project;
 import org.eclipsefoundation.git.eca.model.ValidationRequest;
 import org.eclipsefoundation.git.eca.namespace.GitEcaParameterNames;
 import org.jboss.resteasy.specimpl.MultivaluedMapImpl;
@@ -63,10 +64,22 @@ public class CommitHelper {
     public static MultivaluedMap<String, String> getCommitParams(List<String> commitShas, String projectId, String repoUrl) {
         MultivaluedMap<String, String> params = new MultivaluedMapImpl<>();
         params.put(GitEcaParameterNames.SHAS_RAW, commitShas);
-        params.add(GitEcaParameterNames.PROJECT_ID_RAW, projectId);
         params.add(GitEcaParameterNames.REPO_URL_RAW, repoUrl);
+        if (projectId != null) {
+            params.add(GitEcaParameterNames.PROJECT_ID_RAW, projectId);
+        }
         return params;
     }
+    
+    /**
+     * Centralized way of retrieving a checked project ID from a project for use when interacting with commits and commit data.
+     * 
+     * @param p the current project to attempt to retrieve an ID from
+     * @return the project ID or the given default (empty string).
+     */
+    public static String getProjectId(Project p) {
+        return p != null ? p.getProjectId() : "";
+    }
 
     private CommitHelper() {
     }

[Mikaël Barbero]

why not making Project#getProjectId returning an Optional<String> instead? It would prevent forgetting from calling the CommitHelper#getProjectId static method.

[Martin Lowe]

I did it that way so that downstream wouldn't need to know that the default is never null. This way if its null, it passes back empty string.