Merge pull request #23 from adarshsharma/adarsh_master

Author: quen2404

src/main/java/com/qdesrame/openapi/diff/compare/OpenApiDiff.java

@@ -14,6 +14,8 @@
 import java.util.Optional;
 import java.util.stream.Collectors;
 
+import static com.qdesrame.openapi.diff.compare.PathsDiff.valOrEmpty;
+
 public class OpenApiDiff {
 
     public static final String SWAGGER_VERSION_V2 = "2.0";
@@ -87,7 +89,7 @@ private void initializeFields() {
     private ChangedOpenApi compare() {
         preProcess(oldSpecOpenApi);
         preProcess(newSpecOpenApi);
-        Optional<ChangedPaths> paths = this.pathsDiff.diff(oldSpecOpenApi.getPaths(), newSpecOpenApi.getPaths());
+        Optional<ChangedPaths> paths = this.pathsDiff.diff(valOrEmpty(oldSpecOpenApi.getPaths()), valOrEmpty(newSpecOpenApi.getPaths()));
         this.newEndpoints = new ArrayList<>();
         this.missingEndpoints = new ArrayList<>();
         this.changedOperations = new ArrayList<>();

src/main/java/com/qdesrame/openapi/diff/compare/PathsDiff.java

@@ -2,6 +2,7 @@
 
 import com.qdesrame.openapi.diff.model.ChangedPaths;
 import io.swagger.v3.oas.models.PathItem;
+import io.swagger.v3.oas.models.Paths;
 
 import java.util.*;
 import java.util.regex.Matcher;
@@ -53,4 +54,11 @@ public Optional<ChangedPaths> diff(final Map<String, PathItem> left, final Map<S
         });
         return changedPaths.isDiff() ? Optional.of(changedPaths) : Optional.empty();
     }
+
+    public static Paths valOrEmpty(Paths path) {
+        if (path == null) {
+            path = new Paths();
+        }
+        return path;
+    }
 }