add fail-on-incompatible option

README.md

@@ -76,6 +76,7 @@ usage: openapi-diff <old> <new>
     --query <property=value>    use query param for authorisation
     --state                     Only output diff state: no_changes,
                                 incompatible, compatible
+    --fail-on-incompatible      Fail only if API changes broke backward compatibility
     --trace                     be extra verbose
     --version                   print the version information and exit
     --warn                      Print warning information

src/main/java/com/qdesrame/openapi/diff/Main.java

@@ -28,6 +28,11 @@ public static void main(String... args) {
             .longOpt("state")
             .desc("Only output diff state: no_changes, incompatible, compatible")
             .build());
+    options.addOption(
+        Option.builder()
+            .longOpt("fail-on-incompatible")
+            .desc("Fail only if API changes broke backward compatibility")
+            .build());
     options.addOption(Option.builder().longOpt("trace").desc("be extra verbose").build());
     options.addOption(
         Option.builder().longOpt("debug").desc("Print debugging information").build());
@@ -179,6 +184,8 @@ public static void main(String... args) {
       if (line.hasOption("state")) {
         System.out.println(result.isChanged().getValue());
         System.exit(0);
+      } else if (line.hasOption("fail-on-incompatible")) {
+        System.exit(result.isCompatible() ? 0 : 1);
       } else {
         System.exit(result.isUnchanged() ? 0 : 1);
       }