Wip: Adopt changes from the SOP specification version 2

sop-java-picocli/src/main/java/sop/cli/picocli/SOPExceptionExitCodeMapper.java

@@ -0,0 +1,45 @@
+/*
+ * Copyright 2021 Paul Schaub.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package sop.cli.picocli;
+
+import picocli.CommandLine;
+import sop.exception.SOPGPException;
+
+public class SOPExceptionExitCodeMapper implements CommandLine.IExitCodeExceptionMapper {
+
+    @Override
+    public int getExitCode(Throwable exception) {
+        if (exception instanceof SOPGPException) {
+            return ((SOPGPException) exception).getExitCode();
+        }
+        if (exception instanceof CommandLine.UnmatchedArgumentException) {
+            CommandLine.UnmatchedArgumentException ex = (CommandLine.UnmatchedArgumentException) exception;
+            // Unmatched option of subcommand (eg. `generate-key -k`)
+            if (ex.isUnknownOption()) {
+                return SOPGPException.UnsupportedOption.EXIT_CODE;
+            }
+            // Unmatched subcommand
+            return SOPGPException.UnsupportedSubcommand.EXIT_CODE;
+        }
+        // Invalid option (eg. `--label Invalid`)
+        if (exception instanceof CommandLine.ParameterException) {
+            return SOPGPException.UnsupportedOption.EXIT_CODE;
+        }
+
+        // Others, like IOException etc.
+        return 1;
+    }
+}