SOP: Properly return error codes to the caller, error code 37 for invalid input args

pgpainless-sop/src/main/java/org/pgpainless/sop/PGPainlessCLI.java

@@ -26,7 +26,7 @@ import org.pgpainless.sop.commands.Verify;
 import org.pgpainless.sop.commands.Version;
 import picocli.CommandLine;
 
-@CommandLine.Command(
+@CommandLine.Command(exitCodeOnInvalidInput = 69,
         subcommands = {
                 Armor.class,
                 Dearmor.class,
@@ -41,8 +41,14 @@ import picocli.CommandLine;
 )
 public class PGPainlessCLI implements Runnable {
 
+    public PGPainlessCLI() {
+
+    }
+
     public static void main(String[] args) {
-        CommandLine.run(new PGPainlessCLI(), args);
+        int code = new CommandLine(new PGPainlessCLI())
+                .execute(args);
+        System.exit(code);
     }
 
     @Override

pgpainless-sop/src/main/java/org/pgpainless/sop/commands/Armor.java

@@ -28,7 +28,8 @@ import java.util.Arrays;
 import static org.pgpainless.sop.Print.err_ln;
 
 @CommandLine.Command(name = "armor",
-        description = "Add ASCII Armor to standard input")
+        description = "Add ASCII Armor to standard input",
+        exitCodeOnInvalidInput = 37)
 public class Armor implements Runnable {
 
     private static final byte[] BEGIN_ARMOR = "-----BEGIN PGP".getBytes(StandardCharsets.UTF_8);

pgpainless-sop/src/main/java/org/pgpainless/sop/commands/Dearmor.java

@@ -24,7 +24,8 @@ import java.io.IOException;
 import static org.pgpainless.sop.Print.err_ln;
 
 @CommandLine.Command(name = "dearmor",
-        description = "Remove ASCII Armor from standard input")
+        description = "Remove ASCII Armor from standard input",
+        exitCodeOnInvalidInput = 37)
 public class Dearmor implements Runnable {
 
     @Override

pgpainless-sop/src/main/java/org/pgpainless/sop/commands/Decrypt.java

@@ -43,7 +43,8 @@ import org.pgpainless.key.OpenPgpV4Fingerprint;
 import picocli.CommandLine;
 
 @CommandLine.Command(name = "decrypt",
-        description = "Decrypt a message from standard input")
+        description = "Decrypt a message from standard input",
+        exitCodeOnInvalidInput = 37)
 public class Decrypt implements Runnable {
 
     private static final DateFormat df = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm'Z'");

pgpainless-sop/src/main/java/org/pgpainless/sop/commands/Encrypt.java

@@ -44,7 +44,8 @@ import org.pgpainless.util.Passphrase;
 import picocli.CommandLine;
 
 @CommandLine.Command(name = "encrypt",
-        description = "Encrypt a message from standard input")
+        description = "Encrypt a message from standard input",
+        exitCodeOnInvalidInput = 37)
 public class Encrypt implements Runnable {
 
     public enum Type {

pgpainless-sop/src/main/java/org/pgpainless/sop/commands/ExtractCert.java

@@ -29,7 +29,8 @@ import org.pgpainless.sop.Print;
 import picocli.CommandLine;
 
 @CommandLine.Command(name = "extract-cert",
-        description = "Extract a public key certificate from a secret key from standard input")
+        description = "Extract a public key certificate from a secret key from standard input",
+        exitCodeOnInvalidInput = 37)
 public class ExtractCert implements Runnable {
 
     @CommandLine.Option(names = "--no-armor",

pgpainless-sop/src/main/java/org/pgpainless/sop/commands/GenerateKey.java

@@ -38,7 +38,9 @@ import picocli.CommandLine;
 import static org.pgpainless.sop.Print.err_ln;
 import static org.pgpainless.sop.Print.print_ln;
 
-@CommandLine.Command(name = "generate-key", description = "Generate a secret key")
+@CommandLine.Command(name = "generate-key",
+        description = "Generate a secret key",
+        exitCodeOnInvalidInput = 37)
 public class GenerateKey implements Runnable {
 
     @CommandLine.Option(names = "--no-armor",
@@ -51,6 +53,12 @@ public class GenerateKey implements Runnable {
 
     @Override
     public void run() {
+        if (userId.isEmpty()) {
+            print_ln("At least one user-id expected.");
+            System.exit(1);
+            return;
+        }
+
         try {
             KeyRingBuilderInterface.WithAdditionalUserIdOrPassphrase builder = PGPainless.generateKeyRing()
                     .withSubKey(KeySpec.getBuilder(KeyType.EDDSA(EdDSACurve._Ed25519))
@@ -64,12 +72,6 @@ public class GenerateKey implements Runnable {
                             .withDefaultAlgorithms())
                     .withPrimaryUserId(userId.get(0));
 
-            if (userId.isEmpty()) {
-                print_ln("At least one user-id expected.");
-                System.exit(1);
-                return;
-            }
-
             for (int i = 1; i < userId.size(); i++) {
                 builder.withAdditionalUserId(userId.get(i));
             }

pgpainless-sop/src/main/java/org/pgpainless/sop/commands/Sign.java

@@ -35,7 +35,8 @@ import static org.pgpainless.sop.Print.err_ln;
 import static org.pgpainless.sop.Print.print_ln;
 
 @CommandLine.Command(name = "sign",
-        description = "Create a detached signature on the data from standard input")
+        description = "Create a detached signature on the data from standard input",
+        exitCodeOnInvalidInput = 37)
 public class Sign implements Runnable {
 
     public enum Type {

pgpainless-sop/src/main/java/org/pgpainless/sop/commands/Verify.java

@@ -43,7 +43,8 @@ import static org.pgpainless.sop.Print.err_ln;
 import static org.pgpainless.sop.Print.print_ln;
 
 @CommandLine.Command(name = "verify",
-        description = "Verify a detached signature over the data from standard input")
+        description = "Verify a detached signature over the data from standard input",
+        exitCodeOnInvalidInput = 37)
 public class Verify implements Runnable {
 
     private static final TimeZone tz = TimeZone.getTimeZone("UTC");

pgpainless-sop/src/main/java/org/pgpainless/sop/commands/Version.java

@@ -22,7 +22,8 @@ import java.util.Properties;
 
 import picocli.CommandLine;
 
-@CommandLine.Command(name = "version", description = "Display version information about the tool")
+@CommandLine.Command(name = "version", description = "Display version information about the tool",
+        exitCodeOnInvalidInput = 37)
 public class Version implements Runnable {
 
     @Override

pgpainless-sop/src/test/java/org/pgpainless/sop/ExitCodeTest.java

@@ -0,0 +1,39 @@
+/*
+ * 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 org.pgpainless.sop;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import org.junit.jupiter.api.Test;
+import picocli.CommandLine;
+
+public class ExitCodeTest {
+
+    @Test
+    public void testUnknownCommand_69() {
+        assertEquals(69, new CommandLine(new PGPainlessCLI()).execute("generate-kex"));
+    }
+
+    @Test
+    public void testCommandWithUnknownOption_37() {
+        assertEquals(37, new CommandLine(new PGPainlessCLI()).execute("generate-key", "-k", "\"k is unknown\""));
+    }
+
+    @Test
+    public void successfulVersion_0 () {
+        assertEquals(0, new CommandLine(new PGPainlessCLI()).execute("version"));
+    }
+}