Remove deprecated junit5-system-exit

Replaced with custom test DSL that avoids System.exit

sop-java-picocli/build.gradle

@@ -12,15 +12,12 @@ dependencies {
     testImplementation "org.junit.jupiter:junit-jupiter-api:$junitVersion"
     testRuntimeOnly "org.junit.jupiter:junit-jupiter-engine:$junitVersion"
 
-    // Testing Exit Codes in JUnit
-    // https://todd.ginsberg.com/post/testing-system-exit/
-    testImplementation "com.ginsberg:junit5-system-exit:$junitSysExitVersion"
-
     // Mocking Components
     testImplementation "org.mockito:mockito-core:$mockitoVersion"
 
     // SOP
     implementation(project(":sop-java"))
+    testImplementation(testFixtures(project(":sop-java")))
 
     // CLI
     implementation "info.picocli:picocli:$picocliVersion"

sop-java-picocli/src/test/java/sop/cli/picocli/SOPTest.java

@@ -6,12 +6,13 @@ package sop.cli.picocli;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.mockito.Mockito.mock;
+import static sop.testsuite.assertions.SopExecutionAssertions.assertGenericError;
+import static sop.testsuite.assertions.SopExecutionAssertions.assertUnsupportedSubcommand;
 
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
 
-import com.ginsberg.junit.exit.ExpectSystemExitWithStatus;
 import org.junit.jupiter.api.Test;
 import sop.SOP;
 import sop.exception.SOPGPException;
@@ -34,20 +35,18 @@ import sop.operation.Version;
 public class SOPTest {
 
     @Test
-    @ExpectSystemExitWithStatus(SOPGPException.UnsupportedSubcommand.EXIT_CODE)
     public void assertExitOnInvalidSubcommand() {
         SOP sop = mock(SOP.class);
         SopCLI.setSopInstance(sop);
 
-        SopCLI.main(new String[] {"invalid"});
+        assertUnsupportedSubcommand(() -> SopCLI.execute("invalid"));
     }
 
     @Test
-    @ExpectSystemExitWithStatus(1)
     public void assertThrowsIfNoSOPBackendSet() {
         SopCLI.setSopInstance(null);
-        // At this point, no SOP backend is set, so an InvalidStateException triggers exit(1)
+        // At this point, no SOP backend is set, so an InvalidStateException triggers error code 1
-        SopCLI.main(new String[] {"armor"});
+        assertGenericError(() -> SopCLI.execute("armor"));
     }
 
     @Test

sop-java-picocli/src/test/java/sop/cli/picocli/commands/ArmorCmdTest.java

@@ -4,8 +4,6 @@
 
 package sop.cli.picocli.commands;
 
-import com.ginsberg.junit.exit.ExpectSystemExitWithStatus;
-import com.ginsberg.junit.exit.FailOnSystemExit;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 import sop.Ready;
@@ -24,6 +22,8 @@ import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
+import static sop.testsuite.assertions.SopExecutionAssertions.assertBadData;
+import static sop.testsuite.assertions.SopExecutionAssertions.assertSuccess;
 
 public class ArmorCmdTest {
 
@@ -42,24 +42,22 @@ public class ArmorCmdTest {
 
     @Test
     public void assertDataIsAlwaysCalled() throws SOPGPException.BadData, IOException {
-        SopCLI.main(new String[] {"armor"});
+        assertSuccess(() -> SopCLI.execute("armor"));
         verify(armor, times(1)).data((InputStream) any());
     }
 
     @Test
-    @ExpectSystemExitWithStatus(SOPGPException.BadData.EXIT_CODE)
     public void ifBadDataExit41() throws SOPGPException.BadData, IOException {
         when(armor.data((InputStream) any())).thenThrow(new SOPGPException.BadData(new IOException()));
 
-        SopCLI.main(new String[] {"armor"});
+        assertBadData(() -> SopCLI.execute("armor"));
     }
 
     @Test
-    @FailOnSystemExit
     public void ifNoErrorsNoExit() {
         when(sop.armor()).thenReturn(armor);
 
-        SopCLI.main(new String[] {"armor"});
+        assertSuccess(() -> SopCLI.execute("armor"));
     }
 
     private static Ready nopReady() {

sop-java-picocli/src/test/java/sop/cli/picocli/commands/DearmorCmdTest.java

@@ -9,12 +9,13 @@ import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
+import static sop.testsuite.assertions.SopExecutionAssertions.assertBadData;
+import static sop.testsuite.assertions.SopExecutionAssertions.assertSuccess;
 
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
 
-import com.ginsberg.junit.exit.ExpectSystemExitWithStatus;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 import sop.Ready;
@@ -48,14 +49,13 @@ public class DearmorCmdTest {
 
     @Test
     public void assertDataIsCalled() throws IOException, SOPGPException.BadData {
-        SopCLI.main(new String[] {"dearmor"});
+        assertSuccess(() -> SopCLI.execute("dearmor"));
         verify(dearmor, times(1)).data((InputStream) any());
     }
 
     @Test
-    @ExpectSystemExitWithStatus(SOPGPException.BadData.EXIT_CODE)
     public void assertBadDataCausesExit41() throws IOException, SOPGPException.BadData {
         when(dearmor.data((InputStream) any())).thenThrow(new SOPGPException.BadData(new IOException("invalid armor")));
-        SopCLI.main(new String[] {"dearmor"});
+        assertBadData(() -> SopCLI.execute("dearmor"));
     }
 }

sop-java-picocli/src/test/java/sop/cli/picocli/commands/DecryptCmdTest.java

@@ -4,7 +4,6 @@
 
 package sop.cli.picocli.commands;
 
-import com.ginsberg.junit.exit.ExpectSystemExitWithStatus;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 import org.mockito.ArgumentMatcher;
@@ -42,6 +41,18 @@ import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
+import static sop.testsuite.assertions.SopExecutionAssertions.assertBadData;
+import static sop.testsuite.assertions.SopExecutionAssertions.assertCannotDecrypt;
+import static sop.testsuite.assertions.SopExecutionAssertions.assertGenericError;
+import static sop.testsuite.assertions.SopExecutionAssertions.assertIncompleteVerification;
+import static sop.testsuite.assertions.SopExecutionAssertions.assertKeyIsProtected;
+import static sop.testsuite.assertions.SopExecutionAssertions.assertMissingArg;
+import static sop.testsuite.assertions.SopExecutionAssertions.assertMissingInput;
+import static sop.testsuite.assertions.SopExecutionAssertions.assertOutputExists;
+import static sop.testsuite.assertions.SopExecutionAssertions.assertPasswordNotHumanReadable;
+import static sop.testsuite.assertions.SopExecutionAssertions.assertSuccess;
+import static sop.testsuite.assertions.SopExecutionAssertions.assertUnsupportedAsymmetricAlgo;
+import static sop.testsuite.assertions.SopExecutionAssertions.assertUnsupportedOption;
 
 public class DecryptCmdTest {
 
@@ -74,47 +85,47 @@ public class DecryptCmdTest {
     }
 
     @Test
-    @ExpectSystemExitWithStatus(SOPGPException.MissingArg.EXIT_CODE)
     public void missingArgumentsExceptionCausesExit19() throws SOPGPException.MissingArg, SOPGPException.BadData, SOPGPException.CannotDecrypt, IOException {
         when(decrypt.ciphertext((InputStream) any())).thenThrow(new SOPGPException.MissingArg("Missing arguments."));
-        SopCLI.main(new String[] {"decrypt"});
+        assertMissingArg(() -> SopCLI.execute("decrypt"));
     }
 
     @Test
-    @ExpectSystemExitWithStatus(SOPGPException.BadData.EXIT_CODE)
     public void badDataExceptionCausesExit41() throws SOPGPException.MissingArg, SOPGPException.BadData, SOPGPException.CannotDecrypt, IOException {
         when(decrypt.ciphertext((InputStream) any())).thenThrow(new SOPGPException.BadData(new IOException()));
-        SopCLI.main(new String[] {"decrypt"});
+        assertBadData(() -> SopCLI.execute("decrypt"));
     }
 
     @Test
-    @ExpectSystemExitWithStatus(SOPGPException.PasswordNotHumanReadable.EXIT_CODE)
     public void assertNotHumanReadablePasswordCausesExit31() throws SOPGPException.PasswordNotHumanReadable,
             SOPGPException.UnsupportedOption, IOException {
         File passwordFile = TestFileUtil.writeTempStringFile("pretendThisIsNotReadable");
         when(decrypt.withPassword(any())).thenThrow(new SOPGPException.PasswordNotHumanReadable());
-        SopCLI.main(new String[] {"decrypt", "--with-password", passwordFile.getAbsolutePath()});
+        assertPasswordNotHumanReadable(() ->
+                SopCLI.execute("decrypt", "--with-password", passwordFile.getAbsolutePath())
+        );
     }
 
     @Test
     public void assertWithPasswordPassesPasswordDown() throws SOPGPException.PasswordNotHumanReadable, SOPGPException.UnsupportedOption, IOException {
         File passwordFile = TestFileUtil.writeTempStringFile("orange");
-        SopCLI.main(new String[] {"decrypt", "--with-password", passwordFile.getAbsolutePath()});
+        assertSuccess(() -> SopCLI.execute("decrypt", "--with-password", passwordFile.getAbsolutePath()));
         verify(decrypt, times(1)).withPassword("orange");
     }
 
     @Test
-    @ExpectSystemExitWithStatus(SOPGPException.UnsupportedOption.EXIT_CODE)
     public void assertUnsupportedWithPasswordCausesExit37() throws SOPGPException.PasswordNotHumanReadable, SOPGPException.UnsupportedOption, IOException {
         File passwordFile = TestFileUtil.writeTempStringFile("swordfish");
         when(decrypt.withPassword(any())).thenThrow(new SOPGPException.UnsupportedOption("Decrypting with password not supported."));
-        SopCLI.main(new String[] {"decrypt", "--with-password", passwordFile.getAbsolutePath()});
+        assertUnsupportedOption(() ->
+                SopCLI.execute("decrypt", "--with-password", passwordFile.getAbsolutePath())
+        );
     }
 
     @Test
     public void assertDefaultTimeRangesAreUsedIfNotOverwritten() throws SOPGPException.UnsupportedOption {
         Date now = new Date();
-        SopCLI.main(new String[] {"decrypt"});
+        assertSuccess(() -> SopCLI.execute("decrypt"));
         verify(decrypt, times(1)).verifyNotBefore(AbstractSopCmd.BEGINNING_OF_TIME);
         verify(decrypt, times(1)).verifyNotAfter(
                 ArgumentMatchers.argThat(argument -> {
@@ -125,7 +136,8 @@ public class DecryptCmdTest {
 
     @Test
     public void assertVerifyNotAfterAndBeforeDashResultsInMaxTimeRange() throws SOPGPException.UnsupportedOption {
-        SopCLI.main(new String[] {"decrypt", "--verify-not-before", "-", "--verify-not-after", "-"});
+        assertSuccess(() ->
+                SopCLI.execute("decrypt", "--verify-not-before", "-", "--verify-not-after", "-"));
         verify(decrypt, times(1)).verifyNotBefore(AbstractSopCmd.BEGINNING_OF_TIME);
         verify(decrypt, times(1)).verifyNotAfter(AbstractSopCmd.END_OF_TIME);
     }
@@ -138,54 +150,57 @@ public class DecryptCmdTest {
             return Math.abs(now.getTime() - argument.getTime()) <= 1000;
         };
 
-        SopCLI.main(new String[] {"decrypt", "--verify-not-before", "now", "--verify-not-after", "now"});
+        assertSuccess(() ->
+                SopCLI.execute("decrypt", "--verify-not-before", "now", "--verify-not-after", "now"));
         verify(decrypt, times(1)).verifyNotAfter(ArgumentMatchers.argThat(isMaxOneSecOff));
         verify(decrypt, times(1)).verifyNotBefore(ArgumentMatchers.argThat(isMaxOneSecOff));
     }
 
     @Test
-    @ExpectSystemExitWithStatus(1)
     public void assertMalformedDateInNotBeforeCausesExit1() {
         // ParserException causes exit(1)
-        SopCLI.main(new String[] {"decrypt", "--verify-not-before", "invalid"});
+        assertGenericError(() ->
+                SopCLI.execute("decrypt", "--verify-not-before", "invalid"));
     }
 
     @Test
-    @ExpectSystemExitWithStatus(1)
     public void assertMalformedDateInNotAfterCausesExit1() {
         // ParserException causes exit(1)
-        SopCLI.main(new String[] {"decrypt", "--verify-not-after", "invalid"});
+        assertGenericError(() ->
+                SopCLI.execute("decrypt", "--verify-not-after", "invalid"));
     }
 
     @Test
-    @ExpectSystemExitWithStatus(SOPGPException.UnsupportedOption.EXIT_CODE)
     public void assertUnsupportedNotAfterCausesExit37() throws SOPGPException.UnsupportedOption {
-        when(decrypt.verifyNotAfter(any())).thenThrow(new SOPGPException.UnsupportedOption("Setting upper signature date boundary not supported."));
+        when(decrypt.verifyNotAfter(any())).thenThrow(
-        SopCLI.main(new String[] {"decrypt", "--verify-not-after", "now"});
+                new SOPGPException.UnsupportedOption("Setting upper signature date boundary not supported."));
+        assertUnsupportedOption(() ->
+                SopCLI.execute("decrypt", "--verify-not-after", "now"));
     }
 
     @Test
-    @ExpectSystemExitWithStatus(SOPGPException.UnsupportedOption.EXIT_CODE)
     public void assertUnsupportedNotBeforeCausesExit37() throws SOPGPException.UnsupportedOption {
-        when(decrypt.verifyNotBefore(any())).thenThrow(new SOPGPException.UnsupportedOption("Setting lower signature date boundary not supported."));
+        when(decrypt.verifyNotBefore(any())).thenThrow(
-        SopCLI.main(new String[] {"decrypt", "--verify-not-before", "now"});
+                new SOPGPException.UnsupportedOption("Setting lower signature date boundary not supported."));
+        assertUnsupportedOption(() ->
+                SopCLI.execute("decrypt", "--verify-not-before", "now"));
     }
 
     @Test
-    @ExpectSystemExitWithStatus(SOPGPException.OutputExists.EXIT_CODE)
     public void assertExistingSessionKeyOutFileCausesExit59() throws IOException {
         File tempFile = File.createTempFile("existing-session-key-", ".tmp");
         tempFile.deleteOnExit();
-        SopCLI.main(new String[] {"decrypt", "--session-key-out", tempFile.getAbsolutePath()});
+        assertOutputExists(() ->
+                SopCLI.execute("decrypt", "--session-key-out", tempFile.getAbsolutePath()));
     }
 
     @Test
-    @ExpectSystemExitWithStatus(SOPGPException.UnsupportedOption.EXIT_CODE)
     public void assertWhenSessionKeyCannotBeExtractedExit37() throws IOException {
         Path tempDir = Files.createTempDirectory("session-key-out-dir");
         File tempFile = new File(tempDir.toFile(), "session-key");
         tempFile.deleteOnExit();
-        SopCLI.main(new String[] {"decrypt", "--session-key-out", tempFile.getAbsolutePath()});
+        assertUnsupportedOption(() ->
+                SopCLI.execute("decrypt", "--session-key-out", tempFile.getAbsolutePath()));
     }
 
     @Test
@@ -210,8 +225,10 @@ public class DecryptCmdTest {
         File verificationsFile = new File(tempDir.toFile(), "verifications");
         File keyFile = new File(tempDir.toFile(), "key.asc");
         keyFile.createNewFile();
-        SopCLI.main(new String[] {"decrypt", "--session-key-out", sessionKeyFile.getAbsolutePath(),
+        assertSuccess(() ->
-        "--verifications-out", verificationsFile.getAbsolutePath(), "--verify-with", keyFile.getAbsolutePath()});
+                SopCLI.execute("decrypt", "--session-key-out", sessionKeyFile.getAbsolutePath(),
+                        "--verifications-out", verificationsFile.getAbsolutePath(), "--verify-with",
+                        keyFile.getAbsolutePath()));
 
         ByteArrayOutputStream bytesInFile = new ByteArrayOutputStream();
         try (FileInputStream fileIn = new FileInputStream(sessionKeyFile)) {
@@ -241,10 +258,10 @@ public class DecryptCmdTest {
     }
 
     @Test
-    @ExpectSystemExitWithStatus(SOPGPException.CannotDecrypt.EXIT_CODE)
     public void assertUnableToDecryptExceptionResultsInExit29() throws SOPGPException.CannotDecrypt, SOPGPException.MissingArg, SOPGPException.BadData, IOException {
         when(decrypt.ciphertext((InputStream) any())).thenThrow(new SOPGPException.CannotDecrypt());
-        SopCLI.main(new String[] {"decrypt"});
+        assertCannotDecrypt(() ->
+                SopCLI.execute("decrypt"));
     }
 
     @Test
@@ -258,30 +275,32 @@ public class DecryptCmdTest {
                 return new DecryptionResult(null, Collections.emptyList());
             }
         });
-        SopCLI.main(new String[] {"decrypt", "--verify-with", tempFile.getAbsolutePath(), "--verifications-out", verifyOut.getAbsolutePath()});
+        assertSuccess(() ->
+                SopCLI.execute("decrypt", "--verify-with", tempFile.getAbsolutePath(), "--verifications-out",
+                        verifyOut.getAbsolutePath()));
     }
 
     @Test
-    @ExpectSystemExitWithStatus(SOPGPException.BadData.EXIT_CODE)
     public void badDataInVerifyWithCausesExit41() throws IOException, SOPGPException.BadData {
         when(decrypt.verifyWithCert((InputStream) any())).thenThrow(new SOPGPException.BadData(new IOException()));
         File tempFile = File.createTempFile("verify-with-", ".tmp");
-        SopCLI.main(new String[] {"decrypt", "--verify-with", tempFile.getAbsolutePath()});
+        assertBadData(() ->
+                SopCLI.execute("decrypt", "--verify-with", tempFile.getAbsolutePath()));
     }
 
     @Test
-    @ExpectSystemExitWithStatus(SOPGPException.MissingInput.EXIT_CODE)
     public void unexistentCertFileCausesExit61() {
-        SopCLI.main(new String[] {"decrypt", "--verify-with", "invalid"});
+        assertMissingInput(() ->
+                SopCLI.execute("decrypt", "--verify-with", "invalid"));
     }
 
     @Test
-    @ExpectSystemExitWithStatus(SOPGPException.OutputExists.EXIT_CODE)
     public void existingVerifyOutCausesExit59() throws IOException {
         File certFile = File.createTempFile("existing-verify-out-cert", ".asc");
         File existingVerifyOut = File.createTempFile("existing-verify-out", ".tmp");
 
-        SopCLI.main(new String[] {"decrypt", "--verifications-out", existingVerifyOut.getAbsolutePath(), "--verify-with", certFile.getAbsolutePath()});
+        assertOutputExists(() -> SopCLI.execute("decrypt", "--verifications-out",
+                existingVerifyOut.getAbsolutePath(), "--verify-with", certFile.getAbsolutePath()));
     }
 
     @Test
@@ -305,7 +324,9 @@ public class DecryptCmdTest {
             }
         });
 
-        SopCLI.main(new String[] {"decrypt", "--verifications-out", verifyOut.getAbsolutePath(), "--verify-with", certFile.getAbsolutePath()});
+        assertSuccess(() ->
+                SopCLI.execute("decrypt", "--verifications-out", verifyOut.getAbsolutePath(),
+                        "--verify-with", certFile.getAbsolutePath()));
         try (BufferedReader reader = new BufferedReader(new FileReader(verifyOut))) {
             String line = reader.readLine();
             assertEquals("2021-07-11T20:58:23Z 1B66A707819A920925BC6777C3E0AFC0B2DFF862 C8CD564EBF8D7BBA90611D8D071773658BF6BF86", line);
@@ -320,66 +341,64 @@ public class DecryptCmdTest {
         File sessionKeyFile1 = TestFileUtil.writeTempStringFile(key1.toString());
         File sessionKeyFile2 = TestFileUtil.writeTempStringFile(key2.toString());
 
-        SopCLI.main(new String[] {"decrypt",
+        assertSuccess(() ->
-                "--with-session-key", sessionKeyFile1.getAbsolutePath(),
+                SopCLI.execute("decrypt",
-                "--with-session-key", sessionKeyFile2.getAbsolutePath()});
+                        "--with-session-key", sessionKeyFile1.getAbsolutePath(),
+                        "--with-session-key", sessionKeyFile2.getAbsolutePath()));
         verify(decrypt).withSessionKey(key1);
         verify(decrypt).withSessionKey(key2);
     }
 
     @Test
-    @ExpectSystemExitWithStatus(1)
     public void assertMalformedSessionKeysResultInExit1() throws IOException {
         File sessionKeyFile = TestFileUtil.writeTempStringFile("C7CBDAF42537776F12509B5168793C26B93294E5ABDFA73224FB0177123E9137");
-        SopCLI.main(new String[] {"decrypt",
+        assertGenericError(() ->
-                "--with-session-key", sessionKeyFile.getAbsolutePath()});
+                SopCLI.execute("decrypt",
+                "--with-session-key", sessionKeyFile.getAbsolutePath()));
     }
 
     @Test
-    @ExpectSystemExitWithStatus(SOPGPException.BadData.EXIT_CODE)
     public void assertBadDataInKeysResultsInExit41() throws SOPGPException.KeyIsProtected, SOPGPException.UnsupportedAsymmetricAlgo, SOPGPException.BadData, IOException {
         when(decrypt.withKey((InputStream) any())).thenThrow(new SOPGPException.BadData(new IOException()));
         File tempKeyFile = File.createTempFile("key-", ".tmp");
-        SopCLI.main(new String[] {"decrypt", tempKeyFile.getAbsolutePath()});
+        assertBadData(() -> SopCLI.execute("decrypt", tempKeyFile.getAbsolutePath()));
     }
 
     @Test
-    @ExpectSystemExitWithStatus(SOPGPException.MissingInput.EXIT_CODE)
     public void assertKeyFileNotFoundCausesExit61() {
-        SopCLI.main(new String[] {"decrypt", "nonexistent-key"});
+        assertMissingInput(() -> SopCLI.execute("decrypt", "nonexistent-key"));
     }
 
     @Test
-    @ExpectSystemExitWithStatus(SOPGPException.KeyIsProtected.EXIT_CODE)
     public void assertProtectedKeyCausesExit67() throws IOException, SOPGPException.KeyIsProtected, SOPGPException.UnsupportedAsymmetricAlgo, SOPGPException.BadData {
         when(decrypt.withKey((InputStream) any())).thenThrow(new SOPGPException.KeyIsProtected());
         File tempKeyFile = File.createTempFile("key-", ".tmp");
-        SopCLI.main(new String[] {"decrypt", tempKeyFile.getAbsolutePath()});
+        assertKeyIsProtected(() -> SopCLI.execute("decrypt", tempKeyFile.getAbsolutePath()));
     }
 
     @Test
-    @ExpectSystemExitWithStatus(SOPGPException.UnsupportedAsymmetricAlgo.EXIT_CODE)
     public void assertUnsupportedAlgorithmExceptionCausesExit13() throws SOPGPException.KeyIsProtected, SOPGPException.UnsupportedAsymmetricAlgo, SOPGPException.BadData, IOException {
         when(decrypt.withKey((InputStream) any())).thenThrow(new SOPGPException.UnsupportedAsymmetricAlgo("Unsupported asymmetric algorithm.", new IOException()));
         File tempKeyFile = File.createTempFile("key-", ".tmp");
-        SopCLI.main(new String[] {"decrypt", tempKeyFile.getAbsolutePath()});
+        assertUnsupportedAsymmetricAlgo(() ->
+                SopCLI.execute("decrypt", tempKeyFile.getAbsolutePath()));
     }
 
     @Test
-    @ExpectSystemExitWithStatus(SOPGPException.MissingInput.EXIT_CODE)
     public void assertMissingPassphraseFileCausesExit61() {
-        SopCLI.main(new String[] {"decrypt", "--with-password", "missing"});
+        assertMissingInput(() ->
+                SopCLI.execute("decrypt", "--with-password", "missing"));
     }
 
     @Test
-    @ExpectSystemExitWithStatus(SOPGPException.MissingInput.EXIT_CODE)
     public void assertMissingSessionKeyFileCausesExit61() {
-        SopCLI.main(new String[] {"decrypt", "--with-session-key", "missing"});
+        assertMissingInput(() ->
+                SopCLI.execute("decrypt", "--with-session-key", "missing"));
     }
 
     @Test
-    @ExpectSystemExitWithStatus(SOPGPException.IncompleteVerification.EXIT_CODE)
     public void verifyOutWithoutVerifyWithCausesExit23() {
-        SopCLI.main(new String[] {"decrypt", "--verifications-out", "out.file"});
+        assertIncompleteVerification(() ->
+                SopCLI.execute("decrypt", "--verifications-out", "out.file"));
     }
 }

sop-java-picocli/src/test/java/sop/cli/picocli/commands/EncryptCmdTest.java

@@ -4,7 +4,6 @@
 
 package sop.cli.picocli.commands;
 
-import com.ginsberg.junit.exit.ExpectSystemExitWithStatus;
 import org.jetbrains.annotations.NotNull;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
@@ -28,6 +27,17 @@ import static org.mockito.Mockito.never;
 import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
+import static sop.testsuite.assertions.SopExecutionAssertions.assertBadData;
+import static sop.testsuite.assertions.SopExecutionAssertions.assertCertCannotEncrypt;
+import static sop.testsuite.assertions.SopExecutionAssertions.assertGenericError;
+import static sop.testsuite.assertions.SopExecutionAssertions.assertKeyCannotSign;
+import static sop.testsuite.assertions.SopExecutionAssertions.assertKeyIsProtected;
+import static sop.testsuite.assertions.SopExecutionAssertions.assertMissingArg;
+import static sop.testsuite.assertions.SopExecutionAssertions.assertMissingInput;
+import static sop.testsuite.assertions.SopExecutionAssertions.assertPasswordNotHumanReadable;
+import static sop.testsuite.assertions.SopExecutionAssertions.assertSuccess;
+import static sop.testsuite.assertions.SopExecutionAssertions.assertUnsupportedAsymmetricAlgo;
+import static sop.testsuite.assertions.SopExecutionAssertions.assertUnsupportedOption;
 
 public class EncryptCmdTest {
 
@@ -50,48 +60,50 @@ public class EncryptCmdTest {
     }
 
     @Test
-    @ExpectSystemExitWithStatus(SOPGPException.MissingArg.EXIT_CODE)
+    public void missingBothPasswordAndCertFileCausesMissingArg() {
-    public void missingBothPasswordAndCertFileCauseExit19() {
+        assertMissingArg(() ->
-        SopCLI.main(new String[] {"encrypt", "--no-armor"});
+                SopCLI.execute("encrypt", "--no-armor"));
     }
 
     @Test
-    @ExpectSystemExitWithStatus(SOPGPException.UnsupportedOption.EXIT_CODE)
+    public void as_unsupportedEncryptAsCausesUnsupportedOption() throws SOPGPException.UnsupportedOption {
-    public void as_unsupportedEncryptAsCausesExit37() throws SOPGPException.UnsupportedOption {
         when(encrypt.mode(any())).thenThrow(new SOPGPException.UnsupportedOption("Setting encryption mode not supported."));
 
-        SopCLI.main(new String[] {"encrypt", "--as", "Binary"});
+        assertUnsupportedOption(() ->
+                SopCLI.execute("encrypt", "--as", "Binary"));
     }
 
     @Test
-    @ExpectSystemExitWithStatus(SOPGPException.UnsupportedOption.EXIT_CODE)
+    public void as_invalidModeOptionCausesUnsupportedOption() {
-    public void as_invalidModeOptionCausesExit37() {
+        assertUnsupportedOption(() ->
-        SopCLI.main(new String[] {"encrypt", "--as", "invalid"});
+                SopCLI.execute("encrypt", "--as", "invalid"));
     }
 
     @Test
     public void as_modeIsPassedDown() throws SOPGPException.UnsupportedOption, IOException {
         File passwordFile = TestFileUtil.writeTempStringFile("0rbit");
         for (EncryptAs mode : EncryptAs.values()) {
-            SopCLI.main(new String[] {"encrypt", "--as", mode.name(), "--with-password", passwordFile.getAbsolutePath()});
+            assertSuccess(() ->
+                    SopCLI.execute("encrypt", "--as", mode.name(),
+                            "--with-password", passwordFile.getAbsolutePath()));
             verify(encrypt, times(1)).mode(mode);
         }
     }
 
     @Test
-    @ExpectSystemExitWithStatus(SOPGPException.PasswordNotHumanReadable.EXIT_CODE)
+    public void withPassword_notHumanReadablePasswordCausesPWNotHumanReadable() throws SOPGPException.PasswordNotHumanReadable, SOPGPException.UnsupportedOption, IOException {
-    public void withPassword_notHumanReadablePasswordCausesExit31() throws SOPGPException.PasswordNotHumanReadable, SOPGPException.UnsupportedOption, IOException {
         when(encrypt.withPassword("pretendThisIsNotReadable")).thenThrow(new SOPGPException.PasswordNotHumanReadable());
         File passwordFile = TestFileUtil.writeTempStringFile("pretendThisIsNotReadable");
-        SopCLI.main(new String[] {"encrypt", "--with-password", passwordFile.getAbsolutePath()});
+        assertPasswordNotHumanReadable(() ->
+                SopCLI.execute("encrypt", "--with-password", passwordFile.getAbsolutePath()));
     }
 
     @Test
-    @ExpectSystemExitWithStatus(SOPGPException.UnsupportedOption.EXIT_CODE)
+    public void withPassword_unsupportedWithPasswordCausesUnsupportedOption() throws SOPGPException.PasswordNotHumanReadable, SOPGPException.UnsupportedOption, IOException {
-    public void withPassword_unsupportedWithPasswordCausesExit37() throws SOPGPException.PasswordNotHumanReadable, SOPGPException.UnsupportedOption, IOException {
         when(encrypt.withPassword(any())).thenThrow(new SOPGPException.UnsupportedOption("Encrypting with password not supported."));
         File passwordFile = TestFileUtil.writeTempStringFile("orange");
-        SopCLI.main(new String[] {"encrypt", "--with-password", passwordFile.getAbsolutePath()});
+        assertUnsupportedOption(() ->
+                SopCLI.execute("encrypt", "--with-password", passwordFile.getAbsolutePath()));
     }
 
     @Test
@@ -99,99 +111,107 @@ public class EncryptCmdTest {
         File keyFile1 = File.createTempFile("sign-with-1-", ".asc");
         File keyFile2 = File.createTempFile("sign-with-2-", ".asc");
         File passwordFile = TestFileUtil.writeTempStringFile("password");
-        SopCLI.main(new String[] {"encrypt", "--with-password", passwordFile.getAbsolutePath(), "--sign-with", keyFile1.getAbsolutePath(), "--sign-with", keyFile2.getAbsolutePath()});
+        assertSuccess(() ->
+                SopCLI.execute("encrypt", "--with-password", passwordFile.getAbsolutePath(),
+                        "--sign-with", keyFile1.getAbsolutePath(),
+                        "--sign-with", keyFile2.getAbsolutePath()));
         verify(encrypt, times(2)).signWith((InputStream) any());
     }
 
     @Test
-    @ExpectSystemExitWithStatus(SOPGPException.MissingInput.EXIT_CODE)
+    public void signWith_nonExistentKeyFileCausesMissingInput() {
-    public void signWith_nonExistentKeyFileCausesExit61() {
+        assertMissingInput(() ->
-        SopCLI.main(new String[] {"encrypt", "--with-password", "admin", "--sign-with", "nonExistent.asc"});
+                SopCLI.execute("encrypt", "--with-password", "admin", "--sign-with", "nonExistent.asc"));
     }
 
     @Test
-    @ExpectSystemExitWithStatus(SOPGPException.KeyIsProtected.EXIT_CODE)
+    public void signWith_keyIsProtectedCausesKeyIsProtected() throws SOPGPException.KeyIsProtected, SOPGPException.UnsupportedAsymmetricAlgo, SOPGPException.KeyCannotSign, SOPGPException.BadData, IOException {
-    public void signWith_keyIsProtectedCausesExit67() throws SOPGPException.KeyIsProtected, SOPGPException.UnsupportedAsymmetricAlgo, SOPGPException.KeyCannotSign, SOPGPException.BadData, IOException {
         when(encrypt.signWith((InputStream) any())).thenThrow(new SOPGPException.KeyIsProtected());
         File keyFile = File.createTempFile("sign-with", ".asc");
         File passwordFile = TestFileUtil.writeTempStringFile("starship");
-        SopCLI.main(new String[] {"encrypt", "--sign-with", keyFile.getAbsolutePath(), "--with-password", passwordFile.getAbsolutePath()});
+        assertKeyIsProtected(() ->
+                SopCLI.execute("encrypt", "--sign-with", keyFile.getAbsolutePath(),
+                        "--with-password", passwordFile.getAbsolutePath()));
     }
 
     @Test
-    @ExpectSystemExitWithStatus(SOPGPException.UnsupportedAsymmetricAlgo.EXIT_CODE)
+    public void signWith_unsupportedAsymmetricAlgoCausesUnsupportedAsymAlgo() throws SOPGPException.KeyIsProtected, SOPGPException.UnsupportedAsymmetricAlgo, SOPGPException.KeyCannotSign, SOPGPException.BadData, IOException {
-    public void signWith_unsupportedAsymmetricAlgoCausesExit13() throws SOPGPException.KeyIsProtected, SOPGPException.UnsupportedAsymmetricAlgo, SOPGPException.KeyCannotSign, SOPGPException.BadData, IOException {
         when(encrypt.signWith((InputStream) any())).thenThrow(new SOPGPException.UnsupportedAsymmetricAlgo("Unsupported asymmetric algorithm.", new Exception()));
         File keyFile = File.createTempFile("sign-with", ".asc");
         File passwordFile = TestFileUtil.writeTempStringFile("123456");
-        SopCLI.main(new String[] {"encrypt", "--with-password", passwordFile.getAbsolutePath(), "--sign-with", keyFile.getAbsolutePath()});
+        assertUnsupportedAsymmetricAlgo(() ->
+                SopCLI.execute("encrypt", "--with-password", passwordFile.getAbsolutePath(),
+                        "--sign-with", keyFile.getAbsolutePath()));
     }
 
     @Test
-    @ExpectSystemExitWithStatus(SOPGPException.KeyCannotSign.EXIT_CODE)
+    public void signWith_certCannotSignCausesKeyCannotSign() throws IOException, SOPGPException.KeyIsProtected, SOPGPException.UnsupportedAsymmetricAlgo, SOPGPException.KeyCannotSign, SOPGPException.BadData {
-    public void signWith_certCannotSignCausesExit79() throws IOException, SOPGPException.KeyIsProtected, SOPGPException.UnsupportedAsymmetricAlgo, SOPGPException.KeyCannotSign, SOPGPException.BadData {
         when(encrypt.signWith((InputStream) any())).thenThrow(new SOPGPException.KeyCannotSign());
         File keyFile = File.createTempFile("sign-with", ".asc");
         File passwordFile = TestFileUtil.writeTempStringFile("dragon");
-        SopCLI.main(new String[] {"encrypt", "--with-password", passwordFile.getAbsolutePath(), "--sign-with", keyFile.getAbsolutePath()});
+        assertKeyCannotSign(() ->
+                SopCLI.execute("encrypt", "--with-password", passwordFile.getAbsolutePath(),
+                        "--sign-with", keyFile.getAbsolutePath()));
     }
 
     @Test
-    @ExpectSystemExitWithStatus(SOPGPException.BadData.EXIT_CODE)
+    public void signWith_badDataCausesBadData() throws SOPGPException.KeyIsProtected, SOPGPException.UnsupportedAsymmetricAlgo, SOPGPException.KeyCannotSign, SOPGPException.BadData, IOException {
-    public void signWith_badDataCausesExit41() throws SOPGPException.KeyIsProtected, SOPGPException.UnsupportedAsymmetricAlgo, SOPGPException.KeyCannotSign, SOPGPException.BadData, IOException {
         when(encrypt.signWith((InputStream) any())).thenThrow(new SOPGPException.BadData(new IOException()));
         File keyFile = File.createTempFile("sign-with", ".asc");
         File passwordFile = TestFileUtil.writeTempStringFile("orange");
-        SopCLI.main(new String[] {"encrypt", "--with-password", passwordFile.getAbsolutePath(), "--sign-with", keyFile.getAbsolutePath()});
+        assertBadData(() ->
+                SopCLI.execute("encrypt", "--with-password", passwordFile.getAbsolutePath(),
+                        "--sign-with", keyFile.getAbsolutePath()));
     }
 
     @Test
-    @ExpectSystemExitWithStatus(SOPGPException.MissingInput.EXIT_CODE)
+    public void cert_nonExistentCertFileCausesMissingInput() {
-    public void cert_nonExistentCertFileCausesExit61() {
+        assertMissingInput(() ->
-        SopCLI.main(new String[] {"encrypt", "invalid.asc"});
+                SopCLI.execute("encrypt", "invalid.asc"));
     }
 
     @Test
-    @ExpectSystemExitWithStatus(SOPGPException.UnsupportedAsymmetricAlgo.EXIT_CODE)
+    public void cert_unsupportedAsymmetricAlgorithmCausesUnsupportedAsymAlg() throws IOException, SOPGPException.UnsupportedAsymmetricAlgo, SOPGPException.CertCannotEncrypt, SOPGPException.BadData {
-    public void cert_unsupportedAsymmetricAlgorithmCausesExit13() throws IOException, SOPGPException.UnsupportedAsymmetricAlgo, SOPGPException.CertCannotEncrypt, SOPGPException.BadData {
         when(encrypt.withCert((InputStream) any())).thenThrow(new SOPGPException.UnsupportedAsymmetricAlgo("Unsupported asymmetric algorithm.", new Exception()));
         File certFile = File.createTempFile("cert", ".asc");
-        SopCLI.main(new String[] {"encrypt", certFile.getAbsolutePath()});
+        assertUnsupportedAsymmetricAlgo(() ->
+                SopCLI.execute("encrypt", certFile.getAbsolutePath()));
     }
 
     @Test
-    @ExpectSystemExitWithStatus(SOPGPException.CertCannotEncrypt.EXIT_CODE)
+    public void cert_certCannotEncryptCausesCertCannotEncrypt() throws IOException, SOPGPException.UnsupportedAsymmetricAlgo, SOPGPException.CertCannotEncrypt, SOPGPException.BadData {
-    public void cert_certCannotEncryptCausesExit17() throws IOException, SOPGPException.UnsupportedAsymmetricAlgo, SOPGPException.CertCannotEncrypt, SOPGPException.BadData {
         when(encrypt.withCert((InputStream) any())).thenThrow(new SOPGPException.CertCannotEncrypt("Certificate cannot encrypt.", new Exception()));
         File certFile = File.createTempFile("cert", ".asc");
-        SopCLI.main(new String[] {"encrypt", certFile.getAbsolutePath()});
+        assertCertCannotEncrypt(() ->
+                SopCLI.execute("encrypt", certFile.getAbsolutePath()));
     }
 
     @Test
-    @ExpectSystemExitWithStatus(SOPGPException.BadData.EXIT_CODE)
+    public void cert_badDataCausesBadData() throws IOException, SOPGPException.UnsupportedAsymmetricAlgo, SOPGPException.CertCannotEncrypt, SOPGPException.BadData {
-    public void cert_badDataCausesExit41() throws IOException, SOPGPException.UnsupportedAsymmetricAlgo, SOPGPException.CertCannotEncrypt, SOPGPException.BadData {
         when(encrypt.withCert((InputStream) any())).thenThrow(new SOPGPException.BadData(new IOException()));
         File certFile = File.createTempFile("cert", ".asc");
-        SopCLI.main(new String[] {"encrypt", certFile.getAbsolutePath()});
+        assertBadData(() ->
+                SopCLI.execute("encrypt", certFile.getAbsolutePath()));
     }
 
     @Test
     public void noArmor_notCalledByDefault() throws IOException {
         File passwordFile = TestFileUtil.writeTempStringFile("clownfish");
-        SopCLI.main(new String[] {"encrypt", "--with-password", passwordFile.getAbsolutePath()});
+        assertSuccess(() ->
+                SopCLI.execute("encrypt", "--with-password", passwordFile.getAbsolutePath()));
         verify(encrypt, never()).noArmor();
     }
 
     @Test
     public void noArmor_callGetsPassedDown() throws IOException {
         File passwordFile = TestFileUtil.writeTempStringFile("monkey");
-        SopCLI.main(new String[] {"encrypt", "--with-password", passwordFile.getAbsolutePath(), "--no-armor"});
+        assertSuccess(() ->
+                SopCLI.execute("encrypt", "--with-password", passwordFile.getAbsolutePath(), "--no-armor"));
         verify(encrypt, times(1)).noArmor();
     }
 
     @Test
-    @ExpectSystemExitWithStatus(1)
+    public void writeTo_ioExceptionCausesGenericError() throws IOException {
-    public void writeTo_ioExceptionCausesExit1() throws IOException {
         when(encrypt.plaintext((InputStream) any())).thenReturn(new ReadyWithResult<EncryptionResult>() {
             @Override
             public EncryptionResult writeTo(@NotNull OutputStream outputStream) throws IOException, SOPGPException {
@@ -199,6 +219,7 @@ public class EncryptCmdTest {
             }
         });
         File passwordFile = TestFileUtil.writeTempStringFile("wildcat");
-        SopCLI.main(new String[] {"encrypt", "--with-password", passwordFile.getAbsolutePath()});
+        assertGenericError(() ->
+                SopCLI.execute("encrypt", "--with-password", passwordFile.getAbsolutePath()));
     }
 }

sop-java-picocli/src/test/java/sop/cli/picocli/commands/ExtractCertCmdTest.java

@@ -10,12 +10,14 @@ import static org.mockito.Mockito.never;
 import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
+import static sop.testsuite.assertions.SopExecutionAssertions.assertBadData;
+import static sop.testsuite.assertions.SopExecutionAssertions.assertGenericError;
+import static sop.testsuite.assertions.SopExecutionAssertions.assertSuccess;
 
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
 
-import com.ginsberg.junit.exit.ExpectSystemExitWithStatus;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 import sop.Ready;
@@ -45,32 +47,34 @@ public class ExtractCertCmdTest {
 
     @Test
     public void noArmor_notCalledByDefault() {
-        SopCLI.main(new String[] {"extract-cert"});
+        assertSuccess(() ->
+                SopCLI.execute("extract-cert"));
         verify(extractCert, never()).noArmor();
     }
 
     @Test
     public void noArmor_passedDown() {
-        SopCLI.main(new String[] {"extract-cert", "--no-armor"});
+        assertSuccess(() ->
+                SopCLI.execute("extract-cert", "--no-armor"));
         verify(extractCert, times(1)).noArmor();
     }
 
     @Test
-    @ExpectSystemExitWithStatus(1)
+    public void key_ioExceptionCausesGenericError() throws IOException, SOPGPException.BadData {
-    public void key_ioExceptionCausesExit1() throws IOException, SOPGPException.BadData {
         when(extractCert.key((InputStream) any())).thenReturn(new Ready() {
             @Override
             public void writeTo(OutputStream outputStream) throws IOException {
                 throw new IOException();
             }
         });
-        SopCLI.main(new String[] {"extract-cert"});
+        assertGenericError(() ->
+                SopCLI.execute("extract-cert"));
     }
 
     @Test
-    @ExpectSystemExitWithStatus(SOPGPException.BadData.EXIT_CODE)
+    public void key_badDataCausesBadData() throws IOException, SOPGPException.BadData {
-    public void key_badDataCausesExit41() throws IOException, SOPGPException.BadData {
         when(extractCert.key((InputStream) any())).thenThrow(new SOPGPException.BadData(new IOException()));
-        SopCLI.main(new String[] {"extract-cert"});
+        assertBadData(() ->
+                SopCLI.execute("extract-cert"));
     }
 }

sop-java-picocli/src/test/java/sop/cli/picocli/commands/GenerateKeyCmdTest.java

@@ -10,11 +10,14 @@ import static org.mockito.Mockito.never;
 import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
+import static sop.testsuite.assertions.SopExecutionAssertions.assertGenericError;
+import static sop.testsuite.assertions.SopExecutionAssertions.assertMissingArg;
+import static sop.testsuite.assertions.SopExecutionAssertions.assertSuccess;
+import static sop.testsuite.assertions.SopExecutionAssertions.assertUnsupportedAsymmetricAlgo;
 
 import java.io.IOException;
 import java.io.OutputStream;
 
-import com.ginsberg.junit.exit.ExpectSystemExitWithStatus;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 import org.mockito.InOrder;
@@ -47,19 +50,22 @@ public class GenerateKeyCmdTest {
 
     @Test
     public void noArmor_notCalledByDefault() {
-        SopCLI.main(new String[] {"generate-key", "Alice"});
+        assertSuccess(() ->
+                SopCLI.execute("generate-key", "Alice"));
         verify(generateKey, never()).noArmor();
     }
 
     @Test
     public void noArmor_passedDown() {
-        SopCLI.main(new String[] {"generate-key", "--no-armor", "Alice"});
+        assertSuccess(() ->
+                SopCLI.execute("generate-key", "--no-armor", "Alice"));
         verify(generateKey, times(1)).noArmor();
     }
 
     @Test
     public void userId_multipleUserIdsPassedDownInProperOrder() {
-        SopCLI.main(new String[] {"generate-key", "Alice <alice@pgpainless.org>", "Bob <bob@pgpainless.org>"});
+        assertSuccess(() ->
+                SopCLI.execute("generate-key", "Alice <alice@pgpainless.org>", "Bob <bob@pgpainless.org>"));
 
         InOrder inOrder = Mockito.inOrder(generateKey);
         inOrder.verify(generateKey).userId("Alice <alice@pgpainless.org>");
@@ -69,30 +75,32 @@ public class GenerateKeyCmdTest {
     }
 
     @Test
-    @ExpectSystemExitWithStatus(SOPGPException.MissingArg.EXIT_CODE)
     public void missingArgumentCausesExit19() throws SOPGPException.UnsupportedAsymmetricAlgo, SOPGPException.MissingArg, IOException {
         // TODO: RFC4880-bis and the current Stateless OpenPGP CLI spec allow keys to have no user-ids,
         //  so we might want to change this test in the future.
         when(generateKey.generate()).thenThrow(new SOPGPException.MissingArg("Missing user-id."));
-        SopCLI.main(new String[] {"generate-key"});
+        assertMissingArg(() ->
+                SopCLI.execute("generate-key"));
     }
 
     @Test
-    @ExpectSystemExitWithStatus(SOPGPException.UnsupportedAsymmetricAlgo.EXIT_CODE)
     public void unsupportedAsymmetricAlgorithmCausesExit13() throws SOPGPException.UnsupportedAsymmetricAlgo, SOPGPException.MissingArg, IOException {
         when(generateKey.generate()).thenThrow(new SOPGPException.UnsupportedAsymmetricAlgo("Unsupported asymmetric algorithm.", new Exception()));
-        SopCLI.main(new String[] {"generate-key", "Alice"});
+        assertUnsupportedAsymmetricAlgo(() ->
+                SopCLI.execute("generate-key", "Alice"));
+
     }
 
     @Test
-    @ExpectSystemExitWithStatus(1)
+    public void ioExceptionCausesGenericError() throws SOPGPException.UnsupportedAsymmetricAlgo, SOPGPException.MissingArg, IOException {
-    public void ioExceptionCausesExit1() throws SOPGPException.UnsupportedAsymmetricAlgo, SOPGPException.MissingArg, IOException {
         when(generateKey.generate()).thenReturn(new Ready() {
             @Override
             public void writeTo(OutputStream outputStream) throws IOException {
                 throw new IOException();
             }
         });
-        SopCLI.main(new String[] {"generate-key", "Alice"});
+
+        assertGenericError(() ->
+                SopCLI.execute("generate-key", "Alice"));
     }
 }

sop-java-picocli/src/test/java/sop/cli/picocli/commands/InlineDetachCmdTest.java

@@ -4,7 +4,6 @@
 
 package sop.cli.picocli.commands;
 
-import com.ginsberg.junit.exit.ExpectSystemExitWithStatus;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 import sop.ReadyWithResult;
@@ -26,6 +25,8 @@ import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
+import static sop.testsuite.assertions.SopExecutionAssertions.assertMissingArg;
+import static sop.testsuite.assertions.SopExecutionAssertions.assertSuccess;
 
 public class InlineDetachCmdTest {
 
@@ -41,9 +42,9 @@ public class InlineDetachCmdTest {
     }
 
     @Test
-    @ExpectSystemExitWithStatus(SOPGPException.MissingArg.EXIT_CODE)
+    public void testMissingSignaturesOutResultsInMissingArg() {
-    public void testMissingSignaturesOutResultsInExit19() {
+        assertMissingArg(() ->
-        SopCLI.main(new String[] {"inline-detach"});
+                SopCLI.execute("inline-detach"));
     }
 
     @Test
@@ -67,7 +68,8 @@ public class InlineDetachCmdTest {
                     }
                 });
 
-        SopCLI.main(new String[] {"inline-detach", "--signatures-out", tempFile.getAbsolutePath(), "--no-armor"});
+        assertSuccess(() ->
+                SopCLI.execute("inline-detach", "--signatures-out", tempFile.getAbsolutePath(), "--no-armor"));
         verify(inlineDetach, times(1)).noArmor();
         verify(inlineDetach, times(1)).message((InputStream) any());
     }

sop-java-picocli/src/test/java/sop/cli/picocli/commands/SignCmdTest.java

@@ -10,13 +10,20 @@ import static org.mockito.Mockito.never;
 import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
+import static sop.testsuite.assertions.SopExecutionAssertions.assertBadData;
+import static sop.testsuite.assertions.SopExecutionAssertions.assertExpectedText;
+import static sop.testsuite.assertions.SopExecutionAssertions.assertGenericError;
+import static sop.testsuite.assertions.SopExecutionAssertions.assertKeyIsProtected;
+import static sop.testsuite.assertions.SopExecutionAssertions.assertMissingArg;
+import static sop.testsuite.assertions.SopExecutionAssertions.assertMissingInput;
+import static sop.testsuite.assertions.SopExecutionAssertions.assertSuccess;
+import static sop.testsuite.assertions.SopExecutionAssertions.assertUnsupportedOption;
 
 import java.io.File;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
 
-import com.ginsberg.junit.exit.ExpectSystemExitWithStatus;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 import sop.ReadyWithResult;
@@ -54,70 +61,77 @@ public class SignCmdTest {
 
     @Test
     public void as_optionsAreCaseInsensitive() {
-        SopCLI.main(new String[] {"sign", "--as", "Binary", keyFile.getAbsolutePath()});
+        assertSuccess(() ->
-        SopCLI.main(new String[] {"sign", "--as", "binary", keyFile.getAbsolutePath()});
+                SopCLI.execute("sign", "--as", "Binary", keyFile.getAbsolutePath()));
-        SopCLI.main(new String[] {"sign", "--as", "BINARY", keyFile.getAbsolutePath()});
+        assertSuccess(() ->
+                SopCLI.execute("sign", "--as", "binary", keyFile.getAbsolutePath()));
+        assertSuccess(() ->
+                SopCLI.execute("sign", "--as", "BINARY", keyFile.getAbsolutePath()));
     }
 
     @Test
-    @ExpectSystemExitWithStatus(SOPGPException.UnsupportedOption.EXIT_CODE)
     public void as_invalidOptionCausesExit37() {
-        SopCLI.main(new String[] {"sign", "--as", "Invalid", keyFile.getAbsolutePath()});
+        assertUnsupportedOption(() ->
+                SopCLI.execute("sign", "--as", "Invalid", keyFile.getAbsolutePath()));
     }
 
     @Test
-    @ExpectSystemExitWithStatus(SOPGPException.UnsupportedOption.EXIT_CODE)
     public void as_unsupportedOptionCausesExit37() throws SOPGPException.UnsupportedOption {
         when(detachedSign.mode(any())).thenThrow(new SOPGPException.UnsupportedOption("Setting signing mode not supported."));
-        SopCLI.main(new String[] {"sign", "--as", "binary", keyFile.getAbsolutePath()});
+        assertUnsupportedOption(() ->
+                SopCLI.execute("sign", "--as", "binary", keyFile.getAbsolutePath()));
     }
 
     @Test
-    @ExpectSystemExitWithStatus(SOPGPException.MissingInput.EXIT_CODE)
     public void key_nonExistentKeyFileCausesExit61() {
-        SopCLI.main(new String[] {"sign", "invalid.asc"});
+        assertMissingInput(() ->
+                SopCLI.execute("sign", "invalid.asc"));
     }
 
     @Test
-    @ExpectSystemExitWithStatus(SOPGPException.KeyIsProtected.EXIT_CODE)
     public void key_keyIsProtectedCausesExit67() throws SOPGPException.KeyIsProtected, IOException, SOPGPException.BadData {
         when(detachedSign.key((InputStream) any())).thenThrow(new SOPGPException.KeyIsProtected());
-        SopCLI.main(new String[] {"sign", keyFile.getAbsolutePath()});
+        assertKeyIsProtected(() ->
+                SopCLI.execute("sign", keyFile.getAbsolutePath()));
     }
 
     @Test
-    @ExpectSystemExitWithStatus(SOPGPException.BadData.EXIT_CODE)
     public void key_badDataCausesExit41() throws SOPGPException.KeyIsProtected, IOException, SOPGPException.BadData {
         when(detachedSign.key((InputStream) any())).thenThrow(new SOPGPException.BadData(new IOException()));
-        SopCLI.main(new String[] {"sign", keyFile.getAbsolutePath()});
+        assertBadData(() ->
+                SopCLI.execute("sign", keyFile.getAbsolutePath()));
     }
 
     @Test
-    @ExpectSystemExitWithStatus(SOPGPException.MissingArg.EXIT_CODE)
     public void key_missingKeyFileCausesExit19() {
-        SopCLI.main(new String[] {"sign"});
+        assertMissingArg(() ->
+                SopCLI.execute("sign"));
     }
 
     @Test
     public void noArmor_notCalledByDefault() {
-        SopCLI.main(new String[] {"sign", keyFile.getAbsolutePath()});
+        assertSuccess(() ->
+                SopCLI.execute("sign", keyFile.getAbsolutePath()));
         verify(detachedSign, never()).noArmor();
     }
 
     @Test
     public void noArmor_passedDown() {
-        SopCLI.main(new String[] {"sign", "--no-armor", keyFile.getAbsolutePath()});
+        assertSuccess(() ->
+                SopCLI.execute("sign", "--no-armor", keyFile.getAbsolutePath()));
         verify(detachedSign, times(1)).noArmor();
     }
 
     @Test
     public void withKeyPassword_passedDown() {
-        SopCLI.main(new String[] {"sign", "--with-key-password", passFile.getAbsolutePath(), keyFile.getAbsolutePath()});
+        assertSuccess(() ->
+                SopCLI.execute("sign",
+                        "--with-key-password", passFile.getAbsolutePath(),
+                        keyFile.getAbsolutePath()));
         verify(detachedSign, times(1)).withKeyPassword("sw0rdf1sh");
     }
 
     @Test
-    @ExpectSystemExitWithStatus(1)
     public void data_ioExceptionCausesExit1() throws IOException, SOPGPException.ExpectedText {
         when(detachedSign.data((InputStream) any())).thenReturn(new ReadyWithResult<SigningResult>() {
             @Override
@@ -125,13 +139,14 @@ public class SignCmdTest {
                 throw new IOException();
             }
         });
-        SopCLI.main(new String[] {"sign", keyFile.getAbsolutePath()});
+        assertGenericError(() ->
+                SopCLI.execute("sign", keyFile.getAbsolutePath()));
     }
 
     @Test
-    @ExpectSystemExitWithStatus(SOPGPException.ExpectedText.EXIT_CODE)
     public void data_expectedTextExceptionCausesExit53() throws IOException, SOPGPException.ExpectedText {
         when(detachedSign.data((InputStream) any())).thenThrow(new SOPGPException.ExpectedText());
-        SopCLI.main(new String[] {"sign", keyFile.getAbsolutePath()});
+        assertExpectedText(() ->
+                SopCLI.execute("sign", keyFile.getAbsolutePath()));
     }
 }

sop-java-picocli/src/test/java/sop/cli/picocli/commands/VerifyCmdTest.java

@@ -10,6 +10,11 @@ import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
+import static sop.testsuite.assertions.SopExecutionAssertions.assertBadData;
+import static sop.testsuite.assertions.SopExecutionAssertions.assertMissingInput;
+import static sop.testsuite.assertions.SopExecutionAssertions.assertNoSignature;
+import static sop.testsuite.assertions.SopExecutionAssertions.assertSuccess;
+import static sop.testsuite.assertions.SopExecutionAssertions.assertUnsupportedOption;
 
 import java.io.ByteArrayOutputStream;
 import java.io.File;
@@ -21,7 +26,6 @@ import java.util.Arrays;
 import java.util.Collections;
 import java.util.Date;
 
-import com.ginsberg.junit.exit.ExpectSystemExitWithStatus;
 import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
@@ -76,60 +80,75 @@ public class VerifyCmdTest {
     @Test
     public void notAfter_passedDown() throws SOPGPException.UnsupportedOption, ParseException {
         Date date = UTCUtil.parseUTCDate("2019-10-29T18:36:45Z");
-        SopCLI.main(new String[] {"verify", "--not-after", "2019-10-29T18:36:45Z", signature.getAbsolutePath(), cert.getAbsolutePath()});
+        assertSuccess(() ->
+                SopCLI.execute("verify", "--not-after", "2019-10-29T18:36:45Z",
+                        signature.getAbsolutePath(), cert.getAbsolutePath()));
         verify(detachedVerify, times(1)).notAfter(date);
     }
 
     @Test
     public void notAfter_now() throws SOPGPException.UnsupportedOption {
         Date now = new Date();
-        SopCLI.main(new String[] {"verify", "--not-after", "now", signature.getAbsolutePath(), cert.getAbsolutePath()});
+        assertSuccess(() ->
+                SopCLI.execute("verify", "--not-after", "now",
+                        signature.getAbsolutePath(), cert.getAbsolutePath()));
         verify(detachedVerify, times(1)).notAfter(dateMatcher(now));
     }
 
     @Test
     public void notAfter_dashCountsAsEndOfTime() throws SOPGPException.UnsupportedOption {
-        SopCLI.main(new String[] {"verify", "--not-after", "-", signature.getAbsolutePath(), cert.getAbsolutePath()});
+        assertSuccess(() ->
+                SopCLI.execute("verify", "--not-after", "-",
+                        signature.getAbsolutePath(), cert.getAbsolutePath()));
         verify(detachedVerify, times(1)).notAfter(AbstractSopCmd.END_OF_TIME);
     }
 
     @Test
-    @ExpectSystemExitWithStatus(SOPGPException.UnsupportedOption.EXIT_CODE)
     public void notAfter_unsupportedOptionCausesExit37() throws SOPGPException.UnsupportedOption {
         when(detachedVerify.notAfter(any())).thenThrow(new SOPGPException.UnsupportedOption("Setting upper signature date boundary not supported."));
-        SopCLI.main(new String[] {"verify", "--not-after", "2019-10-29T18:36:45Z", signature.getAbsolutePath(), cert.getAbsolutePath()});
+        assertUnsupportedOption(() ->
+                SopCLI.execute("verify", "--not-after", "2019-10-29T18:36:45Z",
+                        signature.getAbsolutePath(), cert.getAbsolutePath()));
     }
 
     @Test
     public void notBefore_passedDown() throws SOPGPException.UnsupportedOption, ParseException {
         Date date = UTCUtil.parseUTCDate("2019-10-29T18:36:45Z");
-        SopCLI.main(new String[] {"verify", "--not-before", "2019-10-29T18:36:45Z", signature.getAbsolutePath(), cert.getAbsolutePath()});
+        assertSuccess(() ->
+                SopCLI.execute("verify", "--not-before", "2019-10-29T18:36:45Z",
+                        signature.getAbsolutePath(), cert.getAbsolutePath()));
         verify(detachedVerify, times(1)).notBefore(date);
     }
 
     @Test
     public void notBefore_now() throws SOPGPException.UnsupportedOption {
         Date now = new Date();
-        SopCLI.main(new String[] {"verify", "--not-before", "now", signature.getAbsolutePath(), cert.getAbsolutePath()});
+        assertSuccess(() ->
+                SopCLI.execute("verify", "--not-before", "now",
+                        signature.getAbsolutePath(), cert.getAbsolutePath()));
         verify(detachedVerify, times(1)).notBefore(dateMatcher(now));
     }
 
     @Test
     public void notBefore_dashCountsAsBeginningOfTime() throws SOPGPException.UnsupportedOption {
-        SopCLI.main(new String[] {"verify", "--not-before", "-", signature.getAbsolutePath(), cert.getAbsolutePath()});
+        assertSuccess(() ->
+                SopCLI.execute("verify", "--not-before", "-",
+                        signature.getAbsolutePath(), cert.getAbsolutePath()));
         verify(detachedVerify, times(1)).notBefore(AbstractSopCmd.BEGINNING_OF_TIME);
     }
 
     @Test
-    @ExpectSystemExitWithStatus(SOPGPException.UnsupportedOption.EXIT_CODE)
     public void notBefore_unsupportedOptionCausesExit37() throws SOPGPException.UnsupportedOption {
         when(detachedVerify.notBefore(any())).thenThrow(new SOPGPException.UnsupportedOption("Setting lower signature date boundary not supported."));
-        SopCLI.main(new String[] {"verify", "--not-before", "2019-10-29T18:36:45Z", signature.getAbsolutePath(), cert.getAbsolutePath()});
+        assertUnsupportedOption(() ->
+                SopCLI.execute("verify", "--not-before", "2019-10-29T18:36:45Z",
+                        signature.getAbsolutePath(), cert.getAbsolutePath()));
     }
 
     @Test
     public void notBeforeAndNotAfterAreCalledWithDefaultValues() throws SOPGPException.UnsupportedOption {
-        SopCLI.main(new String[] {"verify", signature.getAbsolutePath(), cert.getAbsolutePath()});
+        assertSuccess(() ->
+                SopCLI.execute("verify", signature.getAbsolutePath(), cert.getAbsolutePath()));
         verify(detachedVerify, times(1)).notAfter(dateMatcher(new Date()));
         verify(detachedVerify, times(1)).notBefore(AbstractSopCmd.BEGINNING_OF_TIME);
     }
@@ -139,43 +158,43 @@ public class VerifyCmdTest {
     }
 
     @Test
-    @ExpectSystemExitWithStatus(SOPGPException.MissingInput.EXIT_CODE)
     public void cert_fileNotFoundCausesExit61() {
-        SopCLI.main(new String[] {"verify", signature.getAbsolutePath(), "invalid.asc"});
+        assertMissingInput(() ->
+                SopCLI.execute("verify", signature.getAbsolutePath(), "invalid.asc"));
     }
 
     @Test
-    @ExpectSystemExitWithStatus(SOPGPException.BadData.EXIT_CODE)
     public void cert_badDataCausesExit41() throws SOPGPException.BadData, IOException {
         when(detachedVerify.cert((InputStream) any())).thenThrow(new SOPGPException.BadData(new IOException()));
-        SopCLI.main(new String[] {"verify", signature.getAbsolutePath(), cert.getAbsolutePath()});
+        assertBadData(() ->
+                SopCLI.execute("verify", signature.getAbsolutePath(), cert.getAbsolutePath()));
     }
 
     @Test
-    @ExpectSystemExitWithStatus(SOPGPException.MissingInput.EXIT_CODE)
     public void signature_fileNotFoundCausesExit61() {
-        SopCLI.main(new String[] {"verify", "invalid.sig", cert.getAbsolutePath()});
+        assertMissingInput(() ->
+                SopCLI.execute("verify", "invalid.sig", cert.getAbsolutePath()));
     }
 
     @Test
-    @ExpectSystemExitWithStatus(SOPGPException.BadData.EXIT_CODE)
     public void signature_badDataCausesExit41() throws SOPGPException.BadData, IOException {
         when(detachedVerify.signatures((InputStream) any())).thenThrow(new SOPGPException.BadData(new IOException()));
-        SopCLI.main(new String[] {"verify", signature.getAbsolutePath(), cert.getAbsolutePath()});
+        assertBadData(() ->
+                SopCLI.execute("verify", signature.getAbsolutePath(), cert.getAbsolutePath()));
     }
 
     @Test
-    @ExpectSystemExitWithStatus(SOPGPException.NoSignature.EXIT_CODE)
     public void data_noSignaturesCausesExit3() throws SOPGPException.NoSignature, IOException, SOPGPException.BadData {
         when(detachedVerify.data((InputStream) any())).thenThrow(new SOPGPException.NoSignature());
-        SopCLI.main(new String[] {"verify", signature.getAbsolutePath(), cert.getAbsolutePath()});
+        assertNoSignature(() ->
+                SopCLI.execute("verify", signature.getAbsolutePath(), cert.getAbsolutePath()));
     }
 
     @Test
-    @ExpectSystemExitWithStatus(SOPGPException.BadData.EXIT_CODE)
     public void data_badDataCausesExit41() throws SOPGPException.NoSignature, IOException, SOPGPException.BadData {
         when(detachedVerify.data((InputStream) any())).thenThrow(new SOPGPException.BadData(new IOException()));
-        SopCLI.main(new String[] {"verify", signature.getAbsolutePath(), cert.getAbsolutePath()});
+        assertBadData(() ->
+                SopCLI.execute("verify", signature.getAbsolutePath(), cert.getAbsolutePath()));
     }
 
     @Test
@@ -192,7 +211,8 @@ public class VerifyCmdTest {
         ByteArrayOutputStream out = new ByteArrayOutputStream();
         System.setOut(new PrintStream(out));
 
-        SopCLI.main(new String[] {"verify", signature.getAbsolutePath(), cert.getAbsolutePath()});
+        assertSuccess(() ->
+                SopCLI.execute("verify", signature.getAbsolutePath(), cert.getAbsolutePath()));
 
         System.setOut(originalSout);
 

sop-java-picocli/src/test/java/sop/cli/picocli/commands/VersionCmdTest.java

@@ -4,19 +4,19 @@
 
 package sop.cli.picocli.commands;
 
-import static org.mockito.Mockito.mock;
-import static org.mockito.Mockito.times;
-import static org.mockito.Mockito.verify;
-import static org.mockito.Mockito.when;
-
-import com.ginsberg.junit.exit.ExpectSystemExitWithStatus;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 import sop.SOP;
 import sop.cli.picocli.SopCLI;
-import sop.exception.SOPGPException;
 import sop.operation.Version;
 
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+import static sop.testsuite.assertions.SopExecutionAssertions.assertSuccess;
+import static sop.testsuite.assertions.SopExecutionAssertions.assertUnsupportedOption;
+
 public class VersionCmdTest {
 
     private Version version;
@@ -29,6 +29,8 @@ public class VersionCmdTest {
         when(version.getVersion()).thenReturn("1.0");
         when(version.getExtendedVersion()).thenReturn("MockSop Extended Version Information");
         when(version.getBackendVersion()).thenReturn("Foo");
+        when(version.getSopSpecVersion()).thenReturn("draft-dkg-openpgp-stateless-cli-XX");
+        when(version.getSopVVersion()).thenReturn("1.0");
         when(sop.version()).thenReturn(version);
 
         SopCLI.setSopInstance(sop);
@@ -36,26 +38,41 @@ public class VersionCmdTest {
 
     @Test
     public void assertVersionCommandWorks() {
-        SopCLI.main(new String[] {"version"});
+        assertSuccess(() ->
+                SopCLI.execute("version"));
         verify(version, times(1)).getVersion();
         verify(version, times(1)).getName();
     }
 
     @Test
     public void assertExtendedVersionCommandWorks() {
-        SopCLI.main(new String[] {"version", "--extended"});
+        assertSuccess(() ->
+                SopCLI.execute("version", "--extended"));
         verify(version, times(1)).getExtendedVersion();
     }
 
     @Test
     public void assertBackendVersionCommandWorks() {
-        SopCLI.main(new String[] {"version", "--backend"});
+        assertSuccess(() ->
+                SopCLI.execute("version", "--backend"));
         verify(version, times(1)).getBackendVersion();
     }
 
     @Test
-    @ExpectSystemExitWithStatus(SOPGPException.UnsupportedOption.EXIT_CODE)
+    public void assertSpecVersionCommandWorks() {
+        assertSuccess(() ->
+                SopCLI.execute("version", "--sop-spec"));
+    }
+
+    @Test
+    public void assertSOPVVersionCommandWorks() {
+        assertSuccess(() ->
+                SopCLI.execute("version", "--sopv"));
+    }
+
+    @Test
     public void assertInvalidOptionResultsInExit37() {
-        SopCLI.main(new String[] {"version", "--invalid"});
+        assertUnsupportedOption(() ->
+                SopCLI.execute("version", "--invalid"));
     }
 }

sop-java/src/testFixtures/java/sop/testsuite/assertions/SopExecutionAssertions.java

@@ -0,0 +1,235 @@
+// SPDX-FileCopyrightText: 2024 Paul Schaub <vanitasvitae@fsfe.org>
+//
+// SPDX-License-Identifier: Apache-2.0
+
+package sop.testsuite.assertions;
+
+import sop.exception.SOPGPException;
+
+import java.util.function.IntSupplier;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotEquals;
+
+/**
+ * DSL for testing the return values of SOP method calls.
+ */
+public class SopExecutionAssertions {
+
+    /**
+     * Assert that the execution of the given function returns 0.
+     *
+     * @param function function to execute
+     */
+    public static void assertSuccess(IntSupplier function) {
+        assertEquals(0, function.getAsInt());
+    }
+
+    /**
+     * Assert that the execution of the given function returns a generic error with error code 1.
+     *
+     * @param function function to execute.
+     */
+    public static void assertGenericError(IntSupplier function) {
+        assertEquals(1, function.getAsInt());
+    }
+
+    /**
+     * Assert that the execution of the given function returns a non-zero error code.
+     *
+     * @param function function to execute
+     */
+    public static void assertAnyError(IntSupplier function) {
+        assertNotEquals(0, function.getAsInt());
+    }
+
+    /**
+     * Assert that the execution of the given function returns error code 3
+     * (which corresponds to {@link sop.exception.SOPGPException.NoSignature}).
+     *
+     * @param function function to execute.
+     */
+    public static void assertNoSignature(IntSupplier function) {
+        assertEquals(SOPGPException.NoSignature.EXIT_CODE, function.getAsInt());
+    }
+
+    /**
+     * Assert that the execution of the given function returns error code 13
+     * (which corresponds to {@link sop.exception.SOPGPException.UnsupportedAsymmetricAlgo}).
+     *
+     * @param function function to execute.
+     */
+    public static void assertUnsupportedAsymmetricAlgo(IntSupplier function) {
+        assertEquals(SOPGPException.UnsupportedAsymmetricAlgo.EXIT_CODE, function.getAsInt());
+    }
+
+    /**
+     * Assert that the execution of the given function returns error code 17
+     * (which corresponds to {@link sop.exception.SOPGPException.CertCannotEncrypt}).
+     *
+     * @param function function to execute.
+     */
+    public static void assertCertCannotEncrypt(IntSupplier function) {
+        assertEquals(SOPGPException.CertCannotEncrypt.EXIT_CODE, function.getAsInt());
+    }
+
+    /**
+     * Assert that the execution of the given function returns error code 19
+     * (which corresponds to {@link sop.exception.SOPGPException.MissingArg}).
+     *
+     * @param function function to execute.
+     */
+    public static void assertMissingArg(IntSupplier function) {
+        assertEquals(SOPGPException.MissingArg.EXIT_CODE, function.getAsInt());
+    }
+
+    /**
+     * Assert that the execution of the given function returns error code 23
+     * (which corresponds to {@link sop.exception.SOPGPException.IncompleteVerification}).
+     *
+     * @param function function to execute.
+     */
+    public static void assertIncompleteVerification(IntSupplier function) {
+        assertEquals(SOPGPException.IncompleteVerification.EXIT_CODE, function.getAsInt());
+    }
+
+    /**
+     * Assert that the execution of the given function returns error code 29
+     * (which corresponds to {@link sop.exception.SOPGPException.CannotDecrypt}).
+     *
+     * @param function function to execute.
+     */
+    public static void assertCannotDecrypt(IntSupplier function) {
+        assertEquals(SOPGPException.CannotDecrypt.EXIT_CODE, function.getAsInt());
+    }
+
+    /**
+     * Assert that the execution of the given function returns error code 31
+     * (which corresponds to {@link sop.exception.SOPGPException.PasswordNotHumanReadable}).
+     *
+     * @param function function to execute.
+     */
+    public static void assertPasswordNotHumanReadable(IntSupplier function) {
+        assertEquals(SOPGPException.PasswordNotHumanReadable.EXIT_CODE, function.getAsInt());
+    }
+
+    /**
+     * Assert that the execution of the given function returns error code 37
+     * (which corresponds to {@link sop.exception.SOPGPException.UnsupportedOption}).
+     *
+     * @param function function to execute.
+     */
+    public static void assertUnsupportedOption(IntSupplier function) {
+        assertEquals(SOPGPException.UnsupportedOption.EXIT_CODE, function.getAsInt());
+    }
+
+    /**
+     * Assert that the execution of the given function returns error code 41
+     * (which corresponds to {@link sop.exception.SOPGPException.BadData}).
+     *
+     * @param function function to execute.
+     */
+    public static void assertBadData(IntSupplier function) {
+        assertEquals(SOPGPException.BadData.EXIT_CODE, function.getAsInt());
+    }
+
+    /**
+     * Assert that the execution of the given function returns error code 53
+     * (which corresponds to {@link sop.exception.SOPGPException.ExpectedText}).
+     *
+     * @param function function to execute.
+     */
+    public static void assertExpectedText(IntSupplier function) {
+        assertEquals(SOPGPException.ExpectedText.EXIT_CODE, function.getAsInt());
+    }
+
+    /**
+     * Assert that the execution of the given function returns error code 59
+     * (which corresponds to {@link sop.exception.SOPGPException.OutputExists}).
+     *
+     * @param function function to execute.
+     */
+    public static void assertOutputExists(IntSupplier function) {
+        assertEquals(SOPGPException.OutputExists.EXIT_CODE, function.getAsInt());
+    }
+
+    /**
+     * Assert that the execution of the given function returns error code 61
+     * (which corresponds to {@link sop.exception.SOPGPException.MissingInput}).
+     *
+     * @param function function to execute.
+     */
+    public static void assertMissingInput(IntSupplier function) {
+        assertEquals(SOPGPException.MissingInput.EXIT_CODE, function.getAsInt());
+    }
+
+    /**
+     * Assert that the execution of the given function returns error code 67
+     * (which corresponds to {@link sop.exception.SOPGPException.KeyIsProtected}).
+     *
+     * @param function function to execute.
+     */
+    public static void assertKeyIsProtected(IntSupplier function) {
+        assertEquals(SOPGPException.KeyIsProtected.EXIT_CODE, function.getAsInt());
+    }
+
+    /**
+     * Assert that the execution of the given function returns error code 69
+     * (which corresponds to {@link sop.exception.SOPGPException.UnsupportedSubcommand}).
+     *
+     * @param function function to execute.
+     */
+    public static void assertUnsupportedSubcommand(IntSupplier function) {
+        assertEquals(SOPGPException.UnsupportedSubcommand.EXIT_CODE, function.getAsInt());
+    }
+
+    /**
+     * Assert that the execution of the given function returns error code 71
+     * (which corresponds to {@link sop.exception.SOPGPException.UnsupportedSpecialPrefix}).
+     *
+     * @param function function to execute.
+     */
+    public static void assertUnsupportedSpecialPrefix(IntSupplier function) {
+        assertEquals(SOPGPException.UnsupportedSpecialPrefix.EXIT_CODE, function.getAsInt());
+    }
+
+    /**
+     * Assert that the execution of the given function returns error code 73
+     * (which corresponds to {@link sop.exception.SOPGPException.AmbiguousInput}).
+     *
+     * @param function function to execute.
+     */
+    public static void assertAmbiguousInput(IntSupplier function) {
+        assertEquals(SOPGPException.AmbiguousInput.EXIT_CODE, function.getAsInt());
+    }
+
+    /**
+     * Assert that the execution of the given function returns error code 79
+     * (which corresponds to {@link sop.exception.SOPGPException.KeyCannotSign}).
+     *
+     * @param function function to execute.
+     */
+    public static void assertKeyCannotSign(IntSupplier function) {
+        assertEquals(SOPGPException.KeyCannotSign.EXIT_CODE, function.getAsInt());
+    }
+
+    /**
+     * Assert that the execution of the given function returns error code 83
+     * (which corresponds to {@link sop.exception.SOPGPException.IncompatibleOptions}).
+     *
+     * @param function function to execute.
+     */
+    public static void assertIncompatibleOptions(IntSupplier function) {
+        assertEquals(SOPGPException.IncompatibleOptions.EXIT_CODE, function.getAsInt());
+    }
+
+    /**
+     * Assert that the execution of the given function returns error code 89
+     * (which corresponds to {@link sop.exception.SOPGPException.UnsupportedProfile}).
+     *
+     * @param function function to execute.
+     */
+    public static void assertUnsupportedProfile(IntSupplier function) {
+        assertEquals(SOPGPException.UnsupportedProfile.EXIT_CODE, function.getAsInt());
+    }
+}