Add CLI tests fetching test keys from github pages

See https://github.com/pgpainless/pgpainless.github.io

wkd-java-cli/src/test/java/pgp/wkd/cli/online_test_vectors/GithubPagesTestVectors.java

@@ -0,0 +1,37 @@
+// SPDX-FileCopyrightText: 2022 Paul Schaub <vanitasvitae@fsfe.org>
+//
+// SPDX-License-Identifier: Apache-2.0
+
+package pgp.wkd.cli.online_test_vectors;
+
+import com.ginsberg.junit.exit.ExpectSystemExitWithStatus;
+import org.junit.jupiter.api.Test;
+import pgp.wkd.cli.WKDCLI;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+public class GithubPagesTestVectors extends RedirectSystemStreamsTest {
+
+    // Valid WKD publication.
+    // Cert is available at https://pgpainless.github.io/.well-known/openpgpkey/hu/eprjcbeppbna3f6xabhtpddzpn41nknw
+    private static final String USERID_BASE = "WKD Test <wkd-test-base@pgpainless.github.io> [Base Case - Valid User-ID]";
+    private static final String MAIL_BASE = "wkd-test-base@pgpainless.github.io";
+
+    @Test
+    public void testFetchBaseKeyByMailAddress_Successful() {
+        WKDCLI.main(new String[] {"fetch", MAIL_BASE});
+        assertEquals(718, outContent.size());
+    }
+
+    @Test
+    public void testFetchBaseKeyByUserID_Successful() {
+        WKDCLI.main(new String[] {"fetch", USERID_BASE});
+        assertEquals(718, outContent.size());
+    }
+
+    @Test
+    @ExpectSystemExitWithStatus(1)
+    public void testFetchNonExistentKeyFails() {
+        WKDCLI.main(new String[] {"fetch", "wkd-test-nonexistent@pgpainless.github,io"});
+    }
+}

wkd-java-cli/src/test/java/pgp/wkd/cli/online_test_vectors/RedirectSystemStreamsTest.java

@@ -0,0 +1,31 @@
+// SPDX-FileCopyrightText: 2022 Paul Schaub <vanitasvitae@fsfe.org>
+//
+// SPDX-License-Identifier: Apache-2.0
+
+package pgp.wkd.cli.online_test_vectors;
+
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+
+import java.io.ByteArrayOutputStream;
+import java.io.PrintStream;
+
+public abstract class RedirectSystemStreamsTest {
+
+    protected final ByteArrayOutputStream outContent = new ByteArrayOutputStream();
+    protected final ByteArrayOutputStream errContent = new ByteArrayOutputStream();
+    private final PrintStream originalOut = System.out;
+    private final PrintStream originalErr = System.err;
+
+    @BeforeEach
+    public final void setUpStreams() {
+        System.setOut(new PrintStream(outContent));
+        System.setErr(new PrintStream(errContent));
+    }
+
+    @AfterEach
+    public void restoreStreams() {
+        System.setOut(originalOut);
+        System.setErr(originalErr);
+    }
+}