Reproduced issue #1491 in a unit test

Exception with a cause runs into an infinite loop.

Plan/common/src/test/java/com/djrapitops/plan/utilities/logging/ErrorLoggerTest.java

@@ -0,0 +1,123 @@
+/*
+ *  This file is part of Player Analytics (Plan).
+ *
+ *  Plan is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU Lesser General Public License v3 as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  Plan is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU Lesser General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Lesser General Public License
+ *  along with Plan. If not, see <https://www.gnu.org/licenses/>.
+ */
+package com.djrapitops.plan.utilities.logging;
+
+import com.djrapitops.plan.PlanSystem;
+import com.djrapitops.plugin.logging.L;
+import org.junit.jupiter.api.AfterAll;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.io.TempDir;
+import utilities.mocks.PluginMockComponent;
+
+import java.io.File;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.time.Duration;
+import java.util.Arrays;
+import java.util.List;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
+import static org.junit.jupiter.api.Assertions.assertTimeoutPreemptively;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+class ErrorLoggerTest {
+
+    private static ErrorLogger UNDER_TEST;
+    private static Path LOGS_DIR;
+    private static PlanSystem SYSTEM;
+
+    @BeforeAll
+    static void preparePlugin(@TempDir Path dir) throws Exception {
+        PluginMockComponent component = new PluginMockComponent(dir);
+        SYSTEM = component.getPlanSystem();
+        SYSTEM.enable();
+        UNDER_TEST = SYSTEM.getErrorLogger();
+        LOGS_DIR = SYSTEM.getPlanFiles().getLogsDirectory();
+    }
+
+    @AfterAll
+    static void tearDownPlugin() {
+        SYSTEM.disable();
+    }
+
+    @BeforeEach
+    void clearLogsDir() throws IOException {
+        File[] files = LOGS_DIR.toFile().listFiles();
+        if (files != null) {
+            for (File file : files) {
+                Files.deleteIfExists(file.toPath());
+            }
+        }
+    }
+
+    private File[] getErrorLogFiles() {
+        File[] files = LOGS_DIR.toFile().listFiles();
+        return files != null ? files : new File[]{};
+    }
+
+    private List<String> getLines(String errorName) throws IOException {
+        File[] errorLogFiles = getErrorLogFiles();
+        for (File logFile : errorLogFiles) {
+            if (logFile.getName().contains(errorName)) {
+                try (Stream<String> lines = Files.lines(logFile.toPath())) {
+                    return lines.collect(Collectors.toList());
+                }
+            }
+        }
+        throw new AssertionError("File with name '" + errorName + "' doesn't exist: " + Arrays.toString(errorLogFiles));
+    }
+
+    @Test
+    void simpleErrorIsLogged() throws IOException {
+
+        IllegalStateException error = new IllegalStateException();
+        assertTimeoutPreemptively(Duration.ofMillis(500), () ->
+                UNDER_TEST.log(L.WARN, error, ErrorContext.builder()
+                        .whatToDo("Succeed the test")
+                        .related("Test object")
+                        .build())
+        );
+
+        List<String> lines = getLines(error.getClass().getSimpleName());
+        assertTrue(lines.contains("java.lang.IllegalStateException"), () -> "Did not contain 'java.lang.IllegalStateException', " + lines);
+    }
+
+    @Test
+    void errorWithACauseIsLogged() throws IOException {
+        IllegalStateException error = new IllegalStateException(
+                new IllegalArgumentException(
+                        new NullPointerException()
+                )
+        );
+
+        assertTimeoutPreemptively(Duration.ofMillis(500), () ->
+                UNDER_TEST.log(L.WARN, error, ErrorContext.builder()
+                        .whatToDo("Succeed the test")
+                        .related("Test object")
+                        .build())
+        );
+
+        List<String> lines = getLines(error.getClass().getSimpleName());
+        assertTrue(lines.contains("java.lang.IllegalStateException"), () -> "Did not contain 'java.lang.IllegalStateException', " + lines);
+        assertTrue(lines.contains("caused by: java.lang.IllegalArgumentException"), () -> "Did not contain 'caused by: java.lang.IllegalArgumentException', " + lines);
+        assertTrue(lines.contains("caused by: java.lang.NullPointerException"), () -> "Did not contain 'caused by: java.lang.NullPointerException', " + lines);
+    }
+}