Add Unexpected type (#29)

Signed-off-by: David Greven <[email protected]>
Signed-off-by: Sebastian Becker <[email protected]>

common-types/src/main/java/io/carbynestack/common/Unexpected.java

@@ -0,0 +1,85 @@
+/*
+ * Copyright (c) 2021 - for information on the respective copyright owner
+ * see the NOTICE file and/or the repository https://github.com/carbynestack/common.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+package io.carbynestack.common;
+
+import java.util.Optional;
+
+import static java.util.Objects.requireNonNull;
+import static java.util.Optional.ofNullable;
+
+/**
+ * Represents an unexpected {@link Throwable} based failure reason.
+ *
+ * @version JDK 8
+ * @see CsFailureReason
+ * @since 0.2.0
+ */
+public final class Unexpected implements CsFailureReason {
+    /**
+     * The failure reason.
+     *
+     * @since 0.2.0
+     */
+    private final Throwable throwable;
+
+    /**
+     * Creates an {@code Unexpected} instance from a {@code Throwable}.
+     *
+     * @param throwable the failure reason
+     * @since 0.2.0
+     */
+    public Unexpected(Throwable throwable) {
+        this.throwable = requireNonNull(throwable);
+    }
+
+    /**
+     * {@inheritDoc}
+     *
+     * @return the description synopsis
+     * @see #description()
+     * @since 0.2.0
+     */
+    @Override
+    public String synopsis() {
+        return "An unknown exception has occurred.";
+    }
+
+    /**
+     * {@inheritDoc}
+     *
+     * @return the full description
+     * @see #synopsis()
+     * @since 0.2.0
+     */
+    @Override
+    public String description() {
+        return throwable.getLocalizedMessage();
+    }
+
+    /**
+     * {@inheritDoc}
+     *
+     * @return the stack trace as an {@link Optional}
+     * @since 0.2.0
+     */
+    @Override
+    public Optional<StackTraceElement[]> stackTrace() {
+        return ofNullable(throwable.getStackTrace());
+    }
+
+    /**
+     * {@inheritDoc}
+     *
+     * @return {@code true} if the request should be triggered,
+     * otherwise {@code false}.
+     * @since 0.2.0
+     */
+    @Override
+    public boolean reportIssue() {
+        return true;
+    }
+}

common-types/src/test/java/io/carbynestack/common/UnexpectedTest.java

@@ -0,0 +1,43 @@
+/*
+ * Copyright (c) 2021 - for information on the respective copyright owner
+ * see the NOTICE file and/or the repository https://github.com/carbynestack/common.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+package io.carbynestack.common;
+
+import org.junit.jupiter.api.Test;
+
+import java.io.IOException;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+
+class UnexpectedTest {
+    private final Unexpected unknown = new Unexpected(new IOException("test"));
+
+    @Test
+    void constructor() {
+        assertThatThrownBy(() -> new Unexpected(null)).isExactlyInstanceOf(NullPointerException.class);
+    }
+
+    @Test
+    void synopsis() {
+        assertThat(unknown.synopsis()).isEqualTo("An unknown exception has occurred.");
+    }
+
+    @Test
+    void description() {
+        assertThat(unknown.description()).isEqualTo("test");
+    }
+
+    @Test
+    void stackTrace() {
+        assertThat(unknown.stackTrace()).isNotEmpty();
+    }
+
+    @Test
+    void reportIssue() {
+        assertThat(unknown.reportIssue()).isTrue();
+    }
+}