Add a base class for SciJava-based unit tests

This eases creation + disposal of a unique Context for each test method.

Author: ctrueden

src/test/java/org/scijava/test/AbstractSciJavaTest.java

@@ -0,0 +1,87 @@
+/*
+ * #%L
+ * SciJava Common shared library for SciJava software.
+ * %%
+ * Copyright (C) 2009 - 2016 Board of Regents of the University of
+ * Wisconsin-Madison, Broad Institute of MIT and Harvard, and Max Planck
+ * Institute of Molecular Cell Biology and Genetics.
+ * %%
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ * 
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ * #L%
+ */
+
+package org.scijava.test;
+
+import java.awt.Cursor;
+import java.util.Random;
+
+import org.junit.After;
+import org.junit.Before;
+import org.scijava.Context;
+import org.scijava.plugin.Parameter;
+import org.scijava.service.Service;
+import org.scijava.util.ByteArray;
+import org.scijava.util.FloatArray;
+
+/**
+ * Base class for unit testing of SciJava components.
+ * <p>
+ * Many SciJava-based unit tests need to have a {@link Context} with relevant
+ * services. Following the
+ * <a href="https://en.wikipedia.org/wiki/Don%27t_repeat_yourself">DRY
+ * principle</a>, we should implement it only once. Here.
+ * </p>
+ * 
+ * @author Johannes Schindelin
+ * @author Curtis Rueden
+ */
+public abstract class AbstractSciJavaTest {
+
+	@Parameter
+	protected Context context;
+
+	/** Subclasses can override to create a differently configured context. */
+	protected Context createContext() {
+		return new Context(serviceClasses());
+	}
+
+	/** Subclasses must override to define the services the context will have. */
+	protected abstract Class<? extends Service>[] serviceClasses();
+
+	/** Sets up a SciJava context and injects needed services. */
+	@Before
+	public void setUp() {
+		createContext().inject(this);
+	}
+
+	/**
+	 * Disposes of the {@link Context} that was initialized in {@link #setUp()}.
+	 */
+	@After
+	public synchronized void cleanUp() {
+		if (context != null) {
+			context.dispose();
+			context = null;
+		}
+	}
+
+}