Factor out test value; add comment

Signed-off-by: Scott Kurz <skurz@us.ibm.com>

Author: scottkurz

tests/src/main/java/io/openliberty/tools/eclipse/test/ut/CommandBuilderTest.java

@@ -13,42 +13,64 @@
 
 package io.openliberty.tools.eclipse.test.ut;
 
+import static io.openliberty.tools.eclipse.test.it.utils.SWTBotPluginOperations.unsetBuildCmdPathInPreferences;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 
+import java.io.File;
 import java.nio.file.Path;
 import java.nio.file.Paths;
 
+import org.eclipse.swtbot.eclipse.finder.SWTWorkbenchBot;
 import org.junit.jupiter.api.Test;
 
 import io.openliberty.tools.eclipse.CommandBuilder;
 
 public class CommandBuilderTest {
 
+	
 
+	/**
+	 * Tests the CommandBuilder builds a mvn invocation using the mvnw wrapper found in the project, even when the preference
+	 * is unset
+	 * 
+	 * @throws Exception
+	 */
 	@Test
 	public void testCmdBuilderMvnWrapper() throws Exception {
+		// This allows the test to prove the wrapper is in use even when the preference is unset, since an empty string preference would
+		// resolve to "" + "/bin/mvn" = "/bin/mvn" and would typically be an actual path on Unix/Mac
+        unsetBuildCmdPathInPreferences(new SWTWorkbenchBot(), "Maven");
 		Path projectPath = Paths.get("resources", "applications", "maven", "liberty-maven-test-wrapper-app");
-		String pathEnv="C:\\abc;;C:\\xyz";
-		String retVal = CommandBuilder.getMavenCommandLine(projectPath.toString(), "-a 123", pathEnv, false);
+		String retVal = CommandBuilder.getMavenCommandLine(projectPath.toString(), "-a 123", obfuscatedPath(), false);
 		assertEquals(projectPath.resolve(mvnwName()) + " -a 123", retVal, "Wrong cmd line");
 	}
 
+	/**
+	 * Tests the CommandBuilder builds a mvn invocation using the mvn found in the path, even when there is an empty path element
+	 * 
+	 * @throws Exception
+	 */
 	@Test
 	public void testCmdBuilderMvn() throws Exception {
 		Path projectPath = Paths.get("resources", "applications", "maven", "liberty-maven-test-app");
 		Path mvnPath = Paths.get("resources", "execs");
-		String mvnPathStr = mvnPath.toAbsolutePath().toString();
-		
-		String pathEnv= null; 
+		String pathEnv= obfuscatedPath() + File.pathSeparator + mvnPath.toAbsolutePath().toString();
+		String retVal = CommandBuilder.getMavenCommandLine(projectPath.toString(), "-a 123", pathEnv, false);
+		assertEquals(mvnPath.toAbsolutePath().resolve(mvnName()) + " -a 123", retVal, "Wrong cmd line");
+	}
+
+	/**
+	 * @return 	A platform-dependent path very unlikely to be used, with an empty element
+	 */
+	private String obfuscatedPath() {
 		if (System.getProperty("os.name").contains("Windows")) {
-		    pathEnv="C:\\abc;;C:\\xyz;" +mvnPathStr;
+			return "C:\\abc\\xyz\\123\456;;C:\\xyz\\abc\\456\\123";
 		} else {
-			pathEnv="/a/b/c1::/x/y/z1:" +mvnPathStr;
+			return "/a/b/c/d1/e/f/g::/x/ya/b2/saa/";
 		}
-		String retVal = CommandBuilder.getMavenCommandLine(projectPath.toString(), "-a 123", pathEnv, false);
-		assertEquals(mvnPath.toAbsolutePath().resolve(mvnName()) + " -a 123", retVal, "Wrong cmd line");
 	}
 
+	
 	private String mvnName() {
 		if (System.getProperty("os.name").contains("Windows")) {
 			return "mvn.cmd";