add tests around MojoUtils.getJvm

Author: cstroe

src/main/java/org/scalatest/tools/maven/AbstractScalaTestMojo.java

@@ -319,19 +319,6 @@ public void consumeLine(final String line) {
         }
     }
 
-    private String getJvm()
-    {
-        // use the same JVM as the one used to run Maven (the "java.home" one)
-        String jvmToUse = System.getProperty( "java.home" ) + File.separator + "bin" + File.separator + "java";
-
-        if (isEmpty(jvmToUse)) {
-            jvmToUse = "java";
-        }
-
-        getLog().debug( "Using JVM: " + jvmToUse );
-        return jvmToUse;
-    }
-
     private String buildClassPathEnvironment() {
         StringBuffer buf = new StringBuffer();
         boolean first = true;

src/main/java/org/scalatest/tools/maven/MojoUtils.java

@@ -3,7 +3,8 @@
 import java.util.List;
 import java.util.ArrayList;
 import java.io.File;
-import java.io.IOException;
+
+import static org.apache.commons.lang3.StringUtils.isEmpty;
 
 /**
  * Provides internal utilities for the Mojo's operations.
@@ -121,4 +122,12 @@ static String[] concat(List<String>...lists){
         }
         return c.toArray(new String[c.size()]);
     }
+
+    static String getJvm() {
+        if (!isEmpty(System.getProperty( "java.home" ))) {
+            return System.getProperty( "java.home" ) + File.separator + "bin" + File.separator + "java";
+        } else {
+            return "java";
+        }
+    }
 }

src/test/scala/org/scalatest/tools/maven/MojoUtilsTest.scala

@@ -0,0 +1,31 @@
+package org.scalatest.tools.maven
+
+import org.junit.{Before, Test}
+
+class MojoUtilsTest {
+  private var savedJavaHome: Option[String] = _
+
+  @Before
+  def save() = {
+    savedJavaHome = Option(System.getProperty("java.home"))
+  }
+
+  def restore() = {
+    savedJavaHome match {
+      case None => System.clearProperty("java.home")
+      case Some(value) => System.setProperty("java.home", value)
+    }
+  }
+
+  @Test
+  def getJvmHappyPath() = {
+    System.setProperty("java.home", "/test/jvm")
+    assert(MojoUtils.getJvm == "/test/jvm/bin/java")
+  }
+
+  @Test
+  def getJvmWithoutJavaHome() = {
+    System.clearProperty("java.home")
+    assert(MojoUtils.getJvm == "java")
+  }
+}