import org.junit.Test;

import static org.hamcrest.CoreMatchers.*;
import static org.junit.Assert.*;

public class LibraryTest {

    @Test
    public void testSomeLibraryMethod() {
        assertThat(new Library().someLibraryMethod(), is(true));
    }
}

import org.junit.Test;

import static org.junit.Assert.*;

public class LibraryTest {

    @Test
    public void testSomeLibraryMethod() {
        Library classUnderTest = new Library();
        assertTrue("someLibraryMethod should return 'true'", classUnderTest.someLibraryMethod());
    }
}

--- 
+++ 
@@ -1,12 +1,12 @@
 import org.junit.Test;
 
+import static org.hamcrest.CoreMatchers.*;
 import static org.junit.Assert.*;
 
 public class LibraryTest {
 
     @Test
     public void testSomeLibraryMethod() {
-        Library classUnderTest = new Library();
-        assertTrue("someLibraryMethod should return 'true'", classUnderTest.someLibraryMethod());
+        assertThat(new Library().someLibraryMethod(), is(true));
     }
 }
Use assertThat instead of assertTrue

http://forums.gradle.org/gradle/topics/improvement_ideas_for_the_build_init_plugin
