### Question:
ScalaLanguage extends AbstractLanguage { @Override public String[] getFileSuffixes() { String[] suffixes = configuration.getStringArray(ScalaPlugin.SCALA_FILE_SUFFIXES_KEY); if (suffixes.length == 0) { suffixes = ScalaPlugin.SCALA_FILE_SUFFIXES_DEFAULT_VALUE.split(","); } return suffixes; } ScalaLanguage(Configuration configuration); @Override String[] getFileSuffixes();  }### Answer:
@Test public void test_suffixes_default() { ScalaLanguage scalaLanguage = new ScalaLanguage(new MapSettings().asConfig()); assertThat(scalaLanguage.getFileSuffixes()).containsExactly(".scala"); }
@Test public void test_suffixes_empty() { ScalaLanguage scalaLanguage = new ScalaLanguage(new MapSettings().setProperty(ScalaPlugin.SCALA_FILE_SUFFIXES_KEY, "").asConfig()); assertThat(scalaLanguage.getFileSuffixes()).containsExactly(".scala"); }
@Test public void test_suffixes_custom() { ScalaLanguage scalaLanguage = new ScalaLanguage(new MapSettings().setProperty(ScalaPlugin.SCALA_FILE_SUFFIXES_KEY, ".custom").asConfig()); assertThat(scalaLanguage.getFileSuffixes()).containsExactly(".custom"); }