@Test
  public void isTypeConvertibleShouldReturnTrueForNumericPrimitivesAndWrappers() {
    for (int i = 0; i < TypeUtils._numericPrimitiveClasses.size(); i++) {
      Class sourceType = TypeUtils._numericPrimitiveClasses.get(i);

      TypeUtils._numericPrimitiveClasses.stream().skip(i).forEachOrdered(
          destType -> assertThat(TypeUtils.isTypeConvertible(sourceType, destType)).isTrue());
      TypeUtils._numericWrapperClasses.stream().skip(i).limit(1).forEachOrdered(
          destType -> assertThat(TypeUtils.isTypeConvertible(sourceType, destType)).isTrue());
    }

    for (int i = 0; i < TypeUtils._numericWrapperClasses.size(); i++) {
      Class sourceType = TypeUtils._numericWrapperClasses.get(i);

      TypeUtils._numericPrimitiveClasses.stream().skip(i).forEachOrdered(
          destType -> assertThat(TypeUtils.isTypeConvertible(sourceType, destType)).isTrue());
      TypeUtils._numericWrapperClasses.stream().skip(i).limit(1).forEachOrdered(
          destType -> assertThat(TypeUtils.isTypeConvertible(sourceType, destType)).isTrue());
    }
  }
Can't test every possible combination so try the known, relevant ones.
geode-core/src/test/java/org/apache/geode/cache/query/internal/types/TypeUtilsJUnitTest.java