How to use

SumFunction

in

org.kie.dmn.feel.runtime.functions

  public FEELFnResult<BigDecimal> invoke(@ParameterName("n") Object[] list) {
    if ( list == null ) { 
      // Arrays.asList does not accept null as parameter
      return FEELFnResult.ofError(new InvalidParametersEvent(Severity.ERROR, "n", "the single value list cannot be null"));
    }
    
    return invoke( Arrays.asList( list ) );
  }
}

@Before
public void setUp() {
  sumFunction = new SumFunction();
}

@Test
public void invokeNumberParamSupportedNumber() {
  FunctionTestUtil.assertResult(sumFunction.invoke(BigDecimal.TEN), BigDecimal.TEN);
  FunctionTestUtil.assertResult(sumFunction.invoke(10), BigDecimal.TEN);
  FunctionTestUtil.assertResult(sumFunction.invoke(-10), BigDecimal.valueOf(-10));
  FunctionTestUtil.assertResult(sumFunction.invoke(10.12), BigDecimal.valueOf(10.12));
}

@Test
public void invokeListParamSupportedTypes() {
  FunctionTestUtil.assertResult(sumFunction.invoke(Arrays.asList(4, -1, 12.1, (long) 5, BigDecimal.TEN)), BigDecimal.valueOf(30.1));
}

@Test
public void invokeListParamContainsUnsupportedType() {
  FunctionTestUtil.assertResultError(sumFunction.invoke(Arrays.asList(10, "test", 2)), InvalidParametersEvent.class);
}

  @Test
  public void invokeArrayParamSupportedTypes() {
    FunctionTestUtil.assertResult(sumFunction.invoke(new Object[]{4, -1, 12.1, (long) 5, BigDecimal.TEN}), BigDecimal.valueOf(30.1));
  }
}

@Test
public void invokeListParamContainsUnsupportedNumber() {
  FunctionTestUtil.assertResultError(sumFunction.invoke(Arrays.asList(10, 2, Double.NaN)), InvalidParametersEvent.class);
}

public FEELFnResult<BigDecimal> invoke(@ParameterName( "list" ) List list) {
  if ( list == null ) {
    return FEELFnResult.ofError(new InvalidParametersEvent(Severity.ERROR, "list", "cannot be null"));
  }
  FEELFnResult<BigDecimal> s = sum.invoke( list );
  
  Function<FEELEvent, FEELFnResult<BigDecimal>> ifLeft = (event) -> {
    return FEELFnResult.ofError(new InvalidParametersEvent(Severity.ERROR, "list", "unable to sum the elements which is required to calculate the mean"));
  };
  
  Function<BigDecimal, FEELFnResult<BigDecimal>> ifRight = (sum) -> {
    try {
      return FEELFnResult.ofResult( sum.divide( BigDecimal.valueOf( list.size() ), MathContext.DECIMAL128 ) );
    } catch (Exception e) {
      return FEELFnResult.ofError( new InvalidParametersEvent(Severity.ERROR, "unable to perform division to calculate the mean", e) );
    }
  };
  
  return s.cata(ifLeft, ifRight);
}

@Test
public void invokeNumberParamUnsupportedNumber() {
  FunctionTestUtil.assertResultError(sumFunction.invoke(Double.NaN), InvalidParametersEvent.class);
}

@Test
public void invokeArrayParam() {
  FunctionTestUtil.assertResultError(sumFunction.invoke((Object[]) null), InvalidParametersEvent.class);
}

@Test
public void invokeArrayParamContainsUnsupportedType() {
  FunctionTestUtil.assertResultError(sumFunction.invoke(new Object[]{10, "test", 2}), InvalidParametersEvent.class);
}

@Test
public void invokeNumberParamNull() {
  FunctionTestUtil.assertResultError(sumFunction.invoke((Number) null), InvalidParametersEvent.class);
}

@Test
public void invokeListParam() {
  FunctionTestUtil.assertResultError(sumFunction.invoke((List) null), InvalidParametersEvent.class);
}

@Test
public void invokeArrayParamContainsUnsupportedNumber() {
  FunctionTestUtil.assertResultError(sumFunction.invoke(new Object[]{10, 2, Double.NaN}), InvalidParametersEvent.class);
}