src/testcases/org/apache/poi/ss/formula/functions/TestEOMonth.java

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package org.apache.poi.ss.formula.functions;

import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.assertTrue;

import java.util.Calendar;
import java.util.Date;

import org.apache.poi.ss.formula.OperationEvaluationContext;
import org.apache.poi.ss.formula.eval.BlankEval;
import org.apache.poi.ss.formula.eval.ErrorEval;
import org.apache.poi.ss.formula.eval.NumberEval;
import org.apache.poi.ss.formula.eval.StringEval;
import org.apache.poi.ss.formula.eval.ValueEval;
import org.apache.poi.ss.usermodel.DateUtil;
import org.apache.poi.ss.usermodel.FormulaError;
import org.apache.poi.util.LocaleUtil;
import org.junit.jupiter.api.Test;

class TestEOMonth {

    private static final double BAD_DATE = -1.0;

    private static final double DATE_1900_01_01 = 1.0;
    private static final double DATE_1900_01_31 = 31.0;
    private static final double DATE_1900_02_28 = 59.0;
    private static final double DATE_1902_09_26 = 1000.0;
    private static final double DATE_1902_09_30 = 1004.0;
    private static final double DATE_2034_06_09 = 49104.0;
    private static final double DATE_2034_06_30 = 49125.0;
    private static final double DATE_2034_07_31 = 49156.0;

    private final FreeRefFunction eOMonth = EOMonth.instance;
    private final OperationEvaluationContext ec = new OperationEvaluationContext(null, null, 0, 0, 0, null);

    @Test
    void testEOMonthProperValues() {
        // verify some border-case combinations of startDate and month-increase
        checkValue(DATE_1900_01_01, 0, DATE_1900_01_31);
        checkValue(DATE_1900_01_01, 1, DATE_1900_02_28);
        checkValue(DATE_1902_09_26, 0, DATE_1902_09_30);
        checkValue(DATE_2034_06_09, 0, DATE_2034_06_30);
        checkValue(DATE_2034_06_09, 1, DATE_2034_07_31);
    }

    @Test
    void testEOMonthBadDateValues() {
        checkValue(0.0, -2, BAD_DATE);
        checkValue(0.0, -3, BAD_DATE);
        checkValue(DATE_1900_01_31, -1, BAD_DATE);
    }

    private void checkValue(double startDate, int monthInc, double expectedResult) {
        ValueEval[] ve = {new NumberEval(startDate), new NumberEval(monthInc)};
        NumberEval result = (NumberEval) eOMonth.evaluate(ve, ec);
        assertEquals(expectedResult, result.getNumberValue(), 0);
    }

    @Test
    void testEOMonthZeroDate() {
        NumberEval result = (NumberEval) eOMonth.evaluate(new ValueEval[] {new NumberEval(0), new NumberEval(0)}, ec);
        assertEquals(DATE_1900_01_31, result.getNumberValue(), 0, "0 startDate is 1900-01-00");

        result = (NumberEval) eOMonth.evaluate(new ValueEval[] {new NumberEval(0), new NumberEval(1)}, ec);
        assertEquals(DATE_1900_02_28, result.getNumberValue(), 0, "0 startDate is 1900-01-00");
    }

    @Test
    void testEOMonthInvalidArguments() {
        ValueEval result = eOMonth.evaluate(new ValueEval[] {new NumberEval(DATE_1902_09_26)}, ec);
        assertTrue(result instanceof ErrorEval);
        assertEquals(FormulaError.VALUE.getCode(), ((ErrorEval) result).getErrorCode(), 0);

        result = eOMonth.evaluate(new ValueEval[] {new StringEval("a"), new StringEval("b")}, ec);
        assertTrue(result instanceof ErrorEval);
        assertEquals(FormulaError.VALUE.getCode(), ((ErrorEval) result).getErrorCode(), 0);
    }

    @Test
    void checkOffset() {
        for (int offset=-12; offset<=12; offset++) {
            Calendar cal = LocaleUtil.getLocaleCalendar();
            Date startDate = cal.getTime();

            cal.add(Calendar.MONTH, offset);
            cal.set(Calendar.DAY_OF_MONTH, cal.getActualMaximum(Calendar.DAY_OF_MONTH));
            cal.clear(Calendar.HOUR);
            cal.set(Calendar.HOUR_OF_DAY, 0);
            cal.clear(Calendar.MINUTE);
            cal.clear(Calendar.SECOND);
            cal.clear(Calendar.MILLISECOND);
            Date expDate = cal.getTime();

            ValueEval[] ve = {
                    new NumberEval(DateUtil.getExcelDate(startDate)),
                    new NumberEval(offset)
            };
            NumberEval result = (NumberEval) eOMonth.evaluate(ve, ec);
            Date actDate = DateUtil.getJavaDate(result.getNumberValue());

            assertEquals(expDate, actDate);
        }
    }

    @Test
    void testBug56688() {
        ValueEval[] ve = {new NumberEval(DATE_1902_09_26), new RefEvalImplementation(new NumberEval(0))};
        NumberEval result = (NumberEval) eOMonth.evaluate(ve, ec);
        assertEquals(DATE_1902_09_30, result.getNumberValue(), 0);
    }

    @Test
    void testRefEvalStartDate() {
        ValueEval[] ve = {new RefEvalImplementation(new NumberEval(DATE_1902_09_26)), new NumberEval(0)};
        NumberEval result = (NumberEval) eOMonth.evaluate(ve, ec);
        assertEquals(DATE_1902_09_30, result.getNumberValue(), 0);
    }

    @Test
    void testEOMonthBlankValueEval() {
        NumberEval evaluate = (NumberEval) eOMonth.evaluate(new ValueEval[] {BlankEval.instance, new NumberEval(0)}, ec);
        assertEquals(DATE_1900_01_31, evaluate.getNumberValue(), 0, "Blank is handled as 0");
    }

    @Test
    void testEOMonthBlankRefValueEval() {
        ValueEval[] ve1 = {new RefEvalImplementation(BlankEval.instance), new NumberEval(1)};
        NumberEval result = (NumberEval) eOMonth.evaluate(ve1, ec);
        assertEquals(DATE_1900_02_28, result.getNumberValue(), 0, "Blank is handled as 0");

        ValueEval[] ve2 = {new NumberEval(1), new RefEvalImplementation(BlankEval.instance)};
        result = (NumberEval) eOMonth.evaluate(ve2, ec);
        assertEquals(DATE_1900_01_31, result.getNumberValue(), 0, "Blank is handled as 0");
    }
}