poi/src/test/java/org/apache/poi/hssf/record/TestSharedFormulaRecord.java

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package org.apache.poi.hssf.record;

import static org.junit.jupiter.api.Assertions.assertArrayEquals;
import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.assertNotEquals;

import java.util.stream.Stream;

import org.apache.poi.hssf.HSSFTestDataSamples;
import org.apache.poi.hssf.usermodel.HSSFCell;
import org.apache.poi.hssf.usermodel.HSSFEvaluationWorkbook;
import org.apache.poi.hssf.usermodel.HSSFFormulaEvaluator;
import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.ss.SpreadsheetVersion;
import org.apache.poi.ss.formula.FormulaParser;
import org.apache.poi.ss.formula.FormulaRenderer;
import org.apache.poi.ss.formula.FormulaType;
import org.apache.poi.ss.formula.SharedFormula;
import org.apache.poi.ss.formula.ptg.Ptg;
import org.apache.poi.ss.formula.ptg.RefPtg;
import org.apache.poi.ss.usermodel.CellType;
import org.apache.poi.ss.usermodel.CellValue;
import org.apache.poi.util.LittleEndianInput;
import org.junit.jupiter.api.Test;

final class TestSharedFormulaRecord {

    /**
     * A sample spreadsheet known to have one sheet with 4 shared formula ranges
     */
    private static final String SHARED_FORMULA_TEST_XLS = "SharedFormulaTest.xls";
    /**
     * Binary data for an encoded formula.  Taken from attachment 22062 (bugzilla 45123/45421).
     * The shared formula is in Sheet1!C6:C21, with text "SUMPRODUCT(--(End_Acct=$C6),--(End_Bal))"
     * This data is found at offset 0x1A4A (within the shared formula record).
     * The critical thing about this formula is that it contains shared formula tokens (tRefN*,
     * tAreaN*) with operand class 'array'.
     */
    private static final byte[] SHARED_FORMULA_WITH_REF_ARRAYS_DATA = {
        0x1A, 0x00,
        0x63, 0x02, 0x00, 0x00, 0x00,
        0x6C, 0x00, 0x00, 0x02, (byte)0x80,  // tRefNA
        0x0B,
        0x15,
        0x13,
        0x13,
        0x63, 0x03, 0x00, 0x00, 0x00,
        0x15,
        0x13,
        0x13,
        0x42, 0x02, (byte)0xE4, 0x00,
    };

    /**
     * The method {@code SharedFormulaRecord.convertSharedFormulas()} converts formulas from
     * 'shared formula' to 'single cell formula' format.  It is important that token operand
     * classes are preserved during this transformation, because Excel may not tolerate the
     * incorrect encoding.  The formula here is one such example (Excel displays #VALUE!).
     */
    @Test
    void testConvertSharedFormulasOperandClasses_bug45123() {

        LittleEndianInput in = TestcaseRecordInputStream.createLittleEndian(SHARED_FORMULA_WITH_REF_ARRAYS_DATA);
        int encodedLen = in.readUShort();
        Ptg[] sharedFormula = Ptg.readTokens(encodedLen, in);

        SharedFormula sf = new SharedFormula(SpreadsheetVersion.EXCEL97);
        Ptg[] convertedFormula = sf.convertSharedFormulas(sharedFormula, 100, 200);

        RefPtg refPtg = (RefPtg) convertedFormula[1];
        assertEquals("$C101", refPtg.toFormulaString());
        assertNotEquals(Ptg.CLASS_REF, refPtg.getPtgClass(), "Identified bug 45123");
        confirmOperandClasses(sharedFormula, convertedFormula);
    }

    private static void confirmOperandClasses(Ptg[] originalPtgs, Ptg[] convertedPtgs) {
        int[] exp = Stream.of(originalPtgs).map(Ptg::getPtgClass).mapToInt(Byte::intValue).toArray();
        int[] act = Stream.of(convertedPtgs).map(Ptg::getPtgClass).mapToInt(Byte::intValue).toArray();
        assertArrayEquals(exp, act, "Different operand class");
    }

    @Test
    void testConvertSharedFormulas() {
        HSSFWorkbook wb = new HSSFWorkbook();
        HSSFEvaluationWorkbook fpb = HSSFEvaluationWorkbook.create(wb);
        Ptg[] sharedFormula, convertedFormula;

        SharedFormula sf = new SharedFormula(SpreadsheetVersion.EXCEL97);

        sharedFormula = FormulaParser.parse("A2", fpb, FormulaType.CELL, -1);
        convertedFormula = sf.convertSharedFormulas(sharedFormula, 0, 0);
        confirmOperandClasses(sharedFormula, convertedFormula);
        //conversion relative to [0,0] should return the original formula
        assertEquals("A2", FormulaRenderer.toFormulaString(fpb, convertedFormula));

        convertedFormula = sf.convertSharedFormulas(sharedFormula, 1, 0);
        confirmOperandClasses(sharedFormula, convertedFormula);
        //one row down
        assertEquals("A3", FormulaRenderer.toFormulaString(fpb, convertedFormula));

        convertedFormula = sf.convertSharedFormulas(sharedFormula, 1, 1);
        confirmOperandClasses(sharedFormula, convertedFormula);
        //one row down and one cell right
        assertEquals("B3", FormulaRenderer.toFormulaString(fpb, convertedFormula));

        sharedFormula = FormulaParser.parse("SUM(A1:C1)", fpb, FormulaType.CELL, -1);
        convertedFormula = sf.convertSharedFormulas(sharedFormula, 0, 0);
        confirmOperandClasses(sharedFormula, convertedFormula);
        assertEquals("SUM(A1:C1)", FormulaRenderer.toFormulaString(fpb, convertedFormula));

        convertedFormula = sf.convertSharedFormulas(sharedFormula, 1, 0);
        confirmOperandClasses(sharedFormula, convertedFormula);
        assertEquals("SUM(A2:C2)", FormulaRenderer.toFormulaString(fpb, convertedFormula));

        convertedFormula = sf.convertSharedFormulas(sharedFormula, 1, 1);
        confirmOperandClasses(sharedFormula, convertedFormula);
        assertEquals("SUM(B2:D2)", FormulaRenderer.toFormulaString(fpb, convertedFormula));
    }

    /**
     * Make sure that POI preserves {@link SharedFormulaRecord}s
     */
    @Test
    void testPreserveOnReserialize() {
        HSSFWorkbook wb;
        HSSFSheet sheet;
        HSSFCell cellB32769;
        HSSFCell cellC32769;

        // Reading directly from XLS file
        wb = HSSFTestDataSamples.openSampleWorkbook(SHARED_FORMULA_TEST_XLS);
        sheet = wb.getSheetAt(0);
        cellB32769 = sheet.getRow(32768).getCell(1);
        cellC32769 = sheet.getRow(32768).getCell(2);
        // check reading of formulas which are shared (two cells from a 1R x 8C range)
        assertEquals("B32770*2", cellB32769.getCellFormula());
        assertEquals("C32770*2", cellC32769.getCellFormula());
        confirmCellEvaluation(wb, cellB32769, 4);
        confirmCellEvaluation(wb, cellC32769, 6);
        // Confirm this example really does have SharedFormulas.
        // there are 3 others besides the one at A32769:H32769
        assertEquals(4, countSharedFormulas(sheet));


        // Re-serialize and check again
        wb = HSSFTestDataSamples.writeOutAndReadBack(wb);
        sheet = wb.getSheetAt(0);
        cellB32769 = sheet.getRow(32768).getCell(1);
        cellC32769 = sheet.getRow(32768).getCell(2);
        assertEquals("B32770*2", cellB32769.getCellFormula());
        assertEquals("C32770*2", cellC32769.getCellFormula());
        confirmCellEvaluation(wb, cellB32769, 4);
        assertEquals(4, countSharedFormulas(sheet));
    }

    @Test
    void testUnshareFormulaDueToChangeFormula() {
        HSSFWorkbook wb;
        HSSFSheet sheet;
        HSSFCell cellB32769;
        HSSFCell cellC32769;

        wb = HSSFTestDataSamples.openSampleWorkbook(SHARED_FORMULA_TEST_XLS);
        sheet = wb.getSheetAt(0);
        cellB32769 = sheet.getRow(32768).getCell(1);
        cellC32769 = sheet.getRow(32768).getCell(2);

        // Updating cell formula, causing it to become unshared
        cellB32769.setCellFormula("1+1");
        confirmCellEvaluation(wb, cellB32769, 2);
        // currently (Oct 2008) POI handles this by exploding the whole shared formula group
        assertEquals(3, countSharedFormulas(sheet)); // one less now
        // check that nearby cell of the same group still has the same formula
        assertEquals("C32770*2", cellC32769.getCellFormula());
        confirmCellEvaluation(wb, cellC32769, 6);
    }

    @Test
    void testUnshareFormulaDueToDelete() {
        HSSFWorkbook wb;
        HSSFSheet sheet;
        HSSFCell cell;
        final int ROW_IX = 2;

        // changing shared formula cell to blank
        wb = HSSFTestDataSamples.openSampleWorkbook(SHARED_FORMULA_TEST_XLS);
        sheet = wb.getSheetAt(0);

        assertEquals("A$1*2", sheet.getRow(ROW_IX).getCell(1).getCellFormula());
        cell = sheet.getRow(ROW_IX).getCell(1);
        cell.setBlank();
        assertEquals(3, countSharedFormulas(sheet));

        wb = HSSFTestDataSamples.writeOutAndReadBack(wb);
        sheet = wb.getSheetAt(0);
        assertEquals("A$1*2", sheet.getRow(ROW_IX+1).getCell(1).getCellFormula());

        // deleting shared formula cell
        wb = HSSFTestDataSamples.openSampleWorkbook(SHARED_FORMULA_TEST_XLS);
        sheet = wb.getSheetAt(0);

        assertEquals("A$1*2", sheet.getRow(ROW_IX).getCell(1).getCellFormula());
        cell = sheet.getRow(ROW_IX).getCell(1);
        sheet.getRow(ROW_IX).removeCell(cell);
        assertEquals(3, countSharedFormulas(sheet));

        wb = HSSFTestDataSamples.writeOutAndReadBack(wb);
        sheet = wb.getSheetAt(0);
        assertEquals("A$1*2", sheet.getRow(ROW_IX+1).getCell(1).getCellFormula());
    }

    private static void confirmCellEvaluation(HSSFWorkbook wb, HSSFCell cell, double expectedValue) {
        HSSFFormulaEvaluator fe = new HSSFFormulaEvaluator(wb);
        CellValue cv = fe.evaluate(cell);
        assertEquals(CellType.NUMERIC, cv.getCellType());
        assertEquals(expectedValue, cv.getNumberValue(), 0.0);
    }

    /**
     * @return the number of {@link SharedFormulaRecord}s encoded for the specified sheet
     */
    private static int countSharedFormulas(HSSFSheet sheet) {
        int[] count = { 0 };
        sheet.getSheet().visitContainedRecords(r -> count[0] += r instanceof SharedFormulaRecord ? 1 : 0, 0);
        return count[0];
    }
}