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package org.apache.poi.hssf.record.formula.eval;
import junit.framework.AssertionFailedError;
import junit.framework.TestCase;
import org.apache.poi.hssf.usermodel.HSSFCell;
import org.apache.poi.hssf.usermodel.HSSFFormulaEvaluator;
import org.apache.poi.hssf.usermodel.HSSFRow;
import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.CellValue;
import org.apache.poi.ss.usermodel.ErrorConstants;
/**
* Tests HSSFFormulaEvaluator for its handling of cell formula circular references.
*
* @author Josh Micich
*/
public final class TestCircularReferences extends TestCase {
/**
* Translates StackOverflowError into AssertionFailedError
*/
private static CellValue evaluateWithCycles(HSSFWorkbook wb, HSSFCell testCell)
throws AssertionFailedError {
HSSFFormulaEvaluator evaluator = new HSSFFormulaEvaluator(wb);
try {
return evaluator.evaluate(testCell);
} catch (StackOverflowError e) {
throw new AssertionFailedError( "circular reference caused stack overflow error");
}
}
/**
* Makes sure that the specified evaluated cell value represents a circular reference error.
*/
private static void confirmCycleErrorCode(CellValue cellValue) {
assertTrue(cellValue.getCellType() == HSSFCell.CELL_TYPE_ERROR);
assertEquals(ErrorEval.CIRCULAR_REF_ERROR.getErrorCode(), cellValue.getErrorValue());
}
/**
* ASF Bugzilla Bug 44413
* "INDEX() formula cannot contain its own location in the data array range"
*/
public void testIndexFormula() {
HSSFWorkbook wb = new HSSFWorkbook();
HSSFSheet sheet = wb.createSheet("Sheet1");
int colB = 1;
sheet.createRow(0).createCell(colB).setCellValue(1);
sheet.createRow(1).createCell(colB).setCellValue(2);
sheet.createRow(2).createCell(colB).setCellValue(3);
HSSFRow row4 = sheet.createRow(3);
HSSFCell testCell = row4.createCell(0);
// This formula should evaluate to the contents of B2,
testCell.setCellFormula("INDEX(A1:B4,2,2)");
// However the range A1:B4 also includes the current cell A4. If the other parameters
// were 4 and 1, this would represent a circular reference. Prior to v3.2 POI would
// 'fully' evaluate ref arguments before invoking operators, which raised the possibility of
// cycles / StackOverflowErrors.
CellValue cellValue = evaluateWithCycles(wb, testCell);
assertTrue(cellValue.getCellType() == HSSFCell.CELL_TYPE_NUMERIC);
assertEquals(2, cellValue.getNumberValue(), 0);
}
/**
* Cell A1 has formula "=A1"
*/
public void testSimpleCircularReference() {
HSSFWorkbook wb = new HSSFWorkbook();
HSSFSheet sheet = wb.createSheet("Sheet1");
HSSFRow row = sheet.createRow(0);
HSSFCell testCell = row.createCell(0);
testCell.setCellFormula("A1");
CellValue cellValue = evaluateWithCycles(wb, testCell);
confirmCycleErrorCode(cellValue);
}
/**
* A1=B1, B1=C1, C1=D1, D1=A1
*/
public void testMultiLevelCircularReference() {
HSSFWorkbook wb = new HSSFWorkbook();
HSSFSheet sheet = wb.createSheet("Sheet1");
HSSFRow row = sheet.createRow(0);
row.createCell(0).setCellFormula("B1");
row.createCell(1).setCellFormula("C1");
row.createCell(2).setCellFormula("D1");
HSSFCell testCell = row.createCell(3);
testCell.setCellFormula("A1");
CellValue cellValue = evaluateWithCycles(wb, testCell);
confirmCycleErrorCode(cellValue);
}
public void testIntermediateCircularReferenceResults_bug46898() {
HSSFWorkbook wb = new HSSFWorkbook();
HSSFSheet sheet = wb.createSheet("Sheet1");
HSSFRow row = sheet.createRow(0);
HSSFCell cellA1 = row.createCell(0);
HSSFCell cellB1 = row.createCell(1);
HSSFCell cellC1 = row.createCell(2);
HSSFCell cellD1 = row.createCell(3);
HSSFCell cellE1 = row.createCell(4);
cellA1.setCellFormula("IF(FALSE, 1+B1, 42)");
cellB1.setCellFormula("1+C1");
cellC1.setCellFormula("1+D1");
cellD1.setCellFormula("1+E1");
cellE1.setCellFormula("1+A1");
HSSFFormulaEvaluator fe = new HSSFFormulaEvaluator(wb);
CellValue cv;
// Happy day flow - evaluate A1 first
cv = fe.evaluate(cellA1);
assertEquals(Cell.CELL_TYPE_NUMERIC, cv.getCellType());
assertEquals(42.0, cv.getNumberValue(), 0.0);
cv = fe.evaluate(cellB1); // no circ-ref-error because A1 result is cached
assertEquals(Cell.CELL_TYPE_NUMERIC, cv.getCellType());
assertEquals(46.0, cv.getNumberValue(), 0.0);
// Show the bug - evaluate another cell from the loop first
fe.clearAllCachedResultValues();
cv = fe.evaluate(cellB1);
if (cv.getCellType() == ErrorEval.CIRCULAR_REF_ERROR.getErrorCode()) {
throw new AssertionFailedError("Identified bug 46898");
}
assertEquals(Cell.CELL_TYPE_NUMERIC, cv.getCellType());
assertEquals(46.0, cv.getNumberValue(), 0.0);
// start evaluation on another cell
fe.clearAllCachedResultValues();
cv = fe.evaluate(cellE1);
assertEquals(Cell.CELL_TYPE_NUMERIC, cv.getCellType());
assertEquals(43.0, cv.getNumberValue(), 0.0);
}
}