Sonar fixes

add asserts to tests

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1885585 13f79535-47bb-0310-9956-ffa450edef68

9 files changed, 180 insertions, 229 deletions

diff --git a/src/testcases/org/apache/poi/ss/usermodel/BaseTestSheetShiftRows.java b/src/testcases/org/apache/poi/ss/usermodel/BaseTestSheetShiftRows.java
index 4e93a62156..67d351bffc 100644
--- a/src/testcases/org/apache/poi/ss/usermodel/BaseTestSheetShiftRows.java
+++ b/src/testcases/org/apache/poi/ss/usermodel/BaseTestSheetShiftRows.java
@@ -19,6 +19,7 @@ package org.apache.poi.ss.usermodel;
 
 import static org.apache.poi.POITestCase.skipTest;
 import static org.apache.poi.POITestCase.testPassesNow;
+import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertNotEquals;
 import static org.junit.jupiter.api.Assertions.assertNotNull;
@@ -124,12 +125,12 @@ public abstract class BaseTestSheetShiftRows {
      */
     @Test
     public final void testShiftRow() throws IOException {
-        Workbook wb = _testDataProvider.createWorkbook();
-        Sheet s = wb.createSheet();
-        s.createRow(0).createCell(0).setCellValue("TEST1");
-        s.createRow(3).createCell(0).setCellValue("TEST2");
-        s.shiftRows(0,4,1);
-        wb.close();
+        try (Workbook wb = _testDataProvider.createWorkbook()) {
+            Sheet s = wb.createSheet();
+            s.createRow(0).createCell(0).setCellValue("TEST1");
+            s.createRow(3).createCell(0).setCellValue("TEST2");
+            assertDoesNotThrow(() -> s.shiftRows(0, 4, 1));
+        }
     }
 
     /**
@@ -491,13 +492,12 @@ public abstract class BaseTestSheetShiftRows {
 
     @Test
     void test47169() throws IOException {
-        Workbook wb = _testDataProvider.createWorkbook();
-        Sheet sheet = wb.createSheet();
-        sheet.createRow(30);
-        sheet.shiftRows(29, 29, 1, true, true);
-        sheet.createRow(30);
-
-        wb.close();
+        try (Workbook wb = _testDataProvider.createWorkbook()) {
+            Sheet sheet = wb.createSheet();
+            sheet.createRow(30);
+            sheet.shiftRows(29, 29, 1, true, true);
+            assertDoesNotThrow(() -> sheet.createRow(30));
+        }
     }
 
     /**
diff --git a/src/testcases/org/apache/poi/ss/usermodel/BaseTestWorkbook.java b/src/testcases/org/apache/poi/ss/usermodel/BaseTestWorkbook.java
index 6de40bb4b4..11bb3c9357 100644
--- a/src/testcases/org/apache/poi/ss/usermodel/BaseTestWorkbook.java
+++ b/src/testcases/org/apache/poi/ss/usermodel/BaseTestWorkbook.java
@@ -18,6 +18,7 @@
 package org.apache.poi.ss.usermodel;
 
 import static org.junit.jupiter.api.Assertions.assertArrayEquals;
+import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertFalse;
 import static org.junit.jupiter.api.Assertions.assertNotNull;
@@ -765,8 +766,7 @@ public abstract class BaseTestWorkbook {
 
     @Test
     void test58499() throws IOException {
-        try (Workbook workbook = _testDataProvider.createWorkbook();
-             OutputStream os = new NullOutputStream()) {
+        try (Workbook workbook = _testDataProvider.createWorkbook()) {
             Sheet sheet = workbook.createSheet();
             for (int i = 0; i < 900; i++) {
                 Row r = sheet.createRow(i);
@@ -775,7 +775,7 @@ public abstract class BaseTestWorkbook {
                 c.setCellStyle(cs);
                 c.setCellValue("AAA");
             }
-            workbook.write(os);
+            assertDoesNotThrow(() -> workbook.write(new NullOutputStream()));
         }
     }
 
diff --git a/src/testcases/org/apache/poi/ss/usermodel/TestExcelStyleDateFormatter.java b/src/testcases/org/apache/poi/ss/usermodel/TestExcelStyleDateFormatter.java
index fd904ab1b5..e27557e9b9 100644
--- a/src/testcases/org/apache/poi/ss/usermodel/TestExcelStyleDateFormatter.java
+++ b/src/testcases/org/apache/poi/ss/usermodel/TestExcelStyleDateFormatter.java
@@ -17,6 +17,7 @@
 
 package org.apache.poi.ss.usermodel;
 
+import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertNotNull;
 import static org.junit.jupiter.api.Assertions.assertTrue;
@@ -25,6 +26,7 @@ import java.text.DateFormatSymbols;
 import java.text.FieldPosition;
 import java.text.ParseException;
 import java.text.SimpleDateFormat;
+import java.util.ArrayList;
 import java.util.Date;
 import java.util.HashMap;
 import java.util.List;
@@ -35,111 +37,88 @@ import java.util.stream.Stream;
 
 import org.apache.poi.util.LocaleUtil;
 import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.Arguments;
+import org.junit.jupiter.params.provider.MethodSource;
 
 class TestExcelStyleDateFormatter {
     private static final String EXCEL_DATE_FORMAT = "MMMMM";
     private static final SimpleDateFormat DATE_FORMAT = new SimpleDateFormat("yyyy-MM-dd", Locale.ROOT);
-    private final int jreVersion;
-
-    public TestExcelStyleDateFormatter() {
-        jreVersion = Integer.parseInt(System.getProperty("java.version")
-            .replace("1.8", "8").replaceAll("(\\d+).*", "$1"));
-    }
+    private static final int jreVersion =
+        Integer.parseInt(System.getProperty("java.version").replaceAll("^(?:1\\.)?(\\d+).*", "$1"));
+    private static final String provider = System.getProperty("java.locale.providers");
+    private static final FieldPosition fp = new FieldPosition(java.text.DateFormat.MONTH_FIELD);
+    private static final ExcelStyleDateFormatter formatter = new ExcelStyleDateFormatter(EXCEL_DATE_FORMAT);
 
     /**
      * [Bug 60369] Month format 'MMMMM' issue with TEXT-formula and Java 8
      */
-    @Test
-    void test60369() {
-        Map<Locale, String> testMap = initializeLocales();
-
-        // We have to set up dates as well.
-        List<Date> testDates = Stream.of("1980-01-12", "1995-02-11", "2045-03-10", "2016-04-09", "2017-05-08",
-            "1945-06-07", "1998-07-06", "2099-08-05", "1988-09-04", "2023-10-03", "1978-11-02", "1890-12-01")
-            .map(this::parseDate).collect(Collectors.toList());
-
+    @ParameterizedTest
+    @MethodSource("initializeLocales")
+    void test60369(Locale locale, String expected, Date d, int month) {
         // Let's iterate over the test setup.
-        final String provider = System.getProperty("java.locale.providers");
-        final FieldPosition fp = new FieldPosition(java.text.DateFormat.MONTH_FIELD);
-        final ExcelStyleDateFormatter formatter = new ExcelStyleDateFormatter(EXCEL_DATE_FORMAT);
         final StringBuffer sb = new StringBuffer();
 
-        for (Map.Entry<Locale,String> me : testMap.entrySet()) {
-            final Locale locale = me.getKey();
-            final String expected = me.getValue();
-            formatter.setDateFormatSymbols(DateFormatSymbols.getInstance(locale));
-            int month = 0;
-            for (Date d : testDates) {
-                sb.setLength(0);
-                String result = formatter.format(d, sb, fp).toString();
-                String msg = "Failed testDates for locale " + locale + ", provider: " + provider +
-                        " and date " + d + ", having: " + result;
-
-                int actIdx = localeIndex(locale);
-
-                assertNotNull(result, msg);
-                assertTrue(result.length() > actIdx, msg);
-                assertEquals(expected.charAt(month), result.charAt(actIdx), msg);
-                month++;
-            }
-        }
+        formatter.setDateFormatSymbols(DateFormatSymbols.getInstance(locale));
+        String result = formatter.format(d, sb, fp).toString();
+        String msg = "Failed testDates for locale " + locale + ", provider: " + provider +
+                " and date " + d + ", having: " + result;
+
+        int actIdx = localeIndex(locale);
+
+        assertNotNull(result, msg);
+        assertTrue(result.length() > actIdx, msg);
+        assertEquals(expected.charAt(month), result.charAt(actIdx), msg);
     }
 
     /**
      * Depending on the JRE version, the provider setting and the locale, a different result
      * is expected and selected via an index
      */
-    private int localeIndex(Locale locale) {
-        final String provider = System.getProperty("java.locale.providers");
+    private static int localeIndex(Locale locale) {
         return jreVersion < 9 ||
             !locale.equals (Locale.CHINESE) ||
             (provider != null && (provider.startsWith("JRE") || provider.startsWith("COMPAT")))
             ? 0 : 1;
     }
 
-    private Date parseDate(String dateStr) {
-        try {
-            return DATE_FORMAT.parse(dateStr);
-        } catch (ParseException e) {
-            return new Date(0);
-        }
-    }
-
     /**
      * Setting up the locale to be tested together with a list of asserted
      * unicode-formatted results and put them in a map.
      */
-    private Map<Locale, String> initializeLocales() {
-        Map<Locale, String> testMap = new HashMap<>();
-
-        testMap.put(Locale.GERMAN, "JFMAMJJASOND");
-        testMap.put(new Locale("de", "AT"), "JFMAMJJASOND");
-        testMap.put(Locale.UK, "JFMAMJJASOND");
-        testMap.put(new Locale("en", "IN"), "JFMAMJJASOND");
-        testMap.put(new Locale("in", "ID"), "JFMAMJJASOND");
-        testMap.put(Locale.FRENCH, "jfmamjjasond");
-
-        testMap.put(new Locale("ru", "RU"),
-            "\u044f\u0444\u043c\u0430\u043c\u0438\u0438\u0430\u0441\u043e\u043d\u0434");
-
-        testMap.put(Locale.CHINESE, new String[]{
-            "\u4e00\u4e8c\u4e09\u56db\u4e94\u516d\u4e03\u516b\u4e5d\u5341\u5341\u5341",
-            "123456789111"
-        }[localeIndex(Locale.CHINESE)]);
-
-        testMap.put(new Locale("tr", "TR"),
-            "\u004f\u015e\u004d\u004e\u004d\u0048\u0054\u0041\u0045\u0045\u004b\u0041");
-
-        testMap.put(new Locale("hu", "HU"),
-            "\u006a\u0066\u006d\u00e1\u006d\u006a\u006a\u0061\u0073\u006f\u006e\u0064");
-
-        return testMap;
+    public static Stream<Arguments> initializeLocales() throws ParseException {
+        Object[][] locExps = {
+            { Locale.GERMAN, "JFMAMJJASOND" },
+            { new Locale("de", "AT"), "JFMAMJJASOND" },
+            { Locale.UK, "JFMAMJJASOND" },
+            { new Locale("en", "IN"), "JFMAMJJASOND" },
+            { new Locale("in", "ID"), "JFMAMJJASOND" },
+            { Locale.FRENCH, "jfmamjjasond" },
+            { new Locale("ru", "RU"), "\u044f\u0444\u043c\u0430\u043c\u0438\u0438\u0430\u0441\u043e\u043d\u0434" },
+            { Locale.CHINESE, localeIndex(Locale.CHINESE) == 0 ? "\u4e00\u4e8c\u4e09\u56db\u4e94\u516d\u4e03\u516b\u4e5d\u5341\u5341\u5341" : "123456789111" },
+            { new Locale("tr", "TR"), "\u004f\u015e\u004d\u004e\u004d\u0048\u0054\u0041\u0045\u0045\u004b\u0041" },
+            { new Locale("hu", "HU"), "\u006a\u0066\u006d\u00e1\u006d\u006a\u006a\u0061\u0073\u006f\u006e\u0064" }
+        };
+
+        String[] dates = {
+            "1980-01-12", "1995-02-11", "2045-03-10", "2016-04-09", "2017-05-08",
+            "1945-06-07", "1998-07-06", "2099-08-05", "1988-09-04", "2023-10-03", "1978-11-02", "1890-12-01"
+        };
+
+        List<Arguments> list = new ArrayList<>(locExps.length * dates.length);
+        for (Object[] locExp : locExps) {
+            int month = 0;
+            for (String date : dates) {
+                list.add(Arguments.of(locExp[0], locExp[1], DATE_FORMAT.parse(date), month++));
+            }
+        }
+        return list.stream();
     }
 
     @Test
     void testConstruct() {
-        new ExcelStyleDateFormatter(EXCEL_DATE_FORMAT, LocaleUtil.getUserLocale());
-        new ExcelStyleDateFormatter(EXCEL_DATE_FORMAT);
+        assertDoesNotThrow(() -> new ExcelStyleDateFormatter(EXCEL_DATE_FORMAT, LocaleUtil.getUserLocale()));
+        assertDoesNotThrow(() -> new ExcelStyleDateFormatter(EXCEL_DATE_FORMAT));
     }
 
     @Test
diff --git a/src/testcases/org/apache/poi/ss/util/TestDateFormatConverter.java b/src/testcases/org/apache/poi/ss/util/TestDateFormatConverter.java
index 3113bc95e9..00697bbdb4 100644
--- a/src/testcases/org/apache/poi/ss/util/TestDateFormatConverter.java
+++ b/src/testcases/org/apache/poi/ss/util/TestDateFormatConverter.java
@@ -19,6 +19,9 @@
 
 package org.apache.poi.ss.util;
 
+import static java.text.DateFormat.getDateInstance;
+import static java.text.DateFormat.getDateTimeInstance;
+import static java.text.DateFormat.getTimeInstance;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertNotEquals;
 import static org.junit.jupiter.api.Assertions.assertNotNull;
@@ -45,22 +48,34 @@ import org.apache.poi.ss.usermodel.Row;
 import org.apache.poi.ss.usermodel.Sheet;
 import org.apache.poi.ss.usermodel.Workbook;
 import org.apache.poi.util.LocaleID;
+import org.apache.poi.util.NullOutputStream;
 import org.apache.poi.util.TempFile;
 import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.CsvSource;
 
 final class TestDateFormatConverter {
-    private void outputLocaleDataFormats( Date date, boolean dates, boolean times, int style, String styleName ) throws Exception {
+    @ParameterizedTest
+    @CsvSource({
+        "true, false, " + DateFormat.DEFAULT + ", Default",
+        "true, false, " + DateFormat.SHORT + ", Short",
+        "true, false, " + DateFormat.MEDIUM + ", Medium",
+        "true, false, " + DateFormat.LONG + ", Long",
+        "true, false, " + DateFormat.FULL + ", Full",
+        "true, true, " + DateFormat.DEFAULT + ", Default",
+        "true, true, " + DateFormat.SHORT + ", Short",
+        "true, true, " + DateFormat.MEDIUM + ", Medium",
+        "true, true, " + DateFormat.LONG + ", Long",
+        "true, true, " + DateFormat.FULL + ", Full",
+        "false, true, " + DateFormat.DEFAULT + ", Default",
+        "false, true, " + DateFormat.SHORT + ", Short",
+        "false, true, " + DateFormat.MEDIUM + ", Medium",
+        "false, true, " + DateFormat.LONG + ", Long",
+        "false, true, " + DateFormat.FULL + ", Full"
+    })
+    void testJavaDateFormatsInExcel(boolean dates, boolean times, int style, String styleName ) throws Exception {
         try (Workbook workbook = new HSSFWorkbook()) {
-            String sheetName;
-            if (dates) {
-                if (times) {
-                    sheetName = "DateTimes";
-                } else {
-                    sheetName = "Dates";
-                }
-            } else {
-                sheetName = "Times";
-            }
+            String sheetName = (dates) ? ((times) ? "DateTimes" : "Dates") : "Times";
             Sheet sheet = workbook.createSheet(sheetName);
             Row header = sheet.createRow(0);
             header.createCell(0).setCellValue("locale");
@@ -73,90 +88,51 @@ final class TestDateFormatConverter {
 
             int rowNum = 1;
             for (Locale locale : DateFormat.getAvailableLocales()) {
-                try {
-                    Row row = sheet.createRow(rowNum++);
-
-                    row.createCell(0).setCellValue(locale.toString());
-                    row.createCell(1).setCellValue(locale.getDisplayName(Locale.ROOT));
-
-                    DateFormat dateFormat;
-                    if (dates) {
-                        if (times) {
-                            dateFormat = DateFormat.getDateTimeInstance(style, style, locale);
-                        } else {
-                            dateFormat = DateFormat.getDateInstance(style, locale);
-                        }
-                    } else {
-                        dateFormat = DateFormat.getTimeInstance(style, locale);
-                    }
-
-                    Cell cell = row.createCell(2);
-
-                    cell.setCellValue(date);
-                    CellStyle cellStyle = row.getSheet().getWorkbook().createCellStyle();
-
-                    String javaDateFormatPattern = ((SimpleDateFormat) dateFormat).toPattern();
-                    String excelFormatPattern = DateFormatConverter.convert(locale, javaDateFormatPattern);
-
-                    DataFormat poiFormat = row.getSheet().getWorkbook().createDataFormat();
-                    cellStyle.setDataFormat(poiFormat.getFormat(excelFormatPattern));
-                    row.createCell(3).setCellValue(dateFormat.format(date));
-
-                    cell.setCellStyle(cellStyle);
-
-                    // the formula returns TRUE is the formatted date in column C equals to the string in column D
-                    row.createCell(4).setCellFormula("TEXT(C" + rowNum + ",G" + rowNum + ")=D" + rowNum);
-                    row.createCell(5).setCellValue(javaDateFormatPattern);
-                    row.createCell(6).setCellValue(excelFormatPattern);
-                } catch (Exception e) {
-                    throw new RuntimeException(
-                            "Failed for locale: " + locale + " and style " + style + "\n" +
-                            "Having locales: " + Arrays.toString(DateFormat.getAvailableLocales()), e);
-                }
-            }
+                Row row = sheet.createRow(rowNum++);
+
+                row.createCell(0).setCellValue(locale.toString());
+                row.createCell(1).setCellValue(locale.getDisplayName(Locale.ROOT));
+
+                DateFormat dateFormat = (dates)
+                    ? (times ? getDateTimeInstance(style, style, locale) : getDateInstance(style, locale))
+                    : getTimeInstance(style, locale);
+
+                Cell cell = row.createCell(2);
+                Date date = new Date();
+                cell.setCellValue(date);
+                CellStyle cellStyle = row.getSheet().getWorkbook().createCellStyle();
 
-            File outputFile = TempFile.createTempFile("Locale" + sheetName + styleName, ".xlsx");
-            try (FileOutputStream outputStream = new FileOutputStream(outputFile)) {
-                workbook.write(outputStream);
+                String javaDateFormatPattern = ((SimpleDateFormat) dateFormat).toPattern();
+                String excelFormatPattern = DateFormatConverter.convert(locale, javaDateFormatPattern);
+
+                DataFormat poiFormat = row.getSheet().getWorkbook().createDataFormat();
+                cellStyle.setDataFormat(poiFormat.getFormat(excelFormatPattern));
+                row.createCell(3).setCellValue(dateFormat.format(date));
+
+                cell.setCellStyle(cellStyle);
+
+                // the formula returns TRUE is the formatted date in column C equals to the string in column D
+                row.createCell(4).setCellFormula("TEXT(C" + rowNum + ",G" + rowNum + ")=D" + rowNum);
+                row.createCell(5).setCellValue(javaDateFormatPattern);
+                row.createCell(6).setCellValue(excelFormatPattern);
             }
 
-            //System.out.println("Open " + outputFile.getAbsolutePath() + " in Excel");
+            workbook.write(new NullOutputStream());
         }
     }
 
     @Test
-    void testJavaDateFormatsInExcel() throws Exception {
-        Date date = new Date();
-
-        outputLocaleDataFormats(date, true, false, DateFormat.DEFAULT, "Default" );
-        outputLocaleDataFormats(date, true, false, DateFormat.SHORT, "Short" );
-        outputLocaleDataFormats(date, true, false, DateFormat.MEDIUM, "Medium" );
-        outputLocaleDataFormats(date, true, false, DateFormat.LONG, "Long" );
-        outputLocaleDataFormats(date, true, false, DateFormat.FULL, "Full" );
-
-        outputLocaleDataFormats(date, true, true, DateFormat.DEFAULT, "Default" );
-        outputLocaleDataFormats(date, true, true, DateFormat.SHORT, "Short" );
-        outputLocaleDataFormats(date, true, true, DateFormat.MEDIUM, "Medium" );
-        outputLocaleDataFormats(date, true, true, DateFormat.LONG, "Long" );
-        outputLocaleDataFormats(date, true, true, DateFormat.FULL, "Full" );
-
-        outputLocaleDataFormats(date, false, true, DateFormat.DEFAULT, "Default" );
-        outputLocaleDataFormats(date, false, true, DateFormat.SHORT, "Short" );
-        outputLocaleDataFormats(date, false, true, DateFormat.MEDIUM, "Medium" );
-        outputLocaleDataFormats(date, false, true, DateFormat.LONG, "Long" );
-        outputLocaleDataFormats(date, false, true, DateFormat.FULL, "Full" );
-    }
-
-    @Test
     void testJDK8EmptyLocale() {
         // JDK 8 seems to add an empty locale-string to the list returned via DateFormat.getAvailableLocales()
         // therefore we now cater for this special locale as well
-        DateFormatConverter.getPrefixForLocale(new Locale(""));
+        String prefix = DateFormatConverter.getPrefixForLocale(new Locale(""));
+        assertEquals("", prefix);
     }
 
     @Test
     void testJDK11MyLocale() {
-        DateFormat.getDateTimeInstance(DateFormat.DEFAULT, DateFormat.DEFAULT, Locale.forLanguageTag("my"));
+        DateFormat df = getDateTimeInstance(DateFormat.DEFAULT, DateFormat.DEFAULT, Locale.forLanguageTag("my"));
+        assertNotNull(df);
     }
 
     @Test
diff --git a/src/testcases/org/apache/poi/ss/util/TestExpandedDouble.java b/src/testcases/org/apache/poi/ss/util/TestExpandedDouble.java
index 30f84a3eb7..9465619b79 100644
--- a/src/testcases/org/apache/poi/ss/util/TestExpandedDouble.java
+++ b/src/testcases/org/apache/poi/ss/util/TestExpandedDouble.java
@@ -24,6 +24,8 @@ import static org.junit.jupiter.api.Assertions.assertTrue;
 import java.math.BigInteger;
 
 import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.ValueSource;
 
 /**
  * Tests for {@link ExpandedDouble}
@@ -54,33 +56,27 @@ final class TestExpandedDouble {
 	/**
 	 * Tests specific values for conversion from {@link ExpandedDouble} to {@link NormalisedDecimal} and back
 	 */
-	@Test
-	void testRoundTripShifting() {
-		long[] rawValues = {
-				0x4010000000000004L,
-				0x7010000000000004L,
-				0x1010000000000004L,
-				0x0010000000000001L, // near lowest normal number
-				0x0010000000000000L, // lowest normal number
-				0x000FFFFFFFFFFFFFL, // highest subnormal number
-				0x0008000000000000L, // subnormal number
-
-				0xC010000000000004L,
-				0xE230100010001004L,
-				0x403CE0FFFFFFFFF2L,
-				0x0000000000000001L, // smallest non-zero number (subnormal)
-				0x6230100010000FFEL,
-				0x6230100010000FFFL,
-				0x6230100010001000L,
-				0x403CE0FFFFFFFFF0L, // has single digit round trip error
-				0x2B2BFFFF10001079L,
-		};
-		for (int i = 0; i < rawValues.length; i++) {
-			confirmRoundTrip(i, rawValues[i]);
-		}
-	}
-
-	public static void confirmRoundTrip(int i, long rawBitsA) {
+	@ParameterizedTest
+	@ValueSource(longs = {
+		0x4010000000000004L,
+		0x7010000000000004L,
+		0x1010000000000004L,
+		0x0010000000000001L, // near lowest normal number
+		0x0010000000000000L, // lowest normal number
+		0x000FFFFFFFFFFFFFL, // highest subnormal number
+		0x0008000000000000L, // subnormal number
+
+		0xC010000000000004L,
+		0xE230100010001004L,
+		0x403CE0FFFFFFFFF2L,
+		0x0000000000000001L, // smallest non-zero number (subnormal)
+		0x6230100010000FFEL,
+		0x6230100010000FFFL,
+		0x6230100010001000L,
+		0x403CE0FFFFFFFFF0L, // has single digit round trip error
+		0x2B2BFFFF10001079L,
+	})
+	void confirmRoundTrip(long rawBitsA) {
 		double a = Double.longBitsToDouble(rawBitsA);
 		if (a == 0.0) {
 			// Can't represent 0.0 or -0.0 with NormalisedDecimal
diff --git a/src/testcases/org/apache/poi/ss/util/TestNumberComparer.java b/src/testcases/org/apache/poi/ss/util/TestNumberComparer.java
index 42a0edd841..225d9f835c 100644
--- a/src/testcases/org/apache/poi/ss/util/TestNumberComparer.java
+++ b/src/testcases/org/apache/poi/ss/util/TestNumberComparer.java
@@ -17,6 +17,7 @@
 
 package org.apache.poi.ss.util;
 
+import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertNotEquals;
 import static org.junit.jupiter.api.Assertions.assertTrue;
@@ -24,6 +25,8 @@ import static org.junit.jupiter.api.Assertions.assertTrue;
 import org.apache.poi.ss.util.NumberComparisonExamples.ComparisonExample;
 import org.apache.poi.util.HexDump;
 import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.MethodSource;
 
 /**
  * Tests for {@link NumberComparer}
@@ -46,22 +49,15 @@ final class TestNumberComparer {
 		assertTrue(success, "One or more cases failed.  See stderr");
 	}
 
-    @Test
-	void testRoundTripOnComparisonExamples() {
-		ComparisonExample[] examples = NumberComparisonExamples.getComparisonExamples();
-		for(int i=0;i<examples.length; i++) {
-			ComparisonExample ce = examples[i];
-			confirmRoundTrip(i, ce.getA());
-			confirmRoundTrip(i, ce.getNegA());
-			confirmRoundTrip(i, ce.getB());
-			confirmRoundTrip(i, ce.getNegB());
+    @ParameterizedTest
+	@MethodSource("org.apache.poi.ss.util.NumberComparisonExamples#getComparisonExamples")
+	void testRoundTripOnComparisonExamples(ComparisonExample ce) {
+    	double[] vals = { ce.getA(), ce.getNegA(), ce.getB(), ce.getNegB() };
+    	for (double a : vals) {
+			assertDoesNotThrow(() -> new TestExpandedDouble().confirmRoundTrip(Double.doubleToLongBits(a)));
 		}
 	}
 
-	private void confirmRoundTrip(int i, double a) {
-		TestExpandedDouble.confirmRoundTrip(i, Double.doubleToLongBits(a));
-	}
-
 	/**
 	 * The actual example from bug 47598
 	 */
diff --git a/src/testcases/org/apache/poi/ss/util/TestSheetUtil.java b/src/testcases/org/apache/poi/ss/util/TestSheetUtil.java
index c61ba56401..1731d46371 100644
--- a/src/testcases/org/apache/poi/ss/util/TestSheetUtil.java
+++ b/src/testcases/org/apache/poi/ss/util/TestSheetUtil.java
@@ -17,6 +17,7 @@
 
 package org.apache.poi.ss.util;
 
+import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertNotNull;
 import static org.junit.jupiter.api.Assertions.assertNull;
@@ -93,7 +94,7 @@ final class TestSheetUtil {
     void testCanComputeWidthHSSF() throws IOException {
         try (Workbook wb = new HSSFWorkbook()) {
             // cannot check on result because on some machines we get back false here!
-            SheetUtil.canComputeColumnWidth(wb.getFontAt(0));
+            assertDoesNotThrow(() -> SheetUtil.canComputeColumnWidth(wb.getFontAt(0)));
         }
     }
 
diff --git a/src/testcases/org/apache/poi/util/TestHexDump.java b/src/testcases/org/apache/poi/util/TestHexDump.java
index 4b87b976ae..4a465cb4be 100644
--- a/src/testcases/org/apache/poi/util/TestHexDump.java
+++ b/src/testcases/org/apache/poi/util/TestHexDump.java
@@ -30,6 +30,8 @@ import java.io.UnsupportedEncodingException;
 import org.junit.jupiter.api.AfterAll;
 import org.junit.jupiter.api.BeforeAll;
 import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.ValueSource;
 
 class TestHexDump {
 
@@ -168,21 +170,18 @@ class TestHexDump {
         assertTrue(dump.contains("123456789:;<=>?@"), "Had: \n" + dump);
     }
 
-    @Test
-    void testDumpToStringOutOfIndex1() {
-        assertThrows(ArrayIndexOutOfBoundsException.class, () -> HexDump.dump(new byte[1], 0, -1));
-        assertThrows(ArrayIndexOutOfBoundsException.class, () -> HexDump.dump(new byte[1], 0, 2));
-        assertThrows(ArrayIndexOutOfBoundsException.class, () -> HexDump.dump(new byte[1], 0, 1));
+    @ParameterizedTest
+    @ValueSource(ints = {-1, 2, 1})
+    void testDumpToStringOutOfIndex1(int index) {
+        assertThrows(ArrayIndexOutOfBoundsException.class, () ->
+            HexDump.dump(new byte[1], 0, index));
     }
 
-    @Test
-    void testDumpToStringNoDataEOL1() {
-        HexDump.dump(new byte[0], 0, 1);
-    }
-
-    @Test
-    void testDumpToStringNoDataEOL2() {
-        HexDump.dump(new byte[0], 0, 0);
+    @ParameterizedTest
+    @ValueSource(ints = {0, 1})
+    void testDumpToStringNoDataEOL(int index) {
+        String s = HexDump.dump(new byte[0], 0, index);
+        assertEquals("No Data", s.trim());
     }
 
     private static byte[] testArray() {
diff --git a/src/testcases/org/apache/poi/util/TestIOUtils.java b/src/testcases/org/apache/poi/util/TestIOUtils.java
index 196fcf401b..c39efacfe2 100644
--- a/src/testcases/org/apache/poi/util/TestIOUtils.java
+++ b/src/testcases/org/apache/poi/util/TestIOUtils.java
@@ -181,7 +181,8 @@ final class TestIOUtils {
 
     @Test
     void testSkipFullyBug61294() throws IOException {
-        IOUtils.skipFully(new ByteArrayInputStream(new byte[0]), 1);
+        long skipped = IOUtils.skipFully(new ByteArrayInputStream(new byte[0]), 1);
+        assertEquals(-1L, skipped);
     }
 
     @Test
@@ -215,9 +216,12 @@ final class TestIOUtils {
     @Test
     void testMaxLengthIgnored() throws IOException {
         try (InputStream is = new FileInputStream(TMP)) {
-            IOUtils.toByteArray(is, 90, Integer.MAX_VALUE);
-            IOUtils.toByteArray(is, 90, 100);
-            IOUtils.toByteArray(is, Integer.MAX_VALUE, Integer.MAX_VALUE);
+            int len = IOUtils.toByteArray(is, 90, Integer.MAX_VALUE).length;
+            assertEquals(90, len);
+            len = IOUtils.toByteArray(is, 90, 100).length;
+            assertEquals(90, len);
+            len = IOUtils.toByteArray(is, Integer.MAX_VALUE, Integer.MAX_VALUE).length;
+            assertTrue(len > 300-2*90);
         }
     }