RandomDate: include end date and handle single-day ranges

src/functions/src/main/java/org/apache/jmeter/functions/RandomDate.java

@@ -189,7 +189,7 @@ public String execute(SampleResult previousResult, Sampler currentSampler) throw
         if (localEndDate < localStartDate) {
             log.error("End Date '{}' must be greater than Start Date '{}'", dateEnd, dateStart); // $NON-NLS-1$
         } else {
-            long randomDay = ThreadLocalRandom.current().nextLong(localStartDate, localEndDate);
+            long randomDay = pickRandomDay(localStartDate, localEndDate);
             try {
                 dateString = LocalDate.ofEpochDay(randomDay).format(formatter);
             } catch (DateTimeParseException | NumberFormatException ex) {
@@ -200,6 +200,14 @@ public String execute(SampleResult previousResult, Sampler currentSampler) throw
         return dateString;
     }
 
+    private static long pickRandomDay(long startInclusive, long endExclusive) {
+        if (startInclusive == endExclusive) {
+            return startInclusive;
+        }
+        return ThreadLocalRandom.current()
+                .nextLong(startInclusive, endExclusive);
+    }
+
     @SuppressWarnings("JavaTimeDefaultTimeZone")
     private static DateTimeFormatter createFormatter(LocaleFormatObject format) {
         log.debug("Create a new instance of DateTimeFormatter for format '{}' in the cache", format);

src/functions/src/test/java/org/apache/jmeter/functions/TestTimeRandomDateFunction.java

@@ -69,7 +69,7 @@ void testDefault() throws Exception {
         LocalDate result = LocalDate.parse(value, formatter);
         LocalDate now = LocalDate.now(ZoneId.systemDefault());
         LocalDate max = LocalDate.parse(endDate, formatter);
-        Assertions.assertTrue(now.isBefore(result) && result.isBefore(max));
+        Assertions.assertTrue(!result.isBefore(now) && result.isBefore(max));
     }
 
     @Test
@@ -92,7 +92,7 @@ void testFormatDate() throws Exception {
         LocalDate result = LocalDate.parse(value, formatter);
         LocalDate now = LocalDate.now(ZoneId.systemDefault());
         LocalDate max = LocalDate.parse(endDate, formatter);
-        Assertions.assertTrue(now.isBefore(result) && result.isBefore(max));
+        Assertions.assertTrue(!result.isBefore(now) && result.isBefore(max));
     }
 
     @Test
@@ -141,6 +141,16 @@ void testEmptyFormatDate() throws Exception {
         assertEquals("2111-03-29", value);
     }
 
+    @Test
+    void testSameStartAndEndDateReturnsSameValue() throws Exception {
+        String date = "2111-03-29";
+        Collection<CompoundVariable> params = makeParams("yyyy-MM-dd", date, date, "", "MY_VAR");
+        function.setParameters(params);
+        value = function.execute(result, null);
+        assertEquals(date, value);
+        assertEquals(date, vars.get("MY_VAR"));
+    }
+
     @Test
     void testEndDateBeforeStartDate() throws Exception {
         String startDate = "2111-03-29";

xdocs/changes.xml

@@ -76,6 +76,11 @@ Summary
     <li><pr>5891</pr>Skip Internet Explorer 6-9 conditional comment processing when fetching resource links</li>
   </ul>
 
+  <h3>Functions</h3>
+  <ul>
+    <li><code>__RandomDate</code> now handles identical start and end dates without throwing an exception while preserving Java-like semantics (start inclusive, end exclusive).</li>
+  </ul>
+
  <!--  =================== Thanks =================== -->
 
 <ch_section>Thanks</ch_section>

xdocs/usermanual/functions.xml

@@ -672,7 +672,7 @@ the comma after <code>7</code> is escaped.</note>
 <properties>
         <property name="Time format" required="No">Format string for DateTimeFormatter (default <code>yyyy-MM-dd</code>)</property>
         <property name="Start date" required="No">The start date, the default is <em>now</em></property>
-        <property name="End date" required="Yes">The end date</property>
+        <property name="End date" required="Yes">The end date (exclusive). Add one day if you need the specified date to appear in the output.</property>
         <property name="Locale to use for format" required="No">
         The string format of a locale. The language code must be lowercase. The country code must be uppercase. The separator must be an underscore, e.g. <code>en_EN</code>.
         See <a href="http://www.oracle.com/technetwork/java/javase/javase7locales-334809.html">http://www.oracle.com/technetwork/java/javase/javase7locales-334809.html</a>.
@@ -682,7 +682,7 @@ the comma after <code>7</code> is escaped.</note>
 </properties>
 
 <p>Examples:
-<source>${__RandomDate(,,2050-07-08,,)}</source> will return a random date between <em>now</em> and <code>2050-07-08</code>. For example <code>2039-06-21</code><br/>
+<source>${__RandomDate(,,2050-07-08,,)}</source> will return a random date between <em>now</em> (inclusive) and <code>2050-07-08</code> (exclusive). For example <code>2039-06-21</code><br/>
 <source>${__RandomDate(dd MM yyyy,,08 07 2050,,)}</source> will return a random date with a custom format like <code>04 03 2034</code><br/>
 </p>
 </component>