Log skip reason when data provider returns no data

Closes #2563

Author: krmahadevan

CHANGES.txt

@@ -1,4 +1,5 @@
 Current
+Fixed: GITHUB-2563: Skip test if its data provider provides no data (Krishnan Mahadevan)
 Fixed: GITHUB-2535: TestResult.getEndMillis() returns 0 for skipped configuration - after upgrading testng to 7.0 + (Krishnan Mahadevan)
 Fixed: GITHUB-2638: "[WARN] Ignoring duplicate listener" appears when running .xml suite with <listeners> and <suite-files> (Krishnan Mahadevan)
 Fixed: GITHUB-1297: Passed configuration methods appear in testng-failed.xml, when failure was after passed test (Dzmitry Sankouski)

testng-core-api/src/main/java/org/testng/internal/Utils.java

@@ -240,7 +240,7 @@ public static void error(String errorMessage) {
   }
 
   public static void warn(String warnMsg) {
-    LOG.warn("[Warning] " + warnMsg);
+    LOG.warn(warnMsg);
   }
 
   /* Tokenize the string using the separator. */

testng-core/src/main/java/org/testng/internal/Parameters.java

@@ -800,12 +800,13 @@ public static ParameterHolder handleParameters(
             public boolean hasNext() {
               if (index == 0 && !parameters.hasNext() && !hasWarn) {
                 hasWarn = true;
-                Utils.log(
-                    "",
-                    2,
-                    "Warning: the data provider '"
-                        + dataProviderMethod.getName()
-                        + "' returned an empty array or iterator, so this test is not doing anything");
+                String msg =
+                    String.format(
+                        "The test method '%s' will be skipped since its "
+                            + "data provider '%s' "
+                            + "returned an empty array or iterator. ",
+                        testMethod.getQualifiedName(), dataProviderMethod.getName());
+                Utils.warn(msg);
               }
               return parameters.hasNext();
             }