Add index name validation rule for empty index names (#119960) (#120060)

* Add index name validation rule for empty index names

* Created negative tests for ES|QL index names with only exclusion character

* Added test for `*-`

Author: craigtaverner

server/src/main/java/org/elasticsearch/cluster/metadata/MetadataCreateIndexService.java

@@ -225,6 +225,9 @@ public SystemIndices getSystemIndices() {
      * Validate the name for an index or alias against some static rules.
      */
     public static void validateIndexOrAliasName(String index, BiFunction<String, String, ? extends RuntimeException> exceptionCtor) {
+        if (index == null || index.isEmpty()) {
+            throw exceptionCtor.apply(index, "must not be empty");
+        }
         if (Strings.validFileName(index) == false) {
             throw exceptionCtor.apply(index, "must not contain the following characters " + Strings.INVALID_FILENAME_CHARS);
         }

server/src/test/java/org/elasticsearch/cluster/metadata/MetadataCreateIndexServiceTests.java

@@ -560,6 +560,9 @@ public void testValidateIndexName() throws Exception {
             validateIndexName(checkerService, "..", "must not be '.' or '..'");
 
             validateIndexName(checkerService, "foo:bar", "must not contain ':'");
+
+            validateIndexName(checkerService, "", "must not be empty");
+            validateIndexName(checkerService, null, "must not be empty");
         }));
     }
 

x-pack/plugin/esql/src/test/java/org/elasticsearch/xpack/esql/parser/AbstractStatementParserTests.java

@@ -151,8 +151,12 @@ void expectInvalidIndexNameErrorWithLineNumber(String query, String indexString,
         expectInvalidIndexNameErrorWithLineNumber(query, "\"" + indexString + "\"", lineNumber, indexString);
     }
 
-    void expectInvalidIndexNameErrorWithLineNumber(String query, String indexString, String lineNumber, String error) {
-        expectError(LoggerMessageFormat.format(null, query, indexString), lineNumber + "Invalid index name [" + error);
+    void expectInvalidIndexNameErrorWithLineNumber(String query, String indexString, String lineNumber, String name) {
+        expectError(LoggerMessageFormat.format(null, query, indexString), lineNumber + "Invalid index name [" + name);
+    }
+
+    void expectInvalidIndexNameErrorWithLineNumber(String query, String indexString, String lineNumber, String name, String error) {
+        expectError(LoggerMessageFormat.format(null, query, indexString), lineNumber + "Invalid index name [" + name + "], " + error);
     }
 
     void expectDateMathErrorWithLineNumber(String query, String arg, String lineNumber, String error) {

x-pack/plugin/esql/src/test/java/org/elasticsearch/xpack/esql/parser/StatementParserTests.java

@@ -577,6 +577,9 @@ public void testInvalidCharacterInIndexPattern() {
             expectInvalidIndexNameErrorWithLineNumber(command, "indexpattern, --indexpattern", lineNumber, "-indexpattern");
             expectInvalidIndexNameErrorWithLineNumber(command, "indexpattern, \"--indexpattern\"", lineNumber, "-indexpattern");
             expectInvalidIndexNameErrorWithLineNumber(command, "\"indexpattern, --indexpattern\"", commands.get(command), "-indexpattern");
+            expectInvalidIndexNameErrorWithLineNumber(command, "\"- , -\"", commands.get(command), "", "must not be empty");
+            expectInvalidIndexNameErrorWithLineNumber(command, "\"indexpattern,-\"", commands.get(command), "", "must not be empty");
+            clustersAndIndices(command, "indexpattern", "*-");
             clustersAndIndices(command, "indexpattern", "-indexpattern");
         }