fix: support both .yaml and .yml files case-insensitively in FileUtil.getAllYamlFiles

build.gradle.kts

@@ -23,6 +23,9 @@ dependencies {
     implementation("com.fasterxml.jackson.datatype:jackson-datatype-jsr310:$jacksonVersion")
     implementation("org.slf4j:slf4j-api:2.0.6")
     compileOnly("org.jetbrains:annotations:24.0.0")
+
+    testImplementation("org.junit.jupiter:junit-jupiter-api:5.9.2")
+    testRuntimeOnly("org.junit.jupiter:junit-jupiter-engine:5.9.2")
 }
 
 description = "General-purpose utilities and helper classes shared across Flamingock modules"

src/main/java/io/flamingock/internal/util/FileUtil.java

@@ -28,6 +28,7 @@
 import java.nio.file.Files;
 import java.util.Arrays;
 import java.util.List;
+import java.util.Locale;
 import java.util.Objects;
 
 public final class FileUtil {
@@ -38,10 +39,15 @@ private FileUtil() {
 
 
     public static List<File> getAllYamlFiles(File directory) {
-        FilenameFilter fileNameFilter = (dir, name) -> name.endsWith(".yaml");
+        FilenameFilter fileNameFilter = (dir, name) -> isYamlFileName(name);
         return getAllFiles(directory, fileNameFilter);
     }
 
+    private static boolean isYamlFileName(String fileName) {
+        String normalizedFileName = fileName.toLowerCase(Locale.ROOT);
+        return normalizedFileName.endsWith(".yaml") || normalizedFileName.endsWith(".yml");
+    }
+
     public static List<File> getAllFiles(File directory, FilenameFilter filenameFilter) {
         File[] files = directory.listFiles(filenameFilter);
         return Arrays.asList(Objects.requireNonNull(files));

src/test/java/io/flamingock/internal/util/FileUtilTest.java

@@ -0,0 +1,54 @@
+/*
+ * Copyright 2026 Flamingock (https://www.flamingock.io)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package io.flamingock.internal.util;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.io.TempDir;
+
+import java.io.File;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.List;
+import java.util.stream.Collectors;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+class FileUtilTest {
+
+    @TempDir
+    Path tempDir;
+
+    @Test
+    void shouldReturnYamlAndYmlFilesIgnoringCase() throws Exception {
+        Files.createFile(tempDir.resolve("alpha.yaml"));
+        Files.createFile(tempDir.resolve("bravo.yml"));
+        Files.createFile(tempDir.resolve("charlie.YAML"));
+        Files.createFile(tempDir.resolve("delta.YmL"));
+        Files.createFile(tempDir.resolve("echo.txt"));
+
+        List<String> fileNames = FileUtil.getAllYamlFiles(tempDir.toFile())
+                .stream()
+                .map(File::getName)
+                .sorted()
+                .collect(Collectors.toList());
+
+        assertEquals(4, fileNames.size());
+        assertEquals("alpha.yaml", fileNames.get(0));
+        assertEquals("bravo.yml", fileNames.get(1));
+        assertEquals("charlie.YAML", fileNames.get(2));
+        assertEquals("delta.YmL", fileNames.get(3));
+    }
+}