fix handling empty yaml config file with a comment only

Signed-off-by: Attila Mészáros <a_meszaros@apple.com>

Author: csviri

operator-framework/src/main/java/io/javaoperatorsdk/operator/config/loader/provider/YamlConfigProvider.java

@@ -103,6 +103,9 @@ private static Map<String, Object> load(Path path) {
     try (InputStream in = Files.newInputStream(path)) {
       Map<String, Object> result = MAPPER.readValue(in, Map.class);
       return result != null ? result : Map.of();
+    } catch (com.fasterxml.jackson.databind.exc.MismatchedInputException e) {
+      log.warn("{} contains no configuration data", path);
+      return Map.of();
     } catch (IOException e) {
       throw new UncheckedIOException("Failed to load config YAML from " + path, e);
     }

operator-framework/src/test/java/io/javaoperatorsdk/operator/config/loader/provider/YamlConfigProviderTest.java

@@ -132,6 +132,27 @@ void loadsFromFile(@TempDir Path dir) throws IOException {
     assertThat(provider.getValue("josdk.test.integer", Integer.class)).hasValue(7);
   }
 
+  @Test
+  void returnsEmptyForEmptyFile(@TempDir Path dir) throws IOException {
+    Path file = dir.resolve("empty.yaml");
+    Files.writeString(file, "");
+
+    var provider = new YamlConfigProvider(file);
+    assertThat(provider.getValue("any.key", String.class)).isEmpty();
+  }
+
+  @Test
+  void fileWithCommentOnly(@TempDir Path dir) throws IOException {
+    Path file = dir.resolve("empty.yaml");
+    Files.writeString(
+        file,
+        """
+        # sample comment
+        """);
+    var provider = new YamlConfigProvider(file);
+    assertThat(provider.getValue("any.key", String.class)).isEmpty();
+  }
+
   @Test
   void returnsEmptyForNonExistingFile(@TempDir Path dir) {
     Path missing = dir.resolve("does-not-exist.yaml");