1 files changed, 37 insertions, 0 deletions
diff --git a/core/src/main/java/com/facebook/ktfmt/format/FenceCommentsOp.kt b/core/src/main/java/com/facebook/ktfmt/format/FenceCommentsOp.kt
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+++ b/core/src/main/java/com/facebook/ktfmt/format/FenceCommentsOp.kt
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+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * 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 com.facebook.ktfmt.format
+
+import com.google.common.collect.ImmutableList
+import com.google.googlejavaformat.DocBuilder
+import com.google.googlejavaformat.Op
+
+/**
+ * A dummy [Op] that prevents comments from being moved ahead of it, into parent [Level]s.
+ *
+ * If a comment is the first thing in a [Level], [OpBuilder] moves it outside of that level during
+ * [Doc] building. It does so recursively, until the comment is not the first element of the level.
+ * This behaviour can be very confusing, where comments seem to absorb or ignore expected
+ * indentation.
+ */
+object FenceCommentsOp : Op {
+  val AS_LIST = ImmutableList.of<Op>(FenceCommentsOp)
+
+  override fun add(builder: DocBuilder) {
+    // Do nothing. This Op simply needs to be in the OpsBuilder.
+  }
+}