From 87467871372df6505ef14eb2545a008137e17cad Mon Sep 17 00:00:00 2001
From: Nathan Hughes <nathan.h.hughes@gmail.com>
Date: Wed, 30 Jul 2025 13:35:46 -0400
Subject: [PATCH] add option to force block style when compositing

---
 config_utilities/app/composite_configs.cpp    | 30 +++++++++++++++++++
 .../config_utilities/parsing/commandline.h    |  1 +
 config_utilities/src/commandline.cpp          |  7 +++++
 3 files changed, 38 insertions(+)

diff --git a/config_utilities/app/composite_configs.cpp b/config_utilities/app/composite_configs.cpp
index 1aa7648f..aa2a6b79 100644
--- a/config_utilities/app/composite_configs.cpp
+++ b/config_utilities/app/composite_configs.cpp
@@ -21,6 +21,7 @@ Invalid YAML or missing files get dropped during compositing.
                              multiple times.
   -d/--disable-substitutions: Turn off substitutions resolution
   --no-disable-substitutions: Turn substitution resolution on (currently on by default)
+  --force-block-style: Force emitted YAML to only use block style
 
 Example:
 > echo "{a: 42, bar: hello}" > /tmp/test_in.yaml
@@ -87,6 +88,32 @@ inline void forceBlockForNonLeaves(YAML::Node node) {
   }
 }
 
+inline void forceBlockForAll(YAML::Node node) {
+  switch (node.Type()) {
+    case YAML::NodeType::Sequence:
+      if (node.size() > 0) {
+        node.SetStyle(YAML::EmitterStyle::Block);
+      }
+      for (const auto& child : node) {
+        forceBlockForAll(child);
+      }
+      break;
+    case YAML::NodeType::Map:
+      if (node.size() > 0) {
+        node.SetStyle(YAML::EmitterStyle::Block);
+      }
+      for (const auto& child : node) {
+        forceBlockForAll(child.second);
+      }
+      break;
+    case YAML::NodeType::Null:
+    case YAML::NodeType::Undefined:
+    case YAML::NodeType::Scalar:
+    default:
+      return;
+  }
+}
+
 }  // namespace
 
 int main(int argc, char* argv[]) {
@@ -98,6 +125,9 @@ int main(int argc, char* argv[]) {
   }
 
   forceBlockForNonLeaves(result);
+  if (info.force_block_style) {
+    forceBlockForAll(result);
+  }
 
   YAML::Emitter emit;
   switch (result.Type()) {
diff --git a/config_utilities/include/config_utilities/parsing/commandline.h b/config_utilities/include/config_utilities/parsing/commandline.h
index b4864d50..c7d6d28e 100644
--- a/config_utilities/include/config_utilities/parsing/commandline.h
+++ b/config_utilities/include/config_utilities/parsing/commandline.h
@@ -47,6 +47,7 @@ namespace internal {
 
 struct ParserInfo {
   bool help_present = false;
+  bool force_block_style = false;
 };
 
 /**
diff --git a/config_utilities/src/commandline.cpp b/config_utilities/src/commandline.cpp
index 3a64472a..aefce586 100644
--- a/config_utilities/src/commandline.cpp
+++ b/config_utilities/src/commandline.cpp
@@ -215,6 +215,13 @@ CliParser& CliParser::parse(int& argc, char* argv[], bool remove_args) {
       continue;
     }
 
+    if ((curr_opt == "--force-block-style") && !found_separator) {
+      info.force_block_style = true;
+      spans.emplace_back(Span{i, 0, curr_opt});
+      ++i;
+      continue;
+    }
+
     if (curr_opt == "--" && !found_separator) {
       found_separator = true;
       spans.emplace_back(Span{i, 0, curr_opt});