From cf2107f67852e765cdb705cd4440363311fa58b1 Mon Sep 17 00:00:00 2001
From: oscarmartinez <oscar.martinez@pal-robotics.com>
Date: Thu, 17 Jul 2025 11:07:26 +0200
Subject: [PATCH 1/2] Added chain length getter with tests

---
 include/filters/filter_chain.hpp | 17 ++++++
 test/test_chain.cpp              | 94 ++++++++++++++++++++++++++++++++
 2 files changed, 111 insertions(+)

diff --git a/include/filters/filter_chain.hpp b/include/filters/filter_chain.hpp
index b75d095..dc502af 100644
--- a/include/filters/filter_chain.hpp
+++ b/include/filters/filter_chain.hpp
@@ -31,6 +31,7 @@
 #define FILTERS__FILTER_CHAIN_HPP_
 
 #include <algorithm>
+#include <cstddef>
 #include <sstream>
 #include <string>
 #include <utility>
@@ -294,6 +295,14 @@ class FilterChain
     return true;
   }
 
+  /**
+   * \brief Get the length of the chain (number of configured filters)
+   */
+  size_t get_length()
+  {
+    return reference_pointers_.size();
+  }
+
   rcl_interfaces::msg::SetParametersResult reconfigureCB(std::vector<rclcpp::Parameter> parameters)
   {
     auto result = rcl_interfaces::msg::SetParametersResult();
@@ -470,6 +479,14 @@ class MultiChannelFilterChain
     return true;
   }
 
+  /**
+   * \brief Get the length of the chain (number of configured filters)
+   */
+  size_t get_length()
+  {
+    return reference_pointers_.size();
+  }
+
   rcl_interfaces::msg::SetParametersResult reconfigureCB(std::vector<rclcpp::Parameter> parameters)
   {
     auto result = rcl_interfaces::msg::SetParametersResult();
diff --git a/test/test_chain.cpp b/test/test_chain.cpp
index a439fdd..409b338 100644
--- a/test/test_chain.cpp
+++ b/test/test_chain.cpp
@@ -438,3 +438,97 @@ TEST_F(ChainTest, TenMultiChannelIncrementChains) {
     EXPECT_EQ(11, v1a[i]);
   }
 }
+
+TEST_F(ChainTest, TestChainLength) {
+  filters::FilterChain<int> chain("int");
+
+  std::vector<rclcpp::Parameter> overrides;
+  overrides.emplace_back("OneIncrements.filter1.name", std::string("increment1"));
+  overrides.emplace_back("OneIncrements.filter1.type", std::string("filters/IncrementFilterInt"));
+
+  overrides.emplace_back("TwoIncrements.filter1.name", std::string("increment1"));
+  overrides.emplace_back("TwoIncrements.filter1.type", std::string("filters/IncrementFilterInt"));
+  overrides.emplace_back("TwoIncrements.filter2.name", std::string("increment2"));
+  overrides.emplace_back("TwoIncrements.filter2.type", std::string("filters/IncrementFilterInt"));
+
+  overrides.emplace_back("FiveIncrements.filter1.name", std::string("increment1"));
+  overrides.emplace_back("FiveIncrements.filter1.type", std::string("filters/IncrementFilterInt"));
+  overrides.emplace_back("FiveIncrements.filter2.name", std::string("increment2"));
+  overrides.emplace_back("FiveIncrements.filter2.type", std::string("filters/IncrementFilterInt"));
+  overrides.emplace_back("FiveIncrements.filter3.name", std::string("increment3"));
+  overrides.emplace_back("FiveIncrements.filter3.type", std::string("filters/IncrementFilterInt"));
+  overrides.emplace_back("FiveIncrements.filter4.name", std::string("increment4"));
+  overrides.emplace_back("FiveIncrements.filter4.type", std::string("filters/IncrementFilterInt"));
+  overrides.emplace_back("FiveIncrements.filter5.name", std::string("increment5"));
+  overrides.emplace_back("FiveIncrements.filter5.type", std::string("filters/IncrementFilterInt"));
+  auto node = make_node_with_params(overrides);
+
+  ASSERT_TRUE(
+    chain.configure(
+      "ZeroFilters", node->get_node_logging_interface(), node->get_node_parameters_interface()));
+  EXPECT_EQ(chain.get_length(), 0);
+  chain.clear();
+
+  ASSERT_TRUE(
+    chain.configure(
+      "TwoIncrements", node->get_node_logging_interface(), node->get_node_parameters_interface()));
+  EXPECT_EQ(chain.get_length(), 2);
+  chain.clear();
+
+  ASSERT_TRUE(
+    chain.configure(
+      "FiveIncrements", node->get_node_logging_interface(), node->get_node_parameters_interface()));
+  EXPECT_EQ(chain.get_length(), 5);
+}
+
+TEST_F(ChainTest, TestMultiChannelChainLength) {
+  filters::MultiChannelFilterChain<int> chain("int");
+
+  std::vector<rclcpp::Parameter> overrides;
+  overrides.emplace_back("OneIncrements.filter1.name", std::string("increment1"));
+  overrides.emplace_back(
+    "OneIncrements.filter1.type", std::string("filters/MultiChannelIncrementFilterInt"));
+
+  overrides.emplace_back("TwoIncrements.filter1.name", std::string("increment1"));
+  overrides.emplace_back(
+    "TwoIncrements.filter1.type", std::string("filters/MultiChannelIncrementFilterInt"));
+  overrides.emplace_back("TwoIncrements.filter2.name", std::string("increment2"));
+  overrides.emplace_back(
+    "TwoIncrements.filter2.type", std::string("filters/MultiChannelIncrementFilterInt"));
+
+  overrides.emplace_back("FiveIncrements.filter1.name", std::string("increment1"));
+  overrides.emplace_back(
+    "FiveIncrements.filter1.type", std::string("filters/MultiChannelIncrementFilterInt"));
+  overrides.emplace_back("FiveIncrements.filter2.name", std::string("increment2"));
+  overrides.emplace_back(
+    "FiveIncrements.filter2.type", std::string("filters/MultiChannelIncrementFilterInt"));
+  overrides.emplace_back("FiveIncrements.filter3.name", std::string("increment3"));
+  overrides.emplace_back(
+    "FiveIncrements.filter3.type", std::string("filters/MultiChannelIncrementFilterInt"));
+  overrides.emplace_back("FiveIncrements.filter4.name", std::string("increment4"));
+  overrides.emplace_back(
+    "FiveIncrements.filter4.type", std::string("filters/MultiChannelIncrementFilterInt"));
+  overrides.emplace_back("FiveIncrements.filter5.name", std::string("increment5"));
+  overrides.emplace_back(
+    "FiveIncrements.filter5.type", std::string("filters/MultiChannelIncrementFilterInt"));
+  auto node = make_node_with_params(overrides);
+
+  ASSERT_TRUE(
+    chain.configure(
+      3, "ZeroFilters", node->get_node_logging_interface(), node->get_node_parameters_interface()));
+  EXPECT_EQ(chain.get_length(), 0);
+  chain.clear();
+
+  ASSERT_TRUE(
+    chain.configure(
+      3, "TwoIncrements", node->get_node_logging_interface(),
+      node->get_node_parameters_interface()));
+  EXPECT_EQ(chain.get_length(), 2);
+  chain.clear();
+
+  ASSERT_TRUE(
+    chain.configure(
+      3, "FiveIncrements", node->get_node_logging_interface(),
+      node->get_node_parameters_interface()));
+  EXPECT_EQ(chain.get_length(), 5);
+}

From 67890abe03c99692242dbd51aac6efc05b9e5cca Mon Sep 17 00:00:00 2001
From: oscarmartinez <oscar.martinez@pal-robotics.com>
Date: Thu, 17 Jul 2025 11:29:43 +0200
Subject: [PATCH 2/2] Added throw on unconfigured update call

---
 include/filters/filter_chain.hpp | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/include/filters/filter_chain.hpp b/include/filters/filter_chain.hpp
index dc502af..4269b46 100644
--- a/include/filters/filter_chain.hpp
+++ b/include/filters/filter_chain.hpp
@@ -191,6 +191,9 @@ class FilterChain
    */
   bool update(const T & data_in, T & data_out)
   {
+    if (!configured_) {
+      throw std::runtime_error("The update cannot be called without configuring the filter chain!");
+    }
     bool result;
     size_t list_size = reference_pointers_.size();
     if (list_size == 0) {
@@ -361,6 +364,9 @@ class MultiChannelFilterChain
    */
   bool update(const std::vector<T> & data_in, std::vector<T> & data_out)
   {
+    if (!configured_) {
+      throw std::runtime_error("The update cannot be called without configuring the filter chain!");
+    }
     bool result;
     size_t list_size = reference_pointers_.size();