ignore commented launch dependencies (#13)

Author: Joschi3

package_xml_validation/helpers/find_launch_dependencies.py

@@ -4,6 +4,11 @@
 
 Recursively search a ROS 2 package's launch/ folder and extract
 all referenced ROS 2 package names via a small set of regexes.
+
+Now ignores matches that occur inside comments:
+- Python: # line comments, and triple-quoted blocks
+- XML/.launch: <!-- ... --> comments
+- YAML: # line comments
 """
 
 import os
@@ -29,21 +34,111 @@
     r"\$\(\s*find-pkg-share\s+([A-Za-z0-9_]+)\s*\)",
 ]
 
-# Compile once for speed
 COMPILED = [re.compile(rx) for rx in REGEX_EXPR]
 
+_TRIPLE_QUOTE_BLOCK = re.compile(r"(?s)(['\"]{3})(?:.*?)(\1)")
+_XML_COMMENT_BLOCK = re.compile(r"(?s)<!--.*?-->")
+
+
+def _strip_hash_line_comments_outside_strings(text: str) -> str:
+    """
+    Remove '#' to end-of-line comments that occur OUTSIDE of single/double quoted strings.
+    Preserves newlines.
+    Suitable for Python and YAML after any triple-quoted removal (for Python).
+    """
+    out = []
+    in_single = False
+    in_double = False
+    i = 0
+    n = len(text)
+
+    while i < n:
+        ch = text[i]
+
+        # Handle escapes inside strings
+        if ch == "\\" and (in_single or in_double) and i + 1 < n:
+            out.append(ch)
+            out.append(text[i + 1])
+            i += 2
+            continue
+
+        if not in_single and not in_double:
+            if ch == "#":
+                # skip until end of line (keep the newline itself)
+                while i < n and text[i] not in ("\n", "\r"):
+                    i += 1
+                # fall through to append the newline (if any)
+                continue
+            elif ch == "'":
+                in_single = True
+                out.append(ch)
+                i += 1
+                continue
+            elif ch == '"':
+                in_double = True
+                out.append(ch)
+                i += 1
+                continue
+            else:
+                out.append(ch)
+                i += 1
+                continue
+        else:
+            # inside quotes
+            if in_single and ch == "'":
+                in_single = False
+            elif in_double and ch == '"':
+                in_double = False
+            out.append(ch)
+            i += 1
+
+    return "".join(out)
+
 
-def scan_file(path, found: set[str], verbose: bool = False):
-    """Apply every regex to the file and add matches to `found`."""
+def _decomment_python(text: str) -> str:
+    # 1) drop triple-quoted blocks entirely
+    text = _TRIPLE_QUOTE_BLOCK.sub("", text)
+    # 2) drop '#' comments outside of quoted strings
+    text = _strip_hash_line_comments_outside_strings(text)
+    return text
+
+
+def _decomment_xml(text: str) -> str:
+    # Drop <!-- ... --> blocks
+    return _XML_COMMENT_BLOCK.sub("", text)
+
+
+def _decomment_yaml(text: str) -> str:
+    # YAML has only '#' line comments; be string-aware for ' and "
+    return _strip_hash_line_comments_outside_strings(text)
+
+
+def _decomment_for_suffix(suffix: str, text: str) -> str:
+    s = suffix.lower()
+    if s.endswith(".py"):
+        return _decomment_python(text)
+    if s.endswith(".xml") or s.endswith(".launch"):
+        return _decomment_xml(text)
+    if s.endswith(".yaml") or s.endswith(".yml"):
+        return _decomment_yaml(text)
+    # default: no decommenting
+    return text
+
+
+def scan_file(path: str, found: set[str], verbose: bool = False):
+    """Apply every regex to the file after stripping comments; add matches to `found`."""
     with open(path, encoding="utf-8") as f:
         text = f.read()
 
+    text = _decomment_for_suffix(path, text)
+
     for i, rx in enumerate(COMPILED):
         for m in rx.finditer(text):
-            found.add(m.group(1))
+            pkg = m.group(1)
+            found.add(pkg)
             if verbose:
                 print(
-                    f"Found package '{m.group(1)}' in {os.path.basename(path)} with regex {REGEX_EXPR[i]}"
+                    f"Found package '{pkg}' in {os.path.basename(path)} with regex {REGEX_EXPR[i]}"
                 )
 
 
@@ -52,15 +147,16 @@ def scan_files(launch_dir: str, verbose: bool = False) -> list[str]:
     Extracts launch dependencies from the specified directory.
     Launch dependencies are listed packages names in the launch files.
     It uses regex to extract package names from common launch patterns.
+    Comments are stripped (type-specific) before matching.
     """
     if not os.path.isdir(launch_dir):
         print(f"Error: '{launch_dir}' is not a directory.")
         return []
 
-    pkgs = set()
+    pkgs: set[str] = set()
 
     for root, _, files in os.walk(launch_dir):
         for fn in files:
             if fn.endswith((".py", ".xml", ".yaml", ".launch", ".yml")):
                 scan_file(os.path.join(root, fn), pkgs, verbose)
-    return list(pkgs)
+    return sorted(pkgs)

tests/examples/launch_examples/hector_launch_component_comment.yaml

@@ -0,0 +1,10 @@
+# description: Announcer for Athena Multi Robot
+# provides: announcement
+# launch:
+#   package: athena_announcer_comment
+#   executable: athena_announcer
+description: Announcer for Athena Multi Robot
+provides: announcement
+launch:
+  package: athena_announcer
+  executable: athena_announcer

tests/examples/launch_examples/python_example_comment.launch.py

@@ -0,0 +1,99 @@
+# from https://docs.ros.org/en/rolling/How-To-Guides/Launch-file-different-formats.html
+from launch import LaunchDescription
+from launch.actions import DeclareLaunchArgument, GroupAction, IncludeLaunchDescription
+from launch.substitutions import LaunchConfiguration, PathJoinSubstitution
+from launch_ros.actions import Node, PushROSNamespace
+from launch_ros.substitutions import FindPackageShare
+
+
+def generate_launch_description():
+    # launch_dir = PathJoinSubstitution(
+    #    [FindPackageShare("demo_nodes_cpp_comment"), "launch", "topics"]
+    # )
+    """
+    launch_dir = PathJoinSubstitution(
+        [FindPackageShare("demo_nodes_cpp_commentII"), "launch", "topics"]
+    )
+    """
+    launch_dir = PathJoinSubstitution(
+        [FindPackageShare("demo_nodes_cpp"), "launch", "topics"]
+    )
+    return LaunchDescription(
+        [
+            # args that can be set from the command line or a default will be used
+            DeclareLaunchArgument("background_r", default_value="0"),
+            DeclareLaunchArgument("background_g", default_value="255"),
+            DeclareLaunchArgument("background_b", default_value="0"),
+            DeclareLaunchArgument("chatter_py_ns", default_value="chatter/py/ns"),
+            DeclareLaunchArgument("chatter_xml_ns", default_value="chatter/xml/ns"),
+            DeclareLaunchArgument("chatter_yaml_ns", default_value="chatter/yaml/ns"),
+            # include another launch file
+            IncludeLaunchDescription(
+                PathJoinSubstitution([launch_dir, "talker_listener_launch.py"])
+            ),
+            # include a Python launch file in the chatter_py_ns namespace
+            GroupAction(
+                actions=[
+                    # push_ros_namespace first to set namespace of included nodes for following actions
+                    PushROSNamespace("chatter_py_ns"),
+                    IncludeLaunchDescription(
+                        PathJoinSubstitution([launch_dir, "talker_listener_launch.py"])
+                    ),
+                ]
+            ),
+            # include a xml launch file in the chatter_xml_ns namespace
+            GroupAction(
+                actions=[
+                    # push_ros_namespace first to set namespace of included nodes for following actions
+                    PushROSNamespace("chatter_xml_ns"),
+                    IncludeLaunchDescription(
+                        PathJoinSubstitution([launch_dir, "talker_listener_launch.xml"])
+                    ),
+                ]
+            ),
+            # include a yaml launch file in the chatter_yaml_ns namespace
+            GroupAction(
+                actions=[
+                    # push_ros_namespace first to set namespace of included nodes for following actions
+                    PushROSNamespace("chatter_yaml_ns"),
+                    IncludeLaunchDescription(
+                        PathJoinSubstitution(
+                            [launch_dir, "talker_listener_launch.yaml"]
+                        )
+                    ),
+                ]
+            ),
+            # start a turtlesim_node in the turtlesim1 namespace
+            Node(
+                package="turtlesim",
+                namespace="turtlesim1",
+                executable="turtlesim_node",
+                name="sim",
+            ),
+            # start another turtlesim_node in the turtlesim2 namespace
+            # and use args to set parameters
+            Node(
+                package="turtlesim",
+                namespace="turtlesim2",
+                executable="turtlesim_node",
+                name="sim",
+                parameters=[
+                    {
+                        "background_r": LaunchConfiguration("background_r"),
+                        "background_g": LaunchConfiguration("background_g"),
+                        "background_b": LaunchConfiguration("background_b"),
+                    }
+                ],
+            ),
+            # perform remap so both turtles listen to the same command topic
+            Node(
+                package="turtlesim",
+                executable="mimic",
+                name="mimic",
+                remappings=[
+                    ("/input/pose", "/turtlesim1/turtle1/pose"),
+                    ("/output/cmd_vel", "/turtlesim2/turtle1/cmd_vel"),
+                ],
+            ),
+        ]
+    )

tests/examples/launch_examples/xml_example_comment.launch.xml

@@ -0,0 +1,55 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!-- from https://docs.ros.org/en/rolling/How-To-Guides/Launch-file-different-formats.html -->
+<launch>
+  <!-- args that can be set from the command line or a default will be used -->
+  <arg name="background_r" default="0" />
+  <arg name="background_g" default="255" />
+  <arg name="background_b" default="0" />
+  <arg name="chatter_py_ns" default="chatter/py/ns" />
+  <arg name="chatter_xml_ns" default="chatter/xml/ns" />
+  <arg name="chatter_yaml_ns" default="chatter/yaml/ns" />
+
+  <!-- include another launch file -->
+  <include file="$(find-pkg-share demo_nodes_cpp)/launch/topics/talker_listener_launch.py" />
+  <!--<include file="$(find-pkg-share demo_nodes_cpp_comment)/launch/topics/talker_listener_launch.py" />-->
+  <!-- This is multiline comment
+   this pkg should not be found!!
+   <include file="$(find-pkg-share demo_nodes_cpp_comment)/launch/topics/talker_listener_launch.py" />
+   -->
+  <!-- include a Python launch file in the chatter_py_ns namespace-->
+  <group>
+    <!-- push_ros_namespace to set namespace of included nodes -->
+    <push_ros_namespace namespace="$(var chatter_py_ns)" />
+    <include file="$(find-pkg-share demo_nodes_cpp)/launch/topics/talker_listener_launch.py" />
+  </group>
+
+  <!-- include a xml launch file in the chatter_xml_ns namespace-->
+  <group>
+    <!-- push_ros_namespace to set namespace of included nodes -->
+    <push_ros_namespace namespace="$(var chatter_xml_ns)" />
+    <include file="$(find-pkg-share demo_nodes_cpp)/launch/topics/talker_listener_launch.xml" />
+  </group>
+
+  <!-- include a yaml launch file in the chatter_yaml_ns namespace-->
+  <group>
+    <!-- push_ros_namespace to set namespace of included nodes -->
+    <push_ros_namespace namespace="$(var chatter_yaml_ns)" />
+    <include file="$(find-pkg-share demo_nodes_cpp)/launch/topics/talker_listener_launch.yaml" />
+  </group>
+
+  <!-- start a turtlesim_node in the turtlesim1 namespace -->
+  <node pkg="turtlesim" exec="turtlesim_node" name="sim" namespace="turtlesim1" />
+
+  <!-- start another turtlesim_node in the turtlesim2 namespace and use args to set parameters -->
+  <node pkg="turtlesim" exec="turtlesim_node" name="sim" namespace="turtlesim2">
+    <param name="background_r" value="$(var background_r)" />
+    <param name="background_g" value="$(var background_g)" />
+    <param name="background_b" value="$(var background_b)" />
+  </node>
+
+  <!-- perform remap so both turtles listen to the same command topic -->
+  <node pkg="turtlesim" exec="mimic" name="mimic">
+    <remap from="/input/pose" to="/turtlesim1/turtle1/pose" />
+    <remap from="/output/cmd_vel" to="/turtlesim2/turtle1/cmd_vel" />
+  </node>
+</launch>

tests/examples/launch_examples/yaml_example_comment.launch.yml

@@ -0,0 +1,82 @@
+%YAML 1.2
+# extracted from https://docs.ros.org/en/rolling/How-To-Guides/Launch-file-different-formats.html
+---
+launch:
+# args that can be set from the command line or a default will be used
+- arg:
+    name: "background_r"
+    default: "0"
+- arg:
+    name: "background_g"
+    default: "255"
+- arg:
+    name: "background_b"
+    default: "0"
+- arg:
+    name: "chatter_py_ns"
+    default: "chatter/py/ns"
+- arg:
+    name: "chatter_xml_ns"
+    default: "chatter/xml/ns"
+- arg:
+    name: "chatter_yaml_ns"
+    default: "chatter/yaml/ns"
+
+# include another launch file
+- include:
+    file: "$(find-pkg-share demo_nodes_cpp)/launch/topics/talker_listener_launch.py"
+
+# include a Python launch file in the chatter_py_ns namespace
+- group:
+    - push_ros_namespace:
+        namespace: "$(var chatter_py_ns)"
+    - include:
+        file: "$(find-pkg-share demo_nodes_cpp)/launch/topics/talker_listener_launch.py"
+    #- include:
+    #    file: "$(find-pkg-share demo_nodes_cpp_comment)/launch/topics/talker_listener_launch.py"
+
+# include a xml launch file in the chatter_xml_ns namespace
+- group:
+    - push_ros_namespace:
+        namespace: "$(var chatter_xml_ns)"
+    - include:
+        file: "$(find-pkg-share demo_nodes_cpp)/launch/topics/talker_listener_launch.xml"
+
+# include a yaml launch file in the chatter_yaml_ns namespace
+- group:
+    - push_ros_namespace:
+        namespace: "$(var chatter_yaml_ns)"
+    - include:
+        file: "$(find-pkg-share demo_nodes_cpp)/launch/topics/talker_listener_launch.yaml"
+
+# start a turtlesim_node in the turtlesim1 namespace
+- node:
+    pkg: "turtlesim"
+    exec: "turtlesim_node"
+    name: "sim"
+    namespace: "turtlesim1"
+
+# start another turtlesim_node in the turtlesim2 namespace and use args to set parameters
+- node:
+    pkg: "turtlesim"
+    exec: "turtlesim_node"
+    name: "sim"
+    namespace: "turtlesim2"
+    param:
+    - name: "background_r"
+      value: "$(var background_r)"
+    - name: "background_g"
+      value: "$(var background_g)"
+    - name: "background_b"
+      value: "$(var background_b)"
+
+# perform remap so both turtles listen to the same command topic
+- node:
+    pkg: "turtlesim"
+    exec: "mimic"
+    name: "mimic"
+    remap:
+    - from: "/input/pose"
+      to: "/turtlesim1/turtle1/pose"
+    - from: "/output/cmd_vel"
+      to: "/turtlesim2/turtle1/cmd_vel"