Bash completion for flags

CMakeLists.txt

@@ -71,6 +71,9 @@ set(IGN_MATH_VER ${ignition-math6_VERSION_MAJOR})
 #--------------------------------------
 # Find if ign command is available
 find_program(HAVE_IGN_TOOLS ign)
+if (HAVE_IGN_TOOLS)
+  set(IGN_TOOLS_VER 1)
+endif()
 
 #--------------------------------------
 # Find Tinyxml2

src/cmd/CMakeLists.txt

@@ -42,3 +42,19 @@ file(GENERATE
 
 # Install the ruby command line library in an unversioned location.
 install(FILES ${cmd_script_generated} DESTINATION lib/ruby/ignition)
+
+
+#===============================================================================
+# Bash completion
+
+# Tack version onto and install the bash completion script
+configure_file(
+  "msgs.bash_completion.sh"
+    "${CMAKE_CURRENT_BINARY_DIR}/msgs${PROJECT_VERSION_MAJOR}.bash_completion.sh" @ONLY)
+if (HAVE_IGN_TOOLS)
+  install(
+    FILES
+      ${CMAKE_CURRENT_BINARY_DIR}/msgs${PROJECT_VERSION_MAJOR}.bash_completion.sh
+    DESTINATION
+      ${CMAKE_INSTALL_PREFIX}/${CMAKE_INSTALL_DATAROOTDIR}/gz/gz${IGN_TOOLS_VER}.completion.d)
+endif()

src/cmd/msgs.bash_completion.sh

@@ -0,0 +1,27 @@
+#!/usr/bin/env bash
+
+# bash tab-completion
+
+# This is a per-library function definition, used in conjunction with the
+# top-level entry point in ign-tools.
+
+function _gz_msg
+{
+  if [[ ${COMP_WORDS[COMP_CWORD]} == -* ]]; then
+    # Specify options (-*) word list for this subcommand
+    COMPREPLY=($(compgen -W "
+      -i --info
+      -l --list
+      -h --help
+      --force-version
+      --versions
+      " -- "${COMP_WORDS[COMP_CWORD]}" ))
+    return
+  else
+    # Just use bash default auto-complete, because we never have two
+    # subcommands in the same line. If that is ever needed, change here to
+    # detect subsequent subcommands
+    COMPREPLY=($(compgen -o default -- "${COMP_WORDS[COMP_CWORD]}"))
+    return
+  fi
+}

tools/ign_TEST.cc

@@ -15,6 +15,7 @@
  *
 */
 
+#include <fstream>
 #include <string>
 #include <gtest/gtest.h>
 #include <ignition/msgs/config.hh>
@@ -89,6 +90,30 @@ TEST(CmdLine, MsgInfo)
     << output;
 }
 
+/////////////////////////////////////////////////
+TEST(CmdLine, MsgHelpVsCompletionFlags)
+{
+  // Flags in help message
+  auto output = custom_exec_str("ign msg --help --force-version " + g_version);
+  EXPECT_NE(std::string::npos, output.find("--info")) << output;
+  EXPECT_NE(std::string::npos, output.find("--list")) << output;
+  EXPECT_NE(std::string::npos, output.find("--help")) << output;
+  EXPECT_NE(std::string::npos, output.find("--force-version")) << output;
+  EXPECT_NE(std::string::npos, output.find("--versions")) << output;
+
+  // Flags in bash completion
+  std::ifstream scriptFile(std::string(PROJECT_SOURCE_PATH) +
+    "/src/cmd/msgs.bash_completion.sh");
+  std::string script((std::istreambuf_iterator<char>(scriptFile)),
+    std::istreambuf_iterator<char>());
+
+  EXPECT_NE(std::string::npos, script.find("--info")) << script;
+  EXPECT_NE(std::string::npos, script.find("--list")) << script;
+  EXPECT_NE(std::string::npos, script.find("--help")) << script;
+  EXPECT_NE(std::string::npos, script.find("--force-version")) << script;
+  EXPECT_NE(std::string::npos, script.find("--versions")) << script;
+}
+
 /////////////////////////////////////////////////
 /// Main
 int main(int argc, char **argv)