gz-plugin3: new formula for ionic (#2453)

* Bumps in ionic : ci_matching_branch/bump_ionic_gz-plugin3

* Use - in version string

* Use gz-tools2, fix `head`

---------

Signed-off-by: Addisu Z. Taddese <addisu@openrobotics.org>
Co-authored-by: Steve Peters <scpeters@openrobotics.org>

Formula/gz-plugin3.rb

@@ -0,0 +1,69 @@
+class GzPlugin3 < Formula
+  desc "Plugin libraries for robotics applications"
+  homepage "https://github.com/gazebosim/gz-plugin"
+  url "https://github.com/gazebosim/gz-plugin.git", branch: "main"
+  version "2.999.999-0-20231006"
+  license "Apache-2.0"
+
+  head "https://github.com/gazebosim/gz-plugin.git", branch: "main"
+
+  depends_on "cmake"
+  depends_on "gz-cmake4"
+  depends_on "gz-tools2"
+  depends_on "gz-utils3"
+  depends_on macos: :high_sierra # c++17
+  depends_on "pkg-config"
+
+  def install
+    rpaths = [
+      rpath,
+      rpath(source: libexec/"gz/plugin3", target: lib),
+    ]
+    cmake_args = std_cmake_args
+    cmake_args << "-DBUILD_TESTING=OFF"
+    cmake_args << "-DCMAKE_INSTALL_RPATH=#{rpaths.join(";")}"
+
+    # Use build folder
+    mkdir "build" do
+      system "cmake", "..", *cmake_args
+      system "make", "install"
+    end
+  end
+
+  test do
+    # test CLI executable
+    system libexec/"gz/plugin3/gz-plugin"
+    # build against API
+    (testpath/"test.cpp").write <<-EOS
+      #include <gz/plugin/Loader.hh>
+      int main() {
+        gz::plugin::Loader loader;
+        return loader.InterfacesImplemented().size();
+      }
+    EOS
+    (testpath/"CMakeLists.txt").write <<-EOS
+      cmake_minimum_required(VERSION 3.5 FATAL_ERROR)
+      find_package(gz-plugin3 QUIET REQUIRED COMPONENTS loader)
+      add_executable(test_cmake test.cpp)
+      target_link_libraries(test_cmake gz-plugin3::loader)
+    EOS
+    system "pkg-config", "gz-plugin3-loader"
+    cflags = `pkg-config --cflags gz-plugin3-loader`.split
+    system ENV.cc, "test.cpp",
+                   *cflags,
+                   "-L#{lib}",
+                   "-lgz-plugin3-loader",
+                   "-lc++",
+                   "-o", "test"
+    system "./test"
+    # test building with cmake
+    mkdir "build" do
+      system "cmake", ".."
+      system "make"
+      system "./test_cmake"
+    end
+    # check for Xcode frameworks in bottle
+    cmd_not_grep_xcode = "! grep -rnI 'Applications[/]Xcode' #{prefix}"
+    system cmd_not_grep_xcode
+  end
+end