ignition-plugin2: new formula (#1540)

Add dependency on ignition-utils1

Formula/ignition-plugin2.rb

@@ -0,0 +1,55 @@
+class IgnitionPlugin2 < Formula
+  desc "Plugin libraries for robotics applications"
+  homepage "https://github.com/ignitionrobotics/ign-plugin"
+  url "https://github.com/ignitionrobotics/ign-plugin.git", branch: "main"
+  version "1.999.999~1"
+  license "Apache-2.0"
+
+  depends_on "cmake"
+  depends_on "ignition-cmake2"
+  depends_on "ignition-tools"
+  depends_on "ignition-utils1"
+  depends_on macos: :high_sierra # c++17
+  depends_on "pkg-config"
+
+  def install
+    cmake_args = std_cmake_args
+    cmake_args << "-DBUILD_TESTING=Off"
+    system "cmake", ".", *cmake_args
+    system "make", "install"
+  end
+
+  test do
+    (testpath/"test.cpp").write <<-EOS
+      #include <ignition/plugin/Loader.hh>
+      int main() {
+        ignition::plugin::Loader loader;
+        return loader.InterfacesImplemented().size();
+      }
+    EOS
+    (testpath/"CMakeLists.txt").write <<-EOS
+      cmake_minimum_required(VERSION 3.5 FATAL_ERROR)
+      find_package(ignition-plugin2 QUIET REQUIRED COMPONENTS loader)
+      add_executable(test_cmake test.cpp)
+      target_link_libraries(test_cmake ${IGNITION-PLUGIN_LIBRARIES})
+    EOS
+    system "pkg-config", "ignition-plugin2-loader"
+    cflags = `pkg-config --cflags ignition-plugin2-loader`.split
+    system ENV.cc, "test.cpp",
+                   *cflags,
+                   "-L#{lib}",
+                   "-lignition-plugin2-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