eigen: add test

Closes #34727.

Signed-off-by: Mike McQuaid <mike@mikemcquaid.com>

1 files changed, 19 insertions, 0 deletions

diff --git a/Library/Formula/eigen.rb b/Library/Formula/eigen.rb
index d9d3ec3cc..7850ae8c3 100644
--- a/Library/Formula/eigen.rb
+++ b/Library/Formula/eigen.rb
@@ -29,4 +29,23 @@ class Eigen < Formula
       system 'make install'
     end
   end
+
+  test do
+    (testpath/"test.cpp").write <<-EOS.undent
+      #include <iostream>
+      #include <Eigen/Dense>
+      using Eigen::MatrixXd;
+      int main()
+      {
+        MatrixXd m(2,2);
+        m(0,0) = 3;
+        m(1,0) = 2.5;
+        m(0,1) = -1;
+        m(1,1) = m(1,0) + m(0,1);
+        std::cout << m << std::endl;
+      }
+    EOS
+    system ENV.cxx, "test.cpp", "-I#{include}/eigen3", "-o", "test"
+    assert_equal `./test`.split, %w[3 -1 2.5 1.5]
+  end
 end