expect_evaluate_ruby { 12 + 12 }
.to eq(24)
does not work.
its because when we get the source code for the block it will include any expressions on the same line. So if you say expect_evaluate_ruby { 12 + 12 }.to eq(24) the tree includes the send(:to) part of the tree.
The solution is to repeatedly do .children.first until we find the block.