Division by Zero tests for trig functions

Author: rajithv

spec/functions_spec.rb

@@ -66,8 +66,11 @@
     expect(SymEngine::cos(pi)).to eq(-1)
     expect(SymEngine::tan(pi)).to eq(0)
     expect(SymEngine::csc(pi/2)).to eq(1)
+    expect { SymEngine::csc(pi) }.to raise_error(RuntimeError)
     expect(SymEngine::sec(pi)).to eq(-1)
+    expect { SymEngine::sec(pi/2) }.to raise_error(RuntimeError)
     expect(SymEngine::cot(pi/4)).to eq(1)
+    expect { SymEngine::cot(pi) }.to raise_error(RuntimeError)
 
     expect(SymEngine::asin(1)).to eq(pi/2)
     expect(SymEngine::acos(1)).to eq(0)