add test for init_printing

Author: eendebakpt

symengine/tests/test_printing.py

@@ -1,6 +1,6 @@
 from symengine import (ccode, Symbol, sqrt, Pow, Max, sin, Integer, MutableDenseMatrix)
 from symengine.utilities import raises
-from symengine.printing import CCodePrinter
+from symengine.printing import CCodePrinter, init_printing
 
 def test_ccode():
     x = Symbol("x")
@@ -24,3 +24,9 @@ def test_CCodePrinter():
     assert myprinter.doprint(MutableDenseMatrix(1, 2, [x, y]), "larry") == "larry[0] = x;\nlarry[1] = y;"
     raises(TypeError, lambda: myprinter.doprint(sin(x), Integer))
     raises(RuntimeError, lambda: myprinter.doprint(MutableDenseMatrix(1, 2, [x, y])))
+
+def test_init_printing():
+    x = Symbol("x")
+    assert x._repr_latex_() is None
+    init_printing()
+    assert x._repr_latex_() == '$x$'