Add regression test

Closes sympy/sympy#19442 Closes sympy/sympy#11667
skirpichev · Mar 28, 2021 · 7bf6b54 · 7bf6b54
1 parent e3b8868
commit 7bf6b54
Show file tree

Hide file tree

Showing 2 changed files with 7 additions and 1 deletion.
diff --git a/diofant/tests/series/test_limits.py b/diofant/tests/series/test_limits.py
@@ -25,7 +25,7 @@ def test_basic1():
     assert limit(x**2, x, -oo) == oo
     assert limit(-x**2, x, oo) == -oo
     assert limit(x*log(x), x, 0, dir='+') == 0
-    assert limit(1/x, x, oo) == 0
+    assert limit(1/x, x, oo) == 0  # issue sympy/sympy#11667
     assert limit(exp(x), x, oo) == oo
     assert limit(-exp(x), x, oo) == -oo
     assert limit(exp(x)/x, x, oo) == oo
@@ -846,3 +846,7 @@ def test_sympyissue_19453():
 
     assert limit(e - h*w/2, beta, oo) == 0
     assert limit(e.simplify() - h*w/2, beta, oo) == 0
+
+
+def test_sympyissue_19442():
+    pytest.raises(PoleError, lambda: limit(1/x, x, 0, 'real'))
diff --git a/docs/release/notes-0.13.rst b/docs/release/notes-0.13.rst
@@ -67,3 +67,5 @@ These Sympy issues also were addressed:
 * :sympyissue:`20578`: A strange behavior of limit function
 * :sympyissue:`20444`: Leading Term with log
 * :sympyissue:`19453`: Limit changes from simplification of original expression
+* :sympyissue:`19442`: Non-existent bi-directional limit gives ValueError
+* :sympyissue:`11667`: limit(1/x, x, 0) == oo ??