1 files changed, 66 insertions, 0 deletions
diff --git a/yarnutils/asserts.py b/yarnutils/asserts.py
new file mode 100644
index 0000000..aea055d
--- /dev/null
+++ b/yarnutils/asserts.py
@@ -0,0 +1,66 @@
+# Copyright 2017  Lars Wirzenius
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+# =*= License: GPL-3+ =*=
+
+
+class AssertError(Exception):
+
+    pass
+
+
+def assertTrue(thing):
+    if not thing:
+        raise AssertError('expected {!r} to be true'.format(thing))
+
+
+def assertFalse(thing):
+    if thing:
+        raise AssertError('expected {!r} to be false'.format(thing))
+
+
+def assertEqual(a, b):
+    if a != b:
+        raise AssertError(
+            'expected {!r} and {!r} to be equal, but they are not'.format(
+                a, b))
+
+
+def assertNotEqual(a, b):
+    if a == b:
+        raise AssertError(
+            'expected {!r} and {!r} to be different, but they are not'.format(
+                a, b))
+
+
+def assertGreaterThan(a, b):
+    if a <= b:
+        raise AssertError(
+            'expected {!r} > {!r}, but am disappoint'.format(
+                a, b))
+
+
+def assertLessThan(a, b):
+    if a >= b:
+        raise AssertError(
+            'expected {!r} < {!r}, but am disappoint'.format(
+                a, b))
+
+
+def assertIn(a, b):
+    if a not in b:
+        raise AssertError(
+            'expected {!r} in {!r}, but am disappoint'.format(
+                a, b))