assertpy · selakavon · Nov 9, 2019
diff --git a/assertpy/collection.py b/assertpy/collection.py
@@ -25,7 +25,7 @@
 # ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 # SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
+import operator
 import sys
 import collections
 
@@ -90,3 +90,35 @@ def is_subset_of(self, *supersets):
                 self._err('Expected <%s> to be subset of %s, but %s %s missing.' % (self.val, self._fmt_items(superset), self._fmt_items(missing), 'was' if len(missing) == 1 else 'were'))
 
         return self
+
+    def is_sorted(self, compare_op=operator.ge):
+        """Asserts that value is sorted by at least one of the provided compare functions."""
+
+        # Make compare_op a list
+        try:
+            self._check_iterable(compare_op)
+            compare_ops = compare_op
+        except TypeError as e:
+            compare_ops = [compare_op]
+
+        # Loop through compare_ops and find two unsorted items.
+        op_it = iter(compare_ops)
+        sorted_by_any = False
+
+        while not sorted_by_any:
+            try:
+                op = next(op_it)
+            except StopIteration as si:
+                break
+
+            sorted_by_any = True
+
+            for i in range(len(self.val) - 1):
+                if not op(self.val[i + 1], self.val[i]):
+                    sorted_by_any = False
+                    break
+
+        if not sorted_by_any:
+            self._err('Expected value to be sorted by any of %s, but was not.' % str(compare_ops))
+
+        return self
diff --git a/tests/test_collection.py b/tests/test_collection.py
@@ -25,7 +25,7 @@
 # ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 # SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
+import operator
 import sys
 import collections
 
@@ -162,5 +162,34 @@ def test_is_subset_of_bad_arg_failure():
         assert_that(str(ex)).is_equal_to('one or more superset args must be given')
 
 def test_chaining():
-    assert_that(['a','b','c']).is_iterable().is_type_of(list).is_length(3)
+    assert_that(['a','b','c']).is_iterable().is_type_of(list).is_sorted().is_length(3)
+
+def test_is_sorted_default_compare_op():
+    assert_that([1,2,5,6]).is_sorted()
+
+def test_is_sorted_default_compare_op_failure():
+    try:
+        assert_that([1,5,2,6]).is_sorted()
+        assert fail("should have raised error")
+    except AssertionError as ae:
+        pass
+
+def test_is_sorted_one_compare_op():
+    assert_that([6, 5, 2, 1]).is_sorted(operator.le)
 
+def test_is_sorted_one_compare_op_failure():
+    try:
+        assert_that([6, 2, 5, 1]).is_sorted(operator.le)
+        assert fail("should have raised error")
+    except AssertionError as ae:
+        pass
+
+def test_is_sorted_multiple_compare_ops():
+    assert_that(["d", "c", "b", "a"]).is_sorted([operator.ge, operator.le])
+
+def test_is_sorted_multiple_compare_ops_failure():
+    try:
+        assert_that(["d", "b", "c", "a"]).is_sorted([operator.ge, operator.le])
+        assert fail("should have raised error")
+    except AssertionError as ae:
+        pass