Add test for sort_keys

tests/data/mapping.sort

@@ -0,0 +1,6 @@
+z: 1
+a: 2
+y: 3
+b: 4
+x: 5
+c: 6

tests/data/mapping.sorted

@@ -0,0 +1,6 @@
+a: 2
+b: 4
+c: 6
+x: 5
+y: 3
+z: 1

tests/lib/test_sort_keys.py

@@ -0,0 +1,27 @@
+import yaml
+import pprint
+import sys
+
+def test_sort_keys(input_filename, sorted_filename, verbose=False):
+    input = open(input_filename, 'rb').read().decode('utf-8')
+    sorted = open(sorted_filename, 'rb').read().decode('utf-8')
+    data = yaml.load(input)
+    dump_sorted = yaml.dump(data, default_flow_style=False, sort_keys=True)
+    dump_unsorted = yaml.dump(data, default_flow_style=False, sort_keys=False)
+    if verbose:
+        print("INPUT:")
+        print(input)
+        print("DATA:")
+        print(data)
+
+    assert dump_sorted == sorted
+
+
+
+
+test_sort_keys.unittest = ['.sort', '.sorted']
+
+if __name__ == '__main__':
+    import test_appliance
+    test_appliance.run(globals())
+

tests/lib3/test_sort_keys.py

@@ -0,0 +1,27 @@
+import yaml
+import pprint
+import sys
+
+def test_sort_keys(input_filename, sorted_filename, verbose=False):
+    input = open(input_filename, 'rb').read().decode('utf-8')
+    sorted = open(sorted_filename, 'rb').read().decode('utf-8')
+    data = yaml.load(input)
+    dump_sorted = yaml.dump(data, default_flow_style=False, sort_keys=True)
+    dump_unsorted = yaml.dump(data, default_flow_style=False, sort_keys=False)
+    if verbose:
+        print("INPUT:")
+        print(input)
+        print("DATA:")
+        print(data)
+
+    assert dump_sorted == sorted
+
+    if sys.version_info>=(3,7):
+        assert dump_unsorted == input
+
+test_sort_keys.unittest = ['.sort', '.sorted']
+
+if __name__ == '__main__':
+    import test_appliance
+    test_appliance.run(globals())
+