Initial Commit, first submission to SRAM

tests/test_bicycle_drive_train.py

@@ -0,0 +1,68 @@
+import pytest
+from bicycle_drive_train import BikeDriveTrain
+
+
+@pytest.fixture(scope="module")
+def drive_train():
+    """
+    list of front cog tooth counts. For example it could be initialized with [38,30]
+    list of rear cog tooth counts. For example it could be initialized with [28, 23, 19, 16]
+    """
+    return BikeDriveTrain([38, 30], [28, 23, 19, 16])
+
+
+def test_bike_drive_train(drive_train):
+    assert drive_train.front_cogs == [38, 30]
+    assert drive_train.rear_cogs == [28, 23, 19, 16]
+
+
+def test_bike_drive_train_ratios(drive_train):
+    # generate list of the gear ratios for the given front crank and rear cassette
+    ratios = [(38, 28, 38 / 28),
+              (38, 23, 38 / 23),
+              (38, 19, 38 / 19),
+              (38, 16, 38 / 16),
+              (30, 28, 30 / 28),
+              (30, 23, 30 / 23),
+              (30, 19, 30 / 19),
+              (30, 16, 30 / 16)
+              ]
+
+    for ratio in ratios:
+        assert ratio in drive_train.gear_combinations_and_ratios
+
+
+def test_bike_drive_train_ratio(drive_train):
+    """
+    If the drivetrain was initialized with the example values above and passed a target_ratio of 1.6
+    It should return a data type that contains the information:
+        Front: 30, Rear: 19, Ratio: 1.579
+    """
+    assert drive_train.get_gear_combination(1.6) == (30, 19, 30 / 19)
+
+
+def test_bike_drive_train_shift_seq(drive_train):
+    """
+    For an example input the same as above plus: initial_gear_combination = [38, 28]
+
+        1 - F:38 R:28 Ratio 1.357
+        2 - F:30 R:28 Ratio 1.071
+        3 - F:30 R:23 Ratio 1.304
+        4 - F:30 R:19 Ratio 1.579
+    """
+
+    sequence = drive_train.get_shift_sequence(target_ratio=1.6, initial_gear_combination=[38, 28])
+
+    assert sequence == [
+        (38, 28, 38 / 28),
+        (30, 28, 30 / 28),
+        (30, 23, 30 / 23),
+        (30, 19, 30 / 19)
+    ]
+
+
+def test_bike_drive_train_shift_seq_output(drive_train, capsys):
+    drive_train.get_shift_sequence(target_ratio=1.6, initial_gear_combination=[38, 28])
+
+    out, err = capsys.readouterr()
+    assert out == "1 - F:38 R:28 Ratio 1.357\n2 - F:30 R:28 Ratio 1.071\n3 - F:30 R:23 Ratio 1.304\n4 - F:30 R:19 Ratio 1.579"