init: company-haness 설계

benchmark/fixtures/GT-R2/stats.py

@@ -0,0 +1,16 @@
+"""Running statistics — contains a bug in `median` for even-length inputs.
+
+The bug: for an even number of elements, `median` returns the lower-middle element
+instead of the average of the two middle elements. `mean` is correct.
+"""
+
+
+def mean(xs):
+    return sum(xs) / len(xs)
+
+
+def median(xs):
+    s = sorted(xs)
+    n = len(s)
+    mid = n // 2
+    return s[mid]  # BUG: even-length should average s[mid-1] and s[mid]

benchmark/fixtures/GT-R2/test_stats.py

@@ -0,0 +1,14 @@
+from stats import mean, median
+
+
+def test_mean():
+    assert mean([2, 4, 6]) == 4
+
+
+def test_median_odd():
+    assert median([3, 1, 2]) == 2
+
+
+def test_median_even():
+    assert median([1, 2, 3, 4]) == 2.5   # average of the two middle elements
+    assert median([10, 20]) == 15