series: re-implement according to canonical data (exercism#1379)

mrcfps · cmccandless · commit 178d0b954ede · 2018-04-24T11:32:39.000-04:00
* series: improve documentation

* series: re-implement according to cannonical data
diff --git a/exercises/series/README.md b/exercises/series/README.md
@@ -1,18 +1,18 @@
 # Series
 
 Given a string of digits, output all the contiguous substrings of length `n` in
-that string.
+that string in the order that they appear.
 
 For example, the string "49142" has the following 3-digit series:
 
-- 491
-- 914
-- 142
+- "491"
+- "914"
+- "142"
 
 And the following 4-digit series:
 
-- 4914
-- 9142
+- "4914"
+- "9142"
 
 And if you ask for a 6-digit series from a 5-digit string, you deserve
 whatever you get.
diff --git a/exercises/series/example.py b/exercises/series/example.py
@@ -1,6 +1,5 @@
 def slices(series, length):
-    numbers = [int(digit) for digit in series]
-    if not 1 <= length <= len(numbers):
+    if not 1 <= length <= len(series):
         raise ValueError("Invalid slice length for this series: " + str(
             length))
-    return [numbers[i:i + length] for i in range(len(numbers) - length + 1)]
+    return [series[i:i + length] for i in range(len(series) - length + 1)]
diff --git a/exercises/series/series_test.py b/exercises/series/series_test.py
@@ -9,40 +9,39 @@
 from series import slices
 
 
+# Tests adapted from `problem-specifications//canonical-data.json` @ v1.0.0
+
 class SeriesTest(unittest.TestCase):
-    def test_slices_of_one(self):
-        self.assertEqual(
-            slices("01234", 1),
-            [[0], [1], [2], [3], [4]], )
+    def test_slices_of_one_from_one(self):
+        self.assertEqual(slices("1", 1), ["1"])
+
+    def test_slices_of_one_from_two(self):
+        self.assertEqual(slices("12", 1), ["1", "2"])
 
     def test_slices_of_two(self):
-        self.assertEqual(
-            slices("97867564", 2),
-            [[9, 7], [7, 8], [8, 6], [6, 7], [7, 5], [5, 6], [6, 4]], )
-
-    def test_slices_of_three(self):
-        self.assertEqual(
-            slices("97867564", 3),
-            [[9, 7, 8], [7, 8, 6], [8, 6, 7], [6, 7, 5], [7, 5, 6], [5, 6, 4]],
-        )
-
-    def test_slices_of_four(self):
-        self.assertEqual(
-            slices("01234", 4),
-            [[0, 1, 2, 3], [1, 2, 3, 4]], )
-
-    def test_slices_of_five(self):
-        self.assertEqual(
-            slices("01234", 5),
-            [[0, 1, 2, 3, 4]], )
-
-    def test_overly_long_slice(self):
+        self.assertEqual(slices("35", 2), ["35"])
+
+    def test_slices_of_two_overlap(self):
+        self.assertEqual(slices("9142", 2), ["91", "14", "42"])
+
+    def test_slices_can_include_duplicates(self):
+        self.assertEqual(slices("777777", 3), ["777", "777", "777", "777"])
+
+    def test_slice_length_is_too_large(self):
+        with self.assertRaisesWithMessage(ValueError):
+            slices("12345", 6)
+
+    def test_slice_length_cannot_be_zero(self):
+        with self.assertRaisesWithMessage(ValueError):
+            slices("12345", 0)
+
+    def test_slice_length_cannot_be_negative(self):
         with self.assertRaisesWithMessage(ValueError):
-            slices("012", 4)
+            slices("123", -1)
 
-    def test_overly_short_slice(self):
+    def test_empty_series_is_invalid(self):
         with self.assertRaisesWithMessage(ValueError):
-            slices("01234", 0)
+            slices("", 1)
 
     # Utility functions
     def setUp(self):
