2 Tests, one at a time

just setup

We cannot tell whether count still works after a change, unless we try it by hand each time. Tests try it for us. Each test gives count a text, and compares what it gives back with what we expect. We add the tests one file at a time, and run them after each. One test asks for something that count cannot do yet. It asks count to count "The" and "the" as one word.

What changed

src/tally/__init__.py: changes count. 1 line added, 1 removed. The file.
tests/test_count.py: adds class Count, test_case, test_words. New, 11 lines. The file.
tests/test_empty.py: adds class Empty, test_empty. New, 8 lines. The file.

The diff of src/tally/__init__.py

@@ -5,7 +5,7 @@ import sys
 
 def count(text):
     counts = {}
-    for word in text.split():
+    for word in text.lower().split():
         counts[word] = counts.get(word, 0) + 1
     return counts

The diff of tests/test_count.py

@@ -0,0 +1,11 @@
+import unittest
+
+from tally import count
+
+
+class Count(unittest.TestCase):
+    def test_words(self):
+        self.assertEqual(count("a b a"), {"a": 2, "b": 1})
+
+    def test_case(self):
+        self.assertEqual(count("A a"), {"a": 2})

The diff of tests/test_empty.py

@@ -0,0 +1,8 @@
+import unittest
+
+from tally import count
+
+
+class Empty(unittest.TestCase):
+    def test_empty(self):
+        self.assertEqual(count(""), {})

This change on GitHub. The code after it.