Create test_utils.py

test_utils.py

@@ -0,0 +1,78 @@
+#!/usr/bin/env python3
+
+# To run the tests, use: python3 -m pytest --capture=sys
+
+"""These are general utilities for testing Pokemon Terminal. The data and
+   functions in this file can be used by other `test_*.py` scripts but they
+   should not be imported into or copied into normal scripts in the project.
+   This approach will help us to steer clear of assumption bias and avoid
+   shared code between dev and test."""
+
+import os
+from collections import Counter, namedtuple
+
+MAX_ID = 493
+SCRIPT_DIR = os.path.dirname(os.path.realpath(__file__))
+
+region_info = namedtuple('region_info', 'start end first last')
+region_dict = {
+    'kanto': region_info(1, 151, 'Bulbasaur', 'Mew'),
+    'johto': region_info(152, 251, 'Chikorita', 'Celebi'),
+    'hoenn': region_info(252, 386, 'Treecko', 'Deoxys'),
+    'sinnoh': region_info(387, 493, 'Turtwig', 'Arceus'),
+}
+
+# From: https://en.wikipedia.org/wiki/Pok%C3%A9mon#Generation_1
+_counts = {'kanto': 151, 'johto': 100, 'hoenn': 135, 'sinnoh': 107, 'all': 493}
+
+
+def expected_len(region_name):
+    """Utility function for knowing the standard pokemon population."""
+    if region_name == 'all':
+        return MAX_ID
+    elif region_name == 'extra':
+        return sum(make_extra_counts().values())  # 24
+    region_info = region_dict[region_name]
+    return region_info.end - region_info.start + 1
+
+
+def test_region_dict():
+    """Test if region_dict counts match wikipedia."""
+    assert _counts['all'] == MAX_ID == sum(_counts.values()) // 2
+    for region_name in region_dict:
+        assert _counts[region_name] == expected_len(region_name)
+        # print('{}: {}'.format(region_name, counts[region_name]))
+
+
+def get_region(db, region_name):
+    """Database unfortunately makes db.__get_region() private :-("""
+    func = {
+        'kanto': db.get_kanto,
+        'johto': db.get_johto,
+        'hoenn': db.get_hoenn,
+        'sinnoh': db.get_sinnoh,
+        'extra': db.get_extra,
+        'all': db.get_all
+    }[region_name]
+    return func()
+
+
+def _pokemon_id_to_region(pokemon_id):
+    """Rewrite of Database.__determine_region() avoids sharing implementations
+       between production code and test code."""
+    for region_name, region_info in region_dict.items():
+        if region_info.start <= pokemon_id <= region_info.end:
+            return region_name
+    assert False, '{} is an invalid region'.format(pokemon_id)
+
+
+def make_extra_counts(filename='pokemon.txt'):
+    """Test that correct regions are used in load_all_pokemon.load_extras().
+       Currently generates the dict: {'sinnoh': 14, 'hoenn': 9, 'johto': 1}"""
+    with open(os.path.join(SCRIPT_DIR, 'Data', filename)) as in_file:
+        pokemon_names = tuple([line.split()[0] for line in in_file])
+    filenames = os.listdir(os.path.join(SCRIPT_DIR, 'Images', 'Extra'))
+    father_names = (filename.split('-')[0] for filename in filenames)
+    father_ids = (pokemon_names.index(name) for name in father_names)
+    father_regions = (_pokemon_id_to_region(id) for id in father_ids)
+    return dict(Counter(father_regions))