Added some tests for hash table and made minor adjustments to hash.py.

src/conftest.py

@@ -32,3 +32,11 @@ def bst_right_imbalanced():
     from bst import BST
     test_bst = BST((1, 2, 3, 4, 5, 6, 7, 8, 9, 10))
     return test_bst
+
+
+@pytest.fixture
+def empty_hash():
+    """Initialize empty hash table."""
+    from hash import HashTable
+    test_hash = HashTable()
+    return test_hash

src/hash.py

@@ -10,12 +10,14 @@ def __init__(self, size=10, hash_type='additive'):
         self.hash_type = hash_type
         self.buckets = []
         if hash_type not in ('additive', 'oat'):
-            raise ValueError('Hash funciton unsupported')
+            raise NameError('Hash funciton unsupported')
         for i in range(size):
             self.buckets.append([])
 
     def _hash(self, key):
         """Hash string from user on get method."""
+        if type(key) is not str:
+            raise TypeError('Key must be a string')
         if self.hash_type == 'additive':
             hash = 0
             for char in key:
@@ -51,4 +53,4 @@ def get(self, key):
             for item in self.buckets[idx]:
                 if item[0] == key:
                     return item[1]
-            raise KeyError('Key not found')
+        raise KeyError('Key not found')

src/test_hash.py

@@ -0,0 +1,62 @@
+"""Testing for hash table tree."""
+import pytest
+
+
+def test_hash_initialized(empty_hash):
+    """Test if hash table initailized with attributes."""
+    assert empty_hash.size == 10
+    assert empty_hash.hash_type == 'additive'
+
+
+def test_hash_initiailized_custom_size():
+    """Test if hash table can be initailized with custom size."""
+    from hash import HashTable
+    cust_hash = HashTable(size=100)
+    cust_hash.size == 100
+
+
+def test_hash_initialized_with_oat():
+    """Test if hash table can be initialized using oat hashing function."""
+    from hash import HashTable
+    cust_hash = HashTable(hash_type='oat')
+    cust_hash.hash_type == 'oat'
+
+
+def test_bad_hash_type_raises_error():
+    """Test if ValueError raised if function other than additive or oat is passed."""
+    from hash import HashTable
+    with pytest.raises(NameError):
+        HashTable(hash_type='something')
+
+
+def test_non_string_passed_in_set_raises_error(empty_hash):
+    """Type error raised when non-string passed in set method."""
+    with pytest.raises(TypeError):
+        empty_hash.set(897, 'toast')
+
+
+def test_set_adds_pair(empty_hash):
+    """Test if set adds to key/val pair to bucket."""
+    empty_hash.set('potato', 8)
+    assert empty_hash.buckets[3] == [['potato', 8]]
+
+
+def test_get_returns_correct_val(empty_hash):
+    """Test if correct val returned for get method."""
+    empty_hash.set('jim', 39)
+    assert empty_hash.get('jim') == 39
+
+
+def test_key_can_be_updated_with_new_val(empty_hash):
+    """Test if key's value can be updated."""
+    empty_hash.set('jim', 39)
+    empty_hash.set('jim', 83)
+    assert empty_hash.get('jim') == 83
+
+
+def test_key_not_found_error_raises(empty_hash):
+    """Test if KeyError raised when get used for key not in table."""
+    empty_hash.set('jane', 34)
+    empty_hash.set('andy', 32)
+    with pytest.raises(KeyError):
+        empty_hash.get('bob')