Degenerated Trie Test

Tests for a ByteTrie that degenerates to a doubly linked list

README.md

@@ -3,7 +3,9 @@
 # Bytetrie
 A fast, dependency-free, self-compressing trie with radix 256 in pure python.
 
-![](trie.png)
+| ![Artistic ByteTrie Render](trie.png)                                                                                     |
+|--------------------------------------------------------------------------------------------------------------------------:|
+| *Rendering of a ByteTrie containing [~200,000 cities with a population > 500](http://download.geonames.org/export/dump/)*  |
 
 Bytetrie allows fast prefix search in a large corpus of keys. Each key can be
 associated with arbitrary data. It features fast lookup times at the cost of

tests/conftest.py

@@ -1,5 +1,6 @@
 import pytest
 
 pytest_plugins = [
-   "tries.simple_trie"
+    "tries.simple_trie",
+    "tries.degenerated_trie"
 ]

tests/test_bytetrie_blackbox.py

@@ -2,11 +2,12 @@ import pytest
 
 import sys
 import os
-sys.path.append("tests/tries/")
 
 from bytetrie import ByteTrie
 
+sys.path.append("tests/tries/")
 import simple_trie
+import degenerated_trie
 
 def test_find_all(simple_trie):
     r = simple_trie.find(b"A")
@@ -47,3 +48,18 @@ def test_partial_prefix_find_terminal(simple_trie):
     assert len(r) == 1
     assert r[0].key() == b"ABCDE"
     assert r[0].value() == "ABCDE"
+
+def test_degenerated_find_first_finds_all(degenerated_trie):
+    r = degenerated_trie.find(b"A")
+    assert len(r) == 26
+    assert r[0].key() == b"A"
+    assert r[0].value() == "A"
+
+    assert r[25].key() == b"ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+    assert r[25].value() == "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+
+def test_degenerated_find_last_finds_one(degenerated_trie):
+    r = degenerated_trie.find(b"ABCDEFGHIJKLMNOPQRSTUVWXYZ")
+    assert len(r) == 1
+    assert r[0].key() == b"ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+    assert r[0].value() == "ABCDEFGHIJKLMNOPQRSTUVWXYZ"

tests/tries/degenerated_trie.py

@@ -0,0 +1,51 @@
+"""
+A degenerated ByteTrie fixture. ByteTrie resolves to a doubly-linked list. The
+worst case scenario.
+
+See degenerated_trie.png
+"""
+
+import pytest
+
+from bytetrie import ByteTrie
+
+def insert(trie):
+    """ Shall only be used to insert strings """
+    t = trie
+    def _insert(*vals):
+        for val in vals:
+            t.insert(val.encode('utf-8'), val)
+    return _insert
+
+@pytest.fixture
+def degenerated_trie():
+    t = ByteTrie()
+    ins = insert(t)
+    ins("A")
+    ins("AB")
+    ins("ABC")
+    ins("ABCD")
+    ins("ABCDE")
+    ins("ABCDEF")
+    ins("ABCDEFG")
+    ins("ABCDEFGH")
+    ins("ABCDEFGHI")
+    ins("ABCDEFGHIJ")
+    ins("ABCDEFGHIJK")
+    ins("ABCDEFGHIJKL")
+    ins("ABCDEFGHIJKLM")
+    ins("ABCDEFGHIJKLMN")
+    ins("ABCDEFGHIJKLMNO")
+    ins("ABCDEFGHIJKLMNOP")
+    ins("ABCDEFGHIJKLMNOPQ")
+    ins("ABCDEFGHIJKLMNOPQR")
+    ins("ABCDEFGHIJKLMNOPQRS")
+    ins("ABCDEFGHIJKLMNOPQRST")
+    ins("ABCDEFGHIJKLMNOPQRSTU")
+    ins("ABCDEFGHIJKLMNOPQRSTUV")
+    ins("ABCDEFGHIJKLMNOPQRSTUVW")
+    ins("ABCDEFGHIJKLMNOPQRSTUVWX")
+    ins("ABCDEFGHIJKLMNOPQRSTUVWXY")
+    ins("ABCDEFGHIJKLMNOPQRSTUVWXYZ")
+
+    return t