Add trie_test.dart

Author: happy-san

test/trie/trie_test.dart

@@ -0,0 +1,63 @@
+import 'package:test/test.dart';
+import 'package:algorithms/trie/trie.dart';
+
+void main() {
+  Trie emptyTrie, trie, customTrie;
+
+  setUp(() {
+    emptyTrie = Trie.ofAlphabets();
+
+    trie = Trie.ofAlphabets();
+    trie.add('algorithms');
+
+    customTrie = Trie(
+        {'a', 'b', 'f', 'o', 'r', 'z'}, (value) => value.toString().split(''));
+    customTrie.add('foo');
+  });
+
+  test('Components', () {
+    expect(trie.components,
+        equals({...List.generate(26, (i) => String.fromCharCode(122 - i))}));
+
+    expect(customTrie.components, equals({'f', 'o', 'b', 'a', 'r', 'z'}));
+  });
+
+  test('Empty trie', () {
+    expect(emptyTrie.isEmpty, isTrue);
+    expect(trie.isEmpty, isFalse);
+  });
+
+  test('Add value', () {
+    trie.add('hi');
+    expect(trie.root.children[7].children[8].isValue, isTrue);
+
+    customTrie.add('bar');
+    expect(customTrie.root.children[1].children[0].children[4].isValue, isTrue);
+
+    customTrie.add('baz');
+    expect(customTrie.root.children[1].children[0].children[5].isValue, isTrue);
+  });
+
+  test('Contains value', () {
+    expect(emptyTrie.contains('test'), isFalse);
+
+    expect(trie.contains('algorithm'), isFalse);
+    expect(trie.contains('algorithms'), isTrue);
+
+    expect(customTrie.contains('boar'), isFalse);
+    expect(customTrie.contains('foo'), isTrue);
+  });
+
+  test('Delete value', () {
+    emptyTrie.delete('');
+    emptyTrie.delete('test');
+
+    expect(trie.contains('algorithms'), isTrue);
+    trie.delete('algorithms');
+    expect(trie.contains('algorithms'), isFalse);
+
+    expect(customTrie.contains('foo'), isTrue);
+    customTrie.delete('foo');
+    expect(customTrie.contains('foo'), isFalse);
+  });
+}