Tests: Move AK tests to Tests/AK

Tests/AK/TestTrie.cpp

@@ -0,0 +1,68 @@
+/*
+ * Copyright (c) 2020, the SerenityOS developers.
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <LibTest/TestCase.h>
+
+#include <AK/Trie.h>
+
+TEST_CASE(normal_behaviour)
+{
+    Trie<char, String> dictionary('/', "");
+    constexpr static const char* data[] { "test", "example", "foo", "foobar" };
+    constexpr static const size_t total_chars = 18; // root (1), 'test' (4), 'example' (7), 'foo' (3), 'foobar' (3, "foo" already stored).
+    for (auto& entry : data) {
+        StringView view { entry };
+        auto it = view.begin();
+        dictionary.insert(it, view.end(), view, [](auto& parent, auto& it) -> Optional<String> { return String::formatted("{}{}", parent.metadata_value(), *it); });
+    }
+
+    size_t i = 0;
+    for ([[maybe_unused]] auto& node : dictionary)
+        ++i;
+    EXPECT_EQ(i, total_chars);
+
+    for (auto& entry : data) {
+        StringView view { entry };
+        auto it = view.begin();
+        auto& node = dictionary.traverse_until_last_accessible_node(it, view.end());
+        EXPECT(it.is_end());
+        EXPECT(node.metadata().has_value());
+        EXPECT_EQ(view, node.metadata_value());
+    }
+
+    constexpr static const char* test_data_with_prefix_in_dict[] { "testx", "exampley", "fooa", "foobarb", "fox", "text" };
+    for (auto& entry : test_data_with_prefix_in_dict) {
+        StringView view { entry };
+        auto it = view.begin();
+        auto& node = dictionary.traverse_until_last_accessible_node(it, view.end());
+        EXPECT(!it.is_end());
+        EXPECT(node.metadata().has_value());
+        EXPECT(view.starts_with(node.metadata_value()));
+    }
+}
+
+TEST_CASE(iterate)
+{
+    Trie<int> bunch_of_numbers { 0 };
+    Array<int, 64> input;
+    for (size_t i = 0; i < input.size(); ++i)
+        input[i] = i;
+
+    bunch_of_numbers.insert(input.begin(), input.end());
+
+    // Iteration order is preorder (order between adjacent nodes is not defined, but parents come before children)
+    // in this case, the tree is linear.
+    size_t i = 0;
+    bool is_root = true;
+    for (auto& node : bunch_of_numbers) {
+        if (is_root) {
+            is_root = false;
+            continue;
+        }
+        EXPECT_EQ(input[i], node.value());
+        ++i;
+    }
+}