Upstream Chrome on iOS source code [9/11].

ios/chrome/browser/ui/tab_switcher/tab_switcher_utils_unittest.mm

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "ios/chrome/browser/ui/tab_switcher/tab_switcher_utils.h"
+
+#include "testing/platform_test.h"
+
+class TabSwitcherUtilsTest : public PlatformTest {
+ protected:
+  // Checks that the computed updates/deletions/insertions to go from |initial|
+  //  to |final| correctly match the expected updates/deletions/insertions.
+  void TestLevenshtein(std::vector<size_t> const& initial,
+                       std::vector<size_t> const& final,
+                       std::vector<size_t> const& expectedSubstitutions,
+                       std::vector<size_t> const& expectedDeletions,
+                       std::vector<size_t> const& expectedInsertions) {
+    std::vector<size_t> substitutions;
+    std::vector<size_t> deletions;
+    std::vector<size_t> insertions;
+    ios_internal::MinimalReplacementOperations(initial, final, &substitutions,
+                                               &deletions, &insertions);
+    EXPECT_EQ(substitutions, expectedSubstitutions);
+    EXPECT_EQ(deletions, expectedDeletions);
+    EXPECT_EQ(insertions, expectedInsertions);
+  }
+};
+
+TEST_F(TabSwitcherUtilsTest, TestLevenshteinEmptyVectors) {
+  std::vector<size_t> initial = {};
+  std::vector<size_t> final = {};
+  std::vector<size_t> expectedSubstitutions = {};
+  std::vector<size_t> expectedDeletions = {};
+  std::vector<size_t> expectedInsertions = {};
+  TestLevenshtein(initial, final, expectedSubstitutions, expectedDeletions,
+                  expectedInsertions);
+}
+
+TEST_F(TabSwitcherUtilsTest, TestLevenshteinNoChange) {
+  std::vector<size_t> initial = {1, 2, 3};
+  std::vector<size_t> final = {1, 2, 3};
+  std::vector<size_t> expectedSubstitutions = {};
+  std::vector<size_t> expectedDeletions = {};
+  std::vector<size_t> expectedInsertions = {};
+  TestLevenshtein(initial, final, expectedSubstitutions, expectedDeletions,
+                  expectedInsertions);
+}
+
+TEST_F(TabSwitcherUtilsTest, TestLevenshteinInsertions) {
+  std::vector<size_t> initial = {1};
+  std::vector<size_t> final = {0, 1, 2};
+  std::vector<size_t> expectedSubstitutions = {};
+  std::vector<size_t> expectedDeletions = {};
+  std::vector<size_t> expectedInsertions = {0, 2};
+  TestLevenshtein(initial, final, expectedSubstitutions, expectedDeletions,
+                  expectedInsertions);
+}
+
+TEST_F(TabSwitcherUtilsTest, TestLevenshteinDeletions) {
+  std::vector<size_t> initial = {0, 1, 2, 3, 4, 5};
+  std::vector<size_t> final = {0, 2, 3, 5};
+  std::vector<size_t> expectedSubstitutions = {};
+  std::vector<size_t> expectedDeletions = {1, 4};
+  std::vector<size_t> expectedInsertions = {};
+  TestLevenshtein(initial, final, expectedSubstitutions, expectedDeletions,
+                  expectedInsertions);
+}
+
+TEST_F(TabSwitcherUtilsTest, TestLevenshteinFromAndToEmptyVectors) {
+  std::vector<size_t> empty = {};
+  std::vector<size_t> nonEmpty = {0, 1, 2};
+  std::vector<size_t> expectedSubstitutions = {};
+  std::vector<size_t> expectedDeletions = {};
+  std::vector<size_t> expectedInsertions = {0, 1, 2};
+  TestLevenshtein(empty, nonEmpty, expectedSubstitutions, expectedDeletions,
+                  expectedInsertions);
+
+  // Tests the reverse transformation.
+  TestLevenshtein(nonEmpty, empty, expectedSubstitutions, expectedInsertions,
+                  expectedDeletions);
+}
+
+TEST_F(TabSwitcherUtilsTest, TestLevenshteinSubstitutions) {
+  std::vector<size_t> initial = {0, 1, 2, 3, 4, 5, 6};
+  std::vector<size_t> final = {0, 1, 2, 9, 8, 5, 6};
+  std::vector<size_t> expectedSubstitutions = {3, 4};
+  std::vector<size_t> expectedDeletions = {};
+  std::vector<size_t> expectedInsertions = {};
+  TestLevenshtein(initial, final, expectedSubstitutions, expectedDeletions,
+                  expectedInsertions);
+}
+
+TEST_F(TabSwitcherUtilsTest, TestLevenshteinInsertionAndDeletions) {
+  std::vector<size_t> initial = {0, 1, 2, 3, 4, 5, 6, 7};
+  std::vector<size_t> final = {0, 1, 8, 9, 2, 3, 4, 7};
+  std::vector<size_t> expectedSubstitutions = {};
+  std::vector<size_t> expectedDeletions = {5, 6};
+  std::vector<size_t> expectedInsertions = {2, 3};
+  TestLevenshtein(initial, final, expectedSubstitutions, expectedDeletions,
+                  expectedInsertions);
+
+  // Tests the reverse transformation.
+  TestLevenshtein(final, initial, expectedSubstitutions, expectedInsertions,
+                  expectedDeletions);
+}
+
+TEST_F(TabSwitcherUtilsTest, TestLevenshteinInsertionAndSubstitutions) {
+  std::vector<size_t> initial = {0, 1, 2, 3, 4, 5, 6, 7};
+  std::vector<size_t> final = {0, 1, 2, 99, 98, 3, 4, 97, 96, 7};
+  std::vector<size_t> expectedSubstitutions = {5, 6};
+  std::vector<size_t> expectedDeletions = {};
+  std::vector<size_t> expectedInsertions = {3, 4};
+  TestLevenshtein(initial, final, expectedSubstitutions, expectedDeletions,
+                  expectedInsertions);
+}
+
+TEST_F(TabSwitcherUtilsTest,
+       TestLevenshteinPreferInsertionsAndDeletionsOverSubstitutions) {
+  std::vector<size_t> initial = {0, 1};
+  std::vector<size_t> final = {1, 2};
+  std::vector<size_t> expectedSubstitutions = {};
+  std::vector<size_t> expectedDeletions = {0};
+  std::vector<size_t> expectedInsertions = {1};
+  TestLevenshtein(initial, final, expectedSubstitutions, expectedDeletions,
+                  expectedInsertions);
+}