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// Copyright 2022 The Abseil Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include "absl/strings/internal/damerau_levenshtein_distance.h"
#include <cstdint>
#include "gmock/gmock.h"
#include "gtest/gtest.h"
namespace {
using absl::strings_internal::CappedDamerauLevenshteinDistance;
TEST(Distance, TestDistances) {
EXPECT_THAT(CappedDamerauLevenshteinDistance("ab", "ab", 6), uint8_t{0});
EXPECT_THAT(CappedDamerauLevenshteinDistance("a", "b", 6), uint8_t{1});
EXPECT_THAT(CappedDamerauLevenshteinDistance("ca", "abc", 6), uint8_t{3});
EXPECT_THAT(CappedDamerauLevenshteinDistance("abcd", "ad", 6), uint8_t{2});
EXPECT_THAT(CappedDamerauLevenshteinDistance("abcd", "cadb", 6), uint8_t{4});
EXPECT_THAT(CappedDamerauLevenshteinDistance("abcd", "bdac", 6), uint8_t{4});
EXPECT_THAT(CappedDamerauLevenshteinDistance("ab", "ab", 0), uint8_t{0});
EXPECT_THAT(CappedDamerauLevenshteinDistance("", "", 0), uint8_t{0});
// combinations for 3-character strings:
// 1, 2, 3 removals, insertions or replacements and transpositions
EXPECT_THAT(CappedDamerauLevenshteinDistance("abc", "abc", 6), uint8_t{0});
for (auto res :
{"", "ca", "efg", "ea", "ce", "ceb", "eca", "cae", "cea", "bea"}) {
EXPECT_THAT(CappedDamerauLevenshteinDistance("abc", res, 6), uint8_t{3});
EXPECT_THAT(CappedDamerauLevenshteinDistance(res, "abc", 6), uint8_t{3});
}
for (auto res :
{"a", "b", "c", "ba", "cb", "bca", "cab", "cba", "ace",
"efc", "ebf", "aef", "ae", "be", "eb", "ec", "ecb", "bec",
"bce", "cbe", "ace", "eac", "aeb", "bae", "eab", "eba"}) {
EXPECT_THAT(CappedDamerauLevenshteinDistance("abc", res, 6), uint8_t{2});
EXPECT_THAT(CappedDamerauLevenshteinDistance(res, "abc", 6), uint8_t{2});
}
for (auto res : {"ab", "ac", "bc", "acb", "bac", "ebc", "aec", "abe"}) {
EXPECT_THAT(CappedDamerauLevenshteinDistance("abc", res, 6), uint8_t{1});
EXPECT_THAT(CappedDamerauLevenshteinDistance(res, "abc", 6), uint8_t{1});
}
}
TEST(Distance, TestCutoff) {
// Returing cutoff + 1 if the value is larger than cutoff or string longer
// than MAX_SIZE.
EXPECT_THAT(CappedDamerauLevenshteinDistance("abcd", "a", 3), uint8_t{3});
EXPECT_THAT(CappedDamerauLevenshteinDistance("abcd", "a", 2), uint8_t{3});
EXPECT_THAT(CappedDamerauLevenshteinDistance("abcd", "a", 1), uint8_t{2});
EXPECT_THAT(CappedDamerauLevenshteinDistance("abcdefg", "a", 2), uint8_t{3});
EXPECT_THAT(CappedDamerauLevenshteinDistance("a", "abcde", 2), uint8_t{3});
EXPECT_THAT(CappedDamerauLevenshteinDistance(std::string(102, 'a'),
std::string(102, 'a'), 105),
uint8_t{101});
EXPECT_THAT(CappedDamerauLevenshteinDistance(std::string(100, 'a'),
std::string(100, 'a'), 100),
uint8_t{0});
EXPECT_THAT(CappedDamerauLevenshteinDistance(std::string(100, 'a'),
std::string(100, 'b'), 100),
uint8_t{100});
EXPECT_THAT(CappedDamerauLevenshteinDistance(std::string(100, 'a'),
std::string(99, 'a'), 2),
uint8_t{1});
EXPECT_THAT(CappedDamerauLevenshteinDistance(std::string(100, 'a'),
std::string(101, 'a'), 2),
uint8_t{3});
EXPECT_THAT(CappedDamerauLevenshteinDistance(std::string(100, 'a'),
std::string(101, 'a'), 2),
uint8_t{3});
EXPECT_THAT(CappedDamerauLevenshteinDistance(std::string(UINT8_MAX + 1, 'a'),
std::string(UINT8_MAX + 1, 'b'),
UINT8_MAX),
uint8_t{101});
EXPECT_THAT(CappedDamerauLevenshteinDistance(std::string(UINT8_MAX - 1, 'a'),
std::string(UINT8_MAX - 1, 'b'),
UINT8_MAX),
uint8_t{101});
EXPECT_THAT(
CappedDamerauLevenshteinDistance(std::string(UINT8_MAX, 'a'),
std::string(UINT8_MAX, 'b'), UINT8_MAX),
uint8_t{101});
EXPECT_THAT(CappedDamerauLevenshteinDistance(std::string(UINT8_MAX - 1, 'a'),
std::string(UINT8_MAX - 1, 'a'),
UINT8_MAX),
uint8_t{101});
}
} // namespace