tesseract/unittest/validator_test.cc

// (C) Copyright 2017, Google Inc.
// 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
// http://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 "validator.h"

#include "gmock/gmock.h" // for testing::ElementsAreArray
#include "include_gunit.h"

namespace tesseract {

class TestableValidator : public Validator {
public:
  static ViramaScript TestableMostFrequentViramaScript(const std::vector<char32> &utf32) {
    return MostFrequentViramaScript(utf32);
  }
};

// The majority of Validator is tested by the script-specific tests of its
// subclasses, but the MostFrequentViramaScript function is worth a unittest.
TEST(ValidatorTest, MostFrequentViramaScript) {
  // The most frequent virama script should come out correct, despite
  // distractions from other scripts.
  EXPECT_EQ(ViramaScript::kTelugu, TestableValidator::TestableMostFrequentViramaScript({0xc05}));
  // It is still Telugu surrounded by Latin.
  EXPECT_EQ(ViramaScript::kTelugu,
            TestableValidator::TestableMostFrequentViramaScript({'a', 0xc05, 'b', 'c'}));
  // But not still Telugu surrounded by Devanagari.
  EXPECT_EQ(ViramaScript::kDevanagari,
            TestableValidator::TestableMostFrequentViramaScript({0x905, 0xc05, 0x906, 0x907}));
  EXPECT_EQ(ViramaScript::kKannada,
            TestableValidator::TestableMostFrequentViramaScript({0xc85, 0xc05, 0xc86, 0xc87}));
  EXPECT_EQ(ViramaScript::kBengali,
            TestableValidator::TestableMostFrequentViramaScript({0x985, 0xc05, 0x986, 0x987}));
  // Danda and double Danda don't count as Devanagari, as they are common.
  EXPECT_EQ(ViramaScript::kTelugu,
            TestableValidator::TestableMostFrequentViramaScript({0x964, 0xc05, 0x965, 0x965}));
}

// ValidateCleanAndSegment doesn't modify the input by much, but its
// transformation should be idempotent. (Doesn't change again if re-applied.)
TEST(ValidatorTest, Idempotency) {
  std::vector<char32> str1({0xd24, 0xd23, 0xd32, 0xd4d, '\'', 0x200d, 0x200c, 0x200d, 0x200c});
  std::vector<char32> str2({0xd24, 0xd23, 0xd32, 0xd4d, 0x200c, 0x200d, 0x200c, 0x200d, '\''});
  std::vector<std::vector<char32>> result1, result2, result3, result4;
  EXPECT_TRUE(
      Validator::ValidateCleanAndSegment(GraphemeNormMode::kSingleString, true, str1, &result1));
  EXPECT_TRUE(Validator::ValidateCleanAndSegment(GraphemeNormMode::kSingleString, true, result1[0],
                                                 &result2));
  EXPECT_EQ(result1.size(), result2.size());
  EXPECT_THAT(result2[0], testing::ElementsAreArray(result1[0]));
  EXPECT_TRUE(
      Validator::ValidateCleanAndSegment(GraphemeNormMode::kSingleString, true, str2, &result3));
  EXPECT_TRUE(Validator::ValidateCleanAndSegment(GraphemeNormMode::kSingleString, true, result3[0],
                                                 &result4));
  EXPECT_EQ(result3.size(), result4.size());
  EXPECT_THAT(result4[0], testing::ElementsAreArray(result3[0]));
}

} // namespace tesseract