tesseract/unittest/ligature_table_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 "ligature_table.h"
#include "commandlineflags.h"
#include "fileio.h"
#include "include_gunit.h"
#include "pango_font_info.h"

namespace tesseract {

const char kEngNonLigatureText[] = "fidelity effigy ſteep";
// Same as above text, but with "fi" in the first word and "ffi" in the second
// word replaced with their respective ligatures.
const char kEngLigatureText[] = "fidelity effigy ſteep";
// Same as kEngLigatureText but with "fi" in both words replaced with their
// ligature. The test Verdana font does not support the "ffi" or "ſt" ligature.
const char kRenderableEngLigatureText[] = "fidelity effigy ſteep";

static PangoFontMap *font_map;

class LigatureTableTest : public ::testing::Test {
protected:
  void SetUp() override {
    lig_table_ = LigatureTable::Get();
    if (!font_map) {
      font_map = pango_cairo_font_map_new_for_font_type(CAIRO_FONT_TYPE_FT);
    }
    pango_cairo_font_map_set_default(PANGO_CAIRO_FONT_MAP(font_map));
  }

  static void SetUpTestCase() {
    static std::locale system_locale("");
    std::locale::global(system_locale);

    FLAGS_fonts_dir = TESTING_DIR;
    FLAGS_fontconfig_tmpdir = FLAGS_test_tmpdir;
    file::MakeTmpdir();
    PangoFontInfo::SoftInitFontConfig(); // init early
  }
  LigatureTable *lig_table_;
};

TEST_F(LigatureTableTest, DoesFillLigatureTables) {
  EXPECT_GT(lig_table_->norm_to_lig_table().size(), 0);
  EXPECT_GT(lig_table_->lig_to_norm_table().size(), 0);
}

TEST_F(LigatureTableTest, DoesAddLigatures) {
  EXPECT_STREQ(kEngLigatureText, lig_table_->AddLigatures(kEngNonLigatureText, nullptr).c_str());
}

TEST_F(LigatureTableTest, DoesAddLigaturesWithSupportedFont) {
  PangoFontInfo font;
  EXPECT_TRUE(font.ParseFontDescriptionName("Verdana"));
  printf("1:%s\n", kRenderableEngLigatureText);
  printf("2:%s\n", lig_table_->AddLigatures(kEngNonLigatureText, &font).c_str());
  EXPECT_STREQ(kRenderableEngLigatureText,
               lig_table_->AddLigatures(kEngNonLigatureText, &font).c_str());
}

TEST_F(LigatureTableTest, DoesNotAddLigaturesWithUnsupportedFont) {
  PangoFontInfo font;
  EXPECT_TRUE(font.ParseFontDescriptionName("Lohit Hindi"));
  EXPECT_STREQ(kEngNonLigatureText, lig_table_->AddLigatures(kEngNonLigatureText, &font).c_str());
}

TEST_F(LigatureTableTest, DoesRemoveLigatures) {
  EXPECT_STREQ(kEngNonLigatureText, lig_table_->RemoveLigatures(kEngLigatureText).c_str());
}

TEST_F(LigatureTableTest, TestCustomLigatures) {
  const char *kTestCases[] = {
      "act",       "a\uE003", "publiſh",    "publi\uE006", "ſince",
      "\uE007nce", "aſleep",  "a\uE008eep", "neceſſary",   "nece\uE009ary",
  };
  for (size_t i = 0; i < countof(kTestCases); i += 2) {
    EXPECT_STREQ(kTestCases[i + 1], lig_table_->AddLigatures(kTestCases[i], nullptr).c_str());
    EXPECT_STREQ(kTestCases[i], lig_table_->RemoveLigatures(kTestCases[i + 1]).c_str());
    EXPECT_STREQ(kTestCases[i], lig_table_->RemoveCustomLigatures(kTestCases[i + 1]).c_str());
  }
}

TEST_F(LigatureTableTest, TestRemovesCustomLigatures) {
  const char *kTestCases[] = {
      "fiction",
      "fi\uE003ion",
      "fiction",
  };
  for (size_t i = 0; i < countof(kTestCases); i += 3) {
    EXPECT_STREQ(kTestCases[i + 1], lig_table_->AddLigatures(kTestCases[i], nullptr).c_str());
    EXPECT_STREQ(kTestCases[i + 2], lig_table_->RemoveCustomLigatures(kTestCases[i + 1]).c_str());
  }
}
} // namespace tesseract