// Copyright 2019 The Fuchsia 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 <fidl/utils.h>
#include <lib/fit/function.h>

#include "unittest_helpers.h"

namespace fidl::utils {

namespace {

void compare_id_to_words(std::string id, std::string expected_lowercase_words) {
  std::ostringstream actual;
  for (auto word : id_to_words(id)) {
    if (actual.tellp() > 0) {
      actual << " ";
    }
    actual << word;
  }
  ASSERT_STRING_EQ(expected_lowercase_words, actual.str(), "%s",
                   std::string("Failed for " + id).c_str());
}

TEST(UtilsTests, IdToWords) {
  compare_id_to_words("agent_request_count", "agent request count");
  compare_id_to_words("common", "common");
  compare_id_to_words("Service", "service");
  compare_id_to_words("Blink32", "blink32");
  compare_id_to_words("the21jumpStreet", "the21jump street");
  compare_id_to_words("the21JumpStreet", "the21 jump street");
  compare_id_to_words("onOntologyUpdate", "on ontology update");
  compare_id_to_words("urlLoader", "url loader");
  compare_id_to_words("onUrlLoader", "on url loader");
  compare_id_to_words("OnOntologyUpdate", "on ontology update");
  compare_id_to_words("UrlLoader", "url loader");
  compare_id_to_words("OnUrlLoader", "on url loader");
  compare_id_to_words("kUrlLoader", "url loader");
  compare_id_to_words("kOnUrlLoader", "on url loader");
  compare_id_to_words("WhatIfSomeoneDoes_This", "what if someone does this");
  compare_id_to_words("SOME_CONST", "some const");
  compare_id_to_words("NAME_MIN_LEN", "name min len");
  compare_id_to_words("OnPress", "on press");
  compare_id_to_words("URLLoader", "url loader");
  compare_id_to_words("PPPOE", "pppoe");
  compare_id_to_words("PPP_O_E", "ppp o e");
  compare_id_to_words("PPP_o_E", "ppp o e");

  // Note the next two tests have expected results that may seem
  // counter-intuitive, but if IDs like "URLLoader" are expected to
  // translate to the words "url loader", then these translations
  // are consistent.
  compare_id_to_words("PppOE", "ppp oe");
  compare_id_to_words("PPPoE", "pp po e");
}

void case_test(bool valid_conversion, std::string case_name,
               fit::function<bool(std::string)> is_case,
               fit::function<std::string(std::string)> to_case, std::string original,
               std::string expected) {
  EXPECT_FALSE(is_case(original), "%s", (original + " is " + case_name).c_str());
  std::string converted = to_case(original);
  EXPECT_STRING_EQ(
      converted, expected, "%s",
      ("from '" + original + "' to '" + converted + "' != '" + expected + "'").c_str());
  if (valid_conversion) {
    EXPECT_TRUE(
        is_case(expected), "%s",
        ("from '" + original + "' expected '" + expected + "' is not " + case_name).c_str());
    EXPECT_TRUE(is_case(converted), "%s",
                ("from '" + original + "' to '" + converted + "' is not " + case_name).c_str());
  } else {
    EXPECT_FALSE(is_case(converted), "%s",
                 ("from '" + original + "' to '" + converted + "' was not expected to match " +
                  case_name + ", but did!")
                     .c_str());
  }
}

#define ASSERT_CASE(CASE, FROM, TO) \
  case_test(/*valid_conversion=*/true, #CASE, is_##CASE##_case, to_##CASE##_case, FROM, TO)

#define ASSERT_BAD_CASE(CASE, FROM, TO) \
  case_test(/*valid_conversion=*/false, #CASE, is_##CASE##_case, to_##CASE##_case, FROM, TO)

TEST(UtilsTests, UpperCamelCase) {
  ASSERT_CASE(upper_camel, "x", "X");
  ASSERT_CASE(upper_camel, "xy", "Xy");
  ASSERT_BAD_CASE(upper_camel, "x_y", "XY");
  ASSERT_CASE(upper_camel, "xyz_123", "Xyz123");
  ASSERT_CASE(upper_camel, "xy_z_123", "XyZ123");
  ASSERT_CASE(upper_camel, "xy_z123", "XyZ123");
  ASSERT_CASE(upper_camel, "days_in_a_week", "DaysInAWeek");
  ASSERT_CASE(upper_camel, "android8_0_0", "Android8_0_0");
  ASSERT_CASE(upper_camel, "android_8_0_0", "Android8_0_0");
  ASSERT_CASE(upper_camel, "x_marks_the_spot", "XMarksTheSpot");
  ASSERT_CASE(upper_camel, "RealID", "RealId");
  ASSERT_CASE(upper_camel, "real_id", "RealId");
  ASSERT_BAD_CASE(upper_camel, "real_i_d", "RealID");
  ASSERT_CASE(upper_camel, "real3d", "Real3d");
  ASSERT_CASE(upper_camel, "real3_d", "Real3D");
  ASSERT_CASE(upper_camel, "real_3d", "Real3d");
  ASSERT_CASE(upper_camel, "real_3_d", "Real3D");
  ASSERT_CASE(upper_camel, "sample_x_union", "SampleXUnion");
  ASSERT_CASE(upper_camel, "sample_xunion", "SampleXunion");
  ASSERT_CASE(upper_camel, "URLLoader", "UrlLoader");
  ASSERT_CASE(upper_camel, "is_21Jump_street", "Is21JumpStreet");
  ASSERT_CASE(upper_camel, "URLloader", "UrLloader");
  ASSERT_CASE(upper_camel, "URLLoader", "UrlLoader");
  ASSERT_CASE(upper_camel, "url_loader", "UrlLoader");
  ASSERT_CASE(upper_camel, "URL_LOADER", "UrlLoader");
  ASSERT_CASE(upper_camel, "urlLoader", "UrlLoader");
  ASSERT_CASE(upper_camel, "kUrlLoader", "UrlLoader");
  ASSERT_CASE(upper_camel, "kURLLoader", "UrlLoader");
}

TEST(UtilsTests, LowerCamelCase) {
  ASSERT_CASE(lower_camel, "X", "x");
  ASSERT_CASE(lower_camel, "XY", "xy");
  ASSERT_CASE(lower_camel, "X_Y", "xY");
  ASSERT_CASE(lower_camel, "XYZ_123", "xyz123");
  ASSERT_CASE(lower_camel, "XY_Z_123", "xyZ123");
  ASSERT_CASE(lower_camel, "XY_Z123", "xyZ123");
  ASSERT_CASE(lower_camel, "DAYS_IN_A_WEEK", "daysInAWeek");
  ASSERT_CASE(lower_camel, "ANDROID8_0_0", "android8_0_0");
  ASSERT_CASE(lower_camel, "ANDROID_8_0_0", "android8_0_0");
  ASSERT_CASE(lower_camel, "X_MARKS_THE_SPOT", "xMarksTheSpot");
  ASSERT_CASE(lower_camel, "realID", "realId");
  ASSERT_CASE(lower_camel, "REAL_ID", "realId");
  ASSERT_BAD_CASE(lower_camel, "REAL_I_D", "realID");
  ASSERT_CASE(lower_camel, "REAL3D", "real3D");
  ASSERT_CASE(lower_camel, "REAL3_D", "real3D");
  ASSERT_CASE(lower_camel, "REAL_3D", "real3D");
  ASSERT_CASE(lower_camel, "REAL_3_D", "real3D");
  ASSERT_CASE(lower_camel, "SAMPLE_X_UNION", "sampleXUnion");
  ASSERT_CASE(lower_camel, "SAMPLE_XUNION", "sampleXunion");
  ASSERT_CASE(lower_camel, "URLLoader", "urlLoader");
  ASSERT_CASE(lower_camel, "is_21Jump_street", "is21JumpStreet");
  ASSERT_CASE(lower_camel, "URLloader", "urLloader");
  ASSERT_CASE(lower_camel, "UrlLoader", "urlLoader");
  ASSERT_CASE(lower_camel, "URLLoader", "urlLoader");
  ASSERT_CASE(lower_camel, "url_loader", "urlLoader");
  ASSERT_CASE(lower_camel, "URL_LOADER", "urlLoader");
  ASSERT_CASE(lower_camel, "kUrlLoader", "urlLoader");
  ASSERT_CASE(lower_camel, "kURLLoader", "urlLoader");
}

TEST(UtilsTests, UpperSnakeCase) {
  ASSERT_CASE(upper_snake, "x", "X");
  ASSERT_CASE(upper_snake, "xy", "XY");
  ASSERT_CASE(upper_snake, "xY", "X_Y");
  ASSERT_CASE(upper_snake, "xyz123", "XYZ123");
  ASSERT_CASE(upper_snake, "xyz_123", "XYZ_123");
  ASSERT_CASE(upper_snake, "xyZ123", "XY_Z123");
  ASSERT_CASE(upper_snake, "daysInAWeek", "DAYS_IN_A_WEEK");
  ASSERT_CASE(upper_snake, "android8_0_0", "ANDROID8_0_0");
  ASSERT_CASE(upper_snake, "android_8_0_0", "ANDROID_8_0_0");
  ASSERT_CASE(upper_snake, "xMarksTheSpot", "X_MARKS_THE_SPOT");
  ASSERT_CASE(upper_snake, "realId", "REAL_ID");
  ASSERT_CASE(upper_snake, "realID", "REAL_ID");
  ASSERT_CASE(upper_snake, "real3d", "REAL3D");
  ASSERT_CASE(upper_snake, "real3D", "REAL3_D");
  ASSERT_CASE(upper_snake, "real_3d", "REAL_3D");
  ASSERT_CASE(upper_snake, "real_3D", "REAL_3_D");
  ASSERT_CASE(upper_snake, "sampleXUnion", "SAMPLE_X_UNION");
  ASSERT_CASE(upper_snake, "sampleXunion", "SAMPLE_XUNION");
  ASSERT_CASE(upper_snake, "URLLoader", "URL_LOADER");
  ASSERT_CASE(upper_snake, "is_21Jump_street", "IS_21_JUMP_STREET");
  ASSERT_CASE(upper_snake, "URLloader", "UR_LLOADER");
  ASSERT_CASE(upper_snake, "UrlLoader", "URL_LOADER");
  ASSERT_CASE(upper_snake, "URLLoader", "URL_LOADER");
  ASSERT_CASE(upper_snake, "url_loader", "URL_LOADER");
  ASSERT_CASE(upper_snake, "urlLoader", "URL_LOADER");
  ASSERT_CASE(upper_snake, "kUrlLoader", "URL_LOADER");
  ASSERT_CASE(upper_snake, "kURLLoader", "URL_LOADER");
}

TEST(UtilsTests, LowerSnakeCase) {
  ASSERT_CASE(lower_snake, "X", "x");
  ASSERT_CASE(lower_snake, "Xy", "xy");
  ASSERT_CASE(lower_snake, "XY", "xy");
  ASSERT_CASE(lower_snake, "Xyz123", "xyz123");
  ASSERT_CASE(lower_snake, "Xyz_123", "xyz_123");
  ASSERT_CASE(lower_snake, "XyZ123", "xy_z123");
  ASSERT_CASE(lower_snake, "DaysInAWeek", "days_in_a_week");
  ASSERT_CASE(lower_snake, "Android8_0_0", "android8_0_0");
  ASSERT_CASE(lower_snake, "Android_8_0_0", "android_8_0_0");
  ASSERT_CASE(lower_snake, "XMarksTheSpot", "x_marks_the_spot");
  ASSERT_CASE(lower_snake, "RealId", "real_id");
  ASSERT_CASE(lower_snake, "RealID", "real_id");
  ASSERT_CASE(lower_snake, "Real3d", "real3d");
  ASSERT_CASE(lower_snake, "Real3D", "real3_d");
  ASSERT_CASE(lower_snake, "Real_3d", "real_3d");
  ASSERT_CASE(lower_snake, "Real_3D", "real_3_d");
  ASSERT_CASE(lower_snake, "SampleXUnion", "sample_x_union");
  ASSERT_CASE(lower_snake, "SampleXunion", "sample_xunion");
  ASSERT_CASE(lower_snake, "URLLoader", "url_loader");
  ASSERT_CASE(lower_snake, "is_21Jump_street", "is_21_jump_street");
  ASSERT_CASE(lower_snake, "URLloader", "ur_lloader");
  ASSERT_CASE(lower_snake, "UrlLoader", "url_loader");
  ASSERT_CASE(lower_snake, "URLLoader", "url_loader");
  ASSERT_CASE(lower_snake, "URL_LOADER", "url_loader");
  ASSERT_CASE(lower_snake, "urlLoader", "url_loader");
  ASSERT_CASE(lower_snake, "kUrlLoader", "url_loader");
  ASSERT_CASE(lower_snake, "kURLLoader", "url_loader");
}

TEST(UtilsTests, KonstantCase) {
  ASSERT_CASE(konstant, "URLLoader", "kUrlLoader");
  ASSERT_CASE(konstant, "is_21Jump_street", "kIs21JumpStreet");
  ASSERT_CASE(konstant, "URLloader", "kUrLloader");
  ASSERT_CASE(konstant, "UrlLoader", "kUrlLoader");
  ASSERT_CASE(konstant, "URLLoader", "kUrlLoader");
  ASSERT_CASE(konstant, "url_loader", "kUrlLoader");
  ASSERT_CASE(konstant, "URL_LOADER", "kUrlLoader");
  ASSERT_CASE(konstant, "urlLoader", "kUrlLoader");
  ASSERT_CASE(konstant, "kURLLoader", "kUrlLoader");
}

TEST(UtilsTests, LowerNoSeparatorCase) {
  ASSERT_CASE(lower_no_separator, "URLLoader", "urlloader");
  ASSERT_CASE(lower_no_separator, "is_21Jump_street", "is21jumpstreet");
  ASSERT_CASE(lower_no_separator, "URLloader", "urlloader");
  ASSERT_CASE(lower_no_separator, "UrlLoader", "urlloader");
  ASSERT_CASE(lower_no_separator, "URLLoader", "urlloader");
  ASSERT_CASE(lower_no_separator, "url_loader", "urlloader");
  ASSERT_CASE(lower_no_separator, "URL_LOADER", "urlloader");
  ASSERT_CASE(lower_no_separator, "urlLoader", "urlloader");
  ASSERT_CASE(lower_no_separator, "kUrlLoader", "urlloader");
  ASSERT_CASE(lower_no_separator, "kURLLoader", "urlloader");
}

TEST(UtilsTests, WhitespaceAndComments) {
  ASSERT_TRUE(IsWhitespace(' '));
  ASSERT_TRUE(IsWhitespace('\t'));
  ASSERT_TRUE(IsWhitespace('\v'));
  ASSERT_TRUE(IsWhitespace('\f'));
  ASSERT_TRUE(IsWhitespace('\r'));
  ASSERT_TRUE(IsWhitespace('\n'));
  ASSERT_FALSE(IsWhitespace('\0'));
  ASSERT_FALSE(IsWhitespace('_'));
  ASSERT_FALSE(IsWhitespace('-'));
  ASSERT_FALSE(IsWhitespace('A'));
  ASSERT_FALSE(IsWhitespace('Z'));
  ASSERT_FALSE(IsWhitespace('a'));
  ASSERT_FALSE(IsWhitespace('z'));
  ASSERT_FALSE(IsWhitespace('0'));
  ASSERT_FALSE(IsWhitespace('9'));
  ASSERT_FALSE(IsWhitespace('!'));

  ASSERT_TRUE(IsWhitespaceNoNewline(' '));
  ASSERT_TRUE(IsWhitespaceNoNewline('\t'));
  ASSERT_TRUE(IsWhitespaceNoNewline('\v'));
  ASSERT_TRUE(IsWhitespaceNoNewline('\f'));
  ASSERT_TRUE(IsWhitespaceNoNewline('\r'));
  ASSERT_FALSE(IsWhitespaceNoNewline('\n'));
  ASSERT_FALSE(IsWhitespaceNoNewline('\0'));
  ASSERT_FALSE(IsWhitespaceNoNewline('_'));
  ASSERT_FALSE(IsWhitespaceNoNewline('-'));
  ASSERT_FALSE(IsWhitespaceNoNewline('A'));
  ASSERT_FALSE(IsWhitespaceNoNewline('Z'));
  ASSERT_FALSE(IsWhitespaceNoNewline('a'));
  ASSERT_FALSE(IsWhitespaceNoNewline('z'));
  ASSERT_FALSE(IsWhitespaceNoNewline('0'));
  ASSERT_FALSE(IsWhitespaceNoNewline('9'));
  ASSERT_FALSE(IsWhitespaceNoNewline('!'));

  ASSERT_TRUE(IsBlank(""));
  ASSERT_TRUE(IsBlank(" "));
  ASSERT_TRUE(IsBlank("\t"));
  ASSERT_TRUE(IsBlank("\n"));
  ASSERT_TRUE(IsBlank("\n\n\n"));
  ASSERT_TRUE(IsBlank("  \n  \n  \n"));
  ASSERT_TRUE(IsBlank(" \t\v\f\r\n"));
  ASSERT_TRUE(IsBlank("     "));
  ASSERT_TRUE(IsBlank(" \t \t "));
  ASSERT_TRUE(IsBlank("\t \t \t"));
  ASSERT_FALSE(IsBlank("multi\nline"));
  ASSERT_FALSE(IsBlank("\nmore\nmulti\nline\n"));
  ASSERT_FALSE(IsBlank("\t\t."));
  ASSERT_FALSE(IsBlank("    ."));
  ASSERT_FALSE(IsBlank(".    "));
  ASSERT_FALSE(IsBlank("// Comment "));
  ASSERT_FALSE(IsBlank("/// Doc Comment "));

  ASSERT_TRUE(LineFromOffsetIsBlank("four", 4));
  ASSERT_TRUE(LineFromOffsetIsBlank("four\n", 4));
  ASSERT_TRUE(LineFromOffsetIsBlank("four    ", 4));
  ASSERT_TRUE(LineFromOffsetIsBlank("four    \n", 4));
  ASSERT_TRUE(LineFromOffsetIsBlank("four  \t \t  ", 4));
  ASSERT_TRUE(LineFromOffsetIsBlank("four    \n", 4));
  ASSERT_TRUE(LineFromOffsetIsBlank("four    \t\n", 4));
  ASSERT_TRUE(LineFromOffsetIsBlank("four    \n\t", 4));
  ASSERT_TRUE(LineFromOffsetIsBlank("four    \nmore lines", 4));
  ASSERT_TRUE(LineFromOffsetIsBlank("four    \nmore lines\n", 4));
  ASSERT_TRUE(LineFromOffsetIsBlank("four    \t\n\t", 4));
  ASSERT_FALSE(LineFromOffsetIsBlank("four.", 4));
  ASSERT_FALSE(LineFromOffsetIsBlank("four.\n", 4));
  ASSERT_FALSE(LineFromOffsetIsBlank("fournot blank    \n", 4));
  ASSERT_FALSE(LineFromOffsetIsBlank("four    more chars", 4));
  ASSERT_FALSE(LineFromOffsetIsBlank("four    more chars\n", 4));

  ASSERT_TRUE(FirstLineIsBlank(""));
  ASSERT_TRUE(FirstLineIsBlank(""));
  ASSERT_TRUE(FirstLineIsBlank("\n"));
  ASSERT_TRUE(FirstLineIsBlank("    "));
  ASSERT_TRUE(FirstLineIsBlank("    \n"));
  ASSERT_TRUE(FirstLineIsBlank("  \t \t  "));
  ASSERT_TRUE(FirstLineIsBlank("    \n"));
  ASSERT_TRUE(FirstLineIsBlank("    \t\n"));
  ASSERT_TRUE(FirstLineIsBlank("    \nmore lines"));
  ASSERT_TRUE(FirstLineIsBlank("    \nmore lines\n"));
  ASSERT_TRUE(FirstLineIsBlank("    \n\t"));
  ASSERT_TRUE(FirstLineIsBlank("    \t\n\t"));
  ASSERT_FALSE(FirstLineIsBlank("."));
  ASSERT_FALSE(FirstLineIsBlank(".\n"));
  ASSERT_FALSE(FirstLineIsBlank("not blank    \n"));
  ASSERT_FALSE(FirstLineIsBlank("    more chars"));
  ASSERT_FALSE(FirstLineIsBlank("    more chars\n"));

  ASSERT_TRUE(LineFromOffsetIsRegularComment("four//", 4));
  ASSERT_TRUE(LineFromOffsetIsRegularComment("four//\n", 4));
  ASSERT_TRUE(LineFromOffsetIsRegularComment("four//    ", 4));
  ASSERT_TRUE(LineFromOffsetIsRegularComment("four//    \n", 4));
  ASSERT_TRUE(LineFromOffsetIsRegularComment("four//  \t\n", 4));
  ASSERT_TRUE(LineFromOffsetIsRegularComment("four//not blank    ", 4));
  ASSERT_TRUE(LineFromOffsetIsRegularComment("four//  not blank", 4));
  ASSERT_TRUE(LineFromOffsetIsRegularComment("four//not blank", 4));
  ASSERT_TRUE(LineFromOffsetIsRegularComment("four//not blank    \n", 4));
  ASSERT_TRUE(LineFromOffsetIsRegularComment("four//  not blank\n", 4));
  ASSERT_TRUE(LineFromOffsetIsRegularComment("four//not blank\n", 4));
  ASSERT_TRUE(LineFromOffsetIsRegularComment("four//    \n\t", 4));
  ASSERT_TRUE(LineFromOffsetIsRegularComment("four//    \t\n\t", 4));
  ASSERT_TRUE(LineFromOffsetIsRegularComment("four//    \nmore lines", 4));
  ASSERT_TRUE(LineFromOffsetIsRegularComment("four//    \nmore lines\n", 4));
  ASSERT_FALSE(LineFromOffsetIsRegularComment("four.//", 4));
  ASSERT_FALSE(LineFromOffsetIsRegularComment("four    .//\n", 4));
  ASSERT_FALSE(LineFromOffsetIsRegularComment("fourmore//    ", 4));
  ASSERT_FALSE(LineFromOffsetIsRegularComment("four    more\n//    \n", 4));
  //// Greater than 3 slashes are still interpreted as a regular comment
  ASSERT_TRUE(LineFromOffsetIsRegularComment("four////", 4));
  ASSERT_TRUE(LineFromOffsetIsRegularComment("four////\n", 4));
  ASSERT_TRUE(LineFromOffsetIsRegularComment("four////    ", 4));
  ASSERT_TRUE(LineFromOffsetIsRegularComment("four////    \n", 4));
  ASSERT_TRUE(LineFromOffsetIsRegularComment("four////  \t\n", 4));
  ASSERT_TRUE(LineFromOffsetIsRegularComment("four////not blank    ", 4));
  ASSERT_TRUE(LineFromOffsetIsRegularComment("four////  not blank", 4));
  ASSERT_TRUE(LineFromOffsetIsRegularComment("four////not blank", 4));
  ASSERT_TRUE(LineFromOffsetIsRegularComment("four////not blank    \n", 4));
  ASSERT_TRUE(LineFromOffsetIsRegularComment("four////  not blank\n", 4));
  ASSERT_TRUE(LineFromOffsetIsRegularComment("four////not blank\n", 4));
  ASSERT_TRUE(LineFromOffsetIsRegularComment("four/////", 4));
  ASSERT_TRUE(LineFromOffsetIsRegularComment("four/////\n", 4));
  ASSERT_TRUE(LineFromOffsetIsRegularComment("four/////    ", 4));
  ASSERT_TRUE(LineFromOffsetIsRegularComment("four/////    \n", 4));
  ASSERT_TRUE(LineFromOffsetIsRegularComment("four/////  \t\n", 4));
  ASSERT_TRUE(LineFromOffsetIsRegularComment("four/////not blank    ", 4));
  ASSERT_TRUE(LineFromOffsetIsRegularComment("four/////  not blank", 4));
  ASSERT_TRUE(LineFromOffsetIsRegularComment("four/////not blank", 4));
  ASSERT_TRUE(LineFromOffsetIsRegularComment("four/////not blank    \n", 4));
  ASSERT_TRUE(LineFromOffsetIsRegularComment("four/////  not blank\n", 4));
  ASSERT_TRUE(LineFromOffsetIsRegularComment("four/////not blank\n", 4));
  /// FIDL Doc Comments start with 3 slashes, like this one
  ASSERT_FALSE(LineFromOffsetIsRegularComment("four///", 4));
  ASSERT_FALSE(LineFromOffsetIsRegularComment("four///\n", 4));
  ASSERT_FALSE(LineFromOffsetIsRegularComment("four///    ", 4));
  ASSERT_FALSE(LineFromOffsetIsRegularComment("four///    \n", 4));
  ASSERT_FALSE(LineFromOffsetIsRegularComment("four///  \t\n", 4));
  ASSERT_FALSE(LineFromOffsetIsRegularComment("four///not blank    ", 4));
  ASSERT_FALSE(LineFromOffsetIsRegularComment("four///  not blank", 4));
  ASSERT_FALSE(LineFromOffsetIsRegularComment("four///not blank", 4));
  ASSERT_FALSE(LineFromOffsetIsRegularComment("four///not blank    \n", 4));
  ASSERT_FALSE(LineFromOffsetIsRegularComment("four///  not blank\n", 4));
  ASSERT_FALSE(LineFromOffsetIsRegularComment("four///not blank\n", 4));

  ASSERT_TRUE(FirstLineIsRegularComment("//"));
  ASSERT_TRUE(FirstLineIsRegularComment("//\n"));
  ASSERT_TRUE(FirstLineIsRegularComment("//    "));
  ASSERT_TRUE(FirstLineIsRegularComment("//    \n"));
  ASSERT_TRUE(FirstLineIsRegularComment("//  \t\n"));
  ASSERT_TRUE(FirstLineIsRegularComment("//not blank    "));
  ASSERT_TRUE(FirstLineIsRegularComment("//  not blank"));
  ASSERT_TRUE(FirstLineIsRegularComment("//not blank"));
  ASSERT_TRUE(FirstLineIsRegularComment("//not blank    \n"));
  ASSERT_TRUE(FirstLineIsRegularComment("//  not blank\n"));
  ASSERT_TRUE(FirstLineIsRegularComment("//not blank\n"));
  ASSERT_TRUE(FirstLineIsRegularComment("//    \n\t"));
  ASSERT_TRUE(FirstLineIsRegularComment("//    \t\n\t"));
  ASSERT_TRUE(FirstLineIsRegularComment("//    \nmore lines"));
  ASSERT_TRUE(FirstLineIsRegularComment("//    \nmore lines\n"));
  ASSERT_FALSE(FirstLineIsRegularComment(".//"));
  ASSERT_FALSE(FirstLineIsRegularComment("    .//\n"));
  ASSERT_FALSE(FirstLineIsRegularComment("more//    "));
  ASSERT_FALSE(FirstLineIsRegularComment("    more\n//    \n"));
  //// Greater than 3 slashes are still interpreted as a regular comment
  ASSERT_TRUE(FirstLineIsRegularComment("////"));
  ASSERT_TRUE(FirstLineIsRegularComment("////\n"));
  ASSERT_TRUE(FirstLineIsRegularComment("////    "));
  ASSERT_TRUE(FirstLineIsRegularComment("////    \n"));
  ASSERT_TRUE(FirstLineIsRegularComment("////  \t\n"));
  ASSERT_TRUE(FirstLineIsRegularComment("////not blank    "));
  ASSERT_TRUE(FirstLineIsRegularComment("////  not blank"));
  ASSERT_TRUE(FirstLineIsRegularComment("////not blank"));
  ASSERT_TRUE(FirstLineIsRegularComment("////not blank    \n"));
  ASSERT_TRUE(FirstLineIsRegularComment("////  not blank\n"));
  ASSERT_TRUE(FirstLineIsRegularComment("////not blank\n"));
  ASSERT_TRUE(FirstLineIsRegularComment("/////"));
  ASSERT_TRUE(FirstLineIsRegularComment("/////\n"));
  ASSERT_TRUE(FirstLineIsRegularComment("/////    "));
  ASSERT_TRUE(FirstLineIsRegularComment("/////    \n"));
  ASSERT_TRUE(FirstLineIsRegularComment("/////  \t\n"));
  ASSERT_TRUE(FirstLineIsRegularComment("/////not blank    "));
  ASSERT_TRUE(FirstLineIsRegularComment("/////  not blank"));
  ASSERT_TRUE(FirstLineIsRegularComment("/////not blank"));
  ASSERT_TRUE(FirstLineIsRegularComment("/////not blank    \n"));
  ASSERT_TRUE(FirstLineIsRegularComment("/////  not blank\n"));
  ASSERT_TRUE(FirstLineIsRegularComment("/////not blank\n"));
  /// FIDL Doc Comments start with 3 slashes, like this one
  ASSERT_FALSE(FirstLineIsRegularComment("///"));
  ASSERT_FALSE(FirstLineIsRegularComment("///\n"));
  ASSERT_FALSE(FirstLineIsRegularComment("///    "));
  ASSERT_FALSE(FirstLineIsRegularComment("///    \n"));
  ASSERT_FALSE(FirstLineIsRegularComment("///  \t\n"));
  ASSERT_FALSE(FirstLineIsRegularComment("///not blank    "));
  ASSERT_FALSE(FirstLineIsRegularComment("///  not blank"));
  ASSERT_FALSE(FirstLineIsRegularComment("///not blank"));
  ASSERT_FALSE(FirstLineIsRegularComment("///not blank    \n"));
  ASSERT_FALSE(FirstLineIsRegularComment("///  not blank\n"));
  ASSERT_FALSE(FirstLineIsRegularComment("///not blank\n"));
}

TEST(UtilsTests, IsValidLibraryComponent) {
  ASSERT_TRUE(IsValidLibraryComponent("a"));
  ASSERT_TRUE(IsValidLibraryComponent("abc"));
  ASSERT_TRUE(IsValidLibraryComponent("a2b"));

  ASSERT_FALSE(IsValidLibraryComponent(""));
  ASSERT_FALSE(IsValidLibraryComponent("A"));
  ASSERT_FALSE(IsValidLibraryComponent("2"));
  ASSERT_FALSE(IsValidLibraryComponent("a_c"));
  ASSERT_FALSE(IsValidLibraryComponent("ab_"));
}

TEST(UtilsTests, IsValidIdentifierComponent) {
  ASSERT_TRUE(IsValidIdentifierComponent("a"));
  ASSERT_TRUE(IsValidIdentifierComponent("abc"));
  ASSERT_TRUE(IsValidIdentifierComponent("A"));
  ASSERT_TRUE(IsValidIdentifierComponent("a2b"));
  ASSERT_TRUE(IsValidIdentifierComponent("a_c"));

  ASSERT_FALSE(IsValidIdentifierComponent(""));
  ASSERT_FALSE(IsValidIdentifierComponent("2"));
  ASSERT_FALSE(IsValidIdentifierComponent("ab_"));
}

TEST(UtilsTests, IsValidFullyQualifiedMethodIdentifier) {
  ASSERT_TRUE(IsValidFullyQualifiedMethodIdentifier("lib/Protocol.Method"));
  ASSERT_TRUE(IsValidFullyQualifiedMethodIdentifier("long.lib/Protocol.Method"));

  ASSERT_FALSE(IsValidFullyQualifiedMethodIdentifier("Method"));
  ASSERT_FALSE(IsValidFullyQualifiedMethodIdentifier("lib/Protocol"));
  ASSERT_FALSE(IsValidFullyQualifiedMethodIdentifier("lonG.lib/Protocol.Method"));
  ASSERT_FALSE(IsValidFullyQualifiedMethodIdentifier("long.liB/Protocol.Method"));
}

TEST(UtilsTests, IsOnlyWhitespace) {
  // ---------------40---------------- |
  std::string unformatted = R"FIDL(
/// C1a
/// C1b
library foo.bar;  // C2

/// C3a
/// C3b
using baz.qux;  // C4

/// C5a
/// C5b
resource_definition thing : uint8 {  // C6
    properties {  // C8
/// C9a
/// C9b
        stuff rights;  // C10
    };
};

/// C11a
/// C11b
const MY_CONST string = "abc";  // C12

/// C13a
/// C13b
type MyEnum = enum {  // C14
/// C15a
/// C17b
    MY_VALUE = 1;  // C16
};

/// C17a
/// C17b
type MyTable = resource table {  // C18
/// C19a
/// C19b
    1: field thing;  // C20
};

/// C21a
/// C21b
alias MyAlias = MyStruct;  // C22

/// C23a
/// C23b
protocol MyProtocol {  // C24
/// C25a
/// C25b
    MyMethod(resource struct {  // C26
/// C27a
/// C27b
        data MyTable;  // C28
    }) -> () error MyEnum;  // C29
};  // 30

/// C29a
/// C29b
service MyService {  // C32
/// C31a
/// C31b
    my_protocol client_end:MyProtocol;  // C34
};  // C35
)FIDL";

  // ---------------40---------------- |
  std::string formatted = R"FIDL(
/// C1a
/// C1b
library foo.bar; // C2

/// C3a
/// C3b
using baz.qux; // C4

/// C5a
/// C5b
resource_definition thing : uint8 { // C6
    properties { // C8
        /// C9a
        /// C9b
        stuff rights; // C10
    };
};

/// C11a
/// C11b
const MY_CONST string = "abc"; // C12

/// C13a
/// C13b
type MyEnum = enum { // C14
    /// C15a
    /// C17b
    MY_VALUE = 1; // C16
};

/// C17a
/// C17b
type MyTable = resource table { // C18
    /// C19a
    /// C19b
    1: field thing; // C20
};

/// C21a
/// C21b
alias MyAlias = MyStruct; // C22

/// C23a
/// C23b
protocol MyProtocol { // C24
    /// C25a
    /// C25b
    MyMethod(resource struct { // C26
        /// C27a
        /// C27b
        data MyTable; // C28
    }) -> () error MyEnum; // C29
}; // 30

/// C29a
/// C29b
service MyService { // C32
    /// C31a
    /// C31b
    my_protocol client_end:MyProtocol; // C34
}; // C35
)FIDL";

  ASSERT_TRUE(OnlyWhitespaceChanged(unformatted, formatted));
}

TEST(UtilsTests, CanonicalForm) {
  EXPECT_STRING_EQ(canonicalize(""), "");

  // Basic letter combinations.
  EXPECT_STRING_EQ(canonicalize("a"), "a");
  EXPECT_STRING_EQ(canonicalize("A"), "a");
  EXPECT_STRING_EQ(canonicalize("ab"), "ab");
  EXPECT_STRING_EQ(canonicalize("AB"), "ab");
  EXPECT_STRING_EQ(canonicalize("Ab"), "ab");
  EXPECT_STRING_EQ(canonicalize("aB"), "a_b");
  EXPECT_STRING_EQ(canonicalize("a_b"), "a_b");
  EXPECT_STRING_EQ(canonicalize("A_B"), "a_b");
  EXPECT_STRING_EQ(canonicalize("A_b"), "a_b");
  EXPECT_STRING_EQ(canonicalize("a_B"), "a_b");

  // Digits are treated like lowercase letters.
  EXPECT_STRING_EQ(canonicalize("1"), "1");
  EXPECT_STRING_EQ(canonicalize("a1"), "a1");
  EXPECT_STRING_EQ(canonicalize("A1"), "a1");

  // Leading digits are illegal in FIDL identifiers, so these do not matter.
  EXPECT_STRING_EQ(canonicalize("1a"), "1a");
  EXPECT_STRING_EQ(canonicalize("1A"), "1_a");
  EXPECT_STRING_EQ(canonicalize("12"), "12");

  // Lower/upper snake/camel case conventions.
  EXPECT_STRING_EQ(canonicalize("lowerCamelCase"), "lower_camel_case");
  EXPECT_STRING_EQ(canonicalize("UpperCamelCase"), "upper_camel_case");
  EXPECT_STRING_EQ(canonicalize("lower_snake_case"), "lower_snake_case");
  EXPECT_STRING_EQ(canonicalize("UPPER_SNAKE_CASE"), "upper_snake_case");
  EXPECT_STRING_EQ(canonicalize("Camel_With_Underscores"), "camel_with_underscores");
  EXPECT_STRING_EQ(canonicalize("camelWithAOneLetterWord"), "camel_with_a_one_letter_word");
  EXPECT_STRING_EQ(canonicalize("1_2__3___underscores"), "1_2_3_underscores");

  // Acronym casing.
  EXPECT_STRING_EQ(canonicalize("HTTPServer"), "http_server");
  EXPECT_STRING_EQ(canonicalize("HttpServer"), "http_server");
  EXPECT_STRING_EQ(canonicalize("URLIsATLA"), "url_is_atla");
  EXPECT_STRING_EQ(canonicalize("UrlIsATla"), "url_is_a_tla");

  // Words with digits: H264 encoder.
  EXPECT_STRING_EQ(canonicalize("h264encoder"), "h264encoder");
  EXPECT_STRING_EQ(canonicalize("H264ENCODER"), "h264_encoder");
  EXPECT_STRING_EQ(canonicalize("h264_encoder"), "h264_encoder");
  EXPECT_STRING_EQ(canonicalize("H264_ENCODER"), "h264_encoder");
  EXPECT_STRING_EQ(canonicalize("h264Encoder"), "h264_encoder");
  EXPECT_STRING_EQ(canonicalize("H264Encoder"), "h264_encoder");

  // Words with digits: DDR4 memory.
  EXPECT_STRING_EQ(canonicalize("ddr4memory"), "ddr4memory");
  EXPECT_STRING_EQ(canonicalize("DDR4MEMORY"), "ddr4_memory");
  EXPECT_STRING_EQ(canonicalize("ddr4_memory"), "ddr4_memory");
  EXPECT_STRING_EQ(canonicalize("DDR4_MEMORY"), "ddr4_memory");
  EXPECT_STRING_EQ(canonicalize("ddr4Memory"), "ddr4_memory");
  EXPECT_STRING_EQ(canonicalize("Ddr4Memory"), "ddr4_memory");
  EXPECT_STRING_EQ(canonicalize("DDR4Memory"), "ddr4_memory");

  // Words with digits: A2DP profile.
  EXPECT_STRING_EQ(canonicalize("a2dpprofile"), "a2dpprofile");
  EXPECT_STRING_EQ(canonicalize("A2DPPROFILE"), "a2_dpprofile");
  EXPECT_STRING_EQ(canonicalize("a2dp_profile"), "a2dp_profile");
  EXPECT_STRING_EQ(canonicalize("A2DP_PROFILE"), "a2_dp_profile");
  EXPECT_STRING_EQ(canonicalize("a2dpProfile"), "a2dp_profile");
  EXPECT_STRING_EQ(canonicalize("A2dpProfile"), "a2dp_profile");
  EXPECT_STRING_EQ(canonicalize("A2DPProfile"), "a2_dp_profile");

  // Words with digits: R2D2 is one word.
  EXPECT_STRING_EQ(canonicalize("r2d2isoneword"), "r2d2isoneword");
  EXPECT_STRING_EQ(canonicalize("R2D2ISONEWORD"), "r2_d2_isoneword");
  EXPECT_STRING_EQ(canonicalize("r2d2_is_one_word"), "r2d2_is_one_word");
  EXPECT_STRING_EQ(canonicalize("R2D2_IS_ONE_WORD"), "r2_d2_is_one_word");
  EXPECT_STRING_EQ(canonicalize("r2d2IsOneWord"), "r2d2_is_one_word");
  EXPECT_STRING_EQ(canonicalize("R2d2IsOneWord"), "r2d2_is_one_word");
  EXPECT_STRING_EQ(canonicalize("R2D2IsOneWord"), "r2_d2_is_one_word");

  // Leading and trailing underscores are illegal in FIDL identifiers, so these
  // do not matter.
  EXPECT_STRING_EQ(canonicalize("_"), "");
  EXPECT_STRING_EQ(canonicalize("_a"), "a");
  EXPECT_STRING_EQ(canonicalize("a_"), "a_");
  EXPECT_STRING_EQ(canonicalize("_a_"), "a_");
  EXPECT_STRING_EQ(canonicalize("__a__"), "a_");
}

TEST(UtilsTests, StringStripping) {
  EXPECT_STRING_EQ(strip_konstant_k("kFoobar"), "Foobar");
  EXPECT_STRING_EQ(strip_konstant_k("KFoobar"), "KFoobar");

  EXPECT_STRING_EQ(strip_string_literal_quotes("\"\""), "");
  EXPECT_STRING_EQ(strip_string_literal_quotes("\"foobar\""), "foobar");

  EXPECT_STRING_EQ(strip_doc_comment_slashes(R"FIDL(
  /// A
  /// multiline
  /// comment!
)FIDL"),
                   "\n A\n multiline\n comment!\n");

  EXPECT_STRING_EQ(strip_doc_comment_slashes(R"FIDL(
  ///
  /// With
  ///
  /// empty
  ///
  /// lines
  ///
)FIDL"),
                   "\n\n With\n\n empty\n\n lines\n\n");

  EXPECT_STRING_EQ(strip_doc_comment_slashes(R"FIDL(
  /// With

  /// blank


  /// lines
)FIDL"),
                   "\n With\n\n blank\n\n\n lines\n");

  EXPECT_STRING_EQ(strip_doc_comment_slashes(R"FIDL(
	/// With
		/// tabs
	 /// in
 	/// addition
 	 /// to
	 	/// spaces
)FIDL"),
                   "\n With\n tabs\n in\n addition\n to\n spaces\n");

  EXPECT_STRING_EQ(strip_doc_comment_slashes(R"FIDL(
  /// Weird
/// Offsets
  /// Slash///
  ///Placement ///
       /// And
  ///   Spacing   )FIDL"),
                   "\n Weird\n Offsets\n Slash///\nPlacement ///\n And\n   Spacing   \n");
}

TEST(UtilsTests, StringLiteralLength) {
  ASSERT_EQ(string_literal_length(R"("Hello")"), 5);
  ASSERT_EQ(string_literal_length(R"("\\")"), 1);
  ASSERT_EQ(string_literal_length(R"("\to")"), 2);
  ASSERT_EQ(string_literal_length(R"("\n")"), 1);
  ASSERT_EQ(string_literal_length(R"("\x0a")"), 1);
  ASSERT_EQ(string_literal_length(R"("\x0aa")"), 2);
  ASSERT_EQ(string_literal_length(R"("\012")"), 1);
  ASSERT_EQ(string_literal_length(R"("\0123")"), 2);
  ASSERT_EQ(string_literal_length(R"("\U0001F600")"), 1);
  ASSERT_EQ(string_literal_length(R"("\u2713")"), 1);
  ASSERT_EQ(string_literal_length(R"("")"), 0);
  ASSERT_EQ(string_literal_length(R"("$")"), 1);
  ASSERT_EQ(string_literal_length(R"("¢")"), 2);
  ASSERT_EQ(string_literal_length(R"("€")"), 3);
  ASSERT_EQ(string_literal_length(R"("𐍈")"), 4);
  ASSERT_EQ(string_literal_length(R"("😁")"), 4);
}

}  // namespace

}  // namespace fidl::utils