StringUtilTest.java

/*
 * Copyright 2000-2017 JetBrains s.r.o.
 *
 * 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.
 */
package com.intellij.util.text;

import com.intellij.openapi.util.Comparing;
import com.intellij.openapi.util.text.NaturalComparator;
import com.intellij.openapi.util.text.StringUtil;
import com.intellij.util.LineSeparator;
import com.intellij.xml.util.XmlStringUtil;
import org.jdom.Verifier;
import org.jetbrains.annotations.NotNull;
import org.junit.Test;

import java.nio.CharBuffer;
import java.util.*;

import static org.junit.Assert.*;

/**
 * @author Eugene Zhuravlev
 * @since Dec 22, 2006
 */
public class StringUtilTest {
  @Test
  public void testTrimLeadingChar() throws Exception {
    doTestTrimLeading("", "");
    doTestTrimLeading("", " ");
    doTestTrimLeading("", "    ");
    doTestTrimLeading("a  ", "a  ");
    doTestTrimLeading("a  ", "  a  ");
  }

  @Test
  public void testTrimTrailingChar() throws Exception {
    doTestTrimTrailing("", "");
    doTestTrimTrailing("", " ");
    doTestTrimTrailing("", "    ");
    doTestTrimTrailing("  a", "  a");
    doTestTrimTrailing("  a", "  a  ");
  }

  private static void doTestTrimLeading(@NotNull String expected, @NotNull String string) {
    assertEquals(expected, StringUtil.trimLeading(string));
    assertEquals(expected, StringUtil.trimLeading(string, ' '));
    assertEquals(expected, StringUtil.trimLeading(new StringBuilder(string), ' ').toString());
  }

  private static void doTestTrimTrailing(@NotNull String expected, @NotNull String string) {
    assertEquals(expected, StringUtil.trimTrailing(string));
    assertEquals(expected, StringUtil.trimTrailing(string, ' '));
    assertEquals(expected, StringUtil.trimTrailing(new StringBuilder(string), ' ').toString());
  }

  @Test
  public void testToUpperCase() {
    assertEquals('/', StringUtil.toUpperCase('/'));
    assertEquals(':', StringUtil.toUpperCase(':'));
    assertEquals('A', StringUtil.toUpperCase('a'));
    assertEquals('A', StringUtil.toUpperCase('A'));
    assertEquals('K', StringUtil.toUpperCase('k'));
    assertEquals('K', StringUtil.toUpperCase('K'));

    assertEquals('\u2567', StringUtil.toUpperCase(Character.toLowerCase('\u2567')));
  }

  @Test
  public void testToLowerCase() {
    assertEquals('/', StringUtil.toLowerCase('/'));
    assertEquals(':', StringUtil.toLowerCase(':'));
    assertEquals('a', StringUtil.toLowerCase('a'));
    assertEquals('a', StringUtil.toLowerCase('A'));
    assertEquals('k', StringUtil.toLowerCase('k'));
    assertEquals('k', StringUtil.toLowerCase('K'));

    assertEquals('\u2567', StringUtil.toUpperCase(Character.toLowerCase('\u2567')));
  }

  @Test
  public void testIsEmptyOrSpaces() throws Exception {
    assertTrue(StringUtil.isEmptyOrSpaces(null));
    assertTrue(StringUtil.isEmptyOrSpaces(""));
    assertTrue(StringUtil.isEmptyOrSpaces("                   "));

    assertFalse(StringUtil.isEmptyOrSpaces("1"));
    assertFalse(StringUtil.isEmptyOrSpaces("         12345          "));
    assertFalse(StringUtil.isEmptyOrSpaces("test"));
  }

  @Test
  public void testSplitWithQuotes() {
    final List<String> strings = StringUtil.splitHonorQuotes("aaa bbb   ccc \"ddd\" \"e\\\"e\\\"e\"  ", ' ');
    assertEquals(5, strings.size());
    assertEquals("aaa", strings.get(0));
    assertEquals("bbb", strings.get(1));
    assertEquals("ccc", strings.get(2));
    assertEquals("\"ddd\"", strings.get(3));
    assertEquals("\"e\\\"e\\\"e\"", strings.get(4));
  }

  @Test
  public void testUnPluralize() {
    // synthetic
    assertEquals("plurals", StringUtil.unpluralize("pluralses"));
    assertEquals("Inherits", StringUtil.unpluralize("Inheritses"));
    assertEquals("s", StringUtil.unpluralize("ss"));
    assertEquals("I", StringUtil.unpluralize("Is"));
    assertEquals(null, StringUtil.unpluralize("s"));
    assertEquals("z", StringUtil.unpluralize("zs"));
    // normal
    assertEquals("case", StringUtil.unpluralize("cases"));
    assertEquals("Index", StringUtil.unpluralize("Indices"));
    assertEquals("fix", StringUtil.unpluralize("fixes"));
    assertEquals("man", StringUtil.unpluralize("men"));
    assertEquals("leaf", StringUtil.unpluralize("leaves"));
    assertEquals("cookie", StringUtil.unpluralize("cookies"));
    assertEquals("search", StringUtil.unpluralize("searches"));
    assertEquals("process", StringUtil.unpluralize("process"));
    assertEquals("PROPERTY", StringUtil.unpluralize("PROPERTIES"));
    assertEquals("THIS", StringUtil.unpluralize("THESE"));
  }

  @Test
  public void testPluralize() {
    assertEquals("values", StringUtil.pluralize("value"));
    assertEquals("values", StringUtil.pluralize("values"));
    assertEquals("indices", StringUtil.pluralize("index"));
    assertEquals("matrices", StringUtil.pluralize("matrix"));
    assertEquals("fixes", StringUtil.pluralize("fix"));
    assertEquals("men", StringUtil.pluralize("man"));
    assertEquals("media", StringUtil.pluralize("medium"));
    assertEquals("stashes", StringUtil.pluralize("stash"));
    assertEquals("children", StringUtil.pluralize("child"));
    assertEquals("leaves", StringUtil.pluralize("leaf"));
    assertEquals("These", StringUtil.pluralize("This"));
    assertEquals("cookies", StringUtil.pluralize("cookie"));
    assertEquals("VaLuES", StringUtil.pluralize("VaLuE"));
    assertEquals("PLANS", StringUtil.pluralize("PLAN"));
    assertEquals("stackTraceLineExes", StringUtil.pluralize("stackTraceLineEx"));
    assertEquals("schemas", StringUtil.pluralize("schema")); // anglicized version
    assertEquals("PROPERTIES", StringUtil.pluralize("PROPERTY"));
    assertEquals("THESE", StringUtil.pluralize("THIS"));
  }

  @Test
  public void testStartsWithConcatenation() {
    assertTrue(StringUtil.startsWithConcatenation("something.with.dot", "something", "."));
    assertTrue(StringUtil.startsWithConcatenation("something.with.dot", "", "something."));
    assertTrue(StringUtil.startsWithConcatenation("something.", "something", "."));
    assertTrue(StringUtil.startsWithConcatenation("something", "something", "", "", ""));
    assertFalse(StringUtil.startsWithConcatenation("something", "something", "", "", "."));
    assertFalse(StringUtil.startsWithConcatenation("some", "something", ""));
  }

  @Test
  public void testNaturalCompareTransitivity() {
    String s1 = "#";
    String s2 = "0b";
    String s3 = " 0b";
    assertTrue(StringUtil.naturalCompare(s1, s2) < 0);
    assertTrue(StringUtil.naturalCompare(s2, s3) < 0);
    assertTrue("non-transitive", StringUtil.naturalCompare(s1, s3) < 0);
  }

  @Test
  public void testNaturalCompareStability() {
    assertTrue(StringUtil.naturalCompare("01a1", "1a01") != StringUtil.naturalCompare("1a01", "01a1"));
    assertTrue(StringUtil.naturalCompare("#01A", "# 1A") != StringUtil.naturalCompare("# 1A", "#01A"));
    assertTrue(StringUtil.naturalCompare("aA", "aa") != StringUtil.naturalCompare("aa", "aA"));
  }

  @Test
  public void testNaturalCompare() {

    final List<String> numbers = Arrays.asList("1a000001", "000001a1", "001a0001", "0001A001" , "00001a01", "01a00001");
    numbers.sort(NaturalComparator.INSTANCE);
    assertEquals(Arrays.asList("1a000001", "01a00001", "001a0001", "0001A001" , "00001a01", "000001a1"), numbers);

    final List<String> test = Arrays.asList("test011", "test10", "test10a", "test010");
    test.sort(NaturalComparator.INSTANCE);
    assertEquals(Arrays.asList("test10", "test10a", "test010", "test011"), test);

    final List<String> strings = Arrays.asList("Test99", "tes0", "test0", "testing", "test", "test99", "test011", "test1",
                    "test 3", "test2", "test10a", "test10", "1.2.10.5", "1.2.9.1");
    strings.sort(NaturalComparator.INSTANCE);
    assertEquals(Arrays.asList("1.2.9.1", "1.2.10.5", "tes0", "test", "test0", "test1", "test2", "test 3", "test10", "test10a",
                               "test011", "Test99", "test99", "testing"), strings);

    final List<String> strings2 = Arrays.asList("t1", "t001", "T2", "T002", "T1", "t2");
    strings2.sort(NaturalComparator.INSTANCE);
    assertEquals(Arrays.asList("T1", "t1", "t001", "T2", "t2", "T002"), strings2);
    assertEquals(1 ,StringUtil.naturalCompare("7403515080361171695", "07403515080361171694"));
    assertEquals(-14, StringUtil.naturalCompare("_firstField", "myField1"));
    //idea-80853
    final List<String> strings3 =
      Arrays.asList("C148A_InsomniaCure", "C148B_Escape", "C148C_TersePrincess", "C148D_BagOfMice", "C148E_Porcelain");
    strings3.sort(NaturalComparator.INSTANCE);
    assertEquals(Arrays.asList("C148A_InsomniaCure", "C148B_Escape", "C148C_TersePrincess", "C148D_BagOfMice", "C148E_Porcelain"), strings3);

    final List<String> l = Arrays.asList("a0002", "a0 2", "a001");
    l.sort(NaturalComparator.INSTANCE);
    assertEquals(Arrays.asList("a0 2", "a001", "a0002"), l);
  }

  @Test
  public void testFormatLinks() {
    assertEquals("<a href=\"http://a-b+c\">http://a-b+c</a>", StringUtil.formatLinks("http://a-b+c"));
  }

  @Test
  public void testCopyHeapCharBuffer() {
    String s = "abc.d";
    CharBuffer buffer = CharBuffer.allocate(s.length());
    buffer.append(s);
    buffer.rewind();

    assertNotNull(CharArrayUtil.fromSequenceWithoutCopying(buffer));
    assertNotNull(CharArrayUtil.fromSequenceWithoutCopying(buffer.subSequence(0, 5)));
    //assertNull(CharArrayUtil.fromSequenceWithoutCopying(buffer.subSequence(0, 4))); // end index is not checked
    assertNull(CharArrayUtil.fromSequenceWithoutCopying(buffer.subSequence(1, 5)));
    assertNull(CharArrayUtil.fromSequenceWithoutCopying(buffer.subSequence(1, 2)));
  }

  @Test
  public void testTitleCase() {
    assertEquals("Couldn't Connect to Debugger", StringUtil.wordsToBeginFromUpperCase("Couldn't connect to debugger"));
    assertEquals("Let's Make Abbreviations Like I18n, SQL and CSS", StringUtil.wordsToBeginFromUpperCase("Let's make abbreviations like I18n, SQL and CSS"));
  }

  @Test
  public void testSentenceCapitalization() {
    assertEquals("couldn't connect to debugger", StringUtil.wordsToBeginFromLowerCase("Couldn't Connect to Debugger"));
    assertEquals("let's make abbreviations like I18n, SQL and CSS s SQ sq", StringUtil.wordsToBeginFromLowerCase("Let's Make Abbreviations Like I18n, SQL and CSS S SQ Sq"));
  }

  @Test
  public void testEscapeStringCharacters() {
    assertEquals("\\\"\\n", StringUtil.escapeStringCharacters(3, "\\\"\n", "\"", false, new StringBuilder()).toString());
    assertEquals("\\\"\\n", StringUtil.escapeStringCharacters(2, "\"\n", "\"", false, new StringBuilder()).toString());
    assertEquals("\\\\\\\"\\n", StringUtil.escapeStringCharacters(3, "\\\"\n", "\"", true, new StringBuilder()).toString());
  }

  @Test
  public void testEscapeSlashes() {
    assertEquals("\\/", StringUtil.escapeSlashes("/"));
    assertEquals("foo\\/bar\\foo\\/", StringUtil.escapeSlashes("foo/bar\\foo/"));

    assertEquals("\\\\\\\\server\\\\share\\\\extension.crx", StringUtil.escapeBackSlashes("\\\\server\\share\\extension.crx"));
  }

  @Test
  public void testEscapeQuotes() {
    assertEquals("\\\"", StringUtil.escapeQuotes("\""));
    assertEquals("foo\\\"bar'\\\"", StringUtil.escapeQuotes("foo\"bar'\""));
  }

  @Test
  public void testUnquote() {
    assertEquals("", StringUtil.unquoteString(""));
    assertEquals("\"", StringUtil.unquoteString("\""));
    assertEquals("", StringUtil.unquoteString("\"\""));
    assertEquals("\"", StringUtil.unquoteString("\"\"\""));
    assertEquals("foo", StringUtil.unquoteString("\"foo\""));
    assertEquals("\"foo", StringUtil.unquoteString("\"foo"));
    assertEquals("foo\"", StringUtil.unquoteString("foo\""));
    assertEquals("", StringUtil.unquoteString(""));
    assertEquals("\'", StringUtil.unquoteString("\'"));
    assertEquals("", StringUtil.unquoteString("\'\'"));
    assertEquals("\'", StringUtil.unquoteString("\'\'\'"));
    assertEquals("foo", StringUtil.unquoteString("\'foo\'"));
    assertEquals("\'foo", StringUtil.unquoteString("\'foo"));
    assertEquals("foo\'", StringUtil.unquoteString("foo\'"));

    assertEquals("\'\"", StringUtil.unquoteString("\'\""));
    assertEquals("\"\'", StringUtil.unquoteString("\"\'"));
    assertEquals("\"foo\'", StringUtil.unquoteString("\"foo\'"));
  }

  @SuppressWarnings("SSBasedInspection")
  @Test
  public void testStripQuotesAroundValue() {
    assertEquals("", StringUtil.stripQuotesAroundValue(""));
    assertEquals("", StringUtil.stripQuotesAroundValue("'"));
    assertEquals("", StringUtil.stripQuotesAroundValue("\""));
    assertEquals("", StringUtil.stripQuotesAroundValue("''"));
    assertEquals("", StringUtil.stripQuotesAroundValue("\"\""));
    assertEquals("", StringUtil.stripQuotesAroundValue("'\""));
    assertEquals("foo", StringUtil.stripQuotesAroundValue("'foo'"));
    assertEquals("foo", StringUtil.stripQuotesAroundValue("'foo"));
    assertEquals("foo", StringUtil.stripQuotesAroundValue("foo'"));
    assertEquals("f'o'o", StringUtil.stripQuotesAroundValue("'f'o'o'"));
    assertEquals("f\"o'o", StringUtil.stripQuotesAroundValue("\"f\"o'o'"));
    assertEquals("f\"o'o", StringUtil.stripQuotesAroundValue("f\"o'o"));
    assertEquals("\"'f\"o'o\"", StringUtil.stripQuotesAroundValue("\"\"'f\"o'o\"\""));
    assertEquals("''f\"o'o''", StringUtil.stripQuotesAroundValue("'''f\"o'o'''"));
    assertEquals("foo' 'bar", StringUtil.stripQuotesAroundValue("foo' 'bar"));
  }

  @Test
  public void testUnquoteWithQuotationChar() {
    assertEquals("", StringUtil.unquoteString("", '|'));
    assertEquals("|", StringUtil.unquoteString("|", '|'));
    assertEquals("", StringUtil.unquoteString("||", '|'));
    assertEquals("|", StringUtil.unquoteString("|||", '|'));
    assertEquals("foo", StringUtil.unquoteString("|foo|", '|'));
    assertEquals("|foo", StringUtil.unquoteString("|foo", '|'));
    assertEquals("foo|", StringUtil.unquoteString("foo|", '|'));
  }

  @Test
  public void testIsQuotedString() {
    assertFalse(StringUtil.isQuotedString(""));
    assertFalse(StringUtil.isQuotedString("'"));
    assertFalse(StringUtil.isQuotedString("\""));
    assertTrue(StringUtil.isQuotedString("\"\""));
    assertTrue(StringUtil.isQuotedString("''"));
    assertTrue(StringUtil.isQuotedString("'ab'"));
    assertTrue(StringUtil.isQuotedString("\"foo\""));
  }

  @Test
  public void testJoin() {
    assertEquals("", StringUtil.join(Collections.emptyList(), ","));
    assertEquals("qqq", StringUtil.join(Collections.singletonList("qqq"), ","));
    assertEquals("", StringUtil.join(Collections.singletonList(null), ","));
    assertEquals("a,b", StringUtil.join(Arrays.asList("a", "b"), ","));
    assertEquals("foo,,bar", StringUtil.join(Arrays.asList("foo", "", "bar"), ","));
    assertEquals("foo,,bar", StringUtil.join(new String[]{"foo", "", "bar"}, ","));
  }

  @Test
  public void testSplitByLineKeepingSeparators() {
    assertEquals(Collections.singletonList(""), Arrays.asList(StringUtil.splitByLinesKeepSeparators("")));
    assertEquals(Collections.singletonList("aa"), Arrays.asList(StringUtil.splitByLinesKeepSeparators("aa")));
    assertEquals(Arrays.asList("\n", "\n", "aa\n", "\n", "bb\n", "cc\n", "\n"),
                 Arrays.asList(StringUtil.splitByLinesKeepSeparators("\n\naa\n\nbb\ncc\n\n")));

    assertEquals(Arrays.asList("\r", "\r\n", "\r"), Arrays.asList(StringUtil.splitByLinesKeepSeparators("\r\r\n\r")));
    assertEquals(Arrays.asList("\r\n", "\r", "\r\n"), Arrays.asList(StringUtil.splitByLinesKeepSeparators("\r\n\r\r\n")));

    assertEquals(Arrays.asList("\n", "\r\n", "\n", "\r\n", "\r", "\r", "aa\r", "bb\r\n", "cc\n", "\r", "dd\n", "\n", "\r\n", "\r"),
                 Arrays.asList(StringUtil.splitByLinesKeepSeparators("\n\r\n\n\r\n\r\raa\rbb\r\ncc\n\rdd\n\n\r\n\r")));
  }

  @Test
  public void testReplaceReturnReplacementIfTextEqualsToReplacedText() {
    String newS = "/tmp";
    assertSame(newS,
               StringUtil.replace("$PROJECT_FILE$", "$PROJECT_FILE$".toLowerCase().toUpperCase() /* ensure new String instance */, newS));
  }

  @Test
  public void testReplace() {
    assertEquals("/tmp/filename", StringUtil.replace("$PROJECT_FILE$/filename", "$PROJECT_FILE$", "/tmp"));
  }

  @Test
  public void testEqualsIgnoreWhitespaces() {
    assertTrue(StringUtil.equalsIgnoreWhitespaces(null, null));
    assertFalse(StringUtil.equalsIgnoreWhitespaces("", null));

    assertTrue(StringUtil.equalsIgnoreWhitespaces("", ""));
    assertTrue(StringUtil.equalsIgnoreWhitespaces("\n\t ", ""));
    assertTrue(StringUtil.equalsIgnoreWhitespaces("", "\t\n \n\t"));
    assertTrue(StringUtil.equalsIgnoreWhitespaces("\t", "\n"));

    assertTrue(StringUtil.equalsIgnoreWhitespaces("x", " x"));
    assertTrue(StringUtil.equalsIgnoreWhitespaces("x", "x "));
    assertTrue(StringUtil.equalsIgnoreWhitespaces("x\n", "x"));

    assertTrue(StringUtil.equalsIgnoreWhitespaces("abc", "a\nb\nc\n"));
    assertTrue(StringUtil.equalsIgnoreWhitespaces("x y x", "x y x"));
    assertTrue(StringUtil.equalsIgnoreWhitespaces("xyx", "x y x"));

    assertFalse(StringUtil.equalsIgnoreWhitespaces("x", "\t\n "));
    assertFalse(StringUtil.equalsIgnoreWhitespaces("", " x "));
    assertFalse(StringUtil.equalsIgnoreWhitespaces("", "x "));
    assertFalse(StringUtil.equalsIgnoreWhitespaces("", " x"));
    assertFalse(StringUtil.equalsIgnoreWhitespaces("xyx", "xxx"));
    assertFalse(StringUtil.equalsIgnoreWhitespaces("xyx", "xYx"));
  }

  @Test
  public void testStringHashCodeIgnoreWhitespaces() {
    assertTrue(Comparing.equal(StringUtil.stringHashCodeIgnoreWhitespaces(""), StringUtil.stringHashCodeIgnoreWhitespaces("")));
    assertTrue(Comparing.equal(StringUtil.stringHashCodeIgnoreWhitespaces("\n\t "), StringUtil.stringHashCodeIgnoreWhitespaces("")));
    assertTrue(Comparing.equal(StringUtil.stringHashCodeIgnoreWhitespaces(""), StringUtil.stringHashCodeIgnoreWhitespaces("\t\n \n\t")));
    assertTrue(Comparing.equal(StringUtil.stringHashCodeIgnoreWhitespaces("\t"), StringUtil.stringHashCodeIgnoreWhitespaces("\n")));

    assertTrue(Comparing.equal(StringUtil.stringHashCodeIgnoreWhitespaces("x"), StringUtil.stringHashCodeIgnoreWhitespaces(" x")));
    assertTrue(Comparing.equal(StringUtil.stringHashCodeIgnoreWhitespaces("x"), StringUtil.stringHashCodeIgnoreWhitespaces("x ")));
    assertTrue(Comparing.equal(StringUtil.stringHashCodeIgnoreWhitespaces("x\n"), StringUtil.stringHashCodeIgnoreWhitespaces("x")));

    assertTrue(Comparing.equal(StringUtil.stringHashCodeIgnoreWhitespaces("abc"), StringUtil.stringHashCodeIgnoreWhitespaces("a\nb\nc\n")));
    assertTrue(Comparing.equal(StringUtil.stringHashCodeIgnoreWhitespaces("x y x"), StringUtil.stringHashCodeIgnoreWhitespaces("x y x")));
    assertTrue(Comparing.equal(StringUtil.stringHashCodeIgnoreWhitespaces("xyx"), StringUtil.stringHashCodeIgnoreWhitespaces("x y x")));

    assertFalse(Comparing.equal(StringUtil.stringHashCodeIgnoreWhitespaces("x"), StringUtil.stringHashCodeIgnoreWhitespaces("\t\n ")));
    assertFalse(Comparing.equal(StringUtil.stringHashCodeIgnoreWhitespaces(""), StringUtil.stringHashCodeIgnoreWhitespaces(" x ")));
    assertFalse(Comparing.equal(StringUtil.stringHashCodeIgnoreWhitespaces(""), StringUtil.stringHashCodeIgnoreWhitespaces("x ")));
    assertFalse(Comparing.equal(StringUtil.stringHashCodeIgnoreWhitespaces(""), StringUtil.stringHashCodeIgnoreWhitespaces(" x")));
    assertFalse(Comparing.equal(StringUtil.stringHashCodeIgnoreWhitespaces("xyx"), StringUtil.stringHashCodeIgnoreWhitespaces("xxx")));
    assertFalse(Comparing.equal(StringUtil.stringHashCodeIgnoreWhitespaces("xyx"), StringUtil.stringHashCodeIgnoreWhitespaces("xYx")));
  }

  @Test
  public void testContains() {
    assertTrue(StringUtil.contains("1", "1"));
    assertFalse(StringUtil.contains("1", "12"));
    assertTrue(StringUtil.contains("12", "1"));
    assertTrue(StringUtil.contains("12", "2"));
  }

  @Test
  public void testDetectSeparators() {
    assertEquals(null, StringUtil.detectSeparators(""));
    assertEquals(null, StringUtil.detectSeparators("asd"));
    assertEquals(null, StringUtil.detectSeparators("asd\t"));

    assertEquals(LineSeparator.LF, StringUtil.detectSeparators("asd\n"));
    assertEquals(LineSeparator.LF, StringUtil.detectSeparators("asd\nads\r"));
    assertEquals(LineSeparator.LF, StringUtil.detectSeparators("asd\nads\n"));

    assertEquals(LineSeparator.CR, StringUtil.detectSeparators("asd\r"));
    assertEquals(LineSeparator.CR, StringUtil.detectSeparators("asd\rads\r"));
    assertEquals(LineSeparator.CR, StringUtil.detectSeparators("asd\rads\n"));

    assertEquals(LineSeparator.CRLF, StringUtil.detectSeparators("asd\r\n"));
    assertEquals(LineSeparator.CRLF, StringUtil.detectSeparators("asd\r\nads\r"));
    assertEquals(LineSeparator.CRLF, StringUtil.detectSeparators("asd\r\nads\n"));
  }

  @Test
  public void testFindStartingLineSeparator() {
    assertEquals(null, StringUtil.getLineSeparatorAt("", -1));
    assertEquals(null, StringUtil.getLineSeparatorAt("", 0));
    assertEquals(null, StringUtil.getLineSeparatorAt("", 1));
    assertEquals(null, StringUtil.getLineSeparatorAt("\nHello", -1));
    assertEquals(null, StringUtil.getLineSeparatorAt("\nHello", 1));
    assertEquals(null, StringUtil.getLineSeparatorAt("\nH\rel\nlo", 6));

    assertEquals(LineSeparator.LF, StringUtil.getLineSeparatorAt("\nHello", 0));
    assertEquals(LineSeparator.LF, StringUtil.getLineSeparatorAt("\nH\rel\nlo", 5));
    assertEquals(LineSeparator.LF, StringUtil.getLineSeparatorAt("Hello\n", 5));

    assertEquals(LineSeparator.CR, StringUtil.getLineSeparatorAt("\rH\r\nello", 0));
    assertEquals(LineSeparator.CR, StringUtil.getLineSeparatorAt("Hello\r", 5));
    assertEquals(LineSeparator.CR, StringUtil.getLineSeparatorAt("Hello\b\r", 6));

    assertEquals(LineSeparator.CRLF, StringUtil.getLineSeparatorAt("\rH\r\nello", 2));
    assertEquals(LineSeparator.CRLF, StringUtil.getLineSeparatorAt("\r\nH\r\nello", 0));
    assertEquals(LineSeparator.CRLF, StringUtil.getLineSeparatorAt("\r\nH\r\nello\r\n", 9));
  }

  @Test
  public void testFormatFileSize() {
    assertEquals("0B", StringUtil.formatFileSize(0));
    assertEquals("1B", StringUtil.formatFileSize(1));
    assertEquals("2.15G", StringUtil.formatFileSize(Integer.MAX_VALUE));
    assertEquals("9.22E", StringUtil.formatFileSize(Long.MAX_VALUE));

    assertEquals("60.10K", StringUtil.formatFileSize(60100));

    assertEquals("1.23K", StringUtil.formatFileSize(1234));
    assertEquals("12.35K", StringUtil.formatFileSize(12345));
    assertEquals("123.46K", StringUtil.formatFileSize(123456));
    assertEquals("1.23M", StringUtil.formatFileSize(1234567));
    assertEquals("12.35M", StringUtil.formatFileSize(12345678));
    assertEquals("123.46M", StringUtil.formatFileSize(123456789));
    assertEquals("1.23G", StringUtil.formatFileSize(1234567890));
  }

  @Test
  public void testFormatDuration() {
    assertEquals("0ms", StringUtil.formatDuration(0));
    assertEquals("1ms", StringUtil.formatDuration(1));
    assertEquals("3w 3d 20h 31m 23s 647ms", StringUtil.formatDuration(Integer.MAX_VALUE));
    assertEquals("31ep 7714ml 2c 59yr 5mo 0w 3d 7h 12m 55s 807ms", StringUtil.formatDuration(Long.MAX_VALUE));

    assertEquals("1m 0s 100ms", StringUtil.formatDuration(60100));

    assertEquals("1s 234ms", StringUtil.formatDuration(1234));
    assertEquals("12s 345ms", StringUtil.formatDuration(12345));
    assertEquals("2m 3s 456ms", StringUtil.formatDuration(123456));
    assertEquals("20m 34s 567ms", StringUtil.formatDuration(1234567));
    assertEquals("3h 25m 45s 678ms", StringUtil.formatDuration(12345678));
    assertEquals("1d 10h 17m 36s 789ms", StringUtil.formatDuration(123456789));
    assertEquals("2w 0d 6h 56m 7s 890ms", StringUtil.formatDuration(1234567890));
  }

  @Test
  public void testXmlWrapInCDATA() {
    assertEquals("<![CDATA[abc]]>", XmlStringUtil.wrapInCDATA("abc"));
    assertEquals("<![CDATA[abc]]]><![CDATA[]>]]>", XmlStringUtil.wrapInCDATA("abc]]>"));
    assertEquals("<![CDATA[abc]]]><![CDATA[]>def]]>", XmlStringUtil.wrapInCDATA("abc]]>def"));
    assertEquals("<![CDATA[123<![CDATA[wow<&>]]]><![CDATA[]>]]]><![CDATA[]><![CDATA[123]]>", XmlStringUtil.wrapInCDATA("123<![CDATA[wow<&>]]>]]><![CDATA[123"));
  }

  @Test
  public void testGetPackageName() {
    assertEquals("java.lang", StringUtil.getPackageName("java.lang.String"));
    assertEquals("java.util.Map", StringUtil.getPackageName("java.util.Map.Entry"));
    assertEquals("Map", StringUtil.getPackageName("Map.Entry"));
    assertEquals("", StringUtil.getPackageName("Number"));
  }

  @SuppressWarnings("SpellCheckingInspection")
  @Test
  public void testIndexOf_1() {
    char[] chars = new char[]{'a','b','c','d','a','b','c','d','A','B','C','D'};
    assertEquals(2, StringUtil.indexOf(chars, 'c', 0, 12, false));
    assertEquals(2, StringUtil.indexOf(chars, 'C', 0, 12, false));
    assertEquals(10, StringUtil.indexOf(chars, 'C', 0, 12, true));
    assertEquals(2, StringUtil.indexOf(chars, 'c', -42, 99, false));
  }

  @SuppressWarnings("SpellCheckingInspection")
  @Test
  public void testIndexOf_2() {
    assertEquals(1, StringUtil.indexOf("axaxa", 'x', 0, 5));
    assertEquals(2, StringUtil.indexOf("abcd", 'c', -42, 99));
  }

  @SuppressWarnings("SpellCheckingInspection")
  @Test
  public void testIndexOf_3() {
    assertEquals(1, StringUtil.indexOf("axaXa", 'x', 0, 5, false));
    assertEquals(3, StringUtil.indexOf("axaXa", 'X', 0, 5, true));
    assertEquals(2, StringUtil.indexOf("abcd", 'c', -42, 99, false));
  }

  @SuppressWarnings("SpellCheckingInspection")
  @Test
  public void testIndexOfAny() {
    assertEquals(1, StringUtil.indexOfAny("axa", "x", 0, 5));
    assertEquals(1, StringUtil.indexOfAny("axa", "zx", 0, 5));
    assertEquals(2, StringUtil.indexOfAny("abcd", "c", -42, 99));
  }

  @SuppressWarnings("SpellCheckingInspection")
  @Test
  public void testLastIndexOf() {
    assertEquals(1, StringUtil.lastIndexOf("axaxa", 'x', 0, 2));
    assertEquals(1, StringUtil.lastIndexOf("axaxa", 'x', 0, 3));
    assertEquals(3, StringUtil.lastIndexOf("axaxa", 'x', 0, 5));
    assertEquals(2, StringUtil.lastIndexOf("abcd", 'c', -42, 99));  // #IDEA-144968
  }

  @Test
  public void testEscapingIllegalXmlChars() {
    for (String s : new String[]{"ab\n\0\r\tde", "\\abc\1\2\3\uFFFFdef"}) {
      String escapedText = XmlStringUtil.escapeIllegalXmlChars(s);
      assertNull(Verifier.checkCharacterData(escapedText));
      assertEquals(s, XmlStringUtil.unescapeIllegalXmlChars(escapedText));
    }
  }

  @Test
  public void testCountChars() {
    assertEquals(0, StringUtil.countChars("abcdefgh", 'x'));
    assertEquals(1, StringUtil.countChars("abcdefgh", 'd'));
    assertEquals(5, StringUtil.countChars("abcddddefghd", 'd'));
    assertEquals(4, StringUtil.countChars("abcddddefghd", 'd', 4, false));
    assertEquals(3, StringUtil.countChars("abcddddefghd", 'd', 4, true));
    assertEquals(2, StringUtil.countChars("abcddddefghd", 'd', 4, 6, false));
  }
}