text: const textUtils = require('../src/text-utils')
  
  describe('text utilities', () => {
    describe('.hasPairedCharacter(string)', () =>
      it('returns true when the string contains a surrogate pair, variation sequence, or combined character', () => {
        expect(textUtils.hasPairedCharacter('abc')).toBe(false)
        expect(textUtils.hasPairedCharacter('a\uD835\uDF97b\uD835\uDF97c')).toBe(true)
        expect(textUtils.hasPairedCharacter('\uD835\uDF97')).toBe(true)
        expect(textUtils.hasPairedCharacter('\u2714\uFE0E')).toBe(true)
        expect(textUtils.hasPairedCharacter('e\u0301')).toBe(true)
  
        expect(textUtils.hasPairedCharacter('\uD835')).toBe(false)
        expect(textUtils.hasPairedCharacter('\uDF97')).toBe(false)
        expect(textUtils.hasPairedCharacter('\uFE0E')).toBe(false)
        expect(textUtils.hasPairedCharacter('\u0301')).toBe(false)
  
        expect(textUtils.hasPairedCharacter('\uFE0E\uFE0E')).toBe(false)
        expect(textUtils.hasPairedCharacter('\u0301\u0301')).toBe(false)
      })
    )
  
    describe('.isPairedCharacter(string, index)', () =>
      it('returns true when the index is the start of a high/low surrogate pair, variation sequence, or combined character', () => {
        expect(textUtils.isPairedCharacter('a\uD835\uDF97b\uD835\uDF97c', 0)).toBe(false)
        expect(textUtils.isPairedCharacter('a\uD835\uDF97b\uD835\uDF97c', 1)).toBe(true)
        expect(textUtils.isPairedCharacter('a\uD835\uDF97b\uD835\uDF97c', 2)).toBe(false)
        expect(textUtils.isPairedCharacter('a\uD835\uDF97b\uD835\uDF97c', 3)).toBe(false)
        expect(textUtils.isPairedCharacter('a\uD835\uDF97b\uD835\uDF97c', 4)).toBe(true)
        expect(textUtils.isPairedCharacter('a\uD835\uDF97b\uD835\uDF97c', 5)).toBe(false)
        expect(textUtils.isPairedCharacter('a\uD835\uDF97b\uD835\uDF97c', 6)).toBe(false)
  
        expect(textUtils.isPairedCharacter('a\u2714\uFE0E', 0)).toBe(false)
        expect(textUtils.isPairedCharacter('a\u2714\uFE0E', 1)).toBe(true)
        expect(textUtils.isPairedCharacter('a\u2714\uFE0E', 2)).toBe(false)
        expect(textUtils.isPairedCharacter('a\u2714\uFE0E', 3)).toBe(false)
  
        expect(textUtils.isPairedCharacter('\uD835')).toBe(false)
        expect(textUtils.isPairedCharacter('\uDF97')).toBe(false)
        expect(textUtils.isPairedCharacter('\uFE0E')).toBe(false)
        expect(textUtils.isPairedCharacter('\uFE0E')).toBe(false)
  
        expect(textUtils.isPairedCharacter('\uFE0E\uFE0E')).toBe(false)
  
        expect(textUtils.isPairedCharacter('ae\u0301c', 0)).toBe(false)
        expect(textUtils.isPairedCharacter('ae\u0301c', 1)).toBe(true)
        expect(textUtils.isPairedCharacter('ae\u0301c', 2)).toBe(false)
        expect(textUtils.isPairedCharacter('ae\u0301c', 3)).toBe(false)
        expect(textUtils.isPairedCharacter('ae\u0301c', 4)).toBe(false)
      })
    )
  
    describe('.isDoubleWidthCharacter(character)', () =>
      it('returns true when the character is either japanese, chinese or a full width form', () => {
        expect(textUtils.isDoubleWidthCharacter('我')).toBe(true)
  
        expect(textUtils.isDoubleWidthCharacter('私')).toBe(true)
  
        expect(textUtils.isDoubleWidthCharacter('Ｂ')).toBe(true)
        expect(textUtils.isDoubleWidthCharacter('，')).toBe(true)
        expect(textUtils.isDoubleWidthCharacter('￠')).toBe(true)
  
        expect(textUtils.isDoubleWidthCharacter('a')).toBe(false)
      })
    )
  
    describe('.isHalfWidthCharacter(character)', () =>
      it('returns true when the character is an half width form', () => {
        expect(textUtils.isHalfWidthCharacter('ﾊ')).toBe(true)
        expect(textUtils.isHalfWidthCharacter('ﾋ')).toBe(true)
        expect(textUtils.isHalfWidthCharacter('ﾬ')).toBe(true)
        expect(textUtils.isHalfWidthCharacter('￭')).toBe(true)
  
        expect(textUtils.isHalfWidthCharacter('B')).toBe(false)
      })
    )
  
    describe('.isKoreanCharacter(character)', () =>
      it('returns true when the character is a korean character', () => {
        expect(textUtils.isKoreanCharacter('우')).toBe(true)
        expect(textUtils.isKoreanCharacter('가')).toBe(true)
        expect(textUtils.isKoreanCharacter('ㅢ')).toBe(true)
        expect(textUtils.isKoreanCharacter('ㄼ')).toBe(true)
  
        expect(textUtils.isKoreanCharacter('O')).toBe(false)
      })
    )
  
    describe('.isWrapBoundary(previousCharacter, character)', () =>
      it('returns true when the character is CJK or when the previous character is a space/tab', () => {
        const anyCharacter = 'x'
        expect(textUtils.isWrapBoundary(anyCharacter, '我')).toBe(true)
        expect(textUtils.isWrapBoundary(anyCharacter, '私')).toBe(true)
        expect(textUtils.isWrapBoundary(anyCharacter, 'Ｂ')).toBe(true)
        expect(textUtils.isWrapBoundary(anyCharacter, '，')).toBe(true)
        expect(textUtils.isWrapBoundary(anyCharacter, '￠')).toBe(true)
        expect(textUtils.isWrapBoundary(anyCharacter, 'ﾊ')).toBe(true)
        expect(textUtils.isWrapBoundary(anyCharacter, 'ﾋ')).toBe(true)
        expect(textUtils.isWrapBoundary(anyCharacter, 'ﾬ')).toBe(true)
        expect(textUtils.isWrapBoundary(anyCharacter, '￭')).toBe(true)
        expect(textUtils.isWrapBoundary(anyCharacter, '우')).toBe(true)
        expect(textUtils.isWrapBoundary(anyCharacter, '가')).toBe(true)
        expect(textUtils.isWrapBoundary(anyCharacter, 'ㅢ')).toBe(true)
        expect(textUtils.isWrapBoundary(anyCharacter, 'ㄼ')).toBe(true)
  
        expect(textUtils.isWrapBoundary(' ', 'h')).toBe(true)
        expect(textUtils.isWrapBoundary('\t', 'h')).toBe(true)
        expect(textUtils.isWrapBoundary('a', 'h')).toBe(false)
      })
    )
  })
  