String case conversion in TypeScript

string-case-conversion.ts

const CONVERT_CASE_REGEXP = /[A-Z]{2,}(?=[A-Z][a-z]+[0-9]*|\b)|[A-Z]?[a-z]+[0-9]*|[A-Z]|[0-9]+/g

export class StrCaseConversion {
  static toCamelCase(str: string): string {
    const result = str.match(CONVERT_CASE_REGEXP)
    if (result) {
      const s = result.map(x => x.slice(0, 1).toUpperCase() + x.slice(1).toLowerCase()).join('')
      return s.slice(0, 1).toLowerCase() + s.slice(1)
    }

    return str
  }

  static toPascalCase(str: string): string {
    const result = str.match(CONVERT_CASE_REGEXP)
    if (result) {
      return result.map(x => x.slice(0, 1).toUpperCase() + x.slice(1).toLowerCase()).join('')
    }

    return str
  }

  static toKebabCase(str: string): string {
    const result = str.match(CONVERT_CASE_REGEXP)
    if (result) {
      return result.map(x => x.toLowerCase()).join('-')
    }

    return str
  }

  static toSnakeCase(str: string): string {
    const result = str.match(CONVERT_CASE_REGEXP)
    if (result) {
      return result.map(x => x.toLowerCase()).join('_')
    }

    return str
  }

  static toTitleCase(str: string): string {
    const result = str.match(CONVERT_CASE_REGEXP)
    if (result) {
      return result.map(x => x.slice(0, 1).toUpperCase() + x.slice(1)).join(' ')
    }

    return str
  }

  static toSentenceCase(str: string): string {
    const result = str.match(CONVERT_CASE_REGEXP)
    if (result) {
      const s = result.join(' ')
      return s.slice(0, 1).toUpperCase() + s.slice(1)
    }

    return str
  }
}

// Examples
console.log('TO CAMEL')
console.log(StrCaseConversion.toCamelCase('some_database_field_name'))
console.log(StrCaseConversion.toCamelCase('Some label that needs to be camelized'))
console.log(StrCaseConversion.toCamelCase('some-javascript-property'))
console.log(StrCaseConversion.toCamelCase('some-mixed_string with spaces_underscores-and-hyphens'))
console.log('\n')

console.log('TO PASCAL')
console.log(StrCaseConversion.toPascalCase('some_database_field_name'))
console.log(StrCaseConversion.toPascalCase('Some label that needs to be pascalized'))
console.log(StrCaseConversion.toPascalCase('some-javascript-property'))
console.log(StrCaseConversion.toPascalCase('some-mixed_string with spaces_underscores-and-hyphens'))
console.log('\n')

console.log('TO KEBAB')
console.log(StrCaseConversion.toKebabCase('camelCase'))
console.log(StrCaseConversion.toKebabCase('some text'))
console.log(StrCaseConversion.toKebabCase('some-mixed_string With spaces_underscores-and-hyphens'))
console.log(StrCaseConversion.toKebabCase('AllThe-small Things'))
console.log(StrCaseConversion.toKebabCase('IAmEditingSomeXMLAndHTML'))
console.log('\n')

console.log('TO SNACK')
console.log(StrCaseConversion.toSnakeCase('camelCase'))
console.log(StrCaseConversion.toSnakeCase('some text'))
console.log(StrCaseConversion.toSnakeCase('some-mixed_string With spaces_underscores-and-hyphens'))
console.log(StrCaseConversion.toSnakeCase('AllThe-small Things'))
console.log(StrCaseConversion.toSnakeCase('IAmEditingSomeXMLAndHTML'))
console.log('\n')

console.log('TO TITLE')
console.log(StrCaseConversion.toTitleCase('some_database_field_name'))
console.log(StrCaseConversion.toTitleCase('Some label that needs to be title-cased'))
console.log(StrCaseConversion.toTitleCase('some-package-name'))
console.log(StrCaseConversion.toTitleCase('some-mixed_string with spaces_underscores-and-hyphens'))
console.log('\n')

console.log('TO SENTENCE')
console.log(StrCaseConversion.toSentenceCase('some_database_field_name'))
console.log(StrCaseConversion.toSentenceCase('Some label that needs to be title-cased'))
console.log(StrCaseConversion.toSentenceCase('some-package-name'))
console.log(StrCaseConversion.toSentenceCase('some-mixed_string with spaces_underscores-and-hyphens'))
console.log('\n')