feat(string): add snakeCase, startCase, lowerCase, kebabCase in compat layer (#517)

* Add cases function

* Add benchmarks and re-export in index.ts

* Revert

benchmarks/performance/kebabCase.bench.ts

@@ -1,15 +1,30 @@
 import { bench, describe } from 'vitest';
 import { kebabCase as kebabCaseToolkit } from 'es-toolkit';
+import { kebabCase as kebabCaseToolkitCompat } from 'es-toolkit/compat';
 import { kebabCase as kebabCaseLodash } from 'lodash';
 
 describe('kebabCase', () => {
   bench('es-toolkit/kebabCase', () => {
-    const str = 'camelCase';
-    kebabCaseToolkit(str);
+    kebabCaseToolkit('hello world');
+    kebabCaseToolkit('--foo--bar__baz 123');
+    kebabCaseToolkit('123numericValues');
+    kebabCaseToolkit('XMLHttpRequest');
+    kebabCaseToolkit('hello-World_of XML_httpRequest');
+  });
+
+  bench('es-toolkit/comapt/kebabCase', () => {
+    kebabCaseToolkitCompat('hello world');
+    kebabCaseToolkitCompat('--foo--bar__baz 123');
+    kebabCaseToolkitCompat('123numericValues');
+    kebabCaseToolkitCompat('XMLHttpRequest');
+    kebabCaseToolkitCompat('hello-World_of XML_httpRequest');
   });
 
   bench('lodash/kebabCase', () => {
-    const str = 'camelCase';
-    kebabCaseLodash(str);
+    kebabCaseLodash('hello world');
+    kebabCaseLodash('--foo--bar__baz 123');
+    kebabCaseLodash('123numericValues');
+    kebabCaseLodash('XMLHttpRequest');
+    kebabCaseLodash('hello-World_of XML_httpRequest');
   });
 });

benchmarks/performance/lowerCase.bench.ts

@@ -1,28 +1,36 @@
 import { bench, describe } from 'vitest';
 import { lowerCase as lowerCaseToolkit } from 'es-toolkit';
+import { lowerCase as lowerCaseToolkitCompat } from 'es-toolkit/compat';
 import { lowerCase as lowerCaseLodash } from 'lodash';
 
-describe('lowerCase', () => {
-  describe('short string', () => {
-    bench('es-toolkit/lowerCase', () => {
-      const str = 'camelCase';
-      lowerCaseToolkit(str);
-    });
-
-    bench('lodash/lowerCase', () => {
-      const str = 'camelCase';
-      lowerCaseLodash(str);
-    });
+describe('lowerCase - short string', () => {
+  bench('es-toolkit/lowerCase', () => {
+    const str = 'camelCase';
+    lowerCaseToolkit(str);
   });
 
-  describe('long string', () => {
-    const LONG_STR = 'camelCaseLongString'.repeat(1000);
-    bench('es-toolkit/lowerCase', () => {
-      lowerCaseToolkit(LONG_STR);
-    });
+  bench('es-toolkit/compat/lowerCase', () => {
+    const str = 'camelCase';
+    lowerCaseToolkitCompat(str);
+  });
 
-    bench('lodash/lowerCase', () => {
-      lowerCaseLodash(LONG_STR);
-    });
+  bench('lodash/lowerCase', () => {
+    const str = 'camelCase';
+    lowerCaseLodash(str);
+  });
+});
+
+describe('lowerCase - long string', () => {
+  const LONG_STR = 'camelCaseLongString'.repeat(1000);
+  bench('es-toolkit/lowerCase', () => {
+    lowerCaseToolkit(LONG_STR);
+  });
+
+  bench('es-toolkit/compat/lowerCase', () => {
+    lowerCaseToolkitCompat(LONG_STR);
+  });
+
+  bench('lodash/lowerCase', () => {
+    lowerCaseLodash(LONG_STR);
   });
 });

benchmarks/performance/snakeCase.bench.ts

@@ -1,15 +1,30 @@
 import { bench, describe } from 'vitest';
 import { snakeCase as snakeCaseToolkit } from 'es-toolkit';
+import { snakeCase as snakeCaseToolkitCompat } from 'es-toolkit/compat';
 import { snakeCase as snakeCaseLodash } from 'lodash';
 
 describe('snakeCase', () => {
   bench('es-toolkit/snakeCase', () => {
-    const str = 'camelCase';
-    snakeCaseToolkit(str);
+    snakeCaseToolkit('hello world');
+    snakeCaseToolkit('--foo--bar__baz 123');
+    snakeCaseToolkit('123numericValues');
+    snakeCaseToolkit('XMLHttpRequest');
+    snakeCaseToolkit('hello-World_of XML_httpRequest');
+  });
+
+  bench('es-toolkit/comapt/snakeCase', () => {
+    snakeCaseToolkitCompat('hello world');
+    snakeCaseToolkitCompat('--foo--bar__baz 123');
+    snakeCaseToolkitCompat('123numericValues');
+    snakeCaseToolkitCompat('XMLHttpRequest');
+    snakeCaseToolkitCompat('hello-World_of XML_httpRequest');
   });
 
   bench('lodash/snakeCase', () => {
-    const str = 'camelCase';
-    snakeCaseLodash(str);
+    snakeCaseLodash('hello world');
+    snakeCaseLodash('--foo--bar__baz 123');
+    snakeCaseLodash('123numericValues');
+    snakeCaseLodash('XMLHttpRequest');
+    snakeCaseLodash('hello-World_of XML_httpRequest');
   });
 });

benchmarks/performance/startCase.bench.ts

@@ -1,4 +1,5 @@
 import { startCase as startCaseToolkit } from 'es-toolkit';
+import { startCase as startCaseToolkitCompat } from 'es-toolkit/compat';
 import { startCase as startCaseLodash } from 'lodash';
 import { bench, describe } from 'vitest';
 
@@ -11,6 +12,14 @@ describe('startCase', () => {
     startCaseToolkit('hello-World_of XML_httpRequest');
   });
 
+  bench('es-toolkit/comapt/startCase', () => {
+    startCaseToolkitCompat('hello world');
+    startCaseToolkitCompat('--foo--bar__baz 123');
+    startCaseToolkitCompat('123numericValues');
+    startCaseToolkitCompat('XMLHttpRequest');
+    startCaseToolkitCompat('hello-World_of XML_httpRequest');
+  });
+
   bench('lodash/startCase', () => {
     startCaseLodash('hello world');
     startCaseLodash('--foo--bar__baz 123');

src/compat/index.ts

@@ -83,6 +83,10 @@ export { conforms } from './predicate/conforms.ts';
 export { conformsTo } from './predicate/conformsTo.ts';
 
 export { camelCase } from './string/camelCase.ts';
+export { kebabCase } from './string/kebabCase.ts';
+export { snakeCase } from './string/snakeCase.ts';
+export { startCase } from './string/startCase.ts';
+export { lowerCase } from './string/lowerCase.ts';
 export { startsWith } from './string/startsWith.ts';
 export { endsWith } from './string/endsWith.ts';
 export { padStart } from './string/padStart.ts';

src/compat/string/kebabCase.spec.ts

@@ -0,0 +1,45 @@
+import { describe, it, expect } from 'vitest';
+import { kebabCase } from './kebabCase';
+
+describe('kebabCase', () => {
+  const strings = ['foo bar', 'Foo bar', 'foo Bar', 'Foo Bar', 'FOO BAR', 'fooBar', '--foo-bar--', '__foo_bar__'];
+
+  it(`should convert \`string\``, () => {
+    const actual = strings.map(string => kebabCase(string));
+
+    const expected = actual.map(() => 'foo-bar');
+
+    expect(actual).toEqual(expected);
+  });
+
+  it(`should handle double-converting strings`, () => {
+    const actual = strings.map(string => kebabCase(kebabCase(string)));
+
+    const expected = actual.map(() => 'foo-bar');
+
+    expect(actual).toEqual(expected);
+  });
+
+  it(`should remove contraction apostrophes`, () => {
+    const postfixes = ['d', 'll', 'm', 're', 's', 't', 've'];
+
+    ["'", '\u2019'].forEach(apos => {
+      const actual = postfixes.map(postfix => kebabCase(`a b${apos}${postfix} c`));
+
+      const expected = postfixes.map(postfix => `a-b${postfix}-c`);
+
+      expect(actual).toEqual(expected);
+    });
+  });
+
+  it(`should remove Latin mathematical operators`, () => {
+    const actual = ['\xd7', '\xf7'].map(kebabCase);
+    expect(actual).toEqual(['', '']);
+  });
+
+  it(`should coerce \`string\` to a string`, () => {
+    const string = 'foo bar';
+    expect(kebabCase(Object(string))).toBe('foo-bar');
+    expect(kebabCase({ toString: () => string })).toBe('foo-bar');
+  });
+});

src/compat/string/kebabCase.ts

@@ -0,0 +1,20 @@
+import { kebabCase as kebabCaseToolkit } from '../../string';
+import { normalizeForCase } from '../_internal/normalizeForCase';
+
+/**
+ * Converts a string to kebab case.
+ *
+ * Kebab case is the naming convention in which each word is written in lowercase and separated by a dash (-) character.
+ *
+ * @param {string} str - The string that is to be changed to kebab case.
+ * @returns {string} - The converted string to kebab case.
+ *
+ * @example
+ * const convertedStr1 = kebabCase('camelCase') // returns 'camel-case'
+ * const convertedStr2 = kebabCase('some whitespace') // returns 'some-whitespace'
+ * const convertedStr3 = kebabCase('hyphen-text') // returns 'hyphen-text'
+ * const convertedStr4 = kebabCase('HTTPRequest') // returns 'http-request'
+ */
+export function kebabCase(str: string | object): string {
+  return kebabCaseToolkit(normalizeForCase(str));
+}

src/compat/string/lowerCase.spec.ts

@@ -0,0 +1,45 @@
+import { describe, it, expect } from 'vitest';
+import { lowerCase } from './lowerCase';
+
+describe('lowerCase', () => {
+  const strings = ['foo bar', 'Foo bar', 'foo Bar', 'Foo Bar', 'FOO BAR', 'fooBar', '--foo-bar--', '__foo_bar__'];
+
+  it(`should convert \`string\``, () => {
+    const actual = strings.map(string => lowerCase(string));
+
+    const expected = actual.map(() => 'foo bar');
+
+    expect(actual).toEqual(expected);
+  });
+
+  it(`should handle double-converting strings`, () => {
+    const actual = strings.map(string => lowerCase(lowerCase(string)));
+
+    const expected = actual.map(() => 'foo bar');
+
+    expect(actual).toEqual(expected);
+  });
+
+  it(`should remove contraction apostrophes`, () => {
+    const postfixes = ['d', 'll', 'm', 're', 's', 't', 've'];
+
+    ["'", '\u2019'].forEach(apos => {
+      const actual = postfixes.map(postfix => lowerCase(`a b${apos}${postfix} c`));
+
+      const expected = postfixes.map(postfix => `a b${postfix} c`);
+
+      expect(actual).toEqual(expected);
+    });
+  });
+
+  it(`should remove Latin mathematical operators`, () => {
+    const actual = ['\xd7', '\xf7'].map(lowerCase);
+    expect(actual).toEqual(['', '']);
+  });
+
+  it(`should coerce \`string\` to a string`, () => {
+    const string = 'foo bar';
+    expect(lowerCase(Object(string))).toBe('foo bar');
+    expect(lowerCase({ toString: () => string })).toBe('foo bar');
+  });
+});

src/compat/string/lowerCase.ts

@@ -0,0 +1,20 @@
+import { lowerCase as lowerCaseToolkit } from '../../string/lowerCase';
+import { normalizeForCase } from '../_internal/normalizeForCase';
+
+/**
+ * Converts a string to lower case.
+ *
+ * Lower case is the naming convention in which each word is written in lowercase and separated by an space ( ) character.
+ *
+ * @param {string} str - The string that is to be changed to lower case.
+ * @returns {string} - The converted string to lower case.
+ *
+ * @example
+ * const convertedStr1 = lowerCase('camelCase') // returns 'camel case'
+ * const convertedStr2 = lowerCase('some whitespace') // returns 'some whitespace'
+ * const convertedStr3 = lowerCase('hyphen-text') // returns 'hyphen text'
+ * const convertedStr4 = lowerCase('HTTPRequest') // returns 'http request'
+ */
+export function lowerCase(str: string | object): string {
+  return lowerCaseToolkit(normalizeForCase(str));
+}

src/compat/string/snakeCase.spec.ts

@@ -0,0 +1,45 @@
+import { describe, it, expect } from 'vitest';
+import { snakeCase } from './snakeCase';
+
+describe('snakeCase', () => {
+  const strings = ['foo bar', 'Foo bar', 'foo Bar', 'Foo Bar', 'FOO BAR', 'fooBar', '--foo-bar--', '__foo_bar__'];
+
+  it(`should convert \`string\``, () => {
+    const actual = strings.map(string => snakeCase(string));
+
+    const expected = actual.map(() => 'foo_bar');
+
+    expect(actual).toEqual(expected);
+  });
+
+  it(`should handle double-converting strings`, () => {
+    const actual = strings.map(string => snakeCase(snakeCase(string)));
+
+    const expected = actual.map(() => 'foo_bar');
+
+    expect(actual).toEqual(expected);
+  });
+
+  it(`should remove contraction apostrophes`, () => {
+    const postfixes = ['d', 'll', 'm', 're', 's', 't', 've'];
+
+    ["'", '\u2019'].forEach(apos => {
+      const actual = postfixes.map(postfix => snakeCase(`a b${apos}${postfix} c`));
+
+      const expected = postfixes.map(postfix => `a_b${postfix}_c`);
+
+      expect(actual).toEqual(expected);
+    });
+  });
+
+  it(`should remove Latin mathematical operators`, () => {
+    const actual = ['\xd7', '\xf7'].map(snakeCase);
+    expect(actual).toEqual(['', '']);
+  });
+
+  it(`should coerce \`string\` to a string`, () => {
+    const string = 'foo bar';
+    expect(snakeCase(Object(string))).toBe('foo_bar');
+    expect(snakeCase({ toString: () => string })).toBe('foo_bar');
+  });
+});

src/compat/string/snakeCase.ts

@@ -0,0 +1,20 @@
+import { snakeCase as snakeCaseToolkit } from '../../string/snakeCase';
+import { normalizeForCase } from '../_internal/normalizeForCase';
+
+/**
+ * Converts a string to snake case.
+ *
+ * Snake case is the naming convention in which each word is written in lowercase and separated by an underscore (_) character.
+ *
+ * @param {string} str - The string that is to be changed to snake case.
+ * @returns {string} - The converted string to snake case.
+ *
+ * @example
+ * const convertedStr1 = snakeCase('camelCase') // returns 'camel_case'
+ * const convertedStr2 = snakeCase('some whitespace') // returns 'some_whitespace'
+ * const convertedStr3 = snakeCase('hyphen-text') // returns 'hyphen_text'
+ * const convertedStr4 = snakeCase('HTTPRequest') // returns 'http_request'
+ */
+export function snakeCase(str: string | object): string {
+  return snakeCaseToolkit(normalizeForCase(str));
+}

src/compat/string/startCase.spec.ts

@@ -0,0 +1,45 @@
+import { describe, it, expect } from 'vitest';
+import { startCase } from './startCase';
+
+describe('case methods', () => {
+  const strings = ['foo bar', 'Foo bar', 'foo Bar', 'Foo Bar', 'FOO BAR', 'fooBar', '--foo-bar--', '__foo_bar__'];
+
+  it(`should convert \`string\``, () => {
+    const actual = strings.map(string => startCase(string));
+
+    const expected = actual.map(string => (string === 'FOO BAR' ? 'FOO BAR' : 'Foo Bar'));
+
+    expect(actual).toEqual(expected);
+  });
+
+  it(`should handle double-converting strings`, () => {
+    const actual = strings.map(string => startCase(startCase(string)));
+
+    const expected = actual.map(string => (string === 'FOO BAR' ? 'FOO BAR' : 'Foo Bar'));
+
+    expect(actual).toEqual(expected);
+  });
+
+  it(`should remove contraction apostrophes`, () => {
+    const postfixes = ['d', 'll', 'm', 're', 's', 't', 've'];
+
+    ["'", '\u2019'].forEach(apos => {
+      const actual = postfixes.map(postfix => startCase(`a b${apos}${postfix} c`));
+
+      const expected = postfixes.map(postfix => `A B${postfix} C`);
+
+      expect(actual).toEqual(expected);
+    });
+  });
+
+  it(`should remove Latin mathematical operators`, () => {
+    const actual = ['\xd7', '\xf7'].map(startCase);
+    expect(actual).toEqual(['', '']);
+  });
+
+  it(`should coerce \`string\` to a string`, () => {
+    const string = 'foo bar';
+    expect(startCase(Object(string))).toBe('Foo Bar');
+    expect(startCase({ toString: () => string })).toBe('Foo Bar');
+  });
+});

src/compat/string/startCase.ts

@@ -0,0 +1,19 @@
+import { startCase as startCaseToolkit } from '../../string/startCase';
+import { normalizeForCase } from '../_internal/normalizeForCase';
+
+/**
+ * Converts the first character of each word in a string to uppercase and the remaining characters to lowercase.
+ *
+ * Start case is the naming convention in which each word is written with an initial capital letter.
+ * @param {string} str - The string to convert.
+ * @returns {string} The converted string.
+ *
+ * @example
+ * const result1 = startCase('hello world');  // result will be 'Hello World'
+ * const result2 = startCase('HELLO WORLD');  // result will be 'HELLO WORLD'
+ * const result3 = startCase('hello-world');  // result will be 'Hello World'
+ * const result4 = startCase('hello_world');  // result will be 'Hello World'
+ */
+export function startCase(str: string | object): string {
+  return startCaseToolkit(normalizeForCase(str));
+}

src/string/startCase.ts

@@ -9,7 +9,7 @@ import { getWords } from './_internal/getWords.ts';
  *
  * @example
  * const result1 = startCase('hello world');  // result will be 'Hello World'
- * const result2 = startCase('HELLO WORLD');  // result will be 'Hello World'
+ * const result2 = startCase('HELLO WORLD');  // result will be 'HELLO WORLD'
  * const result3 = startCase('hello-world');  // result will be 'Hello World'
  * const result4 = startCase('hello_world');  // result will be 'Hello World'
  */