Add case functions

Refs: metarhia/impress#1710

PR-URL: #98

Author: tshemsedinov

CHANGELOG.md

@@ -3,6 +3,7 @@
 ## [Unreleased][unreleased]
 
 - Add function `nowDateTimeUTC(date?: Date, timeSep?: string): string`
+- Add case functions: `toLower`, `toCamel`, `spinalToCamel`, and `snakeToCamel`
 
 ## [3.5.16][] - 2021-10-10
 

lib/utilities.js

@@ -85,6 +85,18 @@ const toLowerCamel = (s) => s.charAt(0).toLowerCase() + s.slice(1);
 
 const toUpperCamel = (s) => s.charAt(0).toUpperCase() + s.slice(1);
 
+const toLower = (s) => s.toLowerCase();
+
+const toCamel = (separator) => (s) => {
+  const words = s.split(separator);
+  const first = words.length > 0 ? words.shift().toLowerCase() : '';
+  return first + words.map(toLower).map(toUpperCamel).join('');
+};
+
+const spinalToCamel = toCamel('-');
+
+const snakeToCamel = toCamel('_');
+
 const isConstant = (s) => s === s.toUpperCase();
 
 const twoDigit = (n) => {
@@ -325,6 +337,10 @@ module.exports = {
   isFirstUpper,
   toLowerCamel,
   toUpperCamel,
+  toLower,
+  toCamel,
+  spinalToCamel,
+  snakeToCamel,
   isConstant,
   nowDate,
   nowDateTimeUTC,

metautil.d.ts

@@ -33,6 +33,10 @@ export function between(s: string, prefix: string, suffix: string): string;
 export function isFirstUpper(s: string): boolean;
 export function toLowerCamel(s: string): string;
 export function toUpperCamel(s: string): string;
+export function toLower(s: string): string;
+export function toCamel(separator: string): (s: string) => string;
+export function spinalToCamel(s: string): string;
+export function snakeToCamel(s: string): string;
 export function isConstant(s: string): boolean;
 export function nowDate(date?: Date): string;
 export function nowDateTimeUTC(date?: Date, timeSep?: string): string;

test/utilities.js

@@ -92,6 +92,34 @@ metatests.case(
       ['aBcD', 'ABcD'],
       ['', ''],
     ],
+    'metautil.toLower': [
+      ['abcd', 'abcd'],
+      ['ABCD', 'abcd'],
+      ['', ''],
+    ],
+    'metautil.toCamel': [
+      ['-', (f) => f('ab-cd') === 'abCd'],
+      ['--', (f) => f('AB--CD') === 'abCd'],
+      ['', (f) => f('') === ''],
+    ],
+    'metautil.spinalToCamel': [
+      ['abcd', 'abcd'],
+      ['ab-cd', 'abCd'],
+      ['AB-CD', 'abCd'],
+      ['AB-CD', 'abCd'],
+      ['a', 'a'],
+      ['', ''],
+      ['-', ''],
+    ],
+    'metautil.snakeToCamel': [
+      ['abcd', 'abcd'],
+      ['ab_cd', 'abCd'],
+      ['AB_CD', 'abCd'],
+      ['AB_CD', 'abCd'],
+      ['a', 'a'],
+      ['', ''],
+      ['_', ''],
+    ],
     'metautil.isConstant': [
       ['UPPER', true],
       ['UPPER_SNAKE', true],