Handle Unicode character casing and require Node.js 10

.travis.yml

@@ -2,5 +2,3 @@ language: node_js
 node_js:
   - '12'
   - '10'
-  - '8'
-  - '6'

index.d.ts

@@ -13,6 +13,8 @@ declare const camelcase: {
 	/**
 	Convert a dash/dot/underscore/space separated string to camelCase or PascalCase: `foo-bar` → `fooBar`.
 
+	Correctly handles Unicode strings.
+
 	@param input - String to convert to camel case.
 
 	@example
@@ -27,6 +29,9 @@ declare const camelcase: {
 
 	camelCase('Foo-Bar');
 	//=> 'fooBar'
+
+	camelCase('розовый_пушистый_единороги');
+	//=> 'розовыйПушистыйЕдинороги'
 
 	camelCase('Foo-Bar', {pascalCase: true});
 	//=> 'FooBar'

index.js

@@ -8,21 +8,21 @@ const preserveCamelCase = string => {
 	for (let i = 0; i < string.length; i++) {
 		const character = string[i];
 
-		if (isLastCharLower && /[a-zA-Z]/.test(character) && character.toUpperCase() === character) {
+		if (isLastCharLower && /[\p{Lu}]/u.test(character)) {
 			string = string.slice(0, i) + '-' + string.slice(i);
 			isLastCharLower = false;
 			isLastLastCharUpper = isLastCharUpper;
 			isLastCharUpper = true;
 			i++;
-		} else if (isLastCharUpper && isLastLastCharUpper && /[a-zA-Z]/.test(character) && character.toLowerCase() === character) {
+		} else if (isLastCharUpper && isLastLastCharUpper && /[\p{Ll}]/u.test(character)) {
 			string = string.slice(0, i - 1) + '-' + string.slice(i - 1);
 			isLastLastCharUpper = isLastCharUpper;
 			isLastCharUpper = false;
 			isLastCharLower = true;
 		} else {
-			isLastCharLower = character.toLowerCase() === character && character.toUpperCase() !== character;
+			isLastCharLower = character.toLocaleLowerCase() === character && character.toLocaleUpperCase() !== character;
 			isLastLastCharUpper = isLastCharUpper;
-			isLastCharUpper = character.toUpperCase() === character && character.toLowerCase() !== character;
+			isLastCharUpper = character.toLocaleUpperCase() === character && character.toLocaleLowerCase() !== character;
 		}
 	}
 
@@ -34,11 +34,12 @@ const camelCase = (input, options) => {
 		throw new TypeError('Expected the input to be `string | string[]`');
 	}
 
-	options = Object.assign({
-		pascalCase: false
-	}, options);
+	options = {
+		...{pascalCase: false},
+		...options
+	};
 
-	const postProcess = x => options.pascalCase ? x.charAt(0).toUpperCase() + x.slice(1) : x;
+	const postProcess = x => options.pascalCase ? x.charAt(0).toLocaleUpperCase() + x.slice(1) : x;
 
 	if (Array.isArray(input)) {
 		input = input.map(x => x.trim())
@@ -53,20 +54,20 @@ const camelCase = (input, options) => {
 	}
 
 	if (input.length === 1) {
-		return options.pascalCase ? input.toUpperCase() : input.toLowerCase();
+		return options.pascalCase ? input.toLocaleUpperCase() : input.toLocaleLowerCase();
 	}
 
-	const hasUpperCase = input !== input.toLowerCase();
+	const hasUpperCase = input !== input.toLocaleLowerCase();
 
 	if (hasUpperCase) {
 		input = preserveCamelCase(input);
 	}
 
 	input = input
 		.replace(/^[_.\- ]+/, '')
-		.toLowerCase()
-		.replace(/[_.\- ]+(\w|$)/g, (_, p1) => p1.toUpperCase())
-		.replace(/\d+(\w|$)/g, m => m.toUpperCase());
+		.toLocaleLowerCase()
+		.replace(/[_.\- ]+([\p{Alpha}\p{N}_]|$)/gu, (_, p1) => p1.toLocaleUpperCase())
+		.replace(/\d+([\p{Alpha}\p{N}_]|$)/gu, m => m.toLocaleUpperCase());
 
 	return postProcess(input);
 };

index.test-d.ts

@@ -2,6 +2,7 @@ import {expectType} from 'tsd';
 import camelCase = require('.');
 
 expectType<string>(camelCase('foo-bar'));
+expectType<string>(camelCase('розовый_пушистый_единороги'));
 expectType<string>(camelCase('Foo-Bar', {pascalCase: true}));
 expectType<string>(camelCase(['foo', 'bar']));
 expectType<string>(camelCase(['__foo__', '--bar'], {pascalCase: true}));

package.json

@@ -10,7 +10,7 @@
 		"url": "sindresorhus.com"
 	},
 	"engines": {
-		"node": ">=6"
+		"node": ">=10"
 	},
 	"scripts": {
 		"test": "xo && ava && tsd"

readme.md

@@ -2,6 +2,8 @@
 
 > Convert a dash/dot/underscore/space separated string to camelCase or PascalCase: `foo-bar` → `fooBar`
 
+Correctly handles Unicode strings.
+
 
 ## Install
 
@@ -24,6 +26,9 @@ camelCase('foo_bar');
 camelCase('Foo-Bar');
 //=> 'fooBar'
 
+camelCase('розовый_пушистый_единороги');
+//=> 'розовыйПушистыйЕдинороги'
+
 camelCase('Foo-Bar', {pascalCase: true});
 //=> 'FooBar'
 

test.js

@@ -58,6 +58,12 @@ test('camelCase', t => {
 	t.is(camelCase('1Hello'), '1Hello');
 	t.is(camelCase('1hello'), '1Hello');
 	t.is(camelCase('h2w'), 'h2W');
+	t.is(camelCase('розовый_пушистый-единороги'), 'розовыйПушистыйЕдинороги');
+	t.is(camelCase('розовый_пушистый-единороги'), 'розовыйПушистыйЕдинороги');
+	t.is(camelCase('РОЗОВЫЙ_ПУШИСТЫЙ-ЕДИНОРОГИ'), 'розовыйПушистыйЕдинороги');
+	t.is(camelCase('桑德在这里。'), '桑德在这里。');
+	t.is(camelCase('桑德在这里。'), '桑德在这里。');
+	t.is(camelCase('桑德_在这里。'), '桑德在这里。');
 });
 
 test('camelCase with pascalCase option', t => {
@@ -117,6 +123,11 @@ test('camelCase with pascalCase option', t => {
 	t.is(camelCase('1hello', {pascalCase: true}), '1Hello');
 	t.is(camelCase('1Hello', {pascalCase: true}), '1Hello');
 	t.is(camelCase('h1W', {pascalCase: true}), 'H1W');
+	t.is(camelCase('РозовыйПушистыйЕдинороги', {pascalCase: true}), 'РозовыйПушистыйЕдинороги');
+	t.is(camelCase('розовый_пушистый-единороги', {pascalCase: true}), 'РозовыйПушистыйЕдинороги');
+	t.is(camelCase('РОЗОВЫЙ_ПУШИСТЫЙ-ЕДИНОРОГИ', {pascalCase: true}), 'РозовыйПушистыйЕдинороги');
+	t.is(camelCase('桑德在这里。', {pascalCase: true}), '桑德在这里。');
+	t.is(camelCase('桑德_在这里。', {pascalCase: true}), '桑德在这里。');
 });
 
 test('invalid input', t => {