14 lines
		
	
	
		
			323 B
		
	
	
	
		
			JavaScript
		
	
	
	
	
	
			
		
		
	
	
			14 lines
		
	
	
		
			323 B
		
	
	
	
		
			JavaScript
		
	
	
	
	
	
| 'use strict';
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| module.exports = function (str, sep) {
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| 	if (typeof str !== 'string') {
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| 		throw new TypeError('Expected a string');
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| 	}
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| 
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| 	sep = typeof sep === 'undefined' ? '_' : sep;
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| 
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| 	return str
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| 		.replace(/([a-z\d])([A-Z])/g, '$1' + sep + '$2')
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| 		.replace(/([A-Z]+)([A-Z][a-z\d]+)/g, '$1' + sep + '$2')
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| 		.toLowerCase();
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| };
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