Snake Case to Camel Case Conversion in JavaScript

This challenge focuses on string manipulation in JavaScript. You'll be writing a function that converts strings from snake_case (e.g., my_variable_name) to camelCase (e.g., myVariableName). This is a common task in software development, particularly when integrating with APIs or libraries that use different naming conventions.

Problem Description

You are tasked with creating a JavaScript function called snakeToCamel that takes a single string as input, which is assumed to be in snake_case. The function should convert this string to its equivalent camelCase representation. The first word should be lowercase. Underscores should be treated as delimiters between words, and the following word should be capitalized.

Key Requirements:

• The function must correctly convert valid snake_case strings to camelCase.
• The function should handle empty input strings gracefully.
• The function should handle strings with multiple underscores.
• The function should handle strings that already partially conform to camelCase (e.g., myVariable_name).

Expected Behavior:

The function should return a new string representing the camelCase version of the input. The original string should not be modified.

Edge Cases to Consider:

• Empty string input: Should return an empty string.
• String with only underscores: Should return an empty string.
• String starting with an underscore: Should return an empty string.
• String ending with an underscore: Should return the string with the trailing underscore removed, then converted to camelCase.
• String with consecutive underscores: Should be handled correctly (e.g., my__variable should become myVariable).

Examples

Example 1:

Input: "my_variable_name"
Output: "myVariableName"
Explanation: The underscores are used to identify word boundaries, and each subsequent word is capitalized.

Example 2:

Input: "single_word"
Output: "singleWord"
Explanation: A single word with an underscore is converted to camelCase by capitalizing the word.

Example 3:

Input: "alreadyCamelCase_with_snake"
Output: "alreadyCamelCaseWithSnake"
Explanation: Existing camelCase portions are preserved, and snake_case portions are converted.

Example 4:

Input: ""
Output: ""
Explanation: An empty string remains an empty string.

Example 5:

Input: "____"
Output: ""
Explanation: A string consisting only of underscores should return an empty string.

Example 6:

Input: "_leading_underscore"
Output: ""
Explanation: A string starting with an underscore should return an empty string.

Constraints

• The input string will only contain lowercase letters, uppercase letters, numbers, and underscores.
• The input string's length will be between 0 and 1000 characters, inclusive.
• The function should execute in O(n) time complexity, where n is the length of the input string.

Notes

Consider using regular expressions or string splitting to identify the word boundaries. Remember to handle edge cases carefully to ensure the function behaves as expected in all scenarios. Think about how to efficiently capitalize the appropriate words after splitting the string. Don't forget to return a new string, not modify the original.