Fix leading whitespace dropping the negative sign

[naveentehrpariya]

The global sign was decided by str[0] === '-', reading the raw first character. The parser already tolerates leading whitespace for the magnitude ( 1h → 3600000), but with a leading minus the sign check saw the whitespace instead of the -:

parse('-1h')  // -3600000
parse(' -1h') //  3600000  ← bug

Test the first non-whitespace character with /^\s*-/ instead. Only a leading minus preceded by whitespace is affected; the intentional mid-string-minus behavior (1h-30m, 2hr -40mins) is unchanged.

[dy]

Regex is too heavy. Any way to make it simpler? Via trim I suppose?

[naveentehrpariya]

Good call — dropped the regex, now just String(str).trimStart()[0] === '-'. Tests still green.

[Copilot]

Pull request overview

Fixes an input-parsing bug where a leading whitespace before - caused negative durations to be interpreted as positive, aligning sign detection with the parser’s existing tolerance for leading whitespace.

Changes:

• Update sign detection to check the first non-whitespace character rather than str[0].
• Add test coverage for negative durations preceded by spaces and tabs.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
index.js	Adjusts sign detection to handle leading whitespace before -.
test.js	Adds regression tests for whitespace-prefixed negative inputs.

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