Format decimal

[simbig]

No description provided.

[Copilot]

Pull Request Overview

This PR adds a new formatDecimal function to handle decimal number formatting with configurable precision and trailing zero trimming options.

• Adds formatDecimal function with options for min/max decimals and trailing zero control
• Includes comprehensive test coverage for various formatting scenarios
• Updates imports to include the new function

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

File	Description
src/number.ts	Implements the new formatDecimal function with rounding and formatting logic
src/number.test.ts	Adds test cases covering different decimal formatting scenarios

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[Copilot]

The logic for toFixed should use maxDecimals to ensure proper rounding, then handle minDecimals separately. Currently, when minDecimals > maxDecimals, this will display more decimals than the rounded value supports, potentially showing incorrect precision.

Suggested change

	let str = rounded.toFixed(Math.max(minDecimals, maxDecimals));
	if (trimTrailingZeros) {
	str = str.replace(/(\.[0-9]*?)0+$/, '$1').replace(/\.$/, '');
	// Always round to maxDecimals
	let str = rounded.toFixed(maxDecimals);
	if (trimTrailingZeros) {
	// Remove trailing zeros, but ensure at least minDecimals remain
	const [intPart, decPart = ''] = str.split('.');
	let trimmedDec = decPart.replace(/0+$/, '');
	// Pad with zeros if needed to reach minDecimals, but never more than maxDecimals
	if (trimmedDec.length < minDecimals) {
	trimmedDec = trimmedDec.padEnd(minDecimals, '0');
	}
	// If there are decimals, join; else, just intPart
	str = trimmedDec.length > 0 ? `${intPart}.${trimmedDec}` : intPart;
	} else if (minDecimals < maxDecimals) {
	// If not trimming, pad with zeros to minDecimals if needed
	const [intPart, decPart = ''] = str.split('.');
	let paddedDec = decPart;
	if (paddedDec.length < minDecimals) {
	paddedDec = paddedDec.padEnd(minDecimals, '0');
	}
	str = paddedDec.length > 0 ? `${intPart}.${paddedDec}` : intPart;

[Copilot]

This rounding logic duplicates the existing round function. Consider using round(value, maxDecimals) instead to avoid code duplication and maintain consistency.

Suggested change

	const factor = 10 ** maxDecimals;
	const rounded = Math.round(value * factor) / factor;
	const rounded = round(value, maxDecimals);