eslint-plugin-unicorn/rules/fix/remove-argument.js

More than 300 powerful ESLint rules

import {isCommaToken} from '@eslint-community/eslint-utils';
import {
	getComments,
	getLinebreak,
	getParentheses,
	hasCommentInRange,
} from '../utils/index.js';

/**
@import {TSESTree as ESTree} from '@typescript-eslint/types';
@import * as ESLint from 'eslint';
*/

/**
@param {ESTree.CallExpressionArgument} node
@param {ESLint.Rule.RuleContext} context - The ESLint rule context object.
@returns {Array<number>}
*/
function getArgumentRemovalRange(node, context) {
	const callOrNewExpression = node.parent;
	const index = callOrNewExpression.arguments.indexOf(node);
	const parentheses = getParentheses(node, context);
	const firstToken = parentheses[0] || node;
	const lastToken = parentheses.at(-1) || node;
	const {sourceCode} = context;

	let [start] = sourceCode.getRange(firstToken);
	let [, end] = sourceCode.getRange(lastToken);

	if (callOrNewExpression.arguments.length === 1) {
		// The only argument: also drop a dangling trailing comma if present (`fn(a,)`).
		const tokenAfter = sourceCode.getTokenAfter(lastToken);
		if (isCommaToken(tokenAfter)) {
			[, end] = sourceCode.getRange(tokenAfter);
		}
	} else if (index === 0) {
		// First of several: remove it through the following comma and the gap after it, so
		// `fn(a, b)` becomes `fn(b)` rather than `fn( b)`.
		const commaToken = sourceCode.getTokenAfter(lastToken);
		const tokenAfterComma = sourceCode.getTokenAfter(commaToken, {includeComments: true});
		[end] = sourceCode.getRange(tokenAfterComma);
	} else {
		// Otherwise remove the comma that precedes it.
		const commaToken = sourceCode.getTokenBefore(firstToken);
		[start] = sourceCode.getRange(commaToken);
	}

	return [start, end];
}

/**
@param {ESLint.Rule.RuleFixer} fixer
@param {ESTree.CallExpressionArgument} node
@param {ESLint.Rule.RuleContext} context - The ESLint rule context object.
@returns {ESLint.Rule.Fix}
*/
export default function removeArgument(fixer, node, context) {
	const removalRange = getArgumentRemovalRange(node, context);
	const callOrNewExpression = node.parent;
	const index = callOrNewExpression.arguments.indexOf(node);

	if (hasCommentInRange(context, removalRange)) {
		const {sourceCode} = context;
		const comments = getComments(context).filter(comment => {
			const [commentStart, commentEnd] = sourceCode.getRange(comment);
			return commentStart >= removalRange[0] && commentEnd <= removalRange[1];
		});

		// A line comment runs to the end of the line, it needs a line break after it
		const getCommentText = comment => `${sourceCode.getText(comment)}${comment.type === 'Line' ? getLinebreak(context) : ''}`;

		// Removing the first of several arguments swallows the comma that follows it, so the comments after the argument have to be spliced out of the middle of the range, and the comments inside the argument go before them. Every other position keeps the comments where they are, including the only argument of `fn(a /* comment */,)`.
		if (index === 0 && callOrNewExpression.arguments.length > 1) {
			const parentheses = getParentheses(node, context);
			const lastToken = parentheses.at(-1) || node;
			const [, argumentEnd] = sourceCode.getRange(lastToken);
			const commaToken = sourceCode.getTokenAfter(lastToken);
			const [commaStart, commaEnd] = sourceCode.getRange(commaToken);
			const rangeText = sourceCode.text.slice(...removalRange);
			const argumentCommentsText = comments
				.filter(comment => sourceCode.getRange(comment)[1] <= argumentEnd)
				.map(comment => getCommentText(comment))
				.join(' ');
			const replacement = argumentCommentsText + rangeText.slice(argumentEnd - removalRange[0], commaStart - removalRange[0]) + rangeText.slice(commaEnd - removalRange[0]);

			return fixer.replaceTextRange(removalRange, replacement);
		}

		const text = comments
			.map(comment => ` ${getCommentText(comment)}`)
			.join('');

		return fixer.replaceTextRange(removalRange, text);
	}

	return fixer.removeRange(removalRange);
}

export {
	getArgumentRemovalRange,
};