eslint-plugin-svelte/lib/rules/no-trailing-spaces.js

ESLint plugin for Svelte using AST

import { createRule } from '../utils/index.js';
export default createRule('no-trailing-spaces', {
    meta: {
        type: 'layout',
        docs: {
            description: 'disallow trailing whitespace at the end of lines',
            category: 'Extension Rules',
            recommended: false,
            extensionRule: 'no-trailing-spaces',
            conflictWithPrettier: true
        },
        fixable: 'whitespace',
        schema: [
            {
                type: 'object',
                properties: {
                    skipBlankLines: { type: 'boolean' },
                    ignoreComments: { type: 'boolean' }
                },
                additionalProperties: false
            }
        ],
        messages: {
            trailingSpace: 'Trailing spaces not allowed.'
        }
    },
    create(context) {
        const options = context.options[0];
        const skipBlankLines = options?.skipBlankLines || false;
        const ignoreComments = options?.ignoreComments || false;
        const sourceCode = context.sourceCode;
        const ignoreLineNumbers = new Set();
        if (ignoreComments) {
            for (const { type, loc } of sourceCode.getAllComments()) {
                const endLine = type === 'Block' ? loc.end.line - 1 : loc.end.line;
                for (let i = loc.start.line; i <= endLine; i++) {
                    ignoreLineNumbers.add(i);
                }
            }
        }
        /**
         * Reports a given location.
         */
        function report(loc) {
            context.report({
                loc,
                messageId: 'trailingSpace',
                fix(fixer) {
                    return fixer.removeRange([
                        sourceCode.getIndexFromLoc(loc.start),
                        sourceCode.getIndexFromLoc(loc.end)
                    ]);
                }
            });
        }
        /**
         * Collects the location of the given node as the ignore line numbers.
         */
        function collectIgnoreLineNumbers({ loc }) {
            const endLine = loc.end.line - 1;
            for (let i = loc.start.line; i <= endLine; i++) {
                ignoreLineNumbers.add(i);
            }
        }
        return {
            TemplateElement: collectIgnoreLineNumbers,
            ...(ignoreComments
                ? {
                    SvelteHTMLComment: collectIgnoreLineNumbers
                }
                : {}),
            'Program:exit'() {
                const lines = sourceCode.lines;
                for (let lineIndex = 0; lineIndex < lines.length; lineIndex++) {
                    const line = lines[lineIndex];
                    if (skipBlankLines && !line.trim()) {
                        continue;
                    }
                    const lineNumber = lineIndex + 1;
                    if (ignoreLineNumbers.has(lineNumber)) {
                        continue;
                    }
                    const trimmed = line.trimEnd();
                    if (trimmed === line) {
                        continue;
                    }
                    report({
                        start: { line: lineNumber, column: trimmed.length },
                        end: { line: lineNumber, column: line.length }
                    });
                }
            }
        };
    }
});