/** * @fileoverview enforce a maximum file length * @author Alberto Rodríguez */ "use strict"; //------------------------------------------------------------------------------ // Requirements //------------------------------------------------------------------------------ const astUtils = require("./utils/ast-utils"); //------------------------------------------------------------------------------ // Helpers //------------------------------------------------------------------------------ /** * Creates an array of numbers from `start` up to, but not including, `end` * @param {number} start The start of the range * @param {number} end The end of the range * @returns {number[]} The range of numbers */ function range(start, end) { return [...Array(end - start).keys()].map(x => x + start); } //------------------------------------------------------------------------------ // Rule Definition //------------------------------------------------------------------------------ module.exports = { meta: { type: "suggestion", docs: { description: "enforce a maximum number of lines per file", category: "Stylistic Issues", recommended: false, url: "https://eslint.org/docs/rules/max-lines" }, schema: [ { oneOf: [ { type: "integer", minimum: 0 }, { type: "object", properties: { max: { type: "integer", minimum: 0 }, skipComments: { type: "boolean" }, skipBlankLines: { type: "boolean" } }, additionalProperties: false } ] } ], messages: { exceed: "File has too many lines ({{actual}}). Maximum allowed is {{max}}." } }, create(context) { const option = context.options[0]; let max = 300; if ( typeof option === "object" && Object.prototype.hasOwnProperty.call(option, "max") ) { max = option.max; } else if (typeof option === "number") { max = option; } const skipComments = option && option.skipComments; const skipBlankLines = option && option.skipBlankLines; const sourceCode = context.getSourceCode(); /** * Returns whether or not a token is a comment node type * @param {Token} token The token to check * @returns {boolean} True if the token is a comment node */ function isCommentNodeType(token) { return token && (token.type === "Block" || token.type === "Line"); } /** * Returns the line numbers of a comment that don't have any code on the same line * @param {Node} comment The comment node to check * @returns {number[]} The line numbers */ function getLinesWithoutCode(comment) { let start = comment.loc.start.line; let end = comment.loc.end.line; let token; token = comment; do { token = sourceCode.getTokenBefore(token, { includeComments: true }); } while (isCommentNodeType(token)); if (token && astUtils.isTokenOnSameLine(token, comment)) { start += 1; } token = comment; do { token = sourceCode.getTokenAfter(token, { includeComments: true }); } while (isCommentNodeType(token)); if (token && astUtils.isTokenOnSameLine(comment, token)) { end -= 1; } if (start <= end) { return range(start, end + 1); } return []; } /** * Returns a new array formed by applying a given callback function to each element of the array, and then flattening the result by one level. * TODO(stephenwade): Replace this with array.flatMap when we drop support for Node v10 * @param {any[]} array The array to process * @param {Function} fn The function to use * @returns {any[]} The result array */ function flatMap(array, fn) { const mapped = array.map(fn); const flattened = [].concat(...mapped); return flattened; } return { "Program:exit"() { let lines = sourceCode.lines.map((text, i) => ({ lineNumber: i + 1, text })); /* * If file ends with a linebreak, `sourceCode.lines` will have one extra empty line at the end. * That isn't a real line, so we shouldn't count it. */ if (lines.length > 1 && lines[lines.length - 1].text === "") { lines.pop(); } if (skipBlankLines) { lines = lines.filter(l => l.text.trim() !== ""); } if (skipComments) { const comments = sourceCode.getAllComments(); const commentLines = flatMap(comments, comment => getLinesWithoutCode(comment)); lines = lines.filter( l => !commentLines.includes(l.lineNumber) ); } if (lines.length > max) { const loc = { start: { line: lines[max].lineNumber, column: 0 }, end: { line: sourceCode.lines.length, column: sourceCode.lines[sourceCode.lines.length - 1].length } }; context.report({ loc, messageId: "exceed", data: { max, actual: lines.length } }); } } }; } };