/**
* @fileoverview Rule to check for max length on a line.
* @author Matt DuVall <http://www.mattduvall.com>
* @deprecated in ESLint v8.53.0
*/
'use strict';
//------------------------------------------------------------------------------
// Constants
//------------------------------------------------------------------------------
const OPTIONS_SCHEMA = {
type: 'object',
properties: {
code: {
type: 'integer',
minimum: 0,
},
comments: {
type: 'integer',
minimum: 0,
},
tabWidth: {
type: 'integer',
minimum: 0,
},
ignorePattern: {
type: 'string',
},
ignoreComments: {
type: 'boolean',
},
ignoreStrings: {
type: 'boolean',
},
ignoreUrls: {
type: 'boolean',
},
ignoreTemplateLiterals: {
type: 'boolean',
},
ignoreRegExpLiterals: {
type: 'boolean',
},
ignoreTrailingComments: {
type: 'boolean',
},
},
additionalProperties: false,
};
const OPTIONS_OR_INTEGER_SCHEMA = {
anyOf: [
OPTIONS_SCHEMA,
{
type: 'integer',
minimum: 0,
},
],
};
//------------------------------------------------------------------------------
// Rule Definition
//------------------------------------------------------------------------------
/** @type {import('../types').Rule.RuleModule} */
module.exports = {
meta: {
deprecated: {
message: 'Formatting rules are being moved out of ESLint core.',
url: 'https://eslint.org/blog/2023/10/deprecating-formatting-rules/',
deprecatedSince: '8.53.0',
availableUntil: '10.0.0',
replacedBy: [
{
message:
'ESLint Stylistic now maintains deprecated stylistic core rules.',
url: 'https://eslint.style/guide/migration',
plugin: {
name: '@stylistic/eslint-plugin-js',
url: 'https://eslint.style/packages/js',
},
rule: {
name: 'max-len',
url: 'https://eslint.style/rules/js/max-len',
},
},
],
},
type: 'layout',
docs: {
description: 'Enforce a maximum line length',
recommended: false,
url: 'https://eslint.org/docs/latest/rules/max-len',
},
schema: [
OPTIONS_OR_INTEGER_SCHEMA,
OPTIONS_OR_INTEGER_SCHEMA,
OPTIONS_SCHEMA,
],
messages: {
max: 'This line has a length of {{lineLength}}. Maximum allowed is {{maxLength}}.',
maxComment:
'This line has a comment length of {{lineLength}}. Maximum allowed is {{maxCommentLength}}.',
},
},
create(context) {
/*
* Inspired by http://tools.ietf.org/html/rfc3986#appendix-B, however:
* - They're matching an entire string that we know is a URI
* - We're matching part of a string where we think there *might* be a URL
* - We're only concerned about URLs, as picking out any URI would cause
* too many false positives
* - We don't care about matching the entire URL, any small segment is fine
*/
const URL_REGEXP = /[^:/?#]:\/\/[^?#]/u;
const sourceCode = context.sourceCode;
/**
* Computes the length of a line that may contain tabs. The width of each
* tab will be the number of spaces to the next tab stop.
* @param {string} line The line.
* @param {int} tabWidth The width of each tab stop in spaces.
* @returns {int} The computed line length.
* @private
*/
function computeLineLength(line, tabWidth) {
let extraCharacterCount = 0;
line.replace(/\t/gu, (match, offset) => {
const totalOffset = offset + extraCharacterCount,
previousTabStopOffset = tabWidth ? totalOffset % tabWidth : 0,
spaceCount = tabWidth - previousTabStopOffset;
extraCharacterCount += spaceCount - 1; // -1 for the replaced tab
});
return Array.from(line).length + extraCharacterCount;
}
// The options object must be the last option specified…
const options = Object.assign({}, context.options.at(-1));
// …but max code length…
if (typeof context.options[0] === 'number') {
options.code = context.options[0];
}
// …and tabWidth can be optionally specified directly as integers.
if (typeof context.options[1] === 'number') {
options.tabWidth = context.options[1];
}
const maxLength = typeof options.code === 'number' ? options.code : 80,
tabWidth = typeof options.tabWidth === 'number' ? options.tabWidth : 4,
ignoreComments = !!options.ignoreComments,
ignoreStrings = !!options.ignoreStrings,
ignoreTemplateLiterals = !!options.ignoreTemplateLiterals,
ignoreRegExpLiterals = !!options.ignoreRegExpLiterals,
ignoreTrailingComments =
!!options.ignoreTrailingComments || !!options.ignoreComments,
ignoreUrls = !!options.ignoreUrls,
maxCommentLength = options.comments;
let ignorePattern = options.ignorePattern || null;
if (ignorePattern) {
ignorePattern = new RegExp(ignorePattern, 'u');
}
//--------------------------------------------------------------------------
// Helpers
//--------------------------------------------------------------------------
/**
* Tells if a given comment is trailing: it starts on the current line and
* extends to or past the end of the current line.
* @param {string} line The source line we want to check for a trailing comment on
* @param {number} lineNumber The one-indexed line number for line
* @param {ASTNode} comment The comment to inspect
* @returns {boolean} If the comment is trailing on the given line
*/
function isTrailingComment(line, lineNumber, comment) {
return (
comment &&
comment.loc.start.line === lineNumber &&
lineNumber <= comment.loc.end.line &&
(comment.loc.end.line > lineNumber ||
comment.loc.end.column === line.length)
);
}
/**
* Tells if a comment encompasses the entire line.
* @param {string} line The source line with a trailing comment
* @param {number} lineNumber The one-indexed line number this is on
* @param {ASTNode} comment The comment to remove
* @returns {boolean} If the comment covers the entire line
*/
function isFullLineComment(line, lineNumber, comment) {
const start = comment.loc.start,
end = comment.loc.end,
isFirstTokenOnLine = !line.slice(0, comment.loc.start.column).trim();
return (
comment &&
(start.line < lineNumber ||
(start.line === lineNumber && isFirstTokenOnLine)) &&
(end.line > lineNumber ||
(end.line === lineNumber && end.column === line.length))
);
}
/**
* Check if a node is a JSXEmptyExpression contained in a single line JSXExpressionContainer.
* @param {ASTNode} node A node to check.
* @returns {boolean} True if the node is a JSXEmptyExpression contained in a single line JSXExpressionContainer.
*/
function isJSXEmptyExpressionInSingleLineContainer(node) {
if (
!node ||
!node.parent ||
node.type !== 'JSXEmptyExpression' ||
node.parent.type !== 'JSXExpressionContainer'
) {
return false;
}
const parent = node.parent;
return parent.loc.start.line === parent.loc.end.line;
}
/**
* Gets the line after the comment and any remaining trailing whitespace is
* stripped.
* @param {string} line The source line with a trailing comment
* @param {ASTNode} comment The comment to remove
* @returns {string} Line without comment and trailing whitespace
*/
function stripTrailingComment(line, comment) {
// loc.column is zero-indexed
return line.slice(0, comment.loc.start.column).replace(/\s+$/u, '');
}
/**
* Ensure that an array exists at [key] on `object`, and add `value` to it.
* @param {Object} object the object to mutate
* @param {string} key the object's key
* @param {any} value the value to add
* @returns {void}
* @private
*/
function ensureArrayAndPush(object, key, value) {
if (!Array.isArray(object[key])) {
object[key] = [];
}
object[key].push(value);
}
/**
* Retrieves an array containing all strings (" or ') in the source code.
* @returns {ASTNode[]} An array of string nodes.
*/
function getAllStrings() {
return sourceCode.ast.tokens.filter(
(token) =>
token.type === 'String' ||
(token.type === 'JSXText' &&
sourceCode.getNodeByRangeIndex(token.range[0] - 1).type ===
'JSXAttribute')
);
}
/**
* Retrieves an array containing all template literals in the source code.
* @returns {ASTNode[]} An array of template literal nodes.
*/
function getAllTemplateLiterals() {
return sourceCode.ast.tokens.filter((token) => token.type === 'Template');
}
/**
* Retrieves an array containing all RegExp literals in the source code.
* @returns {ASTNode[]} An array of RegExp literal nodes.
*/
function getAllRegExpLiterals() {
return sourceCode.ast.tokens.filter(
(token) => token.type === 'RegularExpression'
);
}
/**
*
* reduce an array of AST nodes by line number, both start and end.
* @param {ASTNode[]} arr array of AST nodes
* @returns {Object} accululated AST nodes
*/
function groupArrayByLineNumber(arr) {
const obj = {};
for (let i = 0; i < arr.length; i++) {
const node = arr[i];
for (let j = node.loc.start.line; j <= node.loc.end.line; ++j) {
ensureArrayAndPush(obj, j, node);
}
}
return obj;
}
/**
* Returns an array of all comments in the source code.
* If the element in the array is a JSXEmptyExpression contained with a single line JSXExpressionContainer,
* the element is changed with JSXExpressionContainer node.
* @returns {ASTNode[]} An array of comment nodes
*/
function getAllComments() {
const comments = [];
sourceCode.getAllComments().forEach((commentNode) => {
const containingNode = sourceCode.getNodeByRangeIndex(
commentNode.range[0]
);
if (isJSXEmptyExpressionInSingleLineContainer(containingNode)) {
// push a unique node only
if (comments.at(-1) !== containingNode.parent) {
comments.push(containingNode.parent);
}
} else {
comments.push(commentNode);
}
});
return comments;
}
/**
* Check the program for max length
* @param {ASTNode} node Node to examine
* @returns {void}
* @private
*/
function checkProgramForMaxLength(node) {
// split (honors line-ending)
const lines = sourceCode.lines,
// list of comments to ignore
comments =
ignoreComments || maxCommentLength || ignoreTrailingComments ?
getAllComments()
: [];
// we iterate over comments in parallel with the lines
let commentsIndex = 0;
const strings = getAllStrings();
const stringsByLine = groupArrayByLineNumber(strings);
const templateLiterals = getAllTemplateLiterals();
const templateLiteralsByLine = groupArrayByLineNumber(templateLiterals);
const regExpLiterals = getAllRegExpLiterals();
const regExpLiteralsByLine = groupArrayByLineNumber(regExpLiterals);
lines.forEach((line, i) => {
// i is zero-indexed, line numbers are one-indexed
const lineNumber = i + 1;
/*
* if we're checking comment length; we need to know whether this
* line is a comment
*/
let lineIsComment = false;
let textToMeasure;
/*
* We can short-circuit the comment checks if we're already out of
* comments to check.
*/
if (commentsIndex < comments.length) {
let comment;
// iterate over comments until we find one past the current line
do {
comment = comments[++commentsIndex];
} while (comment && comment.loc.start.line <= lineNumber);
// and step back by one
comment = comments[--commentsIndex];
if (isFullLineComment(line, lineNumber, comment)) {
lineIsComment = true;
textToMeasure = line;
} else if (
ignoreTrailingComments &&
isTrailingComment(line, lineNumber, comment)
) {
textToMeasure = stripTrailingComment(line, comment);
// ignore multiple trailing comments in the same line
let lastIndex = commentsIndex;
while (
isTrailingComment(
textToMeasure,
lineNumber,
comments[--lastIndex]
)
) {
textToMeasure = stripTrailingComment(
textToMeasure,
comments[lastIndex]
);
}
} else {
textToMeasure = line;
}
} else {
textToMeasure = line;
}
if (
(ignorePattern && ignorePattern.test(textToMeasure)) ||
(ignoreUrls && URL_REGEXP.test(textToMeasure)) ||
(ignoreStrings && stringsByLine[lineNumber]) ||
(ignoreTemplateLiterals && templateLiteralsByLine[lineNumber]) ||
(ignoreRegExpLiterals && regExpLiteralsByLine[lineNumber])
) {
// ignore this line
return;
}
const lineLength = computeLineLength(textToMeasure, tabWidth);
const commentLengthApplies = lineIsComment && maxCommentLength;
if (lineIsComment && ignoreComments) {
return;
}
const loc = {
start: {
line: lineNumber,
column: 0,
},
end: {
line: lineNumber,
column: textToMeasure.length,
},
};
if (commentLengthApplies) {
if (lineLength > maxCommentLength) {
context.report({
node,
loc,
messageId: 'maxComment',
data: {
lineLength,
maxCommentLength,
},
});
}
} else if (lineLength > maxLength) {
context.report({
node,
loc,
messageId: 'max',
data: {
lineLength,
maxLength,
},
});
}
});
}
//--------------------------------------------------------------------------
// Public API
//--------------------------------------------------------------------------
return {
Program: checkProgramForMaxLength,
};
},
};