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eb39fafa DC |
1 | /** |
2 | * @fileoverview Rule to check for max length on a line. | |
3 | * @author Matt DuVall <http://www.mattduvall.com> | |
4 | */ | |
5 | ||
6 | "use strict"; | |
7 | ||
8 | //------------------------------------------------------------------------------ | |
9 | // Constants | |
10 | //------------------------------------------------------------------------------ | |
11 | ||
12 | const OPTIONS_SCHEMA = { | |
13 | type: "object", | |
14 | properties: { | |
15 | code: { | |
16 | type: "integer", | |
17 | minimum: 0 | |
18 | }, | |
19 | comments: { | |
20 | type: "integer", | |
21 | minimum: 0 | |
22 | }, | |
23 | tabWidth: { | |
24 | type: "integer", | |
25 | minimum: 0 | |
26 | }, | |
27 | ignorePattern: { | |
28 | type: "string" | |
29 | }, | |
30 | ignoreComments: { | |
31 | type: "boolean" | |
32 | }, | |
33 | ignoreStrings: { | |
34 | type: "boolean" | |
35 | }, | |
36 | ignoreUrls: { | |
37 | type: "boolean" | |
38 | }, | |
39 | ignoreTemplateLiterals: { | |
40 | type: "boolean" | |
41 | }, | |
42 | ignoreRegExpLiterals: { | |
43 | type: "boolean" | |
44 | }, | |
45 | ignoreTrailingComments: { | |
46 | type: "boolean" | |
47 | } | |
48 | }, | |
49 | additionalProperties: false | |
50 | }; | |
51 | ||
52 | const OPTIONS_OR_INTEGER_SCHEMA = { | |
53 | anyOf: [ | |
54 | OPTIONS_SCHEMA, | |
55 | { | |
56 | type: "integer", | |
57 | minimum: 0 | |
58 | } | |
59 | ] | |
60 | }; | |
61 | ||
62 | //------------------------------------------------------------------------------ | |
63 | // Rule Definition | |
64 | //------------------------------------------------------------------------------ | |
65 | ||
34eeec05 | 66 | /** @type {import('../shared/types').Rule} */ |
eb39fafa DC |
67 | module.exports = { |
68 | meta: { | |
69 | type: "layout", | |
70 | ||
71 | docs: { | |
72 | description: "enforce a maximum line length", | |
eb39fafa DC |
73 | recommended: false, |
74 | url: "https://eslint.org/docs/rules/max-len" | |
75 | }, | |
76 | ||
77 | schema: [ | |
78 | OPTIONS_OR_INTEGER_SCHEMA, | |
79 | OPTIONS_OR_INTEGER_SCHEMA, | |
80 | OPTIONS_SCHEMA | |
81 | ], | |
82 | messages: { | |
83 | max: "This line has a length of {{lineLength}}. Maximum allowed is {{maxLength}}.", | |
84 | maxComment: "This line has a comment length of {{lineLength}}. Maximum allowed is {{maxCommentLength}}." | |
85 | } | |
86 | }, | |
87 | ||
88 | create(context) { | |
89 | ||
90 | /* | |
91 | * Inspired by http://tools.ietf.org/html/rfc3986#appendix-B, however: | |
92 | * - They're matching an entire string that we know is a URI | |
93 | * - We're matching part of a string where we think there *might* be a URL | |
94 | * - We're only concerned about URLs, as picking out any URI would cause | |
95 | * too many false positives | |
96 | * - We don't care about matching the entire URL, any small segment is fine | |
97 | */ | |
98 | const URL_REGEXP = /[^:/?#]:\/\/[^?#]/u; | |
99 | ||
100 | const sourceCode = context.getSourceCode(); | |
101 | ||
102 | /** | |
103 | * Computes the length of a line that may contain tabs. The width of each | |
104 | * tab will be the number of spaces to the next tab stop. | |
105 | * @param {string} line The line. | |
106 | * @param {int} tabWidth The width of each tab stop in spaces. | |
107 | * @returns {int} The computed line length. | |
108 | * @private | |
109 | */ | |
110 | function computeLineLength(line, tabWidth) { | |
111 | let extraCharacterCount = 0; | |
112 | ||
113 | line.replace(/\t/gu, (match, offset) => { | |
114 | const totalOffset = offset + extraCharacterCount, | |
115 | previousTabStopOffset = tabWidth ? totalOffset % tabWidth : 0, | |
116 | spaceCount = tabWidth - previousTabStopOffset; | |
117 | ||
118 | extraCharacterCount += spaceCount - 1; // -1 for the replaced tab | |
119 | }); | |
120 | return Array.from(line).length + extraCharacterCount; | |
121 | } | |
122 | ||
123 | // The options object must be the last option specified… | |
124 | const options = Object.assign({}, context.options[context.options.length - 1]); | |
125 | ||
126 | // …but max code length… | |
127 | if (typeof context.options[0] === "number") { | |
128 | options.code = context.options[0]; | |
129 | } | |
130 | ||
131 | // …and tabWidth can be optionally specified directly as integers. | |
132 | if (typeof context.options[1] === "number") { | |
133 | options.tabWidth = context.options[1]; | |
134 | } | |
135 | ||
136 | const maxLength = typeof options.code === "number" ? options.code : 80, | |
137 | tabWidth = typeof options.tabWidth === "number" ? options.tabWidth : 4, | |
138 | ignoreComments = !!options.ignoreComments, | |
139 | ignoreStrings = !!options.ignoreStrings, | |
140 | ignoreTemplateLiterals = !!options.ignoreTemplateLiterals, | |
141 | ignoreRegExpLiterals = !!options.ignoreRegExpLiterals, | |
142 | ignoreTrailingComments = !!options.ignoreTrailingComments || !!options.ignoreComments, | |
143 | ignoreUrls = !!options.ignoreUrls, | |
144 | maxCommentLength = options.comments; | |
145 | let ignorePattern = options.ignorePattern || null; | |
146 | ||
147 | if (ignorePattern) { | |
148 | ignorePattern = new RegExp(ignorePattern, "u"); | |
149 | } | |
150 | ||
151 | //-------------------------------------------------------------------------- | |
152 | // Helpers | |
153 | //-------------------------------------------------------------------------- | |
154 | ||
155 | /** | |
156 | * Tells if a given comment is trailing: it starts on the current line and | |
157 | * extends to or past the end of the current line. | |
158 | * @param {string} line The source line we want to check for a trailing comment on | |
159 | * @param {number} lineNumber The one-indexed line number for line | |
160 | * @param {ASTNode} comment The comment to inspect | |
161 | * @returns {boolean} If the comment is trailing on the given line | |
162 | */ | |
163 | function isTrailingComment(line, lineNumber, comment) { | |
164 | return comment && | |
165 | (comment.loc.start.line === lineNumber && lineNumber <= comment.loc.end.line) && | |
166 | (comment.loc.end.line > lineNumber || comment.loc.end.column === line.length); | |
167 | } | |
168 | ||
169 | /** | |
170 | * Tells if a comment encompasses the entire line. | |
171 | * @param {string} line The source line with a trailing comment | |
172 | * @param {number} lineNumber The one-indexed line number this is on | |
173 | * @param {ASTNode} comment The comment to remove | |
174 | * @returns {boolean} If the comment covers the entire line | |
175 | */ | |
176 | function isFullLineComment(line, lineNumber, comment) { | |
177 | const start = comment.loc.start, | |
178 | end = comment.loc.end, | |
179 | isFirstTokenOnLine = !line.slice(0, comment.loc.start.column).trim(); | |
180 | ||
181 | return comment && | |
182 | (start.line < lineNumber || (start.line === lineNumber && isFirstTokenOnLine)) && | |
183 | (end.line > lineNumber || (end.line === lineNumber && end.column === line.length)); | |
184 | } | |
185 | ||
186 | /** | |
187 | * Check if a node is a JSXEmptyExpression contained in a single line JSXExpressionContainer. | |
188 | * @param {ASTNode} node A node to check. | |
189 | * @returns {boolean} True if the node is a JSXEmptyExpression contained in a single line JSXExpressionContainer. | |
190 | */ | |
191 | function isJSXEmptyExpressionInSingleLineContainer(node) { | |
192 | if (!node || !node.parent || node.type !== "JSXEmptyExpression" || node.parent.type !== "JSXExpressionContainer") { | |
193 | return false; | |
194 | } | |
195 | ||
196 | const parent = node.parent; | |
197 | ||
198 | return parent.loc.start.line === parent.loc.end.line; | |
199 | } | |
200 | ||
201 | /** | |
202 | * Gets the line after the comment and any remaining trailing whitespace is | |
203 | * stripped. | |
204 | * @param {string} line The source line with a trailing comment | |
205 | * @param {ASTNode} comment The comment to remove | |
206 | * @returns {string} Line without comment and trailing whitespace | |
207 | */ | |
208 | function stripTrailingComment(line, comment) { | |
209 | ||
210 | // loc.column is zero-indexed | |
211 | return line.slice(0, comment.loc.start.column).replace(/\s+$/u, ""); | |
212 | } | |
213 | ||
214 | /** | |
215 | * Ensure that an array exists at [key] on `object`, and add `value` to it. | |
216 | * @param {Object} object the object to mutate | |
217 | * @param {string} key the object's key | |
609c276f | 218 | * @param {any} value the value to add |
eb39fafa DC |
219 | * @returns {void} |
220 | * @private | |
221 | */ | |
222 | function ensureArrayAndPush(object, key, value) { | |
223 | if (!Array.isArray(object[key])) { | |
224 | object[key] = []; | |
225 | } | |
226 | object[key].push(value); | |
227 | } | |
228 | ||
229 | /** | |
230 | * Retrieves an array containing all strings (" or ') in the source code. | |
231 | * @returns {ASTNode[]} An array of string nodes. | |
232 | */ | |
233 | function getAllStrings() { | |
234 | return sourceCode.ast.tokens.filter(token => (token.type === "String" || | |
235 | (token.type === "JSXText" && sourceCode.getNodeByRangeIndex(token.range[0] - 1).type === "JSXAttribute"))); | |
236 | } | |
237 | ||
238 | /** | |
239 | * Retrieves an array containing all template literals in the source code. | |
240 | * @returns {ASTNode[]} An array of template literal nodes. | |
241 | */ | |
242 | function getAllTemplateLiterals() { | |
243 | return sourceCode.ast.tokens.filter(token => token.type === "Template"); | |
244 | } | |
245 | ||
246 | ||
247 | /** | |
248 | * Retrieves an array containing all RegExp literals in the source code. | |
249 | * @returns {ASTNode[]} An array of RegExp literal nodes. | |
250 | */ | |
251 | function getAllRegExpLiterals() { | |
252 | return sourceCode.ast.tokens.filter(token => token.type === "RegularExpression"); | |
253 | } | |
254 | ||
255 | ||
256 | /** | |
257 | * A reducer to group an AST node by line number, both start and end. | |
258 | * @param {Object} acc the accumulator | |
259 | * @param {ASTNode} node the AST node in question | |
260 | * @returns {Object} the modified accumulator | |
261 | * @private | |
262 | */ | |
263 | function groupByLineNumber(acc, node) { | |
264 | for (let i = node.loc.start.line; i <= node.loc.end.line; ++i) { | |
265 | ensureArrayAndPush(acc, i, node); | |
266 | } | |
267 | return acc; | |
268 | } | |
269 | ||
270 | /** | |
271 | * Returns an array of all comments in the source code. | |
272 | * If the element in the array is a JSXEmptyExpression contained with a single line JSXExpressionContainer, | |
273 | * the element is changed with JSXExpressionContainer node. | |
274 | * @returns {ASTNode[]} An array of comment nodes | |
275 | */ | |
276 | function getAllComments() { | |
277 | const comments = []; | |
278 | ||
279 | sourceCode.getAllComments() | |
280 | .forEach(commentNode => { | |
281 | const containingNode = sourceCode.getNodeByRangeIndex(commentNode.range[0]); | |
282 | ||
283 | if (isJSXEmptyExpressionInSingleLineContainer(containingNode)) { | |
284 | ||
285 | // push a unique node only | |
286 | if (comments[comments.length - 1] !== containingNode.parent) { | |
287 | comments.push(containingNode.parent); | |
288 | } | |
289 | } else { | |
290 | comments.push(commentNode); | |
291 | } | |
292 | }); | |
293 | ||
294 | return comments; | |
295 | } | |
296 | ||
297 | /** | |
298 | * Check the program for max length | |
299 | * @param {ASTNode} node Node to examine | |
300 | * @returns {void} | |
301 | * @private | |
302 | */ | |
303 | function checkProgramForMaxLength(node) { | |
304 | ||
305 | // split (honors line-ending) | |
306 | const lines = sourceCode.lines, | |
307 | ||
308 | // list of comments to ignore | |
309 | comments = ignoreComments || maxCommentLength || ignoreTrailingComments ? getAllComments() : []; | |
310 | ||
311 | // we iterate over comments in parallel with the lines | |
312 | let commentsIndex = 0; | |
313 | ||
314 | const strings = getAllStrings(); | |
315 | const stringsByLine = strings.reduce(groupByLineNumber, {}); | |
316 | ||
317 | const templateLiterals = getAllTemplateLiterals(); | |
318 | const templateLiteralsByLine = templateLiterals.reduce(groupByLineNumber, {}); | |
319 | ||
320 | const regExpLiterals = getAllRegExpLiterals(); | |
321 | const regExpLiteralsByLine = regExpLiterals.reduce(groupByLineNumber, {}); | |
322 | ||
323 | lines.forEach((line, i) => { | |
324 | ||
325 | // i is zero-indexed, line numbers are one-indexed | |
326 | const lineNumber = i + 1; | |
327 | ||
328 | /* | |
329 | * if we're checking comment length; we need to know whether this | |
330 | * line is a comment | |
331 | */ | |
332 | let lineIsComment = false; | |
333 | let textToMeasure; | |
334 | ||
335 | /* | |
336 | * We can short-circuit the comment checks if we're already out of | |
337 | * comments to check. | |
338 | */ | |
339 | if (commentsIndex < comments.length) { | |
340 | let comment = null; | |
341 | ||
342 | // iterate over comments until we find one past the current line | |
343 | do { | |
344 | comment = comments[++commentsIndex]; | |
345 | } while (comment && comment.loc.start.line <= lineNumber); | |
346 | ||
347 | // and step back by one | |
348 | comment = comments[--commentsIndex]; | |
349 | ||
350 | if (isFullLineComment(line, lineNumber, comment)) { | |
351 | lineIsComment = true; | |
352 | textToMeasure = line; | |
353 | } else if (ignoreTrailingComments && isTrailingComment(line, lineNumber, comment)) { | |
354 | textToMeasure = stripTrailingComment(line, comment); | |
355 | ||
356 | // ignore multiple trailing comments in the same line | |
357 | let lastIndex = commentsIndex; | |
358 | ||
359 | while (isTrailingComment(textToMeasure, lineNumber, comments[--lastIndex])) { | |
360 | textToMeasure = stripTrailingComment(textToMeasure, comments[lastIndex]); | |
361 | } | |
362 | } else { | |
363 | textToMeasure = line; | |
364 | } | |
365 | } else { | |
366 | textToMeasure = line; | |
367 | } | |
368 | if (ignorePattern && ignorePattern.test(textToMeasure) || | |
369 | ignoreUrls && URL_REGEXP.test(textToMeasure) || | |
370 | ignoreStrings && stringsByLine[lineNumber] || | |
371 | ignoreTemplateLiterals && templateLiteralsByLine[lineNumber] || | |
372 | ignoreRegExpLiterals && regExpLiteralsByLine[lineNumber] | |
373 | ) { | |
374 | ||
375 | // ignore this line | |
376 | return; | |
377 | } | |
378 | ||
379 | const lineLength = computeLineLength(textToMeasure, tabWidth); | |
380 | const commentLengthApplies = lineIsComment && maxCommentLength; | |
381 | ||
382 | if (lineIsComment && ignoreComments) { | |
383 | return; | |
384 | } | |
385 | ||
6f036462 TL |
386 | const loc = { |
387 | start: { | |
388 | line: lineNumber, | |
389 | column: 0 | |
390 | }, | |
391 | end: { | |
392 | line: lineNumber, | |
393 | column: textToMeasure.length | |
394 | } | |
395 | }; | |
396 | ||
eb39fafa DC |
397 | if (commentLengthApplies) { |
398 | if (lineLength > maxCommentLength) { | |
399 | context.report({ | |
400 | node, | |
6f036462 | 401 | loc, |
eb39fafa DC |
402 | messageId: "maxComment", |
403 | data: { | |
404 | lineLength, | |
405 | maxCommentLength | |
406 | } | |
407 | }); | |
408 | } | |
409 | } else if (lineLength > maxLength) { | |
410 | context.report({ | |
411 | node, | |
6f036462 | 412 | loc, |
eb39fafa DC |
413 | messageId: "max", |
414 | data: { | |
415 | lineLength, | |
416 | maxLength | |
417 | } | |
418 | }); | |
419 | } | |
420 | }); | |
421 | } | |
422 | ||
423 | ||
424 | //-------------------------------------------------------------------------- | |
425 | // Public API | |
426 | //-------------------------------------------------------------------------- | |
427 | ||
428 | return { | |
429 | Program: checkProgramForMaxLength | |
430 | }; | |
431 | ||
432 | } | |
433 | }; |