| /** | |
|  * @fileoverview enforce a particular style for multiline comments | |
|  * @author Teddy Katz | |
|  */ | |
| "use strict"; | |
| 
 | |
| const astUtils = require("./utils/ast-utils"); | |
| 
 | |
| //------------------------------------------------------------------------------ | |
| // Rule Definition | |
| //------------------------------------------------------------------------------ | |
|  | |
| /** @type {import('../shared/types').Rule} */ | |
| module.exports = { | |
|     meta: { | |
|         type: "suggestion", | |
| 
 | |
|         docs: { | |
|             description: "Enforce a particular style for multiline comments", | |
|             recommended: false, | |
|             url: "https://eslint.org/docs/latest/rules/multiline-comment-style" | |
|         }, | |
| 
 | |
|         fixable: "whitespace", | |
|         schema: { | |
|             anyOf: [ | |
|                 { | |
|                     type: "array", | |
|                     items: [ | |
|                         { | |
|                             enum: ["starred-block", "bare-block"] | |
|                         } | |
|                     ], | |
|                     additionalItems: false | |
|                 }, | |
|                 { | |
|                     type: "array", | |
|                     items: [ | |
|                         { | |
|                             enum: ["separate-lines"] | |
|                         }, | |
|                         { | |
|                             type: "object", | |
|                             properties: { | |
|                                 checkJSDoc: { | |
|                                     type: "boolean" | |
|                                 } | |
|                             }, | |
|                             additionalProperties: false | |
|                         } | |
|                     ], | |
|                     additionalItems: false | |
|                 } | |
|             ] | |
|         }, | |
|         messages: { | |
|             expectedBlock: "Expected a block comment instead of consecutive line comments.", | |
|             expectedBareBlock: "Expected a block comment without padding stars.", | |
|             startNewline: "Expected a linebreak after '/*'.", | |
|             endNewline: "Expected a linebreak before '*/'.", | |
|             missingStar: "Expected a '*' at the start of this line.", | |
|             alignment: "Expected this line to be aligned with the start of the comment.", | |
|             expectedLines: "Expected multiple line comments instead of a block comment." | |
|         } | |
|     }, | |
| 
 | |
|     create(context) { | |
|         const sourceCode = context.sourceCode; | |
|         const option = context.options[0] || "starred-block"; | |
|         const params = context.options[1] || {}; | |
|         const checkJSDoc = !!params.checkJSDoc; | |
| 
 | |
|         //---------------------------------------------------------------------- | |
|         // Helpers | |
|         //---------------------------------------------------------------------- | |
|  | |
|         /** | |
|          * Checks if a comment line is starred. | |
|          * @param {string} line A string representing a comment line. | |
|          * @returns {boolean} Whether or not the comment line is starred. | |
|          */ | |
|         function isStarredCommentLine(line) { | |
|             return /^\s*\*/u.test(line); | |
|         } | |
| 
 | |
|         /** | |
|          * Checks if a comment group is in starred-block form. | |
|          * @param {Token[]} commentGroup A group of comments, containing either multiple line comments or a single block comment. | |
|          * @returns {boolean} Whether or not the comment group is in starred block form. | |
|          */ | |
|         function isStarredBlockComment([firstComment]) { | |
|             if (firstComment.type !== "Block") { | |
|                 return false; | |
|             } | |
| 
 | |
|             const lines = firstComment.value.split(astUtils.LINEBREAK_MATCHER); | |
| 
 | |
|             // The first and last lines can only contain whitespace. | |
|             return lines.length > 0 && lines.every((line, i) => (i === 0 || i === lines.length - 1 ? /^\s*$/u : /^\s*\*/u).test(line)); | |
|         } | |
| 
 | |
|         /** | |
|          * Checks if a comment group is in JSDoc form. | |
|          * @param {Token[]} commentGroup A group of comments, containing either multiple line comments or a single block comment. | |
|          * @returns {boolean} Whether or not the comment group is in JSDoc form. | |
|          */ | |
|         function isJSDocComment([firstComment]) { | |
|             if (firstComment.type !== "Block") { | |
|                 return false; | |
|             } | |
| 
 | |
|             const lines = firstComment.value.split(astUtils.LINEBREAK_MATCHER); | |
| 
 | |
|             return /^\*\s*$/u.test(lines[0]) && | |
|                 lines.slice(1, -1).every(line => /^\s* /u.test(line)) && | |
|                 /^\s*$/u.test(lines[lines.length - 1]); | |
|         } | |
| 
 | |
|         /** | |
|          * Processes a comment group that is currently in separate-line form, calculating the offset for each line. | |
|          * @param {Token[]} commentGroup A group of comments containing multiple line comments. | |
|          * @returns {string[]} An array of the processed lines. | |
|          */ | |
|         function processSeparateLineComments(commentGroup) { | |
|             const allLinesHaveLeadingSpace = commentGroup | |
|                 .map(({ value }) => value) | |
|                 .filter(line => line.trim().length) | |
|                 .every(line => line.startsWith(" ")); | |
| 
 | |
|             return commentGroup.map(({ value }) => (allLinesHaveLeadingSpace ? value.replace(/^ /u, "") : value)); | |
|         } | |
| 
 | |
|         /** | |
|          * Processes a comment group that is currently in starred-block form, calculating the offset for each line. | |
|          * @param {Token} comment A single block comment token in starred-block form. | |
|          * @returns {string[]} An array of the processed lines. | |
|          */ | |
|         function processStarredBlockComment(comment) { | |
|             const lines = comment.value.split(astUtils.LINEBREAK_MATCHER) | |
|                 .filter((line, i, linesArr) => !(i === 0 || i === linesArr.length - 1)) | |
|                 .map(line => line.replace(/^\s*$/u, "")); | |
|             const allLinesHaveLeadingSpace = lines | |
|                 .map(line => line.replace(/\s*\*/u, "")) | |
|                 .filter(line => line.trim().length) | |
|                 .every(line => line.startsWith(" ")); | |
| 
 | |
|             return lines.map(line => line.replace(allLinesHaveLeadingSpace ? /\s*\* ?/u : /\s*\*/u, "")); | |
|         } | |
| 
 | |
|         /** | |
|          * Processes a comment group that is currently in bare-block form, calculating the offset for each line. | |
|          * @param {Token} comment A single block comment token in bare-block form. | |
|          * @returns {string[]} An array of the processed lines. | |
|          */ | |
|         function processBareBlockComment(comment) { | |
|             const lines = comment.value.split(astUtils.LINEBREAK_MATCHER).map(line => line.replace(/^\s*$/u, "")); | |
|             const leadingWhitespace = `${sourceCode.text.slice(comment.range[0] - comment.loc.start.column, comment.range[0])}   `; | |
|             let offset = ""; | |
| 
 | |
|             /* | |
|              * Calculate the offset of the least indented line and use that as the basis for offsetting all the lines. | |
|              * The first line should not be checked because it is inline with the opening block comment delimiter. | |
|              */ | |
|             for (const [i, line] of lines.entries()) { | |
|                 if (!line.trim().length || i === 0) { | |
|                     continue; | |
|                 } | |
| 
 | |
|                 const [, lineOffset] = line.match(/^(\s*\*?\s*)/u); | |
| 
 | |
|                 if (lineOffset.length < leadingWhitespace.length) { | |
|                     const newOffset = leadingWhitespace.slice(lineOffset.length - leadingWhitespace.length); | |
| 
 | |
|                     if (newOffset.length > offset.length) { | |
|                         offset = newOffset; | |
|                     } | |
|                 } | |
|             } | |
| 
 | |
|             return lines.map(line => { | |
|                 const match = line.match(/^(\s*\*?\s*)(.*)/u); | |
|                 const [, lineOffset, lineContents] = match; | |
| 
 | |
|                 if (lineOffset.length > leadingWhitespace.length) { | |
|                     return `${lineOffset.slice(leadingWhitespace.length - (offset.length + lineOffset.length))}${lineContents}`; | |
|                 } | |
| 
 | |
|                 if (lineOffset.length < leadingWhitespace.length) { | |
|                     return `${lineOffset.slice(leadingWhitespace.length)}${lineContents}`; | |
|                 } | |
| 
 | |
|                 return lineContents; | |
|             }); | |
|         } | |
| 
 | |
|         /** | |
|          * Gets a list of comment lines in a group, formatting leading whitespace as necessary. | |
|          * @param {Token[]} commentGroup A group of comments containing either multiple line comments or a single block comment. | |
|          * @returns {string[]} A list of comment lines. | |
|          */ | |
|         function getCommentLines(commentGroup) { | |
|             const [firstComment] = commentGroup; | |
| 
 | |
|             if (firstComment.type === "Line") { | |
|                 return processSeparateLineComments(commentGroup); | |
|             } | |
| 
 | |
|             if (isStarredBlockComment(commentGroup)) { | |
|                 return processStarredBlockComment(firstComment); | |
|             } | |
| 
 | |
|             return processBareBlockComment(firstComment); | |
|         } | |
| 
 | |
|         /** | |
|          * Gets the initial offset (whitespace) from the beginning of a line to a given comment token. | |
|          * @param {Token} comment The token to check. | |
|          * @returns {string} The offset from the beginning of a line to the token. | |
|          */ | |
|         function getInitialOffset(comment) { | |
|             return sourceCode.text.slice(comment.range[0] - comment.loc.start.column, comment.range[0]); | |
|         } | |
| 
 | |
|         /** | |
|          * Converts a comment into starred-block form | |
|          * @param {Token} firstComment The first comment of the group being converted | |
|          * @param {string[]} commentLinesList A list of lines to appear in the new starred-block comment | |
|          * @returns {string} A representation of the comment value in starred-block form, excluding start and end markers | |
|          */ | |
|         function convertToStarredBlock(firstComment, commentLinesList) { | |
|             const initialOffset = getInitialOffset(firstComment); | |
| 
 | |
|             return `/*\n${commentLinesList.map(line => `${initialOffset} * ${line}`).join("\n")}\n${initialOffset} */`; | |
|         } | |
| 
 | |
|         /** | |
|          * Converts a comment into separate-line form | |
|          * @param {Token} firstComment The first comment of the group being converted | |
|          * @param {string[]} commentLinesList A list of lines to appear in the new starred-block comment | |
|          * @returns {string} A representation of the comment value in separate-line form | |
|          */ | |
|         function convertToSeparateLines(firstComment, commentLinesList) { | |
|             return commentLinesList.map(line => `// ${line}`).join(`\n${getInitialOffset(firstComment)}`); | |
|         } | |
| 
 | |
|         /** | |
|          * Converts a comment into bare-block form | |
|          * @param {Token} firstComment The first comment of the group being converted | |
|          * @param {string[]} commentLinesList A list of lines to appear in the new starred-block comment | |
|          * @returns {string} A representation of the comment value in bare-block form | |
|          */ | |
|         function convertToBlock(firstComment, commentLinesList) { | |
|             return `/* ${commentLinesList.join(`\n${getInitialOffset(firstComment)}   `)} */`; | |
|         } | |
| 
 | |
|         /** | |
|          * Each method checks a group of comments to see if it's valid according to the given option. | |
|          * @param {Token[]} commentGroup A list of comments that appear together. This will either contain a single | |
|          * block comment or multiple line comments. | |
|          * @returns {void} | |
|          */ | |
|         const commentGroupCheckers = { | |
|             "starred-block"(commentGroup) { | |
|                 const [firstComment] = commentGroup; | |
|                 const commentLines = getCommentLines(commentGroup); | |
| 
 | |
|                 if (commentLines.some(value => value.includes("*/"))) { | |
|                     return; | |
|                 } | |
| 
 | |
|                 if (commentGroup.length > 1) { | |
|                     context.report({ | |
|                         loc: { | |
|                             start: firstComment.loc.start, | |
|                             end: commentGroup[commentGroup.length - 1].loc.end | |
|                         }, | |
|                         messageId: "expectedBlock", | |
|                         fix(fixer) { | |
|                             const range = [firstComment.range[0], commentGroup[commentGroup.length - 1].range[1]]; | |
| 
 | |
|                             return commentLines.some(value => value.startsWith("/")) | |
|                                 ? null | |
|                                 : fixer.replaceTextRange(range, convertToStarredBlock(firstComment, commentLines)); | |
|                         } | |
|                     }); | |
|                 } else { | |
|                     const lines = firstComment.value.split(astUtils.LINEBREAK_MATCHER); | |
|                     const expectedLeadingWhitespace = getInitialOffset(firstComment); | |
|                     const expectedLinePrefix = `${expectedLeadingWhitespace} *`; | |
| 
 | |
|                     if (!/^\*?\s*$/u.test(lines[0])) { | |
|                         const start = firstComment.value.startsWith("*") ? firstComment.range[0] + 1 : firstComment.range[0]; | |
| 
 | |
|                         context.report({ | |
|                             loc: { | |
|                                 start: firstComment.loc.start, | |
|                                 end: { line: firstComment.loc.start.line, column: firstComment.loc.start.column + 2 } | |
|                             }, | |
|                             messageId: "startNewline", | |
|                             fix: fixer => fixer.insertTextAfterRange([start, start + 2], `\n${expectedLinePrefix}`) | |
|                         }); | |
|                     } | |
| 
 | |
|                     if (!/^\s*$/u.test(lines[lines.length - 1])) { | |
|                         context.report({ | |
|                             loc: { | |
|                                 start: { line: firstComment.loc.end.line, column: firstComment.loc.end.column - 2 }, | |
|                                 end: firstComment.loc.end | |
|                             }, | |
|                             messageId: "endNewline", | |
|                             fix: fixer => fixer.replaceTextRange([firstComment.range[1] - 2, firstComment.range[1]], `\n${expectedLinePrefix}/`) | |
|                         }); | |
|                     } | |
| 
 | |
|                     for (let lineNumber = firstComment.loc.start.line + 1; lineNumber <= firstComment.loc.end.line; lineNumber++) { | |
|                         const lineText = sourceCode.lines[lineNumber - 1]; | |
|                         const errorType = isStarredCommentLine(lineText) | |
|                             ? "alignment" | |
|                             : "missingStar"; | |
| 
 | |
|                         if (!lineText.startsWith(expectedLinePrefix)) { | |
|                             context.report({ | |
|                                 loc: { | |
|                                     start: { line: lineNumber, column: 0 }, | |
|                                     end: { line: lineNumber, column: lineText.length } | |
|                                 }, | |
|                                 messageId: errorType, | |
|                                 fix(fixer) { | |
|                                     const lineStartIndex = sourceCode.getIndexFromLoc({ line: lineNumber, column: 0 }); | |
| 
 | |
|                                     if (errorType === "alignment") { | |
|                                         const [, commentTextPrefix = ""] = lineText.match(/^(\s*\*)/u) || []; | |
|                                         const commentTextStartIndex = lineStartIndex + commentTextPrefix.length; | |
| 
 | |
|                                         return fixer.replaceTextRange([lineStartIndex, commentTextStartIndex], expectedLinePrefix); | |
|                                     } | |
| 
 | |
|                                     const [, commentTextPrefix = ""] = lineText.match(/^(\s*)/u) || []; | |
|                                     const commentTextStartIndex = lineStartIndex + commentTextPrefix.length; | |
|                                     let offset; | |
| 
 | |
|                                     for (const [idx, line] of lines.entries()) { | |
|                                         if (!/\S+/u.test(line)) { | |
|                                             continue; | |
|                                         } | |
| 
 | |
|                                         const lineTextToAlignWith = sourceCode.lines[firstComment.loc.start.line - 1 + idx]; | |
|                                         const [, prefix = "", initialOffset = ""] = lineTextToAlignWith.match(/^(\s*(?:\/?\*)?(\s*))/u) || []; | |
| 
 | |
|                                         offset = `${commentTextPrefix.slice(prefix.length)}${initialOffset}`; | |
| 
 | |
|                                         if (/^\s*\//u.test(lineText) && offset.length === 0) { | |
|                                             offset += " "; | |
|                                         } | |
|                                         break; | |
|                                     } | |
| 
 | |
|                                     return fixer.replaceTextRange([lineStartIndex, commentTextStartIndex], `${expectedLinePrefix}${offset}`); | |
|                                 } | |
|                             }); | |
|                         } | |
|                     } | |
|                 } | |
|             }, | |
|             "separate-lines"(commentGroup) { | |
|                 const [firstComment] = commentGroup; | |
| 
 | |
|                 const isJSDoc = isJSDocComment(commentGroup); | |
| 
 | |
|                 if (firstComment.type !== "Block" || (!checkJSDoc && isJSDoc)) { | |
|                     return; | |
|                 } | |
| 
 | |
|                 let commentLines = getCommentLines(commentGroup); | |
| 
 | |
|                 if (isJSDoc) { | |
|                     commentLines = commentLines.slice(1, commentLines.length - 1); | |
|                 } | |
| 
 | |
|                 const tokenAfter = sourceCode.getTokenAfter(firstComment, { includeComments: true }); | |
| 
 | |
|                 if (tokenAfter && firstComment.loc.end.line === tokenAfter.loc.start.line) { | |
|                     return; | |
|                 } | |
| 
 | |
|                 context.report({ | |
|                     loc: { | |
|                         start: firstComment.loc.start, | |
|                         end: { line: firstComment.loc.start.line, column: firstComment.loc.start.column + 2 } | |
|                     }, | |
|                     messageId: "expectedLines", | |
|                     fix(fixer) { | |
|                         return fixer.replaceText(firstComment, convertToSeparateLines(firstComment, commentLines)); | |
|                     } | |
|                 }); | |
|             }, | |
|             "bare-block"(commentGroup) { | |
|                 if (isJSDocComment(commentGroup)) { | |
|                     return; | |
|                 } | |
| 
 | |
|                 const [firstComment] = commentGroup; | |
|                 const commentLines = getCommentLines(commentGroup); | |
| 
 | |
|                 // Disallows consecutive line comments in favor of using a block comment. | |
|                 if (firstComment.type === "Line" && commentLines.length > 1 && | |
|                     !commentLines.some(value => value.includes("*/"))) { | |
|                     context.report({ | |
|                         loc: { | |
|                             start: firstComment.loc.start, | |
|                             end: commentGroup[commentGroup.length - 1].loc.end | |
|                         }, | |
|                         messageId: "expectedBlock", | |
|                         fix(fixer) { | |
|                             return fixer.replaceTextRange( | |
|                                 [firstComment.range[0], commentGroup[commentGroup.length - 1].range[1]], | |
|                                 convertToBlock(firstComment, commentLines) | |
|                             ); | |
|                         } | |
|                     }); | |
|                 } | |
| 
 | |
|                 // Prohibits block comments from having a * at the beginning of each line. | |
|                 if (isStarredBlockComment(commentGroup)) { | |
|                     context.report({ | |
|                         loc: { | |
|                             start: firstComment.loc.start, | |
|                             end: { line: firstComment.loc.start.line, column: firstComment.loc.start.column + 2 } | |
|                         }, | |
|                         messageId: "expectedBareBlock", | |
|                         fix(fixer) { | |
|                             return fixer.replaceText(firstComment, convertToBlock(firstComment, commentLines)); | |
|                         } | |
|                     }); | |
|                 } | |
|             } | |
|         }; | |
| 
 | |
|         //---------------------------------------------------------------------- | |
|         // Public | |
|         //---------------------------------------------------------------------- | |
|  | |
|         return { | |
|             Program() { | |
|                 return sourceCode.getAllComments() | |
|                     .filter(comment => comment.type !== "Shebang") | |
|                     .filter(comment => !astUtils.COMMENTS_IGNORE_PATTERN.test(comment.value)) | |
|                     .filter(comment => { | |
|                         const tokenBefore = sourceCode.getTokenBefore(comment, { includeComments: true }); | |
| 
 | |
|                         return !tokenBefore || tokenBefore.loc.end.line < comment.loc.start.line; | |
|                     }) | |
|                     .reduce((commentGroups, comment, index, commentList) => { | |
|                         const tokenBefore = sourceCode.getTokenBefore(comment, { includeComments: true }); | |
| 
 | |
|                         if ( | |
|                             comment.type === "Line" && | |
|                             index && commentList[index - 1].type === "Line" && | |
|                             tokenBefore && tokenBefore.loc.end.line === comment.loc.start.line - 1 && | |
|                             tokenBefore === commentList[index - 1] | |
|                         ) { | |
|                             commentGroups[commentGroups.length - 1].push(comment); | |
|                         } else { | |
|                             commentGroups.push([comment]); | |
|                         } | |
| 
 | |
|                         return commentGroups; | |
|                     }, []) | |
|                     .filter(commentGroup => !(commentGroup.length === 1 && commentGroup[0].loc.start.line === commentGroup[0].loc.end.line)) | |
|                     .forEach(commentGroupCheckers[option]); | |
|             } | |
|         }; | |
|     } | |
| };
 |