utils.js

/**
 * @author Toru Nagashima <https://github.com/mysticatea>
 * See LICENSE file in root directory for full license.
 */
"use strict"

const escapeStringRegexp = require("escape-string-regexp")
const LINE_PATTERN = /[^\r\n\u2028\u2029]*(?:\r\n|[\r\n\u2028\u2029]|$)/gu

const DIRECTIVE_PATTERN = /^(eslint(?:-env|-enable|-disable(?:(?:-next)?-line)?)?|exported|globals?)(?:\s|$)/u
const LINE_COMMENT_PATTERN = /^eslint-disable-(next-)?line$/u

module.exports = {
    /**
     * Make the location ignoring `eslint-disable` comments.
     *
     * @param {object} location - The location to convert.
     * @returns {object} Converted location.
     */
    toForceLocation(location) {
        return {
            start: {
                line: location.start.line,
                column: -1,
            },
            end: location.end,
        }
    },

    /**
     * Calculate the location of the given rule in the given comment token.
     *
     * @param {Token} comment - The comment token to calculate.
     * @param {string|null} ruleId - The rule name to calculate.
     * @returns {object} The location of the given information.
     */
    toRuleIdLocation(comment, ruleId) {
        if (ruleId == null) {
            return module.exports.toForceLocation(comment.loc)
        }

        const lines = comment.value.match(LINE_PATTERN)
        //eslint-disable-next-line require-unicode-regexp
        const ruleIdPattern = new RegExp(
            `([\\s,]|^)${escapeStringRegexp(ruleId)}(?:[\\s,]|$)`
        )

        {
            const m = ruleIdPattern.exec(lines[0])
            if (m != null) {
                const start = comment.loc.start
                return {
                    start: {
                        line: start.line,
                        column: 2 + start.column + m.index + m[1].length,
                    },
                    end: {
                        line: start.line,
                        column:
                            2 +
                            start.column +
                            m.index +
                            m[1].length +
                            ruleId.length,
                    },
                }
            }
        }

        for (let i = 1; i < lines.length; ++i) {
            const m = ruleIdPattern.exec(lines[i])
            if (m != null) {
                const start = comment.loc.start
                return {
                    start: {
                        line: start.line + i,
                        column: m.index + m[1].length,
                    },
                    end: {
                        line: start.line + i,
                        column: m.index + m[1].length + ruleId.length,
                    },
                }
            }
        }

        /*istanbul ignore next : foolproof */
        return comment.loc
    },

    /**
     * Checks `a` is less than `b` or `a` equals `b`.
     *
     * @param {{line: number, column: number}} a - A location to compare.
     * @param {{line: number, column: number}} b - Another location to compare.
     * @returns {boolean} `true` if `a` is less than `b` or `a` equals `b`.
     */
    lte(a, b) {
        return a.line < b.line || (a.line === b.line && a.column <= b.column)
    },

    /**
     * Parse the given comment token as a directive comment.
     *
     * @param {Token} comment - The comment token to parse.
     * @returns {{kind: string, value: string, description: string | null}|null} The parsed data of the given comment. If `null`, it is not a directive comment.
     */
    parseDirectiveComment(comment) {
        const { text, description } = divideDirectiveComment(comment.value)
        const match = DIRECTIVE_PATTERN.exec(text)

        if (!match) {
            return null
        }
        const directiveText = match[1]
        const lineCommentSupported = LINE_COMMENT_PATTERN.test(directiveText)

        if (comment.type === "Line" && !lineCommentSupported) {
            return null
        }

        if (
            lineCommentSupported &&
            comment.loc.start.line !== comment.loc.end.line
        ) {
            // disable-line comment should not span multiple lines.
            return null
        }

        const directiveValue = text.slice(match.index + directiveText.length)

        return {
            kind: directiveText,
            value: directiveValue.trim(),
            description,
        }
    },

    /**
     * Creates an object hashmap
     * @param {Object[]} values
     * @param {Function} getKey
     */
    keyBy(values, getKey) {
        return values.reduce((accumulator, value) => {
            accumulator[getKey(value)] = value
            return accumulator
        }, {})
    },
}

/**
 * Divides and trims description text and directive comments.
 * @param {string} value The comment text to strip.
 * @returns {{text: string, description: string | null}} The stripped text.
 */
function divideDirectiveComment(value) {
    const divided = value.split(/\s-{2,}\s/u)
    const text = divided[0].trim()
    return {
        text,
        description: divided.length > 1 ? divided[1].trim() : null,
    }
}