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/**
* @fileoverview A module that filters reported problems based on `eslint-disable` and `eslint-enable` comments
* @author Teddy Katz
*/
"use strict";
//------------------------------------------------------------------------------
// Typedefs
//------------------------------------------------------------------------------
/** @typedef {import("../shared/types").LintMessage} LintMessage */
//------------------------------------------------------------------------------
// Module Definition
//------------------------------------------------------------------------------
const escapeRegExp = require("escape-string-regexp");
/**
* Compares the locations of two objects in a source file
* @param {{line: number, column: number}} itemA The first object
* @param {{line: number, column: number}} itemB The second object
* @returns {number} A value less than 1 if itemA appears before itemB in the source file, greater than 1 if
* itemA appears after itemB in the source file, or 0 if itemA and itemB have the same location.
*/
function compareLocations(itemA, itemB) {
return itemA.line - itemB.line || itemA.column - itemB.column;
}
/**
* Groups a set of directives into sub-arrays by their parent comment.
* @param {Iterable<Directive>} directives Unused directives to be removed.
* @returns {Directive[][]} Directives grouped by their parent comment.
*/
function groupByParentComment(directives) {
const groups = new Map();
for (const directive of directives) {
const { unprocessedDirective: { parentComment } } = directive;
if (groups.has(parentComment)) {
groups.get(parentComment).push(directive);
} else {
groups.set(parentComment, [directive]);
}
}
return [...groups.values()];
}
/**
* Creates removal details for a set of directives within the same comment.
* @param {Directive[]} directives Unused directives to be removed.
* @param {Token} commentToken The backing Comment token.
* @returns {{ description, fix, unprocessedDirective }[]} Details for later creation of output Problems.
*/
function createIndividualDirectivesRemoval(directives, commentToken) {
/*
* `commentToken.value` starts right after `//` or `/*`.
* All calculated offsets will be relative to this index.
*/
const commentValueStart = commentToken.range[0] + "//".length;
// Find where the list of rules starts. `\S+` matches with the directive name (e.g. `eslint-disable-line`)
const listStartOffset = /^\s*\S+\s+/u.exec(commentToken.value)[0].length;
/*
* Get the list text without any surrounding whitespace. In order to preserve the original
* formatting, we don't want to change that whitespace.
*
* // eslint-disable-line rule-one , rule-two , rule-three -- comment
* ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
*/
const listText = commentToken.value
.slice(listStartOffset) // remove directive name and all whitespace before the list
.split(/\s-{2,}\s/u)[0] // remove `-- comment`, if it exists
.trimEnd(); // remove all whitespace after the list
/*
* We can assume that `listText` contains multiple elements.
* Otherwise, this function wouldn't be called - if there is
* only one rule in the list, then the whole comment must be removed.
*/
return directives.map(directive => {
const { ruleId } = directive;
const regex = new RegExp(String.raw`(?:^|\s*,\s*)(?<quote>['"]?)${escapeRegExp(ruleId)}\k<quote>(?:\s*,\s*|$)`, "u");
const match = regex.exec(listText);
const matchedText = match[0];
const matchStartOffset = listStartOffset + match.index;
const matchEndOffset = matchStartOffset + matchedText.length;
const firstIndexOfComma = matchedText.indexOf(",");
const lastIndexOfComma = matchedText.lastIndexOf(",");
let removalStartOffset, removalEndOffset;
if (firstIndexOfComma !== lastIndexOfComma) {
/*
* Since there are two commas, this must one of the elements in the middle of the list.
* Matched range starts where the previous rule name ends, and ends where the next rule name starts.
*
* // eslint-disable-line rule-one , rule-two , rule-three -- comment
* ^^^^^^^^^^^^^^
*
* We want to remove only the content between the two commas, and also one of the commas.
*
* // eslint-disable-line rule-one , rule-two , rule-three -- comment
* ^^^^^^^^^^^
*/
removalStartOffset = matchStartOffset + firstIndexOfComma;
removalEndOffset = matchStartOffset + lastIndexOfComma;
} else {
/*
* This is either the first element or the last element.
*
* If this is the first element, matched range starts where the first rule name starts
* and ends where the second rule name starts. This is exactly the range we want
* to remove so that the second rule name will start where the first one was starting
* and thus preserve the original formatting.
*
* // eslint-disable-line rule-one , rule-two , rule-three -- comment
* ^^^^^^^^^^^
*
* Similarly, if this is the last element, we've already matched the range we want to
* remove. The previous rule name will end where the last one was ending, relative
* to the content on the right side.
*
* // eslint-disable-line rule-one , rule-two , rule-three -- comment
* ^^^^^^^^^^^^^
*/
removalStartOffset = matchStartOffset;
removalEndOffset = matchEndOffset;
}
return {
description: `'${ruleId}'`,
fix: {
range: [
commentValueStart + removalStartOffset,
commentValueStart + removalEndOffset
],
text: ""
},
unprocessedDirective: directive.unprocessedDirective
};
});
}
/**
* Creates a description of deleting an entire unused disable comment.
* @param {Directive[]} directives Unused directives to be removed.
* @param {Token} commentToken The backing Comment token.
* @returns {{ description, fix, unprocessedDirective }} Details for later creation of an output Problem.
*/
function createCommentRemoval(directives, commentToken) {
const { range } = commentToken;
const ruleIds = directives.filter(directive => directive.ruleId).map(directive => `'${directive.ruleId}'`);
return {
description: ruleIds.length <= 2
? ruleIds.join(" or ")
: `${ruleIds.slice(0, ruleIds.length - 1).join(", ")}, or ${ruleIds[ruleIds.length - 1]}`,
fix: {
range,
text: " "
},
unprocessedDirective: directives[0].unprocessedDirective
};
}
/**
* Parses details from directives to create output Problems.
* @param {Iterable<Directive>} allDirectives Unused directives to be removed.
* @returns {{ description, fix, unprocessedDirective }[]} Details for later creation of output Problems.
*/
function processUnusedDirectives(allDirectives) {
const directiveGroups = groupByParentComment(allDirectives);
return directiveGroups.flatMap(
directives => {
const { parentComment } = directives[0].unprocessedDirective;
const remainingRuleIds = new Set(parentComment.ruleIds);
for (const directive of directives) {
remainingRuleIds.delete(directive.ruleId);
}
return remainingRuleIds.size
? createIndividualDirectivesRemoval(directives, parentComment.commentToken)
: [createCommentRemoval(directives, parentComment.commentToken)];
}
);
}
/**
* Collect eslint-enable comments that are removing suppressions by eslint-disable comments.
* @param {Directive[]} directives The directives to check.
* @returns {Set<Directive>} The used eslint-enable comments
*/
function collectUsedEnableDirectives(directives) {
/**
* A Map of `eslint-enable` keyed by ruleIds that may be marked as used.
* If `eslint-enable` does not have a ruleId, the key will be `null`.
* @type {Map<string|null, Directive>}
*/
const enabledRules = new Map();
/**
* A Set of `eslint-enable` marked as used.
* It is also the return value of `collectUsedEnableDirectives` function.
* @type {Set<Directive>}
*/
const usedEnableDirectives = new Set();
/*
* Checks the directives backwards to see if the encountered `eslint-enable` is used by the previous `eslint-disable`,
* and if so, stores the `eslint-enable` in `usedEnableDirectives`.
*/
for (let index = directives.length - 1; index >= 0; index--) {
const directive = directives[index];
if (directive.type === "disable") {
if (enabledRules.size === 0) {
continue;
}
if (directive.ruleId === null) {
// If encounter `eslint-disable` without ruleId,
// mark all `eslint-enable` currently held in enabledRules as used.
// e.g.
// /* eslint-disable */ <- current directive
// /* eslint-enable rule-id1 */ <- used
// /* eslint-enable rule-id2 */ <- used
// /* eslint-enable */ <- used
for (const enableDirective of enabledRules.values()) {
usedEnableDirectives.add(enableDirective);
}
enabledRules.clear();
} else {
const enableDirective = enabledRules.get(directive.ruleId);
if (enableDirective) {
// If encounter `eslint-disable` with ruleId, and there is an `eslint-enable` with the same ruleId in enabledRules,
// mark `eslint-enable` with ruleId as used.
// e.g.
// /* eslint-disable rule-id */ <- current directive
// /* eslint-enable rule-id */ <- used
usedEnableDirectives.add(enableDirective);
} else {
const enabledDirectiveWithoutRuleId = enabledRules.get(null);
if (enabledDirectiveWithoutRuleId) {
// If encounter `eslint-disable` with ruleId, and there is no `eslint-enable` with the same ruleId in enabledRules,
// mark `eslint-enable` without ruleId as used.
// e.g.
// /* eslint-disable rule-id */ <- current directive
// /* eslint-enable */ <- used
usedEnableDirectives.add(enabledDirectiveWithoutRuleId);
}
}
}
} else if (directive.type === "enable") {
if (directive.ruleId === null) {
// If encounter `eslint-enable` without ruleId, the `eslint-enable` that follows it are unused.
// So clear enabledRules.
// e.g.
// /* eslint-enable */ <- current directive
// /* eslint-enable rule-id *// <- unused
// /* eslint-enable */ <- unused
enabledRules.clear();
enabledRules.set(null, directive);
} else {
enabledRules.set(directive.ruleId, directive);
}
}
}
return usedEnableDirectives;
}
/**
* This is the same as the exported function, except that it
* doesn't handle disable-line and disable-next-line directives, and it always reports unused
* disable directives.
* @param {Object} options options for applying directives. This is the same as the options
* for the exported function, except that `reportUnusedDisableDirectives` is not supported
* (this function always reports unused disable directives).
* @returns {{problems: LintMessage[], unusedDirectives: LintMessage[]}} An object with a list
* of problems (including suppressed ones) and unused eslint-disable directives
*/
function applyDirectives(options) {
const problems = [];
const usedDisableDirectives = new Set();
for (const problem of options.problems) {
let disableDirectivesForProblem = [];
let nextDirectiveIndex = 0;
while (
nextDirectiveIndex < options.directives.length &&
compareLocations(options.directives[nextDirectiveIndex], problem) <= 0
) {
const directive = options.directives[nextDirectiveIndex++];
if (directive.ruleId === null || directive.ruleId === problem.ruleId) {
switch (directive.type) {
case "disable":
disableDirectivesForProblem.push(directive);
break;
case "enable":
disableDirectivesForProblem = [];
break;
// no default
}
}
}
if (disableDirectivesForProblem.length > 0) {
const suppressions = disableDirectivesForProblem.map(directive => ({
kind: "directive",
justification: directive.unprocessedDirective.justification
}));
if (problem.suppressions) {
problem.suppressions = problem.suppressions.concat(suppressions);
} else {
problem.suppressions = suppressions;
usedDisableDirectives.add(disableDirectivesForProblem[disableDirectivesForProblem.length - 1]);
}
}
problems.push(problem);
}
const unusedDisableDirectivesToReport = options.directives
.filter(directive => directive.type === "disable" && !usedDisableDirectives.has(directive));
const unusedEnableDirectivesToReport = new Set(
options.directives.filter(directive => directive.unprocessedDirective.type === "enable")
);
/*
* If directives has the eslint-enable directive,
* check whether the eslint-enable comment is used.
*/
if (unusedEnableDirectivesToReport.size > 0) {
for (const directive of collectUsedEnableDirectives(options.directives)) {
unusedEnableDirectivesToReport.delete(directive);
}
}
const processed = processUnusedDirectives(unusedDisableDirectivesToReport)
.concat(processUnusedDirectives(unusedEnableDirectivesToReport));
const unusedDirectives = processed
.map(({ description, fix, unprocessedDirective }) => {
const { parentComment, type, line, column } = unprocessedDirective;
let message;
if (type === "enable") {
message = description
? `Unused eslint-enable directive (no matching eslint-disable directives were found for ${description}).`
: "Unused eslint-enable directive (no matching eslint-disable directives were found).";
} else {
message = description
? `Unused eslint-disable directive (no problems were reported from ${description}).`
: "Unused eslint-disable directive (no problems were reported).";
}
return {
ruleId: null,
message,
line: type === "disable-next-line" ? parentComment.commentToken.loc.start.line : line,
column: type === "disable-next-line" ? parentComment.commentToken.loc.start.column + 1 : column,
severity: options.reportUnusedDisableDirectives === "warn" ? 1 : 2,
nodeType: null,
...options.disableFixes ? {} : { fix }
};
});
return { problems, unusedDirectives };
}
/**
* Given a list of directive comments (i.e. metadata about eslint-disable and eslint-enable comments) and a list
* of reported problems, adds the suppression information to the problems.
* @param {Object} options Information about directives and problems
* @param {{
* type: ("disable"|"enable"|"disable-line"|"disable-next-line"),
* ruleId: (string|null),
* line: number,
* column: number,
* justification: string
* }} options.directives Directive comments found in the file, with one-based columns.
* Two directive comments can only have the same location if they also have the same type (e.g. a single eslint-disable
* comment for two different rules is represented as two directives).
* @param {{ruleId: (string|null), line: number, column: number}[]} options.problems
* A list of problems reported by rules, sorted by increasing location in the file, with one-based columns.
* @param {"off" | "warn" | "error"} options.reportUnusedDisableDirectives If `"warn"` or `"error"`, adds additional problems for unused directives
* @param {boolean} options.disableFixes If true, it doesn't make `fix` properties.
* @returns {{ruleId: (string|null), line: number, column: number, suppressions?: {kind: string, justification: string}}[]}
* An object with a list of reported problems, the suppressed of which contain the suppression information.
*/
module.exports = ({ directives, disableFixes, problems, reportUnusedDisableDirectives = "off" }) => {
const blockDirectives = directives
.filter(directive => directive.type === "disable" || directive.type === "enable")
.map(directive => Object.assign({}, directive, { unprocessedDirective: directive }))
.sort(compareLocations);
const lineDirectives = directives.flatMap(directive => {
switch (directive.type) {
case "disable":
case "enable":
return [];
case "disable-line":
return [
{ type: "disable", line: directive.line, column: 1, ruleId: directive.ruleId, unprocessedDirective: directive },
{ type: "enable", line: directive.line + 1, column: 0, ruleId: directive.ruleId, unprocessedDirective: directive }
];
case "disable-next-line":
return [
{ type: "disable", line: directive.line + 1, column: 1, ruleId: directive.ruleId, unprocessedDirective: directive },
{ type: "enable", line: directive.line + 2, column: 0, ruleId: directive.ruleId, unprocessedDirective: directive }
];
default:
throw new TypeError(`Unrecognized directive type '${directive.type}'`);
}
}).sort(compareLocations);
const blockDirectivesResult = applyDirectives({
problems,
directives: blockDirectives,
disableFixes,
reportUnusedDisableDirectives
});
const lineDirectivesResult = applyDirectives({
problems: blockDirectivesResult.problems,
directives: lineDirectives,
disableFixes,
reportUnusedDisableDirectives
});
return reportUnusedDisableDirectives !== "off"
? lineDirectivesResult.problems
.concat(blockDirectivesResult.unusedDirectives)
.concat(lineDirectivesResult.unusedDirectives)
.sort(compareLocations)
: lineDirectivesResult.problems;
};