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Reimplement helpers.isBlankLine to fix an instance of "Polynomial regular expression used on uncontrolled data".

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David Anson 2022-02-11 21:54:43 -08:00
parent b9474e84a3
commit 1c89dd5776
3 changed files with 76 additions and 27 deletions
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45
helpers/helpers.js
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@ -65,22 +65,43 @@ module.exports.isObject = function isObject(obj) {
return (obj !== null) && (typeof obj === "object") && !Array.isArray(obj);
};
// Returns true iff the input line is blank (no content)
// Example: Contains nothing, whitespace, or comment (unclosed start/end okay)
module.exports.isBlankLine = function isBlankLine(line) {
// Call to String.replace follows best practices and is not a security check
// False-positive for js/incomplete-multi-character-sanitization
/**
* Returns true iff the input line is blank (contains nothing, whitespace, or
* comments (unclosed start/end comments allowed)).
*
* @param {string} line Input line.
* @returns {boolean} True iff line is blank.
*/
function isBlankLine(line) {
const startComment = "<!--";
const endComment = "-->";
const removeComments = (s) => {
// eslint-disable-next-line no-constant-condition
while (true) {
const start = s.indexOf(startComment);
const end = s.indexOf(endComment);
if ((end !== -1) && ((start === -1) || (end < start))) {
// Unmatched end comment is first
s = s.slice(end + endComment.length);
} else if ((start !== -1) && (end !== -1)) {
// Start comment is before end comment
s = s.slice(0, start) + s.slice(end + endComment.length);
} else if ((start !== -1) && (end === -1)) {
// Unmatched start comment is last
s = s.slice(0, start);
} else {
// No more comments to remove
return s;
}
}
};
return (
!line ||
!line.trim() ||
!line
.replace(/<!--.*?-->/g, "")
.replace(/<!--.*$/g, "")
.replace(/^.*-->/g, "")
.replace(/>/g, "")
.trim()
!removeComments(line).replace(/>/g, "").trim()
);
};
}
module.exports.isBlankLine = isBlankLine;
/**
* Compare function for Array.prototype.sort for ascending order of numbers.