OwlCyberSecurity - MANAGER

Edit File: rewrite-pattern.js

'use strict';

const generate = require('regjsgen').generate;
const parse = require('regjsparser').parse;
const regenerate = require('regenerate');
const unicodeMatchProperty = require('unicode-match-property-ecmascript');
const unicodeMatchPropertyValue = require('unicode-match-property-value-ecmascript');
const iuMappings = require('./data/iu-mappings.js');
const iBMPMappings = require('./data/i-bmp-mappings.js');
const iuFoldings = require('./data/iu-foldings.js');
const ESCAPE_SETS = require('./data/character-class-escape-sets.js');
const { UNICODE_SET, UNICODE_IV_SET } = require('./data/all-characters.js');

function regenerateContainsAstral(regenerateData) {
	const data = regenerateData.data;
	return data.length >= 1 && data[data.length - 1] >= 0x10000;
}

// https://tc39.es/ecma262/#prod-SyntaxCharacter
const SYNTAX_CHARS = /[\\^$.*+?()[\]{}|]/g;

const ASTRAL_SET = regenerate().addRange(0x10000, 0x10FFFF);

const NEWLINE_SET = regenerate().add(
	// `LineTerminator`s (https://mths.be/es6#sec-line-terminators):
	0x000A, // Line Feed <LF>
	0x000D, // Carriage Return <CR>
	0x2028, // Line Separator <LS>
	0x2029  // Paragraph Separator <PS>
);

// Prepare a Regenerate set containing all code points that are supposed to be
// matched by `/./u`. https://mths.be/es6#sec-atom
const DOT_SET_UNICODE = UNICODE_SET.clone() // all Unicode code points
	.remove(NEWLINE_SET);

const getUnicodeDotSet = (dotAll) => {
	return dotAll ? UNICODE_SET : DOT_SET_UNICODE;
};

const CASE_EQ_FLAG_NONE = 0b00;
const CASE_EQ_FLAG_BMP = 0b01;
const CASE_EQ_FLAG_UNICODE = 0b10;

// Given a range of code points, add any case-equivalent code points in that range
// to a set.
regenerate.prototype.iuAddRange = function(min, max, caseEqFlags) {
	const $this = this;
	do {
		const list = getCaseEquivalents(min, caseEqFlags);
		if (list) {
			$this.add(list);
		}
	} while (++min <= max);
	return $this;
};
regenerate.prototype.iuRemoveRange = function(min, max, caseEqFlags) {
	const $this = this;
	do {
		const list = getCaseEquivalents(min, caseEqFlags);
		if (list) {
			$this.remove(list);
		}
	} while (++min <= max);
	return $this;
};

const wrap = (tree, pattern) => {
	// Wrap the pattern in a non-capturing group.
	return {
		'type': 'group',
		'behavior': 'ignore',
		'body': [tree],
		'raw': `(?:${ pattern })`
	};
};

/**
 * Given any codepoint ch, returns false or an array of characters,
 * such that for every c in the array,
 *   c != ch and Canonicalize(~, c) == Canonicalize(~, ch)
 * 
 * where Canonicalize is defined in
 * https://tc39.es/ecma262/#sec-runtime-semantics-canonicalize-ch
 * @param {number} codePoint input code point
 * @param {number} flags bitwise flags composed of CASE_EQ_FLAG_*
 * @returns false | number[]
 */
const getCaseEquivalents = (codePoint, flags) => {
	if (flags === CASE_EQ_FLAG_NONE) {
		return false;
	}
	let result = ((flags & CASE_EQ_FLAG_UNICODE) ? iuMappings.get(codePoint) : undefined) || [];
	if (typeof result === "number") result = [result];
	if (flags & CASE_EQ_FLAG_BMP) {
		for (const cp of [codePoint].concat(result)) {
			// Fast path for ASCII characters
			if (cp >= 0x41 && cp <= 0x5a) {
				result.push(cp + 0x20);
			} else if (cp >= 0x61 && cp <= 0x7a) {
				result.push(cp - 0x20);
			} else {
				result = result.concat(iBMPMappings.get(cp) || []);
			}
		}
	}
	return result.length == 0 ? false : result;
};

// https://tc39.es/ecma262/#sec-maybesimplecasefolding
const simpleCaseFolding = (codePoint) => {
	// Fast path for ASCII characters
	if (codePoint <= 0x7F) {
		if (codePoint >= 0x41 && codePoint <= 0x5A) {
			return codePoint + 0x20;
		}
		return codePoint;
	}
	return iuFoldings.get(codePoint) || codePoint;
}

if (data.first) {
						data.longStrings = nestedData.longStrings;
						data.maybeIncludesStrings = nestedData.maybeIncludesStrings;
					} else {
						for (const str of data.longStrings) {
							if (!nestedData.longStrings.has(str)) data.longStrings.delete(str);
						}
						if (!nestedData.maybeIncludesStrings) data.maybeIncludesStrings = false;
					}
				}
			};
		}
		case 'subtraction': {
			const regSet = (data, set2) => {
				if (data.first) data.singleChars.add(set2);
				else data.singleChars.remove(set2);
			};
			return {
				single: (data, cp) => {
					if (data.first) data.singleChars.add(cp);
					else data.singleChars.remove(cp);
				},
				regSet: regSet,
				range: (data, start, end) => {
					if (data.first) data.singleChars.addRange(start, end);
					else data.singleChars.removeRange(start, end);
				},
				iuRange: (data, start, end, caseEqFlags) => {
					if (data.first) data.singleChars.iuAddRange(start, end, caseEqFlags);
					else data.singleChars.iuRemoveRange(start, end, caseEqFlags);
				},
				nested: (data, nestedData) => {
					regSet(data, nestedData.singleChars);

const getCharacterClassEmptyData = () => ({
	transformed: config.transform.unicodeFlag,
	singleChars: regenerate(),
	longStrings: new Set(),
	hasEmptyString: false,
	first: true,
	maybeIncludesStrings: false
});

const concatCaseEquivalents = (codePoint, caseEqFlags) => {
	const caseEquivalents = getCaseEquivalents(codePoint, caseEqFlags);
	if (caseEquivalents) {
		return [codePoint, ...caseEquivalents];
	}
	return [codePoint];
};

const computeClassStrings = (classStrings, regenerateOptions, caseEqFlags, shouldApplySCF) => {
	let data = getCharacterClassEmptyData();

for (const string of classStrings.strings) {
		if (string.characters.length === 1) {
			const codePoint = shouldApplySCF ? simpleCaseFolding(string.characters[0].codePoint) : string.characters[0].codePoint
			concatCaseEquivalents(codePoint, caseEqFlags).forEach((cp) => {
				data.singleChars.add(cp);
			});
		} else {
			let stringifiedString = '';
			if (caseEqFlags) {
				for (const ch of string.characters) {
					const codePoint = shouldApplySCF ? simpleCaseFolding(ch.codePoint) : ch.codePoint;
					const set = regenerate(concatCaseEquivalents(codePoint, caseEqFlags));
					stringifiedString += set.toString(regenerateOptions);
				}
			} else {
				for (const ch of string.characters) {
					const codePoint = shouldApplySCF ? simpleCaseFolding(ch.codePoint) : ch.codePoint;
					if (codePoint !== ch.codePoint) {
						stringifiedString += regenerate(codePoint).toString(regenerateOptions);
					} else {
						stringifiedString += generate(ch);
					}
				}
			}

data.longStrings.add(stringifiedString);
			data.maybeIncludesStrings = true;
		}
	}

return data;
}

const computeCharacterClass = (characterClassItem, regenerateOptions, shouldApplySCF) => {
	let data = getCharacterClassEmptyData();

let handlePositive;
	let handleNegative;

let caseEqFlags = configGetCaseEqFlags();

switch (characterClassItem.kind) {
		case 'union':
			handlePositive = buildHandler('union');
			handleNegative = buildHandler('union-negative');
			break;
		case 'intersection':
			handlePositive = buildHandler('intersection');
			handleNegative = buildHandler('subtraction');
			if (config.transform.unicodeSetsFlag) data.transformed = true;
			if (config.isIgnoreCaseMode) {
				shouldApplySCF = true;
			}
			break;
		case 'subtraction':
			handlePositive = buildHandler('subtraction');
			handleNegative = buildHandler('intersection');
			if (config.transform.unicodeSetsFlag) data.transformed = true;
			if (config.isIgnoreCaseMode) {
				shouldApplySCF = true;
			}
			break;
		// The `default` clause is only here as a safeguard; it should never be
		// reached. Code coverage tools should ignore it.
		/* node:coverage ignore next */
		default:
			throw new Error(`Unknown character class kind: ${ characterClassItem.kind }`);
	}

for (const item of characterClassItem.body) {
		switch (item.type) {
			case 'value':
				const codePoint = shouldApplySCF ? simpleCaseFolding(item.codePoint) : item.codePoint;
				const list = concatCaseEquivalents(codePoint, caseEqFlags);
				handlePositive.regSet(data, regenerate(list));
				if (list.length > 1) {
					data.transformed = true;
				}
				break;
			case 'characterClassRange':
				const min = item.min.codePoint;
				const max = item.max.codePoint;
				if (shouldApplySCF) {
					let list = [];
					for (let cp = min; cp <= max; cp++) {
						list.push(simpleCaseFolding(cp));
					}
					handlePositive.regSet(data, regenerate(list));
				} else {
					handlePositive.range(data, min, max);
				}
				if (caseEqFlags) {
					// If shouldApplySCF is true, it is still ok to call iuRange because 
					// the set [min, max] shares the same case equivalents with scf([min, max])
					handlePositive.iuRange(data, min, max, caseEqFlags);
					data.transformed = true;
				}
				break;
			case 'characterClassEscape':
				handlePositive.regSet(data, getCharacterClassEscapeSet(
					item.value,
					config.flags.unicode || config.flags.unicodeSets,
					config.flags.ignoreCase,
					shouldApplySCF
				));
				break;
			case 'unicodePropertyEscape':
				const nestedData = getUnicodePropertyEscapeCharacterClassData(
					item.value,
					item.negative,
					config.flags.unicodeSets && config.isIgnoreCaseMode,
					shouldApplySCF
				);
				handlePositive.nested(data, nestedData);
				data.transformed =
					data.transformed ||
					config.transform.unicodePropertyEscapes ||
					(config.transform.unicodeSetsFlag && (nestedData.maybeIncludesStrings || characterClassItem.kind !== "union" || item.negative));
				break;
			case 'characterClass':
				const handler = item.negative ? handleNegative : handlePositive;
				const res = computeCharacterClass(item, regenerateOptions, shouldApplySCF);
				handler.nested(data, res);
				data.transformed = true;
				break;
			case 'classStrings':
				handlePositive.nested(data, computeClassStrings(item, regenerateOptions, caseEqFlags, shouldApplySCF));
				data.transformed = true;
				break;
			// The `default` clause is only here as a safeguard; it should never be
			// reached. Code coverage tools should ignore it.
			/* node:coverage ignore next */
			default:
				throw new Error(`Unknown term type: ${ item.type }`);
		}

data.first = false;
	}

if (characterClassItem.negative && data.maybeIncludesStrings) {
		throw new SyntaxError('Cannot negate set containing strings');
	}

return data;
}

if (negative) {
			if (config.useUnicodeFlag) {
				update(characterClassItem, `[^${setStr[0] === '[' ? setStr.slice(1, -1) : setStr}]`)
			} else {
				if (config.flags.unicode || config.flags.unicodeSets) {
					if (config.flags.ignoreCase) {
						const astralCharsSet = singleChars.clone().intersection(ASTRAL_SET);
						// Assumption: singleChars do not contain lone surrogates.
						// Regex like /[^\ud800]/u is not supported
						const surrogateOrBMPSetStr = singleChars
							.clone()
							.remove(astralCharsSet)
							.addRange(0xd800, 0xdfff)
							.toString({ bmpOnly: true });
						// Don't generate negative lookahead for astral characters
						// because the case folding is not working anyway as we break
						// code points into surrogate pairs.
						const astralNegativeSetStr = ASTRAL_SET
							.clone()
							.remove(astralCharsSet)
							.toString(regenerateOptions);
						// The transform here does not support lone surrogates.
						update(
							characterClassItem,
							`(?!${surrogateOrBMPSetStr})[^]|${astralNegativeSetStr}`
						);
					} else {
						// Generate negative set directly when case folding is not involved.
						const negativeSet = UNICODE_SET.clone().remove(singleChars);
						update(characterClassItem, negativeSet.toString(regenerateOptions));
					}
				} else {
					update(characterClassItem, `(?!${setStr})[^]`);
				}
			}
		} else {
			const hasEmptyString = longStrings.has('');
			const pieces = Array.from(longStrings).sort((a, b) => b.length - a.length);

if (setStr !== '[]' || longStrings.size === 0) {
				pieces.splice(pieces.length - (hasEmptyString ? 1 : 0), 0, setStr);
			}

update(characterClassItem, pieces.join('|'));
		}
	}
	return characterClassItem;
};

const processModifiers = (item, regenerateOptions, groups) => {
	const enabling = item.modifierFlags.enabling;
	const disabling = item.modifierFlags.disabling;

const oldData = Object.assign({}, config.modifiersData);

for (const flag of enabling) {
		config.modifiersData[flag] = true;
	}
	for (const flag of disabling) {
		config.modifiersData[flag] = false;
	}

if (config.transform.modifiers) {
		delete item.modifierFlags;
		item.behavior = 'ignore';
	}

item.body = item.body.map(term => {
		return processTerm(term, regenerateOptions, groups);
	});

config.modifiersData = oldData;

return item;
}

if (groups.namesConflicts[name]) {
					throw new Error(
						`Group '${ name }' has already been defined in this context.`
					);
				}
				groups.namesConflicts[name] = true;

if (config.transform.namedGroups) {
					delete item.name;
				}

const index = groups.lastIndex;
				if (!groups.names[name]) {
					groups.names[name] = [];
				}
				groups.names[name].push(index);

if (groups.onNamedGroup) {
					groups.onNamedGroup.call(null, name, index);
				}

if (groups.unmatchedReferences[name]) {
					delete groups.unmatchedReferences[name];
				}
			}
			if (item.modifierFlags) {
				return processModifiers(item, regenerateOptions, groups);
			}
			/* falls through */
		case 'quantifier':
			item.body = item.body.map(term => {
				return processTerm(term, regenerateOptions, groups);
			});
			break;
		case 'disjunction':
			const outerNamesConflicts = groups.namesConflicts;
			item.body = item.body.map(term => {
				groups.namesConflicts = Object.create(outerNamesConflicts);
				return processTerm(term, regenerateOptions, groups);
			});
			break;
		case 'alternative':
			item.body = flatMap(item.body, term => {
				const res = processTerm(term, regenerateOptions, groups);
				// Alternatives cannot contain alternatives; flatten them.
				return res.type === 'alternative' ? res.body : res;
			});
			break;
		case 'value':
			const codePoint = item.codePoint;
			const caseEqFlags = configGetCaseEqFlags();
			const list = concatCaseEquivalents(codePoint, caseEqFlags);
			if (list.length === 1 && item.kind === "symbol" && codePoint >= 0x20 && codePoint <= 0x7E) {
				// skip regenerate when it is a printable ASCII symbol
				break;
			}
			const set = regenerate(list);
			update(item, set.toString(regenerateOptions));
			break;
		case 'reference':
			if (item.name) {
				const name = item.name.value;
				const indexes = groups.names[name];
				if (!indexes) {
					groups.unmatchedReferences[name] = true;
				}

if (config.transform.namedGroups) {
					if (indexes) {
						const body = indexes.map(index => ({
							'type': 'reference',
							'matchIndex': index,
							'raw': '\\' + index,
						}));
						if (body.length === 1) {
							return body[0];
						}
						return {
							'type': 'alternative',
							'body': body,
							'raw': body.map(term => term.raw).join(''),
						};
					}

// This named reference comes before the group where it’s defined,
					// so it’s always an empty match.
					return {
						'type': 'group',
						'behavior': 'ignore',
						'body': [],
						'raw': '(?:)',
					};
				}
			}
			break;
		case 'anchor':
			if (config.modifiersData.m && config.transform.modifiers) {
				if (item.kind == 'start') {
					update(item, `(?:^|(?<=${NEWLINE_SET.toString()}))`);
				} else if (item.kind == 'end') {
					update(item, `(?:$|(?=${NEWLINE_SET.toString()}))`);
				}
			}
		case 'empty':
			// Nothing to do here.
			break;
		// The `default` clause is only here as a safeguard; it should never be
		// reached. Code coverage tools should ignore it.
		/* node:coverage ignore next */
		default:
			throw new Error(`Unknown term type: ${ item.type }`);
	}
	return item;
};

const validateOptions = (options) => {
	if (!options) return;

for (const key of Object.keys(options)) {
		const value = options[key];
		switch (key) {
			case 'dotAllFlag':
			case 'unicodeFlag':
			case 'unicodePropertyEscapes':
			case 'unicodeSetsFlag':
			case 'namedGroups':
				if (value != null && value !== false && value !== 'transform') {
					throw new Error(`.${key} must be false (default) or 'transform'.`);
				}
				break;
			// todo: remove modifiers: 'parse' in regexpu-core v7
			case 'modifiers':
				if (value != null && value !== false && value !== 'parse' && value !== 'transform') {
					throw new Error(`.${key} must be false (default), 'parse' or 'transform'.`);
				}
				break;
			case 'onNamedGroup':
			case 'onNewFlags':
				if (value != null && typeof value !== 'function') {
					throw new Error(`.${key} must be a function.`);
				}
				break;
			default:
				throw new Error(`.${key} is not a valid regexpu-core option.`);
		}
	}
};

const hasFlag = (flags, flag) => flags ? flags.includes(flag) : false;
const transform = (options, name) => options ? options[name] === 'transform' : false;

const rewritePattern = (pattern, flags, options) => {
	validateOptions(options);

config.flags.unicode = hasFlag(flags, 'u');
	config.flags.unicodeSets = hasFlag(flags, 'v');
	config.flags.ignoreCase = hasFlag(flags, 'i');
	config.flags.dotAll = hasFlag(flags, 's');
	config.flags.multiline = hasFlag(flags, 'm');

config.transform.dotAllFlag = config.flags.dotAll && transform(options, 'dotAllFlag');
	config.transform.unicodeFlag = (config.flags.unicode || config.flags.unicodeSets) && transform(options, 'unicodeFlag');
	config.transform.unicodeSetsFlag = config.flags.unicodeSets && transform(options, 'unicodeSetsFlag');

// unicodeFlag: 'transform' implies unicodePropertyEscapes: 'transform'
	config.transform.unicodePropertyEscapes = (config.flags.unicode || config.flags.unicodeSets) && (
		transform(options, 'unicodeFlag') || transform(options, 'unicodePropertyEscapes')
	);
	config.transform.namedGroups = transform(options, 'namedGroups');
	config.transform.modifiers = transform(options, 'modifiers');

config.modifiersData.i = undefined;
	config.modifiersData.s = undefined;
	config.modifiersData.m = undefined;

const regjsparserFeatures = {
		// Enable every stable RegExp feature by default
		'modifiers': true,
		'unicodePropertyEscape': true,
		'unicodeSet': true,
		'namedGroups': true,
		'lookbehind': true,
	};

const regenerateOptions = {
		'hasUnicodeFlag': config.useUnicodeFlag,
		'bmpOnly': !config.flags.unicode && !config.flags.unicodeSets
	};

const groups = {
		'onNamedGroup': options && options.onNamedGroup,
		'lastIndex': 0,
		'names': Object.create(null), // { [name]: Array<index> }
		'namesConflicts': Object.create(null), // { [name]: true }
		'unmatchedReferences': Object.create(null) // { [name]: true }
	};

const tree = parse(pattern, flags, regjsparserFeatures);

if (config.transform.modifiers) {
		if (/\(\?[a-z]*-[a-z]+:/.test(pattern)) {
			// the pattern _likely_ contain inline disabled modifiers
			// we need to traverse to make sure that they are actually modifiers and to collect them
			const allDisabledModifiers = Object.create(null)
			const itemStack = [tree];
			let node;
			while (node = itemStack.pop(), node != undefined) {
				if (Array.isArray(node)) {
					Array.prototype.push.apply(itemStack, node);
				} else if (typeof node == 'object' && node != null) {
					for (const key of Object.keys(node)) {
						const value = node[key];
						if (key == 'modifierFlags') {
							for (const flag of value.disabling) {
								allDisabledModifiers[flag] = true;
							}
						} else if (typeof value == 'object' && value != null) {
							itemStack.push(value);
						}
					}
				}
			}
			if (allDisabledModifiers.i) {
				config.modifiersData.i = config.flags.ignoreCase;
			}
			if (allDisabledModifiers.m) {
				config.modifiersData.m = config.flags.multiline;
			}
			if (allDisabledModifiers.s) {
				config.modifiersData.s = config.flags.dotAll;
			}
		}
	}

// Note: `processTerm` mutates `tree` and `groups`.
	processTerm(tree, regenerateOptions, groups);
	assertNoUnmatchedReferences(groups);

return generate(tree);
};

module.exports = rewritePattern;