Fix compiling v set notation to u with unicode properties (#70)

Co-authored-by: Huáng Jùnliàng <jlhwung@gmail.com>
Co-authored-by: Nicolò Ribaudo <hello@nicr.dev>

rewrite-pattern.js

@@ -456,7 +456,7 @@ const computeCharacterClass = (characterClassItem, regenerateOptions) => {
 				data.transformed =
 					data.transformed ||
 					config.transform.unicodePropertyEscapes ||
-					(config.transform.unicodeSetsFlag && nestedData.maybeIncludesStrings);
+					(config.transform.unicodeSetsFlag && (nestedData.maybeIncludesStrings || characterClassItem.kind !== "union"));
 				break;
 			case 'characterClass':
 				const handler = item.negative ? handleNegative : handlePositive;
@@ -819,7 +819,7 @@ const rewritePattern = (pattern, flags, options) => {
 	config.transform.unicodeSetsFlag = config.flags.unicodeSets && transform(options, 'unicodeSetsFlag');
 
 	// unicodeFlag: 'transform' implies unicodePropertyEscapes: 'transform'
-	config.transform.unicodePropertyEscapes = config.flags.unicode && (
+	config.transform.unicodePropertyEscapes = (config.flags.unicode || config.flags.unicodeSets) && (
 		transform(options, 'unicodeFlag') || transform(options, 'unicodePropertyEscapes')
 	);
 	config.transform.namedGroups = transform(options, 'namedGroups');

tests/fixtures/unicode-set.js

@@ -343,6 +343,23 @@ const unicodeSetFixtures = [
 		pattern: '[\\p{ASCII}&&\\p{Control}]',
 		expected: '[\\0-\\x1F\\x7F]',
 	},
+	{
+		pattern: '\\P{ASCII}',
+		expected: '[\\x80-\\u{10FFFF}]',
+		options: { unicodeSetsFlag: "transform", unicodePropertyEscapes: "transform" }
+	},
+	{
+		pattern: '[\\p{ASCII}\\p{Decimal_Number}]',
+		expected: '[\\p{ASCII}\\p{Decimal_Number}]'
+	},
+	{
+		pattern: '[\\p{Lowercase_Letter}]',
+		expected: '[\\p{Lowercase_Letter}]'
+	},
+	{
+		pattern: '^[\\p{Script=Arabic}&&\\p{Number}]$',
+		expected: '^[\\u0660-\\u0669\\u06F0-\\u06F9\\u{10E60}-\\u{10E7E}]$'
+	},
 	{
 		pattern: '.',
 		flags: 'sv',

tests/tests.js

@@ -427,8 +427,6 @@ describe('character classes', () => {
 	}
 });
 
-
-
 describe('unicodeSets (v) flag', () => {
 	// Re-use the unicode fixtures but replacing the input pattern's `u` flag with `v` flag
 	for (const fixture of unicodeFixtures) {