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Fix duplicate named capturing groups and clean up regex test262 exclusions #2320

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Merged
lahma merged 1 commit into from
Mar 6, 2026
Merged

Fix duplicate named capturing groups and clean up regex test262 exclusions #2320

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57 changes: 25 additions & 32 deletions Jint.Tests.Test262/Test262Harness.settings.json
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -6,7 +6,6 @@
"Parallel": true,
"ExcludedFeatures": [
"import-defer",
"regexp-lookbehind",
"regexp-modifiers",
"regexp-unicode-property-escapes",
"regexp-v-flag",
Expand All @@ -33,51 +32,45 @@
// Currently quite impossible to detect if assignment target is CoverParenthesizedExpression
"language/expressions/assignment/fn-name-lhs-cover.js",

// RegExp conversion limitations
// === REGEX EXCLUSIONS ===

// CharacterClassEscapes tests internally use v flag which is not supported
"built-ins/RegExp/CharacterClassEscapes/*.js",

// .NET regex engine: forward backreferences not supported in ECMAScript mode
"built-ins/RegExp/S15.10.2.11_A1_T5.js",
"built-ins/RegExp/S15.10.2.11_A1_T7.js",
"built-ins/RegExp/S15.10.2.5_A1_T4.js",
"language/literals/regexp/named-groups/forward-reference.js",
"built-ins/RegExp/named-groups/non-unicode-references.js",
"built-ins/RegExp/named-groups/unicode-references.js",
"built-ins/RegExp/quantifier-integer-limit.js",
"language/literals/regexp/named-groups/forward-reference.js",

"built-ins/RegExp/CharacterClassEscapes/character-class-digit-class-escape-negative-cases.js",
"built-ins/RegExp/CharacterClassEscapes/character-class-digit-class-escape-positive-cases.js",
"built-ins/RegExp/CharacterClassEscapes/character-class-non-digit-class-escape-negative-cases.js",
"built-ins/RegExp/CharacterClassEscapes/character-class-non-digit-class-escape-positive-cases.js",
"built-ins/RegExp/CharacterClassEscapes/character-class-non-whitespace-class-escape-negative-cases.js",
"built-ins/RegExp/CharacterClassEscapes/character-class-non-whitespace-class-escape-positive-cases.js",
"built-ins/RegExp/CharacterClassEscapes/character-class-non-word-class-escape-negative-cases.js",
"built-ins/RegExp/CharacterClassEscapes/character-class-non-word-class-escape-positive-cases.js",
"built-ins/RegExp/CharacterClassEscapes/character-class-whitespace-class-escape-negative-cases.js",
"built-ins/RegExp/CharacterClassEscapes/character-class-whitespace-class-escape-positive-cases.js",
"built-ins/RegExp/CharacterClassEscapes/character-class-word-class-escape-negative-cases.js",
"built-ins/RegExp/CharacterClassEscapes/character-class-word-class-escape-positive-cases.js",

// RegExp handling problems
// .NET regex engine: lookbehind backreference capture semantics differ from JS
"built-ins/RegExp/lookBehind/back-references-to-captures.js",
"built-ins/RegExp/lookBehind/mutual-recursive.js",

// .NET regex engine: nullable quantifier and lookahead capture group semantics differ
"built-ins/RegExp/nullable-quantifier.js",
"built-ins/RegExp/lookahead-quantifier-match-groups.js",

// .NET regex engine: complex quantifier capture group tracking differs
"built-ins/RegExp/S15.10.2.5_A1_T4.js",
"built-ins/RegExp/prototype/exec/S15.10.6.2_A1_T6.js",

// .NET regex engine: Unicode case folding tables differ from ECMAScript CaseFolding.txt
"language/literals/regexp/u-case-mapping.js",
"built-ins/RegExp/lookahead-quantifier-match-groups.js",
"built-ins/RegExp/unicode_full_case_folding.js",
"built-ins/RegExp/named-groups/duplicate-names-exec.js",

// .NET regex engine: quantifier values exceeding int.MaxValue
"built-ins/RegExp/quantifier-integer-limit.js",

// .NET regex engine: quantified groups with alternation retain captures from previous iterations
// (JavaScript resets non-participating groups per iteration, .NET does not)
"built-ins/RegExp/named-groups/duplicate-names-exec.js",
"built-ins/RegExp/named-groups/duplicate-names-match.js",
"built-ins/RegExp/named-groups/duplicate-names-match.js",
"built-ins/RegExp/named-groups/duplicate-names-match-indices.js",
"built-ins/RegExp/named-groups/duplicate-names-match-indices.js",
"built-ins/RegExp/named-groups/duplicate-names-replace.js",
"built-ins/RegExp/named-groups/duplicate-names-replace.js",
"built-ins/RegExp/named-groups/duplicate-names-replaceall.js",
"built-ins/RegExp/named-groups/duplicate-names-replaceall.js",
"built-ins/RegExp/prototype/exec/duplicate-named-groups-properties.js",
"built-ins/RegExp/named-groups/duplicate-names-test.js",
"built-ins/RegExp/prototype/exec/duplicate-named-groups-properties.js",
"built-ins/RegExp/prototype/exec/duplicate-named-indices-groups-properties.js",
"built-ins/RegExp/prototype/exec/duplicate-named-indices-groups-properties.js",
"built-ins/String/prototype/match/duplicate-named-groups-properties.js",
"built-ins/String/prototype/match/duplicate-named-groups-properties.js",
"built-ins/String/prototype/match/duplicate-named-indices-groups-properties.js",
"built-ins/String/prototype/match/duplicate-named-indices-groups-properties.js",

// requires investigation how to process complex function name evaluation for property
Expand Down
77 changes: 64 additions & 13 deletions Jint/Native/RegExp/RegExpPrototype.cs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -178,16 +178,29 @@ string Evaluator(Match match)
replacerArgs.Add(match.Value);

ObjectInstance? groups = null;
// Pre-initialize groups with unique names in order
for (var i = 1; i < actualGroupCount; i++)
{
var groupName = GetRegexGroupName(rei, i);
if (!string.IsNullOrWhiteSpace(groupName))
{
groups ??= OrdinaryObjectCreate(_engine, null);
if (!groups.HasOwnProperty(groupName))
{
groups.CreateDataPropertyOrThrow(groupName, Undefined);
}
}
}

for (var i = 1; i < actualGroupCount; i++)
{
var capture = match.Groups[i];
replacerArgs.Add(capture.Success ? capture.Value : Undefined);

var groupName = GetRegexGroupName(rei, i);
if (!string.IsNullOrWhiteSpace(groupName))
if (!string.IsNullOrWhiteSpace(groupName) && capture.Success)
{
groups ??= OrdinaryObjectCreate(_engine, null);
groups.CreateDataPropertyOrThrow(groupName, capture.Success ? capture.Value : Undefined);
groups!.CreateDataPropertyOrThrow(groupName, (JsString) capture.Value);
}
}

Expand Down Expand Up @@ -953,8 +966,33 @@ private static JsArray CreateReturnValueArray(
array.CreateDataProperty(PropertyInput, s);

ObjectInstance? groups = null;
List<string>? groupNames = null;
List<string?>? groupNames = null;
var indices = hasIndices ? new List<JsNumber[]?>(actualGroupCount) : null;

// Pre-initialize groups object with all unique names in source order.
// This ensures correct property ordering and that duplicate names don't
// overwrite a successful capture with undefined from a non-participating group.
var hasAnyGroupName = false;
for (uint i = 1; i < actualGroupCount; i++)
{
var groupName = GetRegexGroupName(rei, (int) i);
if (!string.IsNullOrWhiteSpace(groupName))
{
hasAnyGroupName = true;
groups ??= OrdinaryObjectCreate(engine, null);
if (!groups.HasOwnProperty(groupName))
{
groups.CreateDataPropertyOrThrow(groupName, Undefined);
}
}

if (hasIndices)
{
groupNames ??= [];
groupNames.Add(groupName);
}
}

for (uint i = 0; i < actualGroupCount; i++)
{
var capture = match.Groups[(int) i];
Expand All @@ -976,13 +1014,13 @@ private static JsArray CreateReturnValueArray(
}
}

var groupName = GetRegexGroupName(rei, (int) i);
if (!string.IsNullOrWhiteSpace(groupName))
if (i > 0)
{
groups ??= OrdinaryObjectCreate(engine, null);
groups.CreateDataPropertyOrThrow(groupName, capturedValue);
groupNames ??= [];
groupNames.Add(groupName!);
var groupName = GetRegexGroupName(rei, (int) i);
if (!string.IsNullOrWhiteSpace(groupName) && capture?.Success == true)
{
groups!.CreateDataPropertyOrThrow(groupName, capturedValue);
}
}

array.SetIndexValue(i, capturedValue, updateLength: false);
Expand All @@ -992,7 +1030,7 @@ private static JsArray CreateReturnValueArray(

if (hasIndices)
{
var indicesArray = MakeMatchIndicesIndexPairArray(engine, s, indices!, groupNames, groupNames?.Count > 0);
var indicesArray = MakeMatchIndicesIndexPairArray(engine, s, indices!, groupNames, hasAnyGroupName);
array.CreateDataPropertyOrThrow("indices", indicesArray);
}

Expand Down Expand Up @@ -1038,7 +1076,7 @@ private static JsArray MakeMatchIndicesIndexPairArray(
Engine engine,
string s,
List<JsNumber[]?> indices,
List<string>? groupNames,
List<string?>? groupNames,
bool hasGroups)
{
var n = indices.Count;
Expand All @@ -1047,6 +1085,15 @@ private static JsArray MakeMatchIndicesIndexPairArray(
if (hasGroups)
{
groups = OrdinaryObjectCreate(engine, null);

// Pre-initialize all unique group names with undefined for correct property ordering
foreach (var name in groupNames!)
{
if (!string.IsNullOrWhiteSpace(name) && !groups.HasOwnProperty(name))
{
groups.CreateDataPropertyOrThrow(name, Undefined);
}
}
}

a.CreateDataPropertyOrThrow("groups", groups ?? Undefined);
Expand All @@ -1061,7 +1108,11 @@ private static JsArray MakeMatchIndicesIndexPairArray(
a.Push(matchIndexPair);
if (i > 0 && !string.IsNullOrWhiteSpace(groupNames?[i - 1]))
{
groups!.CreateDataPropertyOrThrow(groupNames![i - 1], matchIndexPair);
// For duplicate group names, only update if this group actually matched
if (matchIndices is not null)
{
groups!.CreateDataPropertyOrThrow(groupNames![i - 1], matchIndexPair);
}
}
}
return a;
Expand Down