Report TS1518 for all negated Unicode-set union operands

[Copilot]

Negated v-mode character classes only checked the first union operand for string matching. Operand order could therefore determine whether invalid regex syntax produced TS1518.

• Scanner
  • Accumulate MayContainStrings across each union operand.
  • Report TS1518 when any later operand in a negated union may match multiple characters.

const a = /[^\q{xy}b]/v; // TS1518
const b = /[^b\q{xy}]/v; // TS1518

• Coverage
  • Add a compiler regression case for both operand orders.
  • Accept updated regularExpressionScanning divergence baselines.

[Copilot]

Pull request overview

Fixes Unicode-set scanning so TS1518 is reported regardless of negated union operand order.

Changes:

• Accumulates MayContainStrings across union operands.
• Reports TS1518 for later string-matching operands.
• Adds regression coverage and updates baselines.

Show a summary per file

File	Description
internal/scanner/regexp.go	Accumulates and diagnoses string-matching operands.
testdata/tests/cases/compiler/negatedUnicodeSetUnionMayContainStrings.ts	Tests both operand orders.
testdata/submoduleAccepted.txt	Registers accepted baseline divergences.
testdata/baselines/reference/submoduleAccepted/compiler/regularExpressionScanning(target=es2015).errors.txt.diff	Records ES2015 diagnostic divergence.
testdata/baselines/reference/submoduleAccepted/compiler/regularExpressionScanning(target=esnext).errors.txt.diff	Records ESNext diagnostic divergence.
testdata/baselines/reference/submodule/compiler/regularExpressionScanning(target=es2015).errors.txt	Updates ES2015 diagnostics.
testdata/baselines/reference/submodule/compiler/regularExpressionScanning(target=esnext).errors.txt	Updates ESNext diagnostics.
testdata/baselines/reference/compiler/negatedUnicodeSetUnionMayContainStrings.errors.txt	Captures expected TS1518 errors.
testdata/baselines/reference/compiler/negatedUnicodeSetUnionMayContainStrings.js	Captures JavaScript emit.
testdata/baselines/reference/compiler/negatedUnicodeSetUnionMayContainStrings.symbols	Captures symbol baseline.
testdata/baselines/reference/compiler/negatedUnicodeSetUnionMayContainStrings.types	Captures type baseline.

Review details

• Files reviewed: 11/11 changed files
• Comments generated: 1
• Review effort level: Balanced

[Ryan Cavanaugh (RyanCavanaugh)]

Confirmed failing tests do in fact runtime fail