regexValidity

Reports invalid regular expressions.

✅ This rule is included in the ts logical presets.

It is possible to write regular expression literals that will throw at runtime. This includes invalid patterns, invalid flags, duplicate flags, and conflicting flag combinations. This rule reports those invalid regular expressions.

Examples

Invalid Pattern

❌ Incorre

AEconsB0patteAE <= sp ansty="le--0:#82AAFF;--1:#3B61">B0RegE5<3(sp ansty="le--0:#D9F5DD;--1:#1111">1<1"sp ansty="le--0:#ECC48D;--1:#984E">41<1"sp ansty="le--0:#D6DEEB;--1:#403F">53<);d ivclassNa="meco"><);d>AEconsB0patteAE <= sp ansty="le--0:#82AAFF;--1:#3B61">B0RegE5<3(sp ansty="le--0:#D9F5DD;--1:#1111">1<1"sp ansty="le--0:#ECC48D;--1:#984E">4Da1<1"sp ansty="le--0:#C792EA;--1:#8844">AE<, sp ansty="le--0:#D9F5DD;--1:#1111">1<1"sp ansty="le--0:#ECC48D;--1:#984E">41<1"sp ansty="le--0:#D6DEEB;--1:#403F">53<);d ivclassNa="meco"><);d>AEconsB0patteAE <= sp ansty="le--0:#82AAFF;--1:#3B61">B0RegE5<3(sp ansty="le--0:#D9F5DD;--1:#1111">1<1"sp ansty="le--0:#ECC48D;--1:#984E">4Da1<1"sp ansty="le--0:#C792EA;--1:#8844">AE<, sp ansty="le--0:#D9F5DD;--1:#1111">1<1"sp ansty="le--0:#ECC48D;--1:#984E">4D1<1"sp ansty="le--0:#D6DEEB;--1:#403F">53<);d ivclassNa="meco"><);d>AEconsB0patteAE <= sp ansty="le--0:#82AAFF;--1:#3B61">B0RegE5<3(sp ansty="le--0:#D9F5DD;--1:#1111">1<1"sp ansty="le--0:#ECC48D;--1:#984E">4Da1<1"sp ansty="le--0:#C792EA;--1:#8844">AE<, sp ansty="le--0:#D9F5DD;--1:#1111">1<1"sp ansty="le--0:#ECC48D;--1:#984E">4D1<1"sp ansty="le--0:#D6DEEB;--1:#403F">53<);d ivclassNa="meco"><);d>

44AEco61B0pat44A61B0Re31<111" spans="tyle--0:#ECC48D;--1:#98">4E4D(1<111" spans="tyle--0:#D6DEEB;--1:#40">3F<53) ;divclass="Name"><)")><;di vdivclass="Nameexpressive-">44AEco61B0pat44A61B0Re31<111" spans="tyle--0:#ECC48D;--1:#98">4E41<111" spans="tyle--0:#C792EA;--1:#88">441<111" spans="tyle--0:#ECC48D;--1:#98">41<111" spans="tyle--0:#D6DEEB;--1:#40">3F<53) ;divclass="Name"><;di vdivclass="Nameexpressive-">44AEco61B0pat44A61B0Re31<111" spans="tyle--0:#ECC48D;--1:#98">4E41<111" spans="tyle--0:#C792EA;--1:#88">441<111" spans="tyle--0:#ECC48D;--1:#98">4E<4Dgi spans="tyle--0:#D9F5DD;--1:#11">1<111" spans="tyle--0:#D6DEEB;--1:#40">3F<53) ;divclass="Name"><;di vdivclass="Nameexpressive-">44AEco61B0pat44A61B0Re31<111" spans="tyle--0:#ECC48D;--1:#98">4E41<111" spans="tyle--0:#C792EA;--1:#88">441<111" spans="tyle--0:#ECC48D;--1:#98">41<111" spans="tyle--0:#D6DEEB;--1:#40">3F<53) ;divclass="Name">

Options

This rule is not configurable.

When Not To Use It

If you are working in an environment with different regular expression semantics than the norm, you may prefer to disable this rule.

Further Reading

• MDN: RegExp
• ECMAScript Regular Expression Flags

Equivalents in Other Linters

• Deno: no-invalid-regexp
• ESLint: no-invalid-regexpregexp/no-invalid-regexp
• Oxlint: eslint/no-invalid-regexp