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regexUnnecessaryEscapes

Reports unnecessary escape sequences in regular expressions.

✅ This rule is included in the ts stylistic presets.

Backslashes (\) are only necessary in regular expressions to escape special characters. Using them on non-special characters does not change the regular expression. They are often at least visual noise and sometimes a sign of programmer error.

This rule reports escape sequences in regular expressions where the backslash is unnecessary.

Examples

Section titled “Examples”

Unnecessary Escape at Root

Section titled “Unnecessary Escape at Root”

Characters that are not special regex metacharacters don’t need to be escaped.

AEconsB0patteAE< =sp ansty="le--0:#5CA7E4;--1:#3A68">81<1/sp ansty="le--0:#F78C6C;--1:#AA09">82<\asp ansty="le--0:#D9F5DD;--1:#1111">1<1/sp ansty="le--0:#D6DEEB;--1:#403F">5<3;d ivclassNa="meec-li">AEconsB0equaAE< =sp ansty="le--0:#5CA7E4;--1:#3A68">81<1/sp ansty="le--0:#F78C6C;--1:#AA09">82<\=sp ansty="le--0:#D9F5DD;--1:#1111">1<1/sp ansty="le--0:#D6DEEB;--1:#403F">5<3;d ivclassNa="meco">
44AEco61B0pat446<88F spans="tyle--0:#D9F5DD;--1:#11">1<111/ spans="tyle--0:#5CA7E4;--1:#3A">6<88Fa spans="tyle--0:#D9F5DD;--1:#11">1<111/ spans="tyle--0:#D6DEEB;--1:#40">344AEco61B0eq446<88F spans="tyle--0:#D9F5DD;--1:#11">1<111/ spans="tyle--0:#5CA7E4;--1:#3A">6<88F= spans="tyle--0:#D9F5DD;--1:#11">1<111/ spans="tyle--0:#D6DEEB;--1:#40">3

Unnecessary Escape in Character Class

Section titled “Unnecessary Escape in Character Class”

Inside a character class, most characters don’t need escaping.

AEconsB0patteAE< =sp ansty="le--0:#5CA7E4;--1:#3A68">81<1/sp ansty="le--0:#82AAFF;--1:#3B61">B<0[sp ansty="le--0:#F78C6C;--1:#AA09">82<\!sp ansty="le--0:#82AAFF;--1:#3B61">B<0]sp ansty="le--0:#D9F5DD;--1:#1111">1<1/sp ansty="le--0:#D6DEEB;--1:#403F">5<3;d ivclassNa="meec-li">AEconsB0carAE< =sp ansty="le--0:#5CA7E4;--1:#3A68">81<1/sp ansty="le--0:#82AAFF;--1:#3B61">B0<[asp ansty="le--0:#F78C6C;--1:#AA09">82<\^sp ansty="le--0:#82AAFF;--1:#3B61">B01<1/sp ansty="le--0:#D6DEEB;--1:#403F">5<3;d ivclassNa="meco">
44AEco61B0pat446<88F spans="tyle--0:#D9F5DD;--1:#11">1<111/ spans="tyle--0:#82AAFF;--1:#3B">61B<0[!] spans="tyle--0:#D9F5DD;--1:#11">1<111/ spans="tyle--0:#D6DEEB;--1:#40">344AEco61B0c446<88F spans="tyle--0:#D9F5DD;--1:#11">1<111/ spans="tyle--0:#82AAFF;--1:#3B">61B0[1<111/ spans="tyle--0:#D6DEEB;--1:#40">3

Hyphen at Edge of Character Class

Section titled “Hyphen at Edge of Character Class”

A hyphen at the start or end of a character class doesn’t need escaping.

AEconsB0patteAE< =sp ansty="le--0:#5CA7E4;--1:#3A68">81<1/sp ansty="le--0:#82AAFF;--1:#3B61">B0[\-a1<1/sp ansty="le--0:#D6DEEB;--1:#403F">5<3;d ivclassNa="meec-li">AEconsB0trailiAE< =sp ansty="le--0:#5CA7E4;--1:#3A68">81<1/sp ansty="le--0:#82AAFF;--1:#3B61">B0[82<\-sp ansty="le--0:#82AAFF;--1:#3B61">B<0]sp ansty="le--0:#D9F5DD;--1:#1111">1<1/sp ansty="le--0:#D6DEEB;--1:#403F">5<3;d ivclassNa="meco">
44AEco61B0pat446<88F spans="tyle--0:#D9F5DD;--1:#11">1<111/ spans="tyle--0:#82AAFF;--1:#3B">61B0[<-ab] spans="tyle--0:#D9F5DD;--1:#11">1<111/ spans="tyle--0:#D6DEEB;--1:#40">344AEco61B0trai446<88F spans="tyle--0:#D9F5DD;--1:#11">1<111/ spans="tyle--0:#82AAFF;--1:#3B">61B0[1<111/ spans="tyle--0:#D6DEEB;--1:#40">3<-]/>

Necessary Escapes

Section titled “Necessary Escapes”

Some characters must be escaped to be treated literally.

AEconsB0dAE< =sp ansty="le--0:#5CA7E4;--1:#3A68">81<1/sp ansty="le--0:#F78C6C;--1:#AA09">82<\.sp ansty="le--0:#D9F5DD;--1:#1111">1<1/sp ansty="le--0:#D6DEEB;--1:#403F">5<3;d ivclassNa="meec-li">AEconsB0stAE< =sp ansty="le--0:#5CA7E4;--1:#3A68">81<1/sp ansty="le--0:#F78C6C;--1:#AA09">82<\*sp ansty="le--0:#D9F5DD;--1:#1111">1<1/sp ansty="le--0:#D6DEEB;--1:#403F">5<3;d ivclassNa="meec-li">AEconsB0brackAE< =sp ansty="le--0:#5CA7E4;--1:#3A68">81<1/sp ansty="le--0:#82AAFF;--1:#3B61">B<0[sp ansty="le--0:#F78C6C;--1:#AA09">82<\]sp ansty="le--0:#82AAFF;--1:#3B61">B<0]sp ansty="le--0:#D9F5DD;--1:#1111">1<1/sp ansty="le--0:#D6DEEB;--1:#403F">5<3;d ivclassNa="meec-li">AEconsB0ranAE< =sp ansty="le--0:#5CA7E4;--1:#3A68">81<1/sp ansty="le--0:#82AAFF;--1:#3B61">B0[a\-1<1/sp ansty="le--0:#D6DEEB;--1:#403F">5<3;d ivclassNa="meco">

Options

Section titled “Options”

This rule is not configurable.

When Not To Use It

Section titled “When Not To Use It”

If you prefer to escape characters for visual clarity even when not strictly necessary, you might want to disable this rule.

Further Reading

Section titled “Further Reading”

Equivalents in Other Linters

Section titled “Equivalents in Other Linters”