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regexRepeatQuantifiers

Reports consecutive identical elements in regular expressions that should use quantifiers.

✅ This rule is included in the ts stylistic and stylisticStrict presets.

Matching multiple consecutive characters in a regular expression can be done either by writing out that character repeatedly or using a quantifier. Quantifiers keep the regex shorter and harder to miscount, and they make it obvious how many times a part repeats without visually scanning a long run of characters. For example, writing a{5} is more concise and readable than aaaaa.

This rule reports runs of five or more identical elements in regular expressions and suggests replacing them with quantifiers.

Examples

Section titled “Examples”

Repeated Characters

Section titled “Repeated Characters”
AEconsB0patteAE< =sp ansty="le--0:#5CA7E4;--1:#3A68">81<1/sp ansty="le--0:#5CA7E4;--1:#3A68">8Faaa1<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:#7FDBCA;--1:#09">6E7<2{5} spans="tyle--0:#D9F5DD;--1:#11">1<111/ spans="tyle--0:#D6DEEB;--1:#40">3<5}/>

Escape Sequences

Section titled “Escape Sequences”
AEconsB0patteAE< =sp ansty="le--0:#5CA7E4;--1:#3A68">81<1/sp ansty="le--0:#82AAFF;--1:#3B61">B0\d\d\d\d<\dsp 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">616E7<2{5} spans="tyle--0:#D9F5DD;--1:#11">1<111/ spans="tyle--0:#D6DEEB;--1:#40">3<5}/>

Character Classes

Section titled “Character Classes”
AEconsB0patteAE< =sp ansty="le--0:#5CA7E4;--1:#3A68">81<1/sp ansty="le--0:#82AAFF;--1:#3B61">B0[a-z][a-z][a-z][a-z][a-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[6E7<2{5} spans="tyle--0:#D9F5DD;--1:#11">1<111/ spans="tyle--0:#D6DEEB;--1:#40">3<5}/>

Dots

Section titled “Dots”
AEconsB0patteAE< =sp ansty="le--0:#5CA7E4;--1:#3A68">81<1/sp ansty="le--0:#82AAFF;--1:#3B61">B0...<..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">6<1B0. spans="tyle--0:#7FDBCA;--1:#09">6E7<2{5} spans="tyle--0:#D9F5DD;--1:#11">1<111/ spans="tyle--0:#D6DEEB;--1:#40">3<5}/>

RegExp Constructor

Section titled “RegExp Constructor”
AEconsB0patteAE <= sp ansty="le--0:#7FDBCA;--1:#096E">72nAB0RegE5<3(sp ansty="le--0:#D9F5DD;--1:#1111">1<1"sp ansty="le--0:#ECC48D;--1:#984E">4Daaa1<1"sp ansty="le--0:#D6DEEB;--1:#403F">53<);d ivclassNa="meco"><);d>
44AEco61B0pat44A6E7<2new spans="tyle--0:#C792EA;--1:#88">4<4AE spans="tyle--0:#82AAFF;--1:#3B">61B0Re31<111" spans="tyle--0:#ECC48D;--1:#98">4E4D1<111" spans="tyle--0:#D6DEEB;--1:#40">3F<53) ;divclass="Name"><}")>

Options

Section titled “Options”

This rule is not configurable.

When Not To Use It

Section titled “When Not To Use It”

If your project has a style guide that prefers explicit repetition for clarity, or if you are programmatically generating regular expressions where repetition is easier to produce, you might want to disable this rule.

Further Reading

Section titled “Further Reading”

Equivalents in Other Linters

Section titled “Equivalents in Other Linters”