no-useless-escape false positives on JSX strings

This is a JSX issue, but since it’s in eslint/no-useless-escape I thought it would be appropriate to file here.

What version of ESLint are you using? 2.8.0

What parser (default, Babel-ESLint, etc.) are you using? Babel-ESLint

Please show your full configuration: It’s super long but these should be enough,

module.exports = {

  // base off Airbnb Javascript Style Guide
  // https://github.com/airbnb/javascript
  'extends': [
    'eslint-config-airbnb',
  ],

  'parser': 'babel-eslint',
}

What did you do? Please include the actual source code causing the issue.

<input
  autoComplete="cc-cvc cc-csc"
  maxLength="4"
  pattern="[\d]{3,4}"
  placeholder="CVC"
/>

What did you expect to happen?

The pattern "[\d]{3,4}" would not be flagged as the backslash is not an escape character in this context. (It’s a literal backslash, like in HTML.)

What actually happened? Please include the actual, raw output from ESLint.

  135:21  error  Unnecessary escape character: \d  no-useless-escape

[platinumazure]

Ah well, worth a shot. Thanks for trying those out. I’ll dig in further when I get home. On Apr 18, 2016 4:44 PM, “Turadg Aleahmad” [e-mail] wrote:

Very handy! I changed the parser from “acorn” to “babel-eslint” and the value literal is still “[\d]{3,4}”. (Fwiw, same for Espree, but Typescript parses as “[d]{3,4}”.)

I also commented out babel-eslint in my eslintrc and it made no difference.

— You are receiving this because you commented. Reply to this email directly or view it on GitHub https://github.com/eslint/eslint/issues/5882#issuecomment-211595196

[mysticatea]

I saw the spec: https://facebook.github.io/jsx/ JSXText seems to not have any escape sequence.

And I confirmed this with espree, too. I will fix this.

C:\Users\t-nagashima.AD\Documents\GitHub\eslint [master]> cat test.js
<foo attr="\d"/>;
C:\Users\t-nagashima.AD\Documents\GitHub\eslint [master]> eslint -v
v2.8.0
C:\Users\t-nagashima.AD\Documents\GitHub\eslint [master]> eslint test.js --rule no-useless-escape:2 --parser-options "ecmaFeatures:{jsx:true}" --no-ignore --no-eslintrc

C:\Users\t-nagashima.AD\Documents\GitHub\eslint\test.js
  2:12  error  Unnecessary escape character: \d  no-useless-escape

✖ 1 problem (1 error, 0 warnings)