I have an eslint rule rule cropping up in my code dissuading me from using Math.pow in favor of the ES6 alternative exponentiation operator. In react native I am trying to calculate the distance between touch gestures by calculating the x/y using the pythagorean theorem. The calculation requires I square the x/y of the touches in order to get the distance between the users two fingers. I first used this way:
this.pinch = Math.sqrt((Math.pow((px1 - px2), 2)) + (Math.pow((py1 - py2), 2)));
And I receive the eslint rule:
Math.pow is restricted from being used. Use the exponentiation operator (**) instead. (no-restricted-properties)
I changed the code to the following:
this.pinch = Math.sqrt(((px1 - px2) ** 2) + ((py1 - py2) ** 2));
and now every Jest test suite is failing with this error:
● Test suite failed to run
/Users/egrosskurth/Documents/apps/cv-react-native/src/components/lists/dataTable/CvDataTableGrid.js:234
_this3.pinchStart=Math.sqrt((px1-px2)**2+(py1-py2)**2);
^
SyntaxError: Unexpected token *
I need to know how to transform these characters so they do not break my tests. Here is the current Jest setup I have implemented in my package,json:
"devDependencies": {
"babel-eslint": "8.2.1",
"babel-jest": "22.0.4",
"babel-plugin-transform-decorators-legacy": "1.3.4",
"babel-preset-env": "1.7.0",
"babel-preset-react-native": "4.0.0",
"eslint": "4.15.0",
"eslint-config-airbnb": "16.1.0",
"eslint-plugin-filenames": "1.2.0",
"eslint-plugin-import": "2.8.0",
"eslint-plugin-jsx-a11y": "6.0.3",
"eslint-plugin-react": "7.5.1",
"husky": "0.14.3",
"jest": "22.0.5",
"jest-transform-stub": "1.0.0",
"license-checker": "20.1.0",
"lint-staged": "6.1.0",
"react-test-renderer": "16.3.0-alpha.2",
"reactotron-react-native": "2.0.0",
"rimraf": "2.6.2"
},
"jest": {
"collectCoverageFrom": [
"<rootDir>/src/pages/**/*.{js,jsx}",
"!<rootDir>/src/pages/**/*.styles.{js,jsx}",
"!<rootDir>/src/pages/sda/**",
"<rootDir>/src/components/**/*.{js,jsx}",
"!<rootDir>/src/**/*.styles.{js,jsx}",
"!**/node_modules/**",
"!**/android/**",
"!**/ios/**"
],
"transform": {
".+\\.(css|styl|less|sass|scss|png|jpg|gif|GIF|ttf|woff|woff2)$": "jest-transform-stub",
"^.+\\.jsx$": "babel-jest",
"^.+\\.js$": "babel-jest"
},
"preset": "react-native",
"setupFiles": [
"./__tests__/__mocks__/node-modules/react-native-localization_mock.js",
"./__tests__/setupJest.js"
],
"testMatch": [
"<rootDir>/src/**/*.test.js",
"<rootDir>/__tests__/**/*.test.js"
],
"transformIgnorePatterns": [
"node_modules/(?!mobx-react/native|react-native-view-shot)/"
]
},
"lint-staged": {
"src/**/*.{js,json}": [
"lint",
"test:check",
"git add"
]
}
I have disabled the lint rule on that line for now as the only solution online I have found, is to install a dev dependency just for this. If someone could guide the way I would be very thankful.
