This repository contains a collection of codemod scripts for use with JSCodeshift + it can also be added as a package to use the other transformers it exposes

Setup & Run When Using 'jscodeshift'

npm install -g jscodeshift
git clone https://github.com/anshckr/fix-js.git
jscodeshift -t <codemod-script> <file>

Use the -d option for a dry-run and use -p to print the output for comparison.

Recast Options

Options to recast's printer can be provided through the printOptions command line argument

jscodeshift -t transform.js <file> --printOptions='{"quote":"double"}'

Included Scripts

no-lonely-if

Fixes eslint no-lonely-if rule

jscodeshift -t ./transforms/no-lonely-if.js <file>

else {
  if (someCondition) {
    ...
  } else {
    ...
  }
}

The above will get converted to

else if (someCondition) {
  ...
} else {
  ...
}

no-nested-ternary

Fixes eslint no-nested-ternary rule by converting the nested ConditionalExpressions into an IIFE block with If/Else Statements

jscodeshift -t ./transforms/no-nested-ternary.js <file>

a ? 'a' : b ? 'b' : 'c'

The above will get converted to

(function() {
  if (a) {
    return 'a';
  }

  if (b) {
    return 'b';
  }

  return 'c';
})()

no-unused-vars

Fixes eslint no-unused-vars rule. Adds disable comment/block wherever the function/variable getting fixed is globally exposed

jscodeshift -t ./transforms/no-unused-vars.js <file>

function someFunc(index) {}
var someUsedVar = 0, someUnUsedVar = false;
var someVar = (function(){
  var someInternalVar;

  function someInternalFunc() {};

  someUsedVar = 1;
  return someUsedVar;
})();

The above will get converted to

// eslint-disable-next-line no-unused-vars
function someFunc() {}
var someUsedVar = 0;
window.someUnUsedVar = false;

window.someVar = (function(){
  someUsedVar = 1;
  return someUsedVar;
})();

Options:

--skip-disable-comments=true: Doesn't add eslint disable comment/block to globals exposed

react-action-as

Transforms all named export actions use 'as' while importing. Also converts the 'bindActionCreators' objectExpressionNode to use the as imported action

jscodeshift -t ./transforms/react-action-as.js <file>

import { someAction } from '../actions';

const mapDispatchToProps = (dispatch) =>
  bindActionCreators(
    {
      someAction
    },
    dispatch
  );

The above will get converted to

import { someAction as someActionAction } from '../actions';

const mapDispatchToProps = (dispatch) =>
  bindActionCreators(
    {
      someAction: someActionAction
    },
    dispatch
  );

react-destruct-assign

Transformer to fix react/destructuring-assignment rule

jscodeshift -t ./transforms/react-destruct-assign.js <file>

render() {
    if (this.props.someProp) {
        return this.state.someState;
    }
}

The above will get converted to

render() {
    const { someProp } = this.props;
    const { someState } = this.state;
    if (someProp) {
        return someState;
    }
}

block-scoped-var

Transformer that moves all the variable declarators to their scope level

jscodeshift -t ./transforms/block-scoped-var.js <file>

function someFunc() {
  if (someCondition) {
    var i = 1;
  } else {
    var i = 2;
  }

  for (var j = 0; j < i; j++) {
    ...
  }

  for (var k in someObj) {
    ...
  }
}

The above will get converted to

function someFunc() {
  var i, j, k;
  if (someCondition) {
    i = 1;
  } else {
    i = 2;
  }

  for (j = 0; j < i; j++) {
    ...
  }

  for (k in someObj) {
    ...
  }
}

no-camelcase

Transformer to fix all the non camel cased variables and function names in a JS file

jscodeshift -t ./transforms/no-camelcase.js <file>

Options:

--fix-exposed-functions=true: Fixes non camel-cased functions that are exposed from the file

--fix-dependencies=true: Finds all the dependencies needed by the file and fixes them if they are not camel-cased

var _some_var, $some_var;
function some_func() {}
some_func();

The above will get converted to (with no options passed)

var someVar, $someVar;
function some_func() {}
some_func();

Setup & Run When Using As A Package

$ npm i @anshckr/fix-js

In Node.js:

var {
  fixJSsAtPath,
  transformLeakingGlobalsVars,
  transformUnusedAssignedVars,
  transformNoUnderscoreDangle
} = require('@anshckr/fix-js');

API

1. fixJSsAtPath (Transforms all the JS files at the dirPath)

| Parameter | Type | Description | | :--- | :--- | :--- | | dirPath | String | Required. The directory path where you want to run the transform at | | transformer | Function | Required. The transformer which will modify the JS files | | paramsIgnoreFilesRegex | Regex | Optional. Regular expression to match file names to ignore during transform. Default: /$^/ | | paramsIgnoreFoldersRegex | Regex | Optional. Regular expression to match folder names to ignore during transform. Default: /$^/ | | paramsIgnoreableExternalDeps | Array | Optional. Array of dependencies to ignore during transform. Default: [] |

2. transformLeakingGlobalsVars (Transformer to fix all the leaking globals from a JS file)

| Parameter | Type | Description | | :--- | :--- | :--- | | filePath | String | Required. The file path you want to fix | | dependencies | Function | Optional. Array of dependencies you want to fix for the file at filePath. Default: All the global dependencies for the file | | updateInplace | Boolean | Optional. Whether to update the file or not. Default: false |

Returns

| Type | Description | | :--- | :--- | | String | Transformed file content |

Example

for (i = 0; i < 10; i++) {....}

In the above code if we don't declare i in the upper scope like var i then i becomes a global leak

The utility will declare these types leaking variables

3. transformUnusedAssignedVars (Transformer to fix all the unused assigned variables from a JS file)

| Parameter | Type | Description | | :--- | :--- | :--- | | filePath | String | Required. The file path you want to fix | | updateInplace | Boolean | Optional. Whether to update the file or not. Default: false |

Returns

| Type | Description | | :--- | :--- | | String | Transformed file content |

4. transformNoUnderscoreDangle (Transformer to fix leading '__' in function names to "_", removes "_" from function params)

| Parameter | Type | Description | | :--- | :--- | :--- | | filePath | String | Required. The file path you want to fix | | updateInplace | Boolean | Optional. Whether to update the file or not. Default: false | | collectedGlobals | Object | Optional. Contains two keys globalsExposed, dependencies for the file. Default: {} |

Returns

| Type | Description | | :--- | :--- | | String | Transformed file content |

Example

function __someFunc(_someParam) {
  ..._someParam
}
__someFunc();

The above will get converted to

function _someFunc(someParam) {
  ...someParam
}
_someFunc();

Usage

Refer the example folder

🤝 Contributing

Contributions, issues and feature requests are welcome!Feel free to check issues page. You can also take a look at the contributing guide.

Show your support

Give a ⭐️ if this project helped you!

License

@anshckr/fix-js is freely distributable under the terms of the MIT license