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