next-js-codemod

js-codemod 

This repository contains a collection of codemod scripts for use with
JSCodeshift.

$3

``sh
npm install -g jscodeshift
git clone https://github.com/cpojer/js-codemod.git
jscodeshift -t
`

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

$3

#### arrow-function-arguments

`sh
jscodeshift -t js-codemod/transforms/arrow-function-arguments.js
`

#### arrow-function

Transforms callbacks only when it can guarantee it won't break this context in the function. Also transforms function() { }.bind(this) calls to () => {}.

`sh
jscodeshift -t js-codemod/transforms/arrow-function.js
`

##### Options:

--inline-single-expressions=true: If you are feeling lucky and you know that returning the value of single-expression functions will not affect the behavior of your application you can specify the option and it will transform function() { relay(); } to () => relay() instead of () => { relay(); }.

--max-width=120: Try the best it can to keep line lengths under the specified length.

#### invalid-requires

`sh
jscodeshift -t js-codemod/transforms/invalid-requires.js
`

#### jest-update

`sh
jscodeshift -t js-codemod/transforms/jest-update.js
`

#### no-reassign-params

Converts functions to not reassign to parameters. This is useful to turn on in conjunction with Flow's const_params option.

`sh
jscodeshift -t js-codemod/transforms/no-reassign-params.js
`

#### no-vars

Conservatively converts var to const or let.

`sh
jscodeshift -t js-codemod/transforms/no-vars.js
`

#### object-shorthand

Transforms object literals to use ES6 shorthand
for properties and methods.

`sh
jscodeshift -t js-codemod/transforms/object-shorthand.js
`

#### outline-require

`sh
jscodeshift -t js-codemod/transforms/outline-require.js
`

#### rm-copyProperties

`sh
jscodeshift -t js-codemod/transforms/rm-copyProperties.js
`

#### rm-merge

`sh
jscodeshift -t js-codemod/transforms/rm-merge.js
`

#### rm-object-assign

`sh
jscodeshift -t js-codemod/transforms/rm-object-assign.js
`

#### rm-requires

Removes any requires where the imported value is not referenced. Additionally
if any module is required more than once the two requires will be merged.

`sh
jscodeshift -t js-codemod/transforms/rm-requires.js
`

#### template-literals

Replaces string concatenation with template literals.

`sh
jscodeshift -t js-codemod/transforms/template-literals.js
`

Adapted from "How to write a codemod" by Ramana Venkata.

Areas of improvement:

- Comments in the middle of string concatenation are currently added before the
string but after the assignment. Perhaps in these situations, the string
concatenation should be preserved as-is.

- Nested concatenation inside template literals is not currently simplified.
Currently, a + b${'c' + d} becomes ${a}b${'c' + d} but it would ideally
become ${a}b${c${d}}.

- Unnecessary escaping of quotes from the resulting template literals is
currently not removed. This is possibly the domain of a different transform.

- Unicode escape sequences are converted to unicode characters when the
simplified concatenation results in a string literal instead of a template
literal. It would be nice to perserve the original--whether it be a unicode
escape sequence or a unicode character.

#### touchable

`sh
jscodeshift -t js-codemod/transforms/touchable.js
`

#### trailing-commas

Adds trailing commas to array and object literals.

`sh
jscodeshift -t js-codemod/transforms/trailing-commas.js
`

#### unchain-variables

Unchains chained variable declarations.

`sh
jscodeshift -t js-codemod/transforms/unchain-variables.js
`

#### underscore-to-lodash-native

Replaces underscore (or lodash) to ES6 + lodash, preferring native ES6 array methods. Member imports are used by default to allow tree-shaking, but the --split-imports=true option will split each lodash import into its own lodash/ import.

`sh
jscodeshift -t js-codemod/transforms/underscore-to-lodash-native.js
`

#### unquote-properties

Removes quotes from object properties whose keys are strings which are valid
identifiers.

`sh
jscodeshift -t js-codemod/transforms/unquote-properties.js
`

#### updated-computed-props

`sh
jscodeshift -t js-codemod/transforms/updated-computed-props.js
`

#### use-strict

Adds a top-level 'use strict' statement to JavaScript files

`sh
jscodeshift -t js-codemod/transforms/use-strict.js
`

$3

jscodeshift-imports helpers for modifying import and require statements,
see docs.

$3

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

`sh
jscodeshift -t transform.js --printOptions='{"quote":"double"}'
``