• NAME
• INSTALLATION
• SYNOPSIS
• DESCRIPTION
• OPTIONS
  • comment
  • label
  • prefix
  • remove
• USAGE
• DEVELOPMENT
• COMPATIBILITY
• CAVEATS
• SEE ALSO
• VERSION
• AUTHOR
• COPYRIGHT AND LICENSE

babel-plugin-inline-functions - a Babel plugin to inline selected functions

$ npm install babel-plugin-inline-functions

$ cat test.js

function __INLINE__coalesce (value) {
    return value ?? ''
}

const foo = __INLINE__coalesce(options.foo)

$ babel --plugins inline-functions test.js

const foo = options.foo ?? ''

This is a Babel plugin which inlines calls to selected functions within the scope in which the functions are declared. Only functions which contain a single return statement are inlined. Arguments passed to inlined functions are substituted for the corresponding parameters in the function body and (by default) the original function is removed.

Functions can be marked for inlining by using a custom prefix in the function name, a comment before the function declaration, or a label for the return statement in the function's body. By default, functions whose names begin with "__INLINE__" are inlined, but this can be modified or disabled via the plugin's options.

The following plugin options are supported.

• Type: string | false
• Default: false

Select functions for inlining by the presence of a block comment before the function keyword in the declaration. If set, the comment body is trimmed and compared to the option's value, and, if equal, the function is inlined. If set to false (as it is by default), function declaration comments are not checked.

{
    "plugins": [
        ["inline-functions", {
            "comment": "inline"
        }]
    ]
}

/* inline */ function coalesce (value) {
    return value ?? ''
}

const foo = coalesce(options.foo)

const foo = options.foo ?? ''

• Type: string | false
• Default: false

Select functions for inlining by the presence of a label with this name before the return statement. If set to false (as it is by default), return statement labels are not checked.

{
    "plugins": [
        ["inline-functions", {
            "label": "inline"
        }]
    ]
}

function coalesce (value) {
    inline: return value ?? ''
}

const foo = coalesce(options.foo)

const foo = options.foo ?? ''

• Type: string | false
• Default: "__INLINE__"

Select functions for inlining whose names start with the specified prefix. If set to false, function names are not checked.

{
    "plugins": [
        ["inline-functions", {
            "prefix": "__inline__"
        }]
    ]
}

function __inline__coalesce (value) {
    return value ?? ''
}

const foo = __inline__coalesce(options.foo)

const foo = options.foo ?? ''

• Type: boolean
• Default: true

Remove the inlined function declaration. If set to false, the declaration is preserved.

{
    "plugins": [
        ["inline-functions", {
            "remove": false
        }]
    ]
}

function __INLINE__coalesce (value) {
    return value ?? ''
}

const foo = __INLINE__coalesce(options.foo)

function __INLINE__coalesce (value) {
    return value ?? ''
}

const foo = options.foo ?? ''

{
    "plugins": ["inline-functions"]
}

$ babel --plugins inline-functions script.js

require('@babel/core').transform(code, {
    plugins: ['inline-functions']
})

• Babel 6+ (only Babel 7+ is tested/supported)
• Maintained node versions

• inlining may bloat your code
• inlining may not speed things up and may even slow things down¹
• only works with functions that have a single return statement and simple (i.e. non-destructuring) parameters: keep things simple

¹ Particularly on v8, which may have a better idea of what should be inlined when, and the memory/speed tradeoffs, than the developer.

• babel-plugin-nofn - convert some array-method calls to inline loops

1.0.1

• Emile Cantin
• chocolateboy - maintainer

Copyright © 2016-2020 by Emile Cantin.

This is free software; you can redistribute it and/or modify it under the terms of the ISC License.