Babel-preset-njs NPM

= babel-preset-njs :npm-name: babel-preset-njs :gh-name: jirutka/{npm-name} :gh-branch: master :ci-workflow: npmjs :babel-doc-uri: https://babeljs.io/docs/en :object-rest-spread-mdn-uri: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Spread_syntax#Spread_in_object_literals :array-spread-mdn-uri: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Spread_syntax#Spread_in_array_literals :array-destructuring-mdn-uri: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Destructuring_assignment#Array_destructuring

ifdef::env-github[] image:https://img.shields.io/npm/v/{npm-name}.svg[npm Version, link="https://www.npmjs.org/package/{npm-name}"] image:https://github.com/{gh-name}/workflows/{ci-workflow}/badge.svg[CI State, link=https://github.com/{gh-name}/actions?query=workflow%3A%22{ci-workflow}%22] endif::env-github[]

A https://babeljs.io[Babel] https://babeljs.io/docs/en/presets[preset] for transforming JavaScript code with modern language features into code compatible with https://github.com/nginx/njs[njs] (NGINX JavaScript). This preset includes support for all the ECMAScript features up to ES2021 -- see <> for a complete list.

TIP: Take a look at https://github.com/jirutka/njs-typescript-starter[njs-typescript-starter] for a complete starter template for developing njs scripts for https://nginx.org[NGINX] server in https://www.typescriptlang.org[TypeScript] (including integration tests).

== Installation

source, sh, subs="+attributes"

using npm:

npm install --save-dev {npm-name}

or using yarn:

yarn add --dev {npm-name}

=== Compatibility Matrix

|=== | preset-njs | njs | Babel

| 0.1.0 – 0.2.1 | ≥ 0.5.0 | 7 | 0.7.0 | ≥ 0.7.0 | 7 |===

== Usage

=== With a Configuration File (Recommended)

source, json, subs="+attributes"

{ "presets": "{npm-name}"

}

=== Via CLI

source, sh, subs="+attributes" babel --presets {npm-name} script.js

=== Via Node API

source, js, subs="+attributes"

require('@babel/core').transform('code', { presets: require('{npm-name}'),

})

== Plugins :babel-plugin-uri: https://babeljs.io/docs/en/babel-plugin :included: ✓{nbsp}included :not-needed: ✗{nbsp}not{nbsp}needed :incompatible: ⚠{nbsp}incompatible

ifdef::npm-readme[] The list of included Babel plugins is available https://github.com/{gh-name}/blob/{gh-branch}/README.adoc#plugins[here].

endif::npm-readme[] ifndef::npm-readme[] The following table lists all relevant https://babeljs.io/docs/en/plugins#transform-plugins[Babel transform plugins] for ECMAScript features up to ES2021.

The State column is one of:

{included} -- The plugin is included in this preset, i.e. njs doesn’t support this feature (or part of it) yet.
{not-needed} -- The plugin is not needed, i.e. njs already supports this feature.
{incompatible} -- The plugin is not compatible with njs, i.e. requires features that njs doesn’t support yet.

| {babel-plugin-uri}-transform-member-expression-literalsmember-expression-literals | ES3 | {not-needed} |

| {babel-plugin-uri}-transform-property-literalsproperty-literals | ES3 | {not-needed} |

| {babel-plugin-uri}-transform-reserved-wordsreserved-words | ES3 | {not-needed} |

| {babel-plugin-uri}-transform-property-mutatorsproperty-mutators | ES5 | {not-needed} |

| {babel-plugin-uri}-transform-arrow-functionsarrow-functions | ES2015 | {not-needed} |

| {babel-plugin-uri}-transform-block-scoped-functionsblock-scoped-functions | ES2015 | {not-needed} |

| {babel-plugin-uri}-transform-block-scopingblock-scoping | ES2015 | {not-needed} | since njs 0.6.0

| {babel-plugin-uri}-transform-classesclasses | ES2015 | {included} |

| {babel-plugin-uri}-transform-computed-propertiescomputed-properties | ES2015 | {not-needed} | since njs 0.3.4

| {babel-plugin-uri}-transform-destructuringdestructuring | ES2015 | {included} |

| {babel-plugin-uri}-transform-duplicate-keysduplicate-keys | ES2015 | {not-needed} |

| {babel-plugin-uri}-transform-for-offor-of | ES2015 | {not-needed} |

| {babel-plugin-uri}-transform-function-namefunction-name | ES2015 | {incompatible} | https://github.com/nginx/njs/issues/360[njs bug #360]

| {babel-plugin-uri}-transform-instanceofinstanceof | ES2015 | {not-needed} |

| {babel-plugin-uri}-transform-literalsliterals | ES2015 | {not-needed} |

| {babel-plugin-uri}-transform-new-targetnew-target | ES2015 | {not-needed} |

| {babel-plugin-uri}-transform-object-superobject-super | ES2015 | {included} |

| {babel-plugin-uri}-transform-parametersparameters | ES2015 | {included} | Only rest parameters are supported.

| {babel-plugin-uri}-transform-shorthand-propertiesshorthand-properties | ES2015 | {not-needed} |

| {babel-plugin-uri}-transform-spreadspread | ES2015 | {included} |

| {babel-plugin-uri}-transform-sticky-regexsticky-regex | ES2015 | {not-needed} | since njs 0.6.0

| {babel-plugin-uri}-transform-template-literalstemplate-literals | ES2015 | {not-needed} |

| {babel-plugin-uri}-transform-typeof-symboltypeof-symbol | ES2015 | {not-needed} |

| {babel-plugin-uri}-transform-unicode-escapesunicode-escapes | ES2015 | {not-needed} | Supported, but not in identifiers (e.g. variable name).

| {babel-plugin-uri}-transform-unicode-regexunicode-regex | ES2015 | {included} |

| {babel-plugin-uri}-transform-exponentiation-operatorexponentiation-operator | ES2016 | {not-needed} |

| {babel-plugin-uri}-transform-async-to-generatorasync-to-generator | ES2017 | {not-needed} | since njs 0.7.0

| {babel-plugin-uri}-proposal-async-generator-functionsasync-generator-functions | ES2018 | {incompatible} | njs doesn’t support generators yet

| {babel-plugin-uri}-transform-dotall-regexdotall-regex | ES2018 | {included} |

| {babel-plugin-uri}-transform-named-capturing-groups-regexnamed-capturing-groups-regex | ES2018 | {not-needed} |

| {babel-plugin-uri}-proposal-object-rest-spreadobject-rest-spread | ES2018 | {included} |

| {babel-plugin-uri}-proposal-unicode-property-regexunicode-property-regex | ES2018 | {included} |

| {babel-plugin-uri}-proposal-optional-catch-bindingoptional-catch-binding | ES2019 | {included} |

| {babel-plugin-uri}-proposal-json-stringsjson-strings | ES2019 | {not-needed} |

| {babel-plugin-uri}-proposal-dynamic-importdynamic-import | ES2020 | {incompatible} | njs has only limited support of ES modules.

| {babel-plugin-uri}-proposal-export-namespace-fromexport-namespace-from | ES2020 | {included} |

| {babel-plugin-uri}-proposal-nullish-coalescing-operatornullish-coalescing-operator | ES2020 | {not-needed} |

| {babel-plugin-uri}-proposal-optional-chainingoptional-chaining | ES2020 | {included} |

| {babel-plugin-uri}-proposal-logical-assignment-operatorslogical-assignment-operators | ES2021 | {included} |

| {babel-plugin-uri}-proposal-numeric-separatornumeric-separator | ES2021 | {not-needed} | |===

== Enabled Assumptions

The following assumptions are enabled for better performance and match with the behaviour of the TypeScript transpiler.

{babel-doc-uri}/assumptions#constantsuperconstantSuper
{babel-doc-uri}/assumptions#noclasscallsnoClassCalls
{babel-doc-uri}/assumptions#setclassmethodssetClassMethods
{babel-doc-uri}/assumptions#superiscallableconstructorsuperIsCallableConstructor
{babel-doc-uri}/assumptions#ignorefunctionlengthignoreFunctionLength
{babel-doc-uri}/assumptions#iterableisarrayiterableIsArray ({babel-plugin-uri}-transform-for-of#assumearrayfor-of, {babel-plugin-uri}-transform-spread#loosespread, {babel-plugin-uri}-transform-destructuring#loosedestructuring)
{babel-doc-uri}/assumptions#nodocumentallnoDocumentAll
{babel-doc-uri}/assumptions#nonewarrowsnoNewArrows
{babel-doc-uri}/assumptions#setspreadpropertiessetSpreadProperties