unplugin-inline-enum

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Inline enum values to optimize bundle size.

This fork adds support for computed enum members that reference other members of the same enum or other enums.

Features

- Inline enum values to reduce bundle size
- Simplify generated enums in JavaScript
- Support for computed enum members with complex expressions

``ts
export enum TestEnum {
a = 1,
b = 'foo',
}
console.log(TestEnum.a, TestEnum.b)

// before
export let TestEnum
;(function (TestEnum) {
TestEnum[(TestEnum.a = 1)] = 'a'
TestEnum.b = 'foo'
})(TestEnum || (TestEnum = {}))

console.log(TestEnum.a, TestEnum.b)

// after
const TestEnum = {
a: 1,
'1': 'a',
b: 'foo',
}
console.log(1, 'foo')
`

Supported Enum Patterns

This plugin handles virtually all TypeScript enum patterns that can be statically analyzed at build time.

$3

Standard numeric enums with auto-incrementing values:

`ts
export enum Direction {
Up, // 0
Down, // 1
Left, // 2
Right, // 3
}
`

Numeric enums with a custom starting value:

`ts
export enum StatusCode {
OK = 200,
Created, // 201
Accepted, // 202
NoContent = 204,
BadRequest = 400,
NotFound, // 401
}
`

String enums:

`ts
export enum LogLevel {
Debug = "DEBUG",
Info = "INFO",
Warn = "WARN",
Error = "ERROR",
}
`

Mixed (heterogeneous) enums:

`ts
export enum Mixed {
No = 0,
Yes = "YES",
Maybe = 1,
}
`

$3

Members that reference other members of the same enum:

`ts
export enum Sizes {
Base = 16,
Small = Base / 2, // 8
Large = Base * 2, // 32
ExtraLarge = Large * 2, // 64
}
`

Members that reference other enums:

`ts
export enum Config {
MaxItems = 100,
PageSize = 10,
}

export enum Derived {
TotalPages = Config.MaxItems / Config.PageSize, // 10
}
`

Complex nested expressions with parentheses:

`ts
export enum RuleIds {
MaxRules = 1000,
RuleRange = MaxRules / 8, // 125
FirstGroup = 1,
SecondGroup = FirstGroup + RuleRange, // 126
ThirdGroup = SecondGroup + RuleRange, // 251
}
`

$3

Bit flags using shift operators:

`ts
export enum Permissions {
None = 0,
Read = 1 << 0, // 1
Write = 1 << 1, // 2
Execute = 1 << 2, // 4
Delete = 1 << 3, // 8
}
`

Combining flags with bitwise OR:

`ts
export enum Permissions {
None = 0,
Read = 1,
Write = 2,
Execute = 4,
ReadWrite = Read | Write, // 3
ReadExecute = Read | Execute, // 5
All = Read | Write | Execute, // 7
}
`

Other bitwise operations:

`ts
export enum BitwiseOps {
A = 0b1111,
B = 0b1010,
And = A & B, // 10
Or = A | B, // 15
Xor = A ^ B, // 5
NotA = ~A, // -16
}
`

$3

All standard arithmetic operators are supported:

`ts
export enum Math {
A = 100,
B = 7,
Sum = A + B, // 107
Difference = A - B, // 93
Product = A * B, // 700
Quotient = A / B, // 14.285714...
Remainder = A % B, // 2
}
`

$3

Negative values and other unary operators:

`ts
export enum Values {
Positive = 42,
Negative = -42,
BitwiseNot = ~0, // -1
}
`

$3

Hexadecimal, octal, and binary literals:

`ts
export enum Literals {
Hex = 0xff, // 255
Octal = 0o77, // 63
Binary = 0b11111111, // 255
Scientific = 1e6, // 1000000
}
`

$3

Floating point numbers:

`ts
export enum Constants {
Pi = 3.14159,
E = 2.71828,
Half = 0.5,
}
`

Infinity (from overflow):

`ts
export enum Extremes {
Huge = 1e309, // Infinity
Tiny = -1e309, // -Infinity
}
`

$3

Enum members with non-identifier keys:

`ts
export enum SpecialKeys {
"kebab-case" = 1,
"with spaces" = 2,
"123numeric" = 3,
}
`

$3

Simple template literals (without embedded expressions):

`ts
export enum Templates {
Message = Hello, World!,
Quoted = String with "quotes",
}
`

Unsupported Patterns

The following patterns cannot be statically analyzed and will cause build errors:

Function calls:
`ts
export enum Invalid {
Value = Math.floor(3.5), // Error: CallExpression not supported
}
`

External references:
`ts
const EXTERNAL = 100;
export enum Invalid {
Value = EXTERNAL, // Error: cannot resolve external reference
}
`

Runtime expressions:
`ts
export enum Invalid {
Value = Date.now(), // Error: cannot evaluate at build time
}
`

If you need these patterns, keep the enum as-is and the plugin will skip it.

Installation

`bash


npm

npm i -D @iceman8911/unplugin-inline-enum

jsr

npx jsr add -D @iceman8911/@unplugin/inline-enum
`

Vite

`ts
// vite.config.ts
import InlineEnum from '@iceman8911/unplugin-inline-enum/vite'

export default defineConfig({
plugins: [InlineEnum()],
})
`




Rollup

`ts
// rollup.config.js
import InlineEnum from '@iceman8911/unplugin-inline-enum/rollup'

export default {
plugins: [InlineEnum()],
}
`




Rolldown

`ts
// rolldown.config.js
import InlineEnum from '@iceman8911/unplugin-inline-enum/rolldown'

export default {
plugins: [InlineEnum()],
}
`




esbuild

`ts
// esbuild.config.js
import { build } from 'esbuild'

build({
plugins: [require('@iceman8911/unplugin-inline-enum/esbuild')()],
})
`




Webpack

`ts
// webpack.config.js
module.exports = {
/ ... /
plugins: [require('@iceman8911/unplugin-inline-enum/webpack')()],
}
``

Options

Refer to docs.

Credits

Thanks to @xiaoxiangmoe and
@yangmingshan for their contributions in the
PR.

Sponsors

License

MIT License © 2024-PRESENT Kevin Deng

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[unit-test-href]: https://github.com/unplugin/unplugin-inline-enum/actions/workflows/unit-test.yml