api

Documentation

Overview

This API exposes esbuild's two main operations: building and transforming. It's intended for integrating esbuild into other tools as a library.

If you are just trying to run esbuild from Go without the overhead of creating a child process, there is also an API for the command-line interface itself: https://godoc.org/github.com/evanw/esbuild/pkg/cli.

Build API

This function runs an end-to-end build operation. It takes an array of file paths as entry points, parses them and all of their dependencies, and returns the output files to write to the file system. The available options roughly correspond to esbuild's command-line flags.

Example usage:

package main

import (
    "fmt"
    "io/ioutil"

    "github.com/evanw/esbuild/pkg/api"
)

func main() {
    result := api.Build(api.BuildOptions{
        EntryPoints: []string{"input.js"},
        Outfile:     "output.js",
        Bundle:      true,
    })

    fmt.Printf("%d errors and %d warnings\n",
        len(result.Errors), len(result.Warnings))

    for _, out := range result.OutputFiles {
        ioutil.WriteFile(out.Path, out.Contents, 0644)
    }
}

Transform API

This function transforms a string of source code into JavaScript. It can be used to minify JavaScript, convert TypeScript/JSX to JavaScript, or convert newer JavaScript to older JavaScript. The available options roughly correspond to esbuild's command-line flags.

Example usage:

package main

import (
    "fmt"
    "os"

    "github.com/evanw/esbuild/pkg/api"
)

func main() {
    jsx := `
        import * as React from 'react'
        import * as ReactDOM from 'react-dom'

        ReactDOM.render(
            <h1>Hello, world!</h1>,
            document.getElementById('root')
        );
    `

    result := api.Transform(jsx, api.TransformOptions{
        Loader: api.LoaderJSX,
    })

    fmt.Printf("%d errors and %d warnings\n",
        len(result.Errors), len(result.Warnings))

    os.Stdout.Write(result.JS)
}

Index

• type BuildOptions
• type BuildResult
  • func Build(options BuildOptions) BuildResult
• type Format
• type Loader
• type Location
• type LogLevel
• type Message
• type OutputFile
• type Platform
• type SourceMap
• type StderrColor
• type StrictOptions
• type Target
• type TransformOptions
• type TransformResult
  • func Transform(input string, options TransformOptions) TransformResult

Types

type BuildOptions

type BuildOptions struct {
	Color      StderrColor
	ErrorLimit int
	LogLevel   LogLevel

	Sourcemap SourceMap
	Target    Target
	Strict    StrictOptions

	MinifyWhitespace  bool
	MinifyIdentifiers bool
	MinifySyntax      bool

	JSXFactory  string
	JSXFragment string
	Defines     map[string]string

	GlobalName        string
	Bundle            bool
	Outfile           string
	Metafile          string
	Outdir            string
	Platform          Platform
	Format            Format
	Externals         []string
	Loaders           map[string]Loader
	ResolveExtensions []string

	EntryPoints []string
}

type BuildResult

type BuildResult struct {
	Errors   []Message
	Warnings []Message

	OutputFiles []OutputFile
}

func Build

func Build(options BuildOptions) BuildResult

type Format

type Format uint8

const (
	FormatDefault Format = iota
	FormatIIFE
	FormatCommonJS
	FormatESModule
)

type Loader

type Loader uint8

const (
	LoaderJS Loader = iota
	LoaderJSX
	LoaderTS
	LoaderTSX
	LoaderJSON
	LoaderText
	LoaderBase64
	LoaderDataURL
	LoaderFile
)

type Location

type Location struct {
	File     string
	Line     int // 1-based
	Column   int // 0-based, in bytes
	Length   int // in bytes
	LineText string
}

type LogLevel

type LogLevel uint8

const (
	LogLevelSilent LogLevel = iota
	LogLevelInfo
	LogLevelWarning
	LogLevelError
)

type Message

type Message struct {
	Text     string
	Location *Location
}

type OutputFile

type OutputFile struct {
	Path     string
	Contents []byte
}

type Platform

type Platform uint8

const (
	PlatformBrowser Platform = iota
	PlatformNode
)

type SourceMap

type SourceMap uint8

const (
	SourceMapNone SourceMap = iota
	SourceMapInline
	SourceMapLinked
	SourceMapExternal
)

type StderrColor

type StderrColor uint8

const (
	ColorIfTerminal StderrColor = iota
	ColorNever
	ColorAlways
)

type StrictOptions

type StrictOptions struct {
	NullishCoalescing bool
	ClassFields       bool
}

type Target

type Target uint8

const (
	ESNext Target = iota
	ES2015
	ES2016
	ES2017
	ES2018
	ES2019
	ES2020
)

type TransformOptions

type TransformOptions struct {
	Color      StderrColor
	ErrorLimit int
	LogLevel   LogLevel

	Sourcemap SourceMap
	Target    Target
	Strict    StrictOptions

	MinifyWhitespace  bool
	MinifyIdentifiers bool
	MinifySyntax      bool

	JSXFactory  string
	JSXFragment string
	Defines     map[string]string

	Sourcefile string
	Loader     Loader
}

type TransformResult

type TransformResult struct {
	Errors   []Message
	Warnings []Message

	JS          []byte
	JSSourceMap []byte
}

func Transform

func Transform(input string, options TransformOptions) TransformResult