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 ( "os" "github.com/evanw/esbuild/pkg/api" ) func main() { result := api.Build(api.BuildOptions{ EntryPoints: []string{"input.js"}, Outfile: "output.js", Bundle: true, Write: true, LogLevel: api.LogLevelInfo, }) if len(result.Errors) > 0 { os.Exit(1) } } 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.Code) }
package api

type SourceMap uint8

const (
	SourceMapNone SourceMap = iota
	SourceMapInline
	SourceMapLinked
	SourceMapExternal
	SourceMapInlineAndExternal
)

type SourcesContent uint8

const (
	SourcesContentInclude SourcesContent = iota
	SourcesContentExclude
)

type Target uint8

const (
	ESNext Target = iota
	ES5
	ES2015
	ES2016
	ES2017
	ES2018
	ES2019
	ES2020
)

type Loader uint8

const (
	LoaderNone Loader = iota
	LoaderJS
	LoaderJSX
	LoaderTS
	LoaderTSX
	LoaderJSON
	LoaderText
	LoaderBase64
	LoaderDataURL
	LoaderFile
	LoaderBinary
	LoaderCSS
	LoaderDefault
)

type Platform uint8

const (
	PlatformBrowser Platform = iota
	PlatformNode
	PlatformNeutral
)

type Format uint8

const (
	FormatDefault Format = iota
	FormatIIFE
	FormatCommonJS
	FormatESModule
)

type EngineName uint8

const (
	EngineChrome EngineName = iota
	EngineEdge
	EngineFirefox
	EngineIOS
	EngineNode
	EngineSafari
)

type Engine struct {
	Name    EngineName
	Version string
}

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

type Message struct {
	Text     string
	Location *Location
	Notes    []Note
Optional user-specified data that is passed through unmodified. You can use this to stash the original error, for example.
	Detail interface{}
}

type Note struct {
	Text     string
	Location *Location
}

type StderrColor uint8

const (
	ColorIfTerminal StderrColor = iota
	ColorNever
	ColorAlways
)

type LogLevel uint8

const (
	LogLevelSilent LogLevel = iota
	LogLevelInfo
	LogLevelWarning
	LogLevelError
)

type Charset uint8

const (
	CharsetDefault Charset = iota
	CharsetASCII
	CharsetUTF8
)

type TreeShaking uint8

const (
	TreeShakingDefault TreeShaking = iota
	TreeShakingIgnoreAnnotations
)
////////////////////////////////////////////////////////////////////////////// Build API

type BuildOptions struct {
	Color      StderrColor
	ErrorLimit int
	LogLevel   LogLevel

	Sourcemap      SourceMap
	SourcesContent SourcesContent

	Target  Target
	Engines []Engine

	MinifyWhitespace  bool
	MinifyIdentifiers bool
	MinifySyntax      bool
	Charset           Charset
	TreeShaking       TreeShaking

	JSXFactory  string
	JSXFragment string

	Define    map[string]string
	Pure      []string
	AvoidTDZ  bool
	KeepNames bool

	GlobalName        string
	Bundle            bool
	PreserveSymlinks  bool
	Splitting         bool
	Outfile           string
	Metafile          string
	Outdir            string
	Outbase           string
	AbsWorkingDir     string
	Platform          Platform
	Format            Format
	External          []string
	MainFields        []string
	Loader            map[string]Loader
	ResolveExtensions []string
	Tsconfig          string
	OutExtensions     map[string]string
	PublicPath        string
	Inject            []string
	Banner            string
	Footer            string
	NodePaths         []string // The "NODE_PATH" variable from Node.js

	ChunkNames string
	AssetNames string

	EntryPoints []string
	Stdin       *StdinOptions
	Write       bool
	Incremental bool
	Plugins     []Plugin

	Watch *WatchMode
}

type WatchMode struct {
	SpinnerBusy string
	SpinnerIdle []string
	OnRebuild   func(BuildResult)
}

type StdinOptions struct {
	Contents   string
	ResolveDir string
	Sourcefile string
	Loader     Loader
}

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

	OutputFiles []OutputFile

	Rebuild func() BuildResult // Only when "Incremental: true"
	Stop    func()             // Only when "Watch: true"
}

type OutputFile struct {
	Path     string
	Contents []byte
}

func ( BuildOptions) BuildResult {
	return buildImpl().result
}
////////////////////////////////////////////////////////////////////////////// Transform API

type TransformOptions struct {
	Color      StderrColor
	ErrorLimit int
	LogLevel   LogLevel

	Sourcemap      SourceMap
	SourcesContent SourcesContent

	Target     Target
	Format     Format
	GlobalName string
	Engines    []Engine

	MinifyWhitespace  bool
	MinifyIdentifiers bool
	MinifySyntax      bool
	Charset           Charset
	TreeShaking       TreeShaking

	JSXFactory  string
	JSXFragment string
	TsconfigRaw string
	Footer      string
	Banner      string

	Define    map[string]string
	Pure      []string
	AvoidTDZ  bool
	KeepNames bool

	Sourcefile string
	Loader     Loader
}

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

	Code []byte
	Map  []byte
}

func ( string,  TransformOptions) TransformResult {
	return transformImpl(, )
}
////////////////////////////////////////////////////////////////////////////// Serve API

type ServeOptions struct {
	Port      uint16
	Host      string
	Servedir  string
	OnRequest func(ServeOnRequestArgs)
}

type ServeOnRequestArgs struct {
	RemoteAddress string
	Method        string
	Path          string
	Status        int
	TimeInMS      int // The time to generate the response, not to send it
}

type ServeResult struct {
	Port uint16
	Host string
	Wait func() error
	Stop func()
}

func ( ServeOptions,  BuildOptions) (ServeResult, error) {
	return serveImpl(, )
}
////////////////////////////////////////////////////////////////////////////// Plugin API

type Plugin struct {
	Name  string
	Setup func(PluginBuild)
}

type PluginBuild interface {
	OnResolve(options OnResolveOptions, callback func(OnResolveArgs) (OnResolveResult, error))
	OnLoad(options OnLoadOptions, callback func(OnLoadArgs) (OnLoadResult, error))
}

type OnResolveOptions struct {
	Filter    string
	Namespace string
}

type OnResolveArgs struct {
	Path       string
	Importer   string
	Namespace  string
	ResolveDir string
	Kind       ResolveKind
	PluginData interface{}
}

type OnResolveResult struct {
	PluginName string

	Errors   []Message
	Warnings []Message

	Path       string
	External   bool
	Namespace  string
	PluginData interface{}
}

type OnLoadOptions struct {
	Filter    string
	Namespace string
}

type OnLoadArgs struct {
	Path       string
	Namespace  string
	PluginData interface{}
}

type OnLoadResult struct {
	PluginName string

	Errors   []Message
	Warnings []Message

	Contents   *string
	ResolveDir string
	Loader     Loader
	PluginData interface{}
}

type ResolveKind uint8

const (
	ResolveEntryPoint ResolveKind = iota
	ResolveJSImportStatement
	ResolveJSRequireCall
	ResolveJSDynamicImport
	ResolveJSRequireResolve
	ResolveCSSImportRule
	ResolveCSSURLToken