ast.go

package ast

import "github.com/evanw/esbuild/internal/logger"

// This file contains data structures that are used with the AST packages for
// both JavaScript and CSS. This helps the bundler treat both AST formats in
// a somewhat format-agnostic manner.

type ImportKind uint8

const (
	// An ES6 import or re-export statement
	ImportStmt ImportKind = iota

	// A call to "require()"
	ImportRequire

	// An "import()" expression with a string argument
	ImportDynamic

	// A call to "require.resolve()"
	ImportRequireResolve

	// A CSS "@import" rule
	ImportAt

	// A CSS "url(...)" token
	ImportURL

	// An entry point provided by the user
	ImportEntryPoint
)

func (kind ImportKind) StringForMetafile() string {
	switch kind {
	case ImportStmt:
		return "import-statement"
	case ImportRequire:
		return "require-call"
	case ImportDynamic:
		return "dynamic-import"
	case ImportRequireResolve:
		return "require-resolve"
	case ImportAt:
		return "import-rule"
	case ImportURL:
		return "url-token"
	case ImportEntryPoint:
		return "entry-point"
	default:
		panic("Internal error")
	}
}

func (kind ImportKind) IsFromCSS() bool {
	return kind == ImportAt || kind == ImportURL
}

type ImportRecord struct {
	Range logger.Range
	Path  logger.Path

	// The resolved source index for an internal import (within the bundle) or
	// nil for an external import (not included in the bundle)
	SourceIndex *uint32

	// Sometimes the parser creates an import record and decides it isn't needed.
	// For example, TypeScript code may have import statements that later turn
	// out to be type-only imports after analyzing the whole file.
	IsUnused bool

	// If this is true, the import contains syntax like "* as ns". This is used
	// to determine whether modules that have no exports need to be wrapped in a
	// CommonJS wrapper or not.
	ContainsImportStar bool

	// If true, this "export * from 'path'" statement is evaluated at run-time by
	// calling the "__exportStar()" helper function
	CallsRunTimeExportStarFn bool

	// Tell the printer to wrap this call to "require()" in "__toModule(...)"
	WrapWithToModule bool

	// True for require calls like this: "try { require() } catch {}". In this
	// case we shouldn't generate an error if the path could not be resolved.
	IsInsideTryBody bool

	// If true, this was originally written as a bare "import 'file'" statement
	WasOriginallyBareImport bool

	Kind ImportKind
}