import

[ddkwork]

package main

import (
	"fmt"
	"go/ast"
	"go/parser"
	"go/printer"
	"go/token"
	"os"
)

func main() {
	src := `
package main

import "fmt"

func main() {
    fmt.Println("Hello, World!")
}
`

	fset := token.NewFileSet()
	node, err := parser.ParseFile(fset, "", src, parser.ParseComments)
	if err != nil {
		fmt.Println(err)
		return
	}

	newImport := &ast.GenDecl{
		Tok: token.IMPORT,
		Specs: []ast.Spec{
			&ast.ImportSpec{
				Path: &ast.BasicLit{
					Kind:  token.STRING,
					Value: `"time"`,
				},
			},
		},
	}

	node.Decls = append([]ast.Decl{newImport}, node.Decls...)

	printer.Fprint(os.Stdout, fset, node)
}