This script generates Javascript classes for go structs.

generate_javascript_class.go

package main

import (
	"fmt"
	"go/ast"
	"go/parser"
	"go/token"
	"log"
	"reflect"
	"strings"
)

func main() {
	var fileSet token.FileSet
	packages, err := parser.ParseDir(&fileSet, "./", nil, parser.AllErrors)
	if err != nil {
		log.Println(err)
	}

	for _, pkg := range packages {
		for _, file := range pkg.Files {
			for _, decl := range file.Decls {
				genDecl, ok := decl.(*ast.GenDecl)
				if !ok {
					continue
				}
				for _, spec := range genDecl.Specs {
					typeSpec, ok := spec.(*ast.TypeSpec)
					if !ok || !typeSpec.Name.IsExported() {
						continue
					}
					structureSpec, ok := typeSpec.Type.(*ast.StructType)
					if !ok {
						continue
					}

					fmt.Printf("class %s {\n", typeSpec.Name)
					for _, field := range structureSpec.Fields.List {
						tpStr := typeString(field.Type)
						if field.Tag == nil || len(field.Tag.Value) < 2{
							for _, name := range field.Names {
								fmt.Printf("\t%s: %s\n", name, tpStr)
							}
							continue
						}

						tag := reflect.StructTag(field.Tag.Value[1:len(field.Tag.Value)])
						jsonTag, ok := tag.Lookup("json")
						if !ok {
							for _, name := range field.Names {
								fmt.Printf("\t%s: %s\n", name, tpStr)
							}
							continue
						}

						jsonTag = strings.TrimSpace(strings.Split(jsonTag, ",")[0])

						fmt.Printf("\t%s: %s\n", jsonTag, tpStr)
					}
					fmt.Println("}")
				}
			}
		}
	}
}

func typeString(node ast.Expr) string {
	switch nd := node.(type) {
	case *ast.SelectorExpr:
		ident, ok := nd.X.(*ast.Ident)
		if !ok {
			return "undefined"
		}
		switch nd.Sel.Name {
		case "Time":
			switch ident.Name {
			case "time":
				return "String"
			}
		case "ObjectID":
			switch ident.Name {
			case "primitive":
				return "String"
			}
		}
	case *ast.Ident:
		switch nd.Name {
		case "int", "float64":
			return "Number"
		case "bool":
			return "Boolean"
		case "string":
			return "String"
		}
		return nd.Name
	case *ast.ArrayType:
		return typeString(nd.Elt) + "[]"
	}
	return "undefined"
}