Convert Golang structs to Typescript interfaces
Handle
- json tags, like
omitemptyandinlineappropriately uuid.UUID&time.Timeconversion- type generation for arrays
- setting custom names for the generated typescript interfaces
- types which use generics (see
examples/5-generic-struct)
go get github.com/tompston/gut| main.go | example.gen.ts |
|---|---|
package main
import (
"fmt"
"time"
"github.com/google/uuid"
"github.com/tompston/gut"
)
func main() {
// define which structs you want to convert
ex1 := gut.Convert(User{})
ex2 := gut.Convert(Comments{})
ex3 := gut.Convert(MyRandomStruct{})
// concat all of the interfaces together
interfaces := fmt.Sprintln(ex1, ex2, ex3)
if err := gut.Generate("./example.gen.ts",interfaces); err != nil {
fmt.Println(err)
}
}
type User struct {
ID uuid.UUID `json:"user_id"`
Username string `json:"username"`
CreatedAt time.Time `json:"created_at"`
Comments `json:"comments,omitempty"`
}
type Comments []struct {
ID int `json:"comment_id"`
Value string `json:"value"`
}
type MyRandomStruct struct {
MyFloat float64
MyInterface interface{}
Ex1 map[string]map[string]string
IntArray []int
} |
export type UuidType = string;
export type BigIntType = BigInt;
export type DateType = Date;
export interface User {
user_id: UuidType;
username: string;
created_at: DateType;
comments?: {
comment_id: number;
value: string;
}[];
}
export type CommentsArray = Comments[];
export interface Comments {
comment_id: number;
value: string;
}
export interface MyRandomStruct {
MyFloat: number;
MyInterface: any;
Ex1: { [key: string]: { [key: string]: string } };
IntArray: number[];
} |
To format the generated typescript code, you can run deno fmt .
I wanted to solve the problem of converting golang structs to typescript interfaces, so that the backend and frontend clients could be in-sync, but I found that the current packages which try to do this had bugs and did not have the features I wanted. So I had to write it from scratch (with some help from ChatGPT)
go test . -v -count=1-
Handle cases when the convertable struct is an array
-
Handle json ",omitempty" tags
-
Handle json ",inline" tags (embeded structs)
- If a struct has a field with an json ",inline" tag, then the generated
typescript interface will have all of the fields from the embeded struct
inside of it. (see
examples/4-struct-with-inline)
- If a struct has a field with an json ",inline" tag, then the generated
typescript interface will have all of the fields from the embeded struct
inside of it. (see
-
handle
uuid.UUID&time.Timeconversion -
Avoid duplicate interface names, by generating only one typescript interface which will hold all of the types that are present in the struct.
-
Flexible typescript type system for the converted
time.Time,uuid.UUIDandint64/uint64types. -
optionally generate the type which holds an array of interfaces
-
Ability to optionally rename the generated typescript interface to a custom name
-
flexibility in exporting the converted go structs from packages
Convert()returns a string which holds the generated typescript interface, thus grouping the structs from multiple packages, concatenating them together and then saving them to a single file is quite trivial.
-
Keep the package simple.
gutexports only 2 funtionsConvert()-> converts the struct into a ts stringGenerate()-> save the converted ts interfaces to a file + define the settings for the types
- The generated TS code is not formatted. Maybe I'll fix this later. The current way to format can be done by using
deno fmt . - There might be bugs.
The initial draft of the code was generated by ChatGPT. After some heavy refactoring, this is the end result.
| main.go | example.gen.ts |
|---|---|
package main
import (
"fmt"
"time"
"github.com/google/uuid"
"github.com/tompston/gut"
)
func main() {
// Insetad of generating an interface called User,
// create one with a custom name
ex1 := gut.Convert(User{},
gut.Type{Name: "MyCustomInterface"})
// Generate both the interface for the struct and
// also a type which holds an array of interfaces.
// + optionally you can also rename it.
ex2 := gut.Convert(MyRandomStruct{},
gut.Type{IsArray: true, ArrayTypeName: "ArrayOfMyRandomStructs"})
// concat all of the interfaces together
interfaces := fmt.Sprintln(ex1, ex2)
if err := gut.Generate("./example.gen.ts", interfaces); err != nil {
fmt.Println(err)
}
}
type User struct {
ID uuid.UUID `json:"user_id"`
Username string `json:"username"`
CreatedAt time.Time `json:"created_at"`
Comments `json:"comments,omitempty"`
}
type Comments []struct {
ID int `json:"comment_id"`
Value string `json:"value"`
}
type MyRandomStruct struct {
MyFloat float64
MyInterface interface{}
Ex1 map[string]map[string]string `json:"ex_1"`
IntArray []int `json:"int_array"`
OptionalStringArray []string `json:"opt_str_array,omitempty"`
} |
export type UuidType = string;
export type BigIntType = BigInt;
export type DateType = Date;
export interface MyCustomInterface {
user_id: UuidType;
username: string;
created_at: DateType;
comments?: {
comment_id: number;
value: string;
}[];
}
export type ArrayOfMyRandomStructs = MyRandomStruct[];
export interface MyRandomStruct {
MyFloat: number;
MyInterface: any;
ex_1: { [key: string]: { [key: string]: string } };
int_array: number[];
opt_str_array?: string[];
} |
| main.go | example.gen.ts |
|---|---|
package main
import (
"fmt"
"time"
"github.com/google/uuid"
"github.com/tompston/gut"
)
func main() {
// Insetad of generating an interface called User,
// create one with a custom name
ex1 := gut.Convert(User{},
gut.Type{Name: "MyCustomInterface"})
if err := gut.Generate(
"./example.gen.ts", ex1, gut.Settings{
FirstLine: "// This is a custom comment in the file\n",
DateType: "string",
UuidType: "string",
BigIntType: "number",
}); err != nil {
fmt.Println(err)
}
}
type User struct {
ID uuid.UUID `json:"user_id"`
Username string `json:"username"`
CreatedAt time.Time `json:"created_at"`
} |
// This is a custom comment in the file
export type UuidType = string;
export type BigIntType = number;
export type DateType = string;
export interface MyCustomInterface {
user_id: UuidType;
username: string;
created_at: DateType;
} |