cdklabsjson2jsii
Generates jsii-compatible structs from JSON schemas
Usage
const g = TypeGenerator.forStruct('Person', {
definitions: {
Name: {
description: 'Represents a name of a person',
required: ['FirstName', 'last_name'],
properties: {
FirstName: {
type: 'string',
description: 'The first name of the person',
},
last_name: {
type: 'string',
description: 'The last name of the person',
},
},
},
},
required: ['name'],
properties: {
name: {
description: 'The person\'s name',
$ref: '#/definitions/Name',
},
favorite_color: {
description: 'Favorite color. Default is green',
enum: ['red', 'green', 'blue', 'yellow'],
},
},
});
fs.writeFileSync('person.ts', g.render());
ts
/**
* @schema Person
*/
export interface Person {
/**
* The person's name
*
* @schema Person#name
*/
readonly name: Name;
/**
* Favorite color. Default is green
*
* @default green
* @schema Person#favorite_color
*/
readonly favoriteColor?: PersonFavoriteColor;
}
/**
* Converts an object of type 'Person' to JSON representation.
*/
/* eslint-disable max-len, quote-props */
export function toJson_Person(obj: Person | undefined): Record<string, any> | undefined {
if (obj === undefined) { return undefined; }
const result = {
'name': toJson_Name(obj.name),
'favorite_color': obj.favoriteColor,
};
// filter undefined values
return Object.entries(result).reduce((r, i) => (i[1] === undefined) ? r : ({ ...r, [i[0]]: i[1] }), {});
}
/* eslint-enable max-len, quote-props */
/**
* Represents a name of a person
*
* @schema Name
*/
export interface Name {
/**
* The first name of the person
*
* @schema Name#FirstName
*/
readonly firstName: string;
/**
* The last name of the person
*
* @schema Name#last_name
*/
readonly lastName: string;
}
/**
* Converts an object of type 'Name' to JSON representation.
*/
/* eslint-disable max-len, quote-props */
export function toJson_Name(obj: Name | undefined): Record<string, any> | undefined {
if (obj === undefined) { return undefined; }
const result = {
'FirstName': obj.firstName,
'last_name': obj.lastName,
};
// filter undefined values
return Object.entries(result).reduce((r, i) => (i[1] === undefined) ? r : ({ ...r, [i[0]]: i[1] }), {});
}
/* eslint-enable max-len, quote-props */
/**
* Favorite color. Default is green
*
* @default green
* @schema PersonFavoriteColor
*/
export enum PersonFavoriteColor {
/** red */
RED = 'red',
/** green */
GREEN = 'green',
/** blue */
BLUE = 'blue',
/** yellow */
YELLOW = 'yellow',
}
The generated code includes JSII structs (TypeScript interfaces) and enums based
on the schema (Person, Name and PersonFavoriteColor) as well as a function
toJson_Xyz() for each struct.
The toJson() functions are required in order to serialize objects back to their
original schema format.
For example, the following expression:
toJson_Person({
name: {
firstName: 'Jordan',
lastName: 'McJordan'
},
favoriteColor: PersonFavoriteColor.GREEN
})
Will return:
{
"name": {
"FirstName": "Jordan",
"last_name": "McJordan"
},
"favorite_color": "green"
}
Use cases
Type aliases
It is possible to offer an alias to a type definition using addAlias(from,
to). The type generator will resolve any references to the original type with
the alias:
const gen = new TypeGenerator();
gen.addDefinition('TypeA', { type: 'object', properties: { ref: { $ref: '#/definitions/TypeB' } } } );
gen.addDefinition('TypeC', { type: 'object', properties: { field: { type: 'string' } } });
gen.addAlias('TypeB', 'TypeC');
gen.emitType('TypeA');
This will output:
interface TypeA {
readonly ref: TypeC;
}
interface TypeC {
readonly field: string;
}
Language bindings
Once you generate jsii-compatible TypeScript source (such as person.ts above),
you can use jsii-srcmak in order to
produce source code in any of the jsii supported languages.
The following command will produce Python sources for the Person types:
$ jsii-srcmak gen/ts \
--python-outdir gen/py --python-module-name person \
--java-outdir gen/java --java-package person
See the jsii-srcmak for library usage.
Contributions
All contributions are celebrated.
License
Distributed under the Apache 2.0 license.