TsSchema

Uses ActiveRecord to generate a schema.d.ts file for use in typescript frontends.

Installation

bundle add "ts_schema"

Then generate the initializer file:

rails generate ts_schema:install

Usage

All options with their defaults are in the generated initializer file.

By default, every migration will auto generate a new schema file, replacing the existing one. You can disable this behavior in the config file.

You can manually generate the schema file by running:

rails ts_schema:generate

Default type mappings

Ruby Type	Typescript Type
string	string
text	string
integer	number
enum	number
bigint	number
float	number
decimal	number
json	Record<string, any>
jsonb	Record<string, any>
binary	string
boolean	boolean
date	string
datetime	string
timestamp	string
datetime_with_timezone	string
inet	string
cidr	string
macaddr	string

Initializer options

Option	Default	Values	Description
case	`:camel`	`:camel` `:snake` `:pascal`	camelCase snake_case PascalCase
output	`Rails.root.join('app', 'assets', 'javascripts', 'schema.d.ts')`	Any path	Path to output generated file
auto_generate	`true`	`boolean`	Whether to automatically (re)generate the defenitions after running migrations
custom_types	`{}`	`{ ruby_type: 'typescriptType' }`	Use to add or override type mappings for any type
default_type	`:string`	Any typescript type	The default output type to use if a ruby type is not included in the type mappings
include_associated	`true`	`boolean`	Whether to include associated models as fields on the generated interfaces
parent_classes	`["ApplicationRecord"]`	Array of string names of top level classes	Any class names included in this array will be querried for subclasses to generate types for
additional_models	`[]`	Array of string names of ActiveRecord models	Add model names which don't inherit from classes included in `parent_classes`, but which should have types generated
field_overrides	`{ encrypted_password: :password, password: :optional, }`	Hash of field names with the following values: `:optional`: Makes it an optional field by adding '?' to the defintion (example: password?: string) `:omit`: Omits the field from being output in the schema entirely `[string]`: Field name override. Will replace any instance of the hash key with the value. The default values replace `password` with `encrypted_password`	Overwrite, omit, or make optional any field name. Applies to all generated classes
field_type_overrides	`{}`	`{ field_name: 'typescriptType' }`	Override all instances of a field name in any record with the supplied type. Useful for polymorphic associations, for example: `commentable_type: "'Product'
namespace	`:schema`	string\|symbol	The typescript namespace to contain generated types
schema_type	`:interface`	`:interface`\|`:type`	Whether to generate typescript definitions as types or interfaces. Interfaces are recommended since they are easier to extend
indent	`:tab`	`:tab`\|`:space`	Indentation using tabs or spaces
spaces	`2`	number	Number of spaces for indentation if indentation is set to spaces

Gotchas

Sometimes ActiveRecord's inflections will alter the class name. For instance, with a class named Five; "Fives".singularize returns "Fife", which is not the classname. In the case where Rails alters the classname for an association, you must explicitly define it on the association in the model using class_name. Example: has_many :fives, class_name: "Five".

License

The gem is available as open source under the terms of the MIT License.

ts_schema