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    3.0.1 • Public • Published


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    Generate io-ts codecs for classes by decorating props


    $ npm install --save @orchestrator/gen-io-ts

    NOTE: Library uses globalThis variable to get Reflect object. You can either provide it manually via provideReflect() function or make sure that Reflect API is loaded globally (via polyfills).

    If required - you may need to load globalThis polyfill.


    First decorate your properties that you want to validate:

    // my-class.ts
    import { Property } from '@orchestrator/gen-io-ts';
    class MyClass {
      @Property() // This will validate `prop` to be a string
      prop: string;
      internalProp: any;

    Now generate codec type for your decorated class:

    // main.ts
    import { genIoType } from '@orchestrator/gen-io-ts';
    import { MyClass } from './my-class.ts';
    const myClassType = genIoType(MyClass);
    // Then you can validate the type
    myClassType.decode({ prop: 'ok' }); // This will produce Right({prop: 'ok'})
    myClassType.decode({ prop: false }); // This will produce Left([...])

    You can now report any validation errors as usual in io-ts:

    import { ThrowReporter } from 'io-ts/lib/ThrowReporter';{...})); // This will throw errors

    NOTE: By default every property is optional. To change it - see Required property section.

    Advanced usage

    Required property

    Every property is configured to be NOT required, which means you can assign null/undefined values and validation will not fail.

    To change that set isRequired option to true:

    import { Property } from '@orchestrator/gen-io-ts';
    class MyClass {
      @Property({ isRequired: true }) // Will now fail if `null/undefined` was set
      prop: string;

    Custom type

    Allows to override default inferred type with custom:

    import { Property } from '@orchestrator/gen-io-ts';
    class MyClass {
      @Property({ type: typeOf(Boolean) }) // Will now allow only booleans instead of strings
      prop: string;

    Custom type factories

    Allows to override/adjust(refine) default type:

    import * as t from 'io-ts';
    import { Property } from '@orchestrator/gen-io-ts';
    class MyClass {
        typeFactory: type => t.refine(type, str => str.length > 0, 'NotEmpty'),
      }) // Will now allow only non empty strings
      prop: string;

    See: io-ts Refinements for more usage info.

    This project was generated with Angular CLI version 7.1.4.

    Development server

    Run ng serve for a dev server. Navigate to http://localhost:4200/. The app will automatically reload if you change any of the source files.

    Code scaffolding

    Run ng generate component component-name to generate a new component. You can also use ng generate directive|pipe|service|class|guard|interface|enum|module.


    Run ng build to build the project. The build artifacts will be stored in the dist/ directory. Use the --prod flag for a production build.

    Running unit tests

    Run ng test to execute the unit tests via Karma.

    Running end-to-end tests

    Run ng e2e to execute the end-to-end tests via Protractor.

    Further help

    To get more help on the Angular CLI use ng help or go check out the Angular CLI README.


    npm i @orchestrator/gen-io-ts

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    • gund
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