@sakartvelosoft/types-metadata

Framework for metadata bound to types and properties

This an experimental package to provide functionality of binding arbitrary metadata to types and properties. Package done as much generic as possible, almost without binding to specific use cases.

Package done intentionally without decorators as decorators API is still experimental and not so tests-friendly due to usage of global context

Usage

Binding alias to types

import {createTypesRegistry} from "@sakartvelosoft/types-metadata";

class TestClass {
    prop1: string;
    prop2: boolean;
    prop3: number;
    prop4: Date;
}
let registry = createTypesRegistry();
registry.bindTypeAlias(TestClass, 'test-class');
expect(registry.getTypeAlias(TestClass)).eq('test-class');
expect(registry.resolveType('test-class').alias).eq('test-class');
expect(registry.resolveType('test-class').name).eq(TestClass.name);
expect(registry.resolveType('TestClass')).equal(registry.resolveType('test-class'));

Binding default fixed values to properties

        class TestClass2 {
            text: string;
        }

        let registry = createTypesRegistry();
        registry.configureType(TestClass2, api => api.withDefaultValues({
            text: 'DEFAULT TEXT'
        }));
        let instance = registry.forType(TestClass2).createEmpty();
        expect(instance.text).to.be.eq("DEFAULT TEXT");

Adding generated properties

        class TestRecord {
            timestamp: Date;
            id: string;
            text: string
        }

        let registry = createTypesRegistry();
        registry.configureType(TestRecord, api => api.withPropertyGenerator('timestamp', () => new Date())
            .withPropertyGenerator('id', () => randomBytes(32).toString('base64url')));
        let rec = registry.create<TestRecord>(TestRecord, {
            text: 'Testing'
        });
        expect(rec).instanceof(TestRecord);
        expect(typeof rec.id).is.eq('string');
        expect(rec.timestamp).instanceof(Date);
        expect(rec.text).eq('Testing');