type-declaration.ts

import * as ts from 'typescript';
import { IType } from '../collections';
import { any_type, ElementKind } from '../constants';
import {
  create_element,
  is_element,
  IElement,
  IElementOptions,
} from '../element';
import { transform } from '../transform';
import { create_type_parameters } from '../utils';
import { IGenericDeclaration } from './generic-declaration';

export interface ITypeDeclarationOptions extends IElementOptions {
  name: string;
  export?: boolean;
  generics?: IGenericDeclaration[];
  type?: IType;
}

export interface ITypeDeclaration
  extends IElement<ElementKind.TypeDeclaration>,
    ITypeDeclarationOptions {}

export const create_type_declaration = (
  options: ITypeDeclarationOptions,
): ITypeDeclaration => ({
  ...create_element(ElementKind.TypeDeclaration),
  ...options,
});

export const is_type_declaration = (value: any): value is ITypeDeclaration =>
  is_element(value) && value.kind === ElementKind.TypeDeclaration;

// tslint:disable:ter-indent

/**
 * @hidden
 */
export const transform_type_declaration = (
  element: ITypeDeclaration,
  path: IElement<any>[],
) =>
  ts.createTypeAliasDeclaration(
    /* decorators      */ undefined,
    /* modifiers       */ element.export === true
      ? [ts.createToken(ts.SyntaxKind.ExportKeyword)]
      : undefined,
    /* name            */ element.name,
    /* typeParameters  */ create_type_parameters(element.generics, path),
    /* type            */ transform(
      element.type || any_type,
      path,
    ) as ts.TypeNode,
  );