ApiClass.ts

// Copyright (c) Microsoft Corporation. All rights reserved. Licensed under the MIT license.
// See LICENSE in the project root for license information.

import { DeclarationReference, Meaning, Navigation, Component } from '@microsoft/tsdoc/lib/beta/DeclarationReference';
import { ApiItemKind } from '../items/ApiItem';
import { ApiDeclaredItem, IApiDeclaredItemOptions, IApiDeclaredItemJson } from '../items/ApiDeclaredItem';
import { ApiItemContainerMixin, IApiItemContainerMixinOptions } from '../mixins/ApiItemContainerMixin';
import { ApiReleaseTagMixin, IApiReleaseTagMixinOptions } from '../mixins/ApiReleaseTagMixin';
import { IExcerptTokenRange } from '../mixins/Excerpt';
import { HeritageType } from './HeritageType';
import { IApiNameMixinOptions, ApiNameMixin } from '../mixins/ApiNameMixin';
import { ApiTypeParameterListMixin, IApiTypeParameterListMixinOptions, IApiTypeParameterListMixinJson
  } from '../mixins/ApiTypeParameterListMixin';
import { DeserializerContext } from './DeserializerContext';

/**
 * Constructor options for {@link ApiClass}.
 * @public
 */
export interface IApiClassOptions extends
  IApiItemContainerMixinOptions,
  IApiNameMixinOptions,
  IApiReleaseTagMixinOptions,
  IApiDeclaredItemOptions,
  IApiTypeParameterListMixinOptions {

  extendsTokenRange: IExcerptTokenRange | undefined;
  implementsTokenRanges: IExcerptTokenRange[];
}

export interface IApiClassJson extends
  IApiDeclaredItemJson,
  IApiTypeParameterListMixinJson {
  extendsTokenRange?: IExcerptTokenRange;
  implementsTokenRanges: IExcerptTokenRange[];
}

/**
 * Represents a TypeScript class declaration.
 *
 * @remarks
 *
 * This is part of the {@link ApiModel} hierarchy of classes, which are serializable representations of
 * API declarations.
 *
 * `ApiClass` represents a TypeScript declaration such as this:
 *
 * ```ts
 * export class X { }
 * ```
 *
 * @public
 */
export class ApiClass extends ApiItemContainerMixin(ApiNameMixin(ApiTypeParameterListMixin(ApiReleaseTagMixin(
  ApiDeclaredItem)))) {

  /**
   * The base class that this class inherits from (using the `extends` keyword), or undefined if there is no base class.
   */
  public readonly extendsType: HeritageType | undefined;

  private readonly _implementsTypes: HeritageType[] = [];

  public constructor(options: IApiClassOptions) {
    super(options);

    if (options.extendsTokenRange) {
      this.extendsType = new HeritageType(this.buildExcerpt(options.extendsTokenRange));
    } else {
      this.extendsType = undefined;
    }

    for (const implementsTokenRange of options.implementsTokenRanges) {
      this._implementsTypes.push(new HeritageType(this.buildExcerpt(implementsTokenRange)));
    }
  }

  public static getContainerKey(name: string): string {
    return `${name}|${ApiItemKind.Class}`;
  }

  /** @override */
  public static onDeserializeInto(options: Partial<IApiClassOptions>, context: DeserializerContext,
    jsonObject: IApiClassJson): void {

    super.onDeserializeInto(options, context, jsonObject);

    options.extendsTokenRange = jsonObject.extendsTokenRange;
    options.implementsTokenRanges = jsonObject.implementsTokenRanges;
  }

  /** @override */
  public get kind(): ApiItemKind {
    return ApiItemKind.Class;
  }

  /** @override */
  public get containerKey(): string {
    return ApiClass.getContainerKey(this.name);
  }

  /**
   * The list of interfaces that this class implements using the `implements` keyword.
   */
  public get implementsTypes(): ReadonlyArray<HeritageType> {
    return this._implementsTypes;
  }

  /** @override */
  public serializeInto(jsonObject: Partial<IApiClassJson>): void {
    super.serializeInto(jsonObject);

    // Note that JSON does not support the "undefined" value, so we simply omit the field entirely if it is undefined
    if (this.extendsType) {
      jsonObject.extendsTokenRange = this.extendsType.excerpt.tokenRange;
    }

    jsonObject.implementsTokenRanges = this.implementsTypes.map(x => x.excerpt.tokenRange);
  }

  /** @beta @override */
  public buildCanonicalReference(): DeclarationReference {
    const nameComponent: Component = DeclarationReference.parseComponent(this.name);
    return (this.parent ? this.parent.canonicalReference : DeclarationReference.empty())
      .addNavigationStep(Navigation.Exports, nameComponent)
      .withMeaning(Meaning.Class);
  }
}