54 lines
1.4 KiB
TypeScript
54 lines
1.4 KiB
TypeScript
import { getJson } from '../../misc/fetch';
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import { IObject, isCollectionOrOrderedCollection, ICollection, IOrderedCollection } from './type';
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export default class Resolver {
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private history: Set<string>;
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constructor() {
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this.history = new Set();
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}
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public getHistory(): string[] {
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return Array.from(this.history);
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}
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public async resolveCollection(value: string | IObject): Promise<ICollection | IOrderedCollection> {
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const collection = typeof value === 'string'
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? await this.resolve(value)
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: value;
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if (isCollectionOrOrderedCollection(collection)) {
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return collection;
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} else {
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throw new Error(`unknown collection type: ${collection.type}`);
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}
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}
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public async resolve(value: string | IObject): Promise<IObject> {
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if (value == null) {
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throw new Error('resolvee is null (or undefined)');
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}
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if (typeof value !== 'string') {
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return value;
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}
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if (this.history.has(value)) {
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throw new Error('cannot resolve already resolved one');
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}
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this.history.add(value);
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const object = await getJson(value, 'application/activity+json, application/ld+json');
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if (object == null || (
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Array.isArray(object['@context']) ?
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!object['@context'].includes('https://www.w3.org/ns/activitystreams') :
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object['@context'] !== 'https://www.w3.org/ns/activitystreams'
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)) {
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throw new Error('invalid response');
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}
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return object;
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}
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}
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