files-hash-service.ts

import { executeActionByChunks } from "../common/helpers";
import { DEFAULT_CHUNK_SIZE } from "../common/constants";

export class FilesHashService implements IFilesHashService {
	constructor(private $fs: IFileSystem,
		private $logger: ILogger) { }

	public async generateHashes(files: string[]): Promise<IStringDictionary> {
		const result: IStringDictionary = {};

		const action = async (file: string) => {
			try {
				const isFile = this.$fs.getFsStats(file).isFile();
				if (isFile) {
					result[file] = await this.$fs.getFileShasum(file);
				}
			} catch (err) {
				this.$logger.trace(`Unable to generate hash for file ${file}. Error is: ${err}`);
			}
		};

		await executeActionByChunks(files, DEFAULT_CHUNK_SIZE, action);

		return result;
	}

	public async getChanges(files: string[], oldHashes: IStringDictionary): Promise<IStringDictionary> {
		const newHashes = await this.generateHashes(files);
		return this.getChangesInShasums(oldHashes, newHashes);
	}

	public hasChangesInShasums(oldHashes: IStringDictionary, newHashes: IStringDictionary): boolean {
		return !!_.keys(this.getChangesInShasums(oldHashes, newHashes)).length;
	}

	private getChangesInShasums(oldHashes: IStringDictionary, newHashes: IStringDictionary): IStringDictionary {
		return _.omitBy(newHashes, (hash: string, pathToFile: string) => !!_.find(oldHashes, (oldHash: string, oldPath: string) => pathToFile === oldPath && hash === oldHash));
	}
}
$injector.register("filesHashService", FilesHashService);