Method watch

lib/Watching.js:374–415

* Processes the provided file. * @param {Iterable<string>} files watched files * @param {Iterable<string>} dirs watched directories * @param {Iterable<string>} missing watched existence entries * @returns {void}

(files, dirs, missing)

	 * @returns {void}
	 */
	watch(files, dirs, missing) {
		this.pausedWatcher = null;
		this.watcher =
			/** @type {WatchFileSystem} */
			(this.compiler.watchFileSystem).watch(
				files,
				dirs,
				missing,
				/** @type {number} */ (this.lastWatcherStartTime),
				this.watchOptions,
				(
					err,
					fileTimeInfoEntries,
					contextTimeInfoEntries,
					changedFiles,
					removedFiles
				) => {
					if (err) {
						this.compiler.modifiedFiles = undefined;
						this.compiler.removedFiles = undefined;
						this.compiler.fileTimestamps = undefined;
						this.compiler.contextTimestamps = undefined;
						this.compiler.fsStartTime = undefined;
						return this.handler(err);
					}
					this._invalidate(
						fileTimeInfoEntries,
						contextTimeInfoEntries,
						changedFiles,
						removedFiles
					);
					this._onChange();
				},
				(fileName, changeTime) => {
					if (!this._invalidReported) {
						this._invalidReported = true;
						this.compiler.hooks.invalid.call(fileName, changeTime);
					}
					this._onInvalid();
				}
			);
	}

	/**
	 * Processes the provided error callback.