Method appendFiles

web/input/input-state-container.react.js:719–774

(
    threadInfo: ThreadInfo,
    files: $ReadOnlyArray<File>,
  )

  }

  async appendFiles(
    threadInfo: ThreadInfo,
    files: $ReadOnlyArray<File>,
  ): Promise<boolean> {
    const selectionTime = Date.now();
    const { pushModal } = this.props;

    const appendResults = await Promise.all(
      files.map(file => this.appendFile(threadInfo, file, selectionTime)),
    );

    if (appendResults.some(({ result }) => !result.success)) {
      pushModal(<InvalidUploadModal />);

      const time = Date.now() - selectionTime;
      const reports = [];
      for (const appendResult of appendResults) {
        const { steps } = appendResult;
        let { result } = appendResult;
        let uploadLocalID;
        if (result.success) {
          uploadLocalID = result.pendingUpload.localID;
          result = { success: false, reason: 'web_sibling_validation_failed' };
        }
        const mediaMission = { steps, result, userTime: time, totalTime: time };
        reports.push({ mediaMission, uploadLocalID });
      }
      this.queueMediaMissionReports(reports);

      return false;
    }

    const newUploads = appendResults.map(({ result }) => {
      invariant(result.success, 'any failed validation should be caught above');
      return result.pendingUpload;
    });

    const newUploadsObject = _keyBy('localID')(newUploads);
    this.setState(
      prevState => {
        const newThreadID = this.getRealizedOrPendingThreadID(threadInfo.id);
        const prevUploads = prevState.pendingUploads[newThreadID];
        const mergedUploads = prevUploads
          ? { ...prevUploads, ...newUploadsObject }
          : newUploadsObject;
        return {
          pendingUploads: {
            ...prevState.pendingUploads,
            [newThreadID]: mergedUploads,
          },
        };
      },
      () => this.uploadFiles(threadInfo, newUploads),
    );
    return true;
  }

  async appendFile(