async bestGuessSHA1()

in source/checksum/lib/validation/index.js [268:297]

• 24 lines of code
• 4 McCabe index (conditional complexity)

  async bestGuessSHA1() {
    /* try tag first */
    const chksum = this.tags.find(x => x.Key === this.getChecksumTagName());
    if (chksum && chksum.Value.match(/^([0-9a-fA-F]{40})$/)) {
      this.comparedWith = 'object-tagging';
      return chksum.Value;
    }

    const params = {
      Bucket: this.bucket,
      Key: this.key,
    };
    const s3 = new AWS.S3({
      apiVersion: '2006-03-01',
      signatureVersion: 'v4',
      customUserAgent: process.env.ENV_CUSTOM_USER_AGENT,
    });

    const {
      Metadata = {},
    } = await s3.headObject(params).promise();

    /* try x-amz-meta-sha1 metadata */
    if (Metadata.sha1) {
      this.comparedWith = 'object-metadata';
      return Metadata.sha1;
    }

    return undefined;
  }