How to use pouchdb-errors - 10 common examples

// CouchDB doesn't always return the right content-type for JSON data, so
    // we check for ^{ and }$ (ignoring leading/trailing whitespace)
    if (!options.binary && (options.json || !options.processData) &&
        typeof data !== 'object' &&
        (/json/.test(content_type) ||
         (/^[\s]*\{/.test(data) && /\}[\s]*$/.test(data)))) {
      try {
        data = JSON.parse(data.toString());
      } catch (e) {}
    }

    if (response.statusCode >= 200 && response.statusCode < 300) {
      onSuccess(data, response, callback);
    } else {
      error = generateErrorFromResponse(data);
      error.status = response.statusCode;
      callback(error);
    }
  });
}

return request(options, function (err, response, body) {

    if (err) {
      return callback(generateErrorFromResponse(err));
    }

    var error;
    var content_type = response.headers && response.headers['content-type'];
    var data = body || defaultBody();

    // CouchDB doesn't always return the right content-type for JSON data, so
    // we check for ^{ and }$ (ignoring leading/trailing whitespace)
    if (!options.binary && (options.json || !options.processData) &&
        typeof data !== 'object' &&
        (/json/.test(content_type) ||
         (/^[\s]*\{/.test(data) && /\}[\s]*$/.test(data)))) {
      try {
        data = JSON.parse(data.toString());
      } catch (e) {}
    }

}

  var attachmentError;
  req.docs.forEach(function (doc) {
    if (doc._attachments) {
      Object.keys(doc._attachments).forEach(function (name) {
        attachmentError = attachmentError || attachmentNameError(name);
        if (!doc._attachments[name].content_type) {
          guardedConsole('warn', 'Attachment', name, 'on document', doc._id, 'is missing content_type');
        }
      });
    }
  });

  if (attachmentError) {
    return callback(createError(BAD_REQUEST, attachmentError));
  }

  if (!('new_edits' in opts)) {
    if ('new_edits' in req) {
      opts.new_edits = req.new_edits;
    } else {
      opts.new_edits = true;
    }
  }

  var adapter = this;
  if (!opts.new_edits && !isRemote(adapter)) {
    // ensure revisions of the same doc are sorted, so that
    // the local adapter processes them correctly (#2935)
    req.docs.sort(compareByIdThenRev);
  }

stores.docStore.get(id, function (err, metadata) {
      if (err || !metadata) {
        return callback(createError(MISSING_DOC, 'missing'))
      }

      var rev = getWinningRev(metadata)
      var deleted = getIsDeleted(metadata, rev)
      if (deleted && !opts.rev) {
        return callback(createError(MISSING_DOC, 'deleted'))
      }

      rev = opts.rev ? opts.rev : rev

      var seq = metadata.rev_map[rev]

      stores.bySeqStore.get(formatSeq(seq), function (err, doc) {
        if (err) {
          return callback(createError(MISSING_DOC, 'error'))
        }
        if (!doc) {
          return callback(createError(MISSING_DOC))
        }
        /* istanbul ignore if */
        if ('_id' in doc && doc._id !== metadata.id) {
          // this failing implies something very wrong

function insertDoc(docInfo, resultsIdx, callback) {
    // Cant insert new deleted documents
    var winningRev = calculateWinningRev(docInfo.metadata);
    var deleted = isDeleted(docInfo.metadata, winningRev);
    if ('was_delete' in opts && deleted) {
      results[resultsIdx] = createError(MISSING_DOC, 'deleted');
      return callback();
    }

    // 4712 - detect whether a new document was inserted with a _rev
    var inConflict = newEdits && rootIsMissing(docInfo);

    if (inConflict) {
      var err = createError(REV_CONFLICT);
      results[resultsIdx] = err;
      return callback();
    }

    var delta = deleted ? 0 : 1;

    writeDoc(docInfo, winningRev, deleted, deleted, false,
      delta, resultsIdx, callback);
  }

txn.get(stores.localStore, doc._id, function (err, resp) {
      if (err) {
        /* istanbul ignore if */
        if (err.name !== 'NotFoundError') {
          return callback(err);
        } else {
          return callback(createError(MISSING_DOC));
        }
      }
      if (resp._rev !== doc._rev) {
        return callback(createError(REV_CONFLICT));
      }
      txn.batch([{
        prefix: stores.localStore,
        type: 'del',
        key: doc._id
      }]);
      var ret = {ok: true, id: doc._id, rev: '0-0'};
      if (opts.ctx) {
        // don't execute immediately
        return callback(null, ret);
      }
      txn.execute(db, function (err) {
        /* istanbul ignore if */
        if (err) {
          return callback(err);
        }

var att = docInfo.data._attachments[key];

        if (att.stub) {
          // still need to update the refs mapping
          var id = docInfo.data._id;
          var rev = docInfo.data._rev;
          saveAttachmentRefs(id, rev, att.digest, attachmentSaved);
          continue;
        }
        var data;
        if (typeof att.data === 'string') {
          // input is assumed to be a base64 string
          try {
            data = pouchdbBinaryUtils.atob(att.data);
          } catch (e) {
            callback(pouchdbErrors.createError(pouchdbErrors.BAD_ARG,
                     'Attachment is not a valid base64 string'));
            return;
          }
          doMD5(docInfo, key, attachmentSaved)(data);
        } else {
          prepareAttachmentForStorage(att.data,
            doMD5(docInfo, key, attachmentSaved));
        }
      }

      function finish() {
        var seq = docInfo.metadata.rev_map[docInfo.metadata.rev];
        /* istanbul ignore if */
        if (seq) {
          // check that there aren't any existing revisions with the same
          // revision id, else we shouldn't do anything

var att = docInfo.data._attachments[key];

        if (att.stub) {
          // still need to update the refs mapping
          var id = docInfo.data._id;
          var rev = docInfo.data._rev;
          saveAttachmentRefs(id, rev, att.digest, attachmentSaved);
          continue;
        }
        var data;
        if (typeof att.data === 'string') {
          // input is assumed to be a base64 string
          try {
            data = pouchdbBinaryUtils.atob(att.data);
          } catch (e) {
            callback(pouchdbErrors.createError(pouchdbErrors.BAD_ARG,
                     'Attachment is not a valid base64 string'));
            return;
          }
          doMD5(docInfo, key, attachmentSaved)(data);
        } else {
          prepareAttachmentForStorage(att.data,
            doMD5(docInfo, key, attachmentSaved));
        }
      }

      function finish() {
        var seq = docInfo.metadata.rev_map[docInfo.metadata.rev];
        /* istanbul ignore if */
        if (seq) {
          // check that there aren't any existing revisions with the same
          // revision id, else we shouldn't do anything

stores.bySeqStore.get(formatSeq(seq), function (err, doc) {
        if (!doc) {
          return callback(pouchdbErrors.createError(pouchdbErrors.MISSING_DOC));
        }
        /* istanbul ignore if */
        if ('_id' in doc && doc._id !== metadata.id) {
          // this failing implies something very wrong
          return callback(new Error('wrong doc returned'));
        }
        doc._id = metadata.id;
        if ('_rev' in doc) {
          /* istanbul ignore if */
          if (doc._rev !== rev) {
            // this failing implies something very wrong
            return callback(new Error('wrong doc returned'));
          }
        } else {
          // we didn't always store this
          doc._rev = rev;

stores.bySeqStore.get(formatSeq(seq), function (err, doc) {
        if (!doc) {
          return callback(pouchdbErrors.createError(pouchdbErrors.MISSING_DOC));
        }
        /* istanbul ignore if */
        if ('_id' in doc && doc._id !== metadata.id) {
          // this failing implies something very wrong
          return callback(new Error('wrong doc returned'));
        }
        doc._id = metadata.id;
        if ('_rev' in doc) {
          /* istanbul ignore if */
          if (doc._rev !== rev) {
            // this failing implies something very wrong
            return callback(new Error('wrong doc returned'));
          }
        } else {
          // we didn't always store this
          doc._rev = rev;