function setUrl()

in lambda/index.js [121:152]

• 27 lines of code
• 3 McCabe index (conditional complexity)

function setUrl(url, callback, salt) {
  let id = computeId(url, salt);

  const params = {
    TableName: process.env.DDB_TABLE,
    Item: {
      id: { S: id },
      target: { S: url }
    },
    // Ensure that puts are idempotent
    ConditionExpression: "attribute_not_exists(id) OR target = :url",
    ExpressionAttributeValues: {
      ":url": {S: url}
    }
  };

  dynamodb.putItem(params, (err, data) => {
    if (err) {
      if(err.code === 'ConditionalCheckFailedException') {
        console.warn('Collision on ' + id + ' for ' + url + '; retrying...');
        // Retry with the attempted ID as the salt.
        // Eventually there will not be a collision.
        return setUrl(url, callback, id);
      } else {
        console.error('Dynamo error on save: ', err);
        return done(500, JSON.stringify({error: 'Internal Server Error: ' + err}), 'application/json', callback);
      }
    } else {
      return done(200, id, 'text/plain', callback);
    }
  });
}