Masters of the Universe Coding Assignment

As a business user I need a tool that reads an accounting log in csv format that sums up all amounts per account_id and month and outputs a csv with summaries so we can double check the bookings easily.

Acceptance Criteria

• the tool accepts 2 file names (input and output)
• output is a csv file with following fields
  • MONTH - the month of the booking in format yyyy/mm
  • ACCOUNT_ID - an ACCOUNT_ID from the input file
  • AMOUNT - the sum of all input amounts for a ACCOUNT_ID per MONTH with 2 decimal places
• empty lines in the input file are ignored
• the amount from the input is summed up, grouped by ACCOUNT_ID and MONTH
• the output has a header line (MONTH,ACCOUNT_ID,AMOUNT)
• the output should be sorted by MONTH and ACCOUNT_ID

Format for the input csv

• separator is a comma ','
• the file has a header line
• there are no quotes used
• there can't be a comma in one of the fields
• the file may contain empty lines (no character or just white spaces)
• the file is encoded in UTF-8 without BOM marker
• the file has 4 columns
  • TIME_STAMP - time of booking in format yyyy-mm-dd hh:mi:ss
  • ACCOUNT_ID - Integer number
  • EMPLOYEE - String (name of employee)
  • AMOUNT - floating point number

Sample files:

• good_input.csv - a sample input file that has no validation error
• good_output.csv - expected output from processing good_input.csv

Nice to have

• the tool writes a error file with rejected records with a pipe '|' and the error reason
• the header and each line is checked for the expected number of columns
• every field is trimmed from whitespace
• input record validation is done
  • no field may be empty after trimming
  • TIME_STAMP must be in expected format
  • only valid ACCOUNT_ID are accepted, list of IDs:
    • 10101
    • 10302
    • 10506
    • 10780
• input lines that are rejected in validation are written to an error csv file
• the error records have an additional column with a reason for being rejected

Sample files for 'Nice to have':

• input_with_error.csv - a sample input file that has all kinds of validation problems
• good_output_without_error.csv - expected output file
• input_with_error_output.csv - expected error output from processing input_with_error.csv