A 32-Column Receipt

A 32-Column Receipt

The shop's thermal receipt printer prints exactly 32 characters per line: the first 20 columns hold the item description, the last 12 hold the amount, right-aligned so the decimal points stack up. Your codeunit produces those lines, plus the zero-padded document number printed at the top of every receipt.

Requirements

Create a codeunit named "Receipt Formatter" with two public procedures:

procedure ReceiptLine(Description: Text; Amount: Decimal): Text
procedure DocumentNo(Prefix: Code[10]; Seq: Integer): Code[20]

Rules for ReceiptLine:

1. The result is always exactly 32 characters long.
2. Columns 1–20 hold Description, left-aligned and padded with spaces on the right. A description longer than 20 characters is cut to its first 20 characters. An empty description leaves 20 spaces.
3. Columns 21–32 hold Amount, right-aligned (spaces on the left) with exactly two decimals — 3.5 prints as 3.50, 2 as 2.00. The decimal separator is always a period, whatever region the server runs under, and there is no thousands separator: 1234567.8 prints as 1234567.80. A negative amount keeps its minus sign directly in front of the first digit: -3.5 prints as -3.50.
4. Amount always lies between -99999999.99 and 99999999.99 and never carries more than two decimals, so the amount column never overflows.

Rules for DocumentNo:

5. The result is Prefix, a hyphen, and Seq zero-padded on the left to at least five digits: DocumentNo('INV', 42) returns INV-00042.
6. Longer sequences keep every digit — DocumentNo('INV', 100000) returns INV-100000, and DocumentNo('RCP', 99999) returns RCP-99999. Seq is always at least 1 and at most 999999; Prefix is always 1–10 uppercase letters.

The starter already compiles, but its DocumentNo pads on the wrong side: PadStr adds its filler characters at the end of the string, so sequence 42 comes out as 42000. PadStr is still the right tool for the description column — it pads on the right and truncates longer text — but the zeros need a method that pads on the left.

For the amount, Format(Value, Length, FormatString) does both jobs in one call: with a positive Length the result is exactly that many characters — a number gets its padding spaces on the left, and a value longer than Length is silently cut, so never rely on it to complain. The format string decides the digits: <Precision,2:2> forces exactly two decimals, and the standard format picks the separators — standard format 0 inserts thousands separators, standard format 1 follows the server's region settings for both separators, and standard format 2 (like 9) always uses a period and never a thousands separator. Pick the one that prints the same on every server.

Pick object IDs in the range 50100–50199, and reference other objects by name, never by ID.

Examples

|Coffee                      3.50|
|Extra Large Cappucci       12.00|
|Refund                     -3.50|
|Catering              1234567.80|

The | marks are not part of the line — they show where the 32 columns start and end.

What the tests check

The grading tests compare every ReceiptLine result character for character against the expected 32-character line: a short description (Coffee, 3.5), a generated description of 1–19 letters, a generated 35-character description that must be cut to 20, an empty description, a whole-number amount (2), a negative amount (-3.5), and 1234567.8, whose line must show 1234567.80 with no thousands separator. One test feeds a generated description of 1–40 letters and a generated amount and only checks that the line is 32 characters long. For DocumentNo, the tests expect INV-00042, INV-100000, RCP-99999 and a generated prefix with a generated sequence between 1 and 99999 — so zeros pasted at the wrong end, a six-digit sequence cut to five digits, or a hardcoded prefix all fail.

Learn More

• Format method (Any, Integer, Text) — the three rules for the Length argument, including the silent truncation.
• Formatting values, dates, and time — <Precision>, <Filler Character>, <Integer,n> and the standard decimal formats side by side for US and European regions.
• Text.PadStr method — pads at the end or truncates, with a worked example.
• Text.PadLeft method — right-aligns by padding on the left with any character.