Collect Every Problem, Not Just the First

Medium

errorinfo

collectible-errors

validation

Collect Every Problem, Not Just the First

The nightly webshop import dumps order lines into staging batches, and the current validator gives up at the first broken line — the operations team fixes one field, reruns, hits the next error, and burns the whole morning clearing a batch one failure at a time.

You'll build a validator with two faces: checking a single line still fails fast with a precise error, but checking a whole batch reports every broken line in one run.

What you get

The starter ships a staging table named "Import Order Line" with the fields "Batch Code" (Code[20]), "Line No." (Integer), "Item No." (Code[20]), Quantity (Decimal) and "Unit Price" (Decimal), keyed on Batch Code + Line No. Keep it unchanged and include it in your submission — the grading tests seed it directly by these names.

Requirements

Create a codeunit named "Import Line Validator" with two public procedures:

procedure ValidateLine(ImportOrderLine: Record "Import Order Line")
procedure ValidateBatch(BatchCode: Code[20]; var Problems: List of [Text])

ValidateLine checks the rules below in this order and raises an error carrying the exact message of the first broken rule, where %1 is the line's "Line No."; a line that passes all three rules returns silently:

Line %1: Item No. is missing. — when "Item No." is blank.
Line %1: Quantity must be greater than zero. — when Quantity is zero or negative.
Line %1: Unit Price cannot be negative. — when "Unit Price" is below zero. A price of exactly 0 is valid.

ValidateBatch:

examines every "Import Order Line" whose "Batch Code" equals BatchCode, and nothing else — lines of other batches must never influence the result;
fills Problems with exactly one entry per broken line — the same message ValidateLine would raise for that line — ordered by "Line No." ascending;
a line breaking several rules still contributes exactly one entry: its first broken rule in the order above;
clears whatever input Problems already contains;
never raises an error itself — a batch where every single line is broken still returns normally, and a clean batch yields an empty list.

What the tests check

Direct ValidateLine calls: a fully valid line and a zero-price line pass silently; a blank Item No., a zero quantity, a negative quantity and a negative price each raise exactly the message above (note casing and the trailing period), a line breaking all three rules raises the Item No. message, and a line with a valid Item No. but both a bad quantity and a bad price raises the Quantity message — the rules are checked in exactly the order above. ValidateBatch runs: a clean batch yields zero problems; a mixed five-line batch yields exactly its three broken lines' messages in line order; a batch where every line is broken returns normally with every line reported; a line breaking several rules shows up exactly once; a broken line in a second batch stays out of the result; and calling the procedure twice leaves the list holding one run's findings, not two.

Learn More

Hint 1

ValidateLine is the easy half — a chain of checks that errors out. The interesting question is how ValidateBatch can call something that raises errors, once per line, and still reach the last line of the batch.

Hint 2

An ErrorInfo created with ErrorInfo.Create(Message, true) is collectible: raised inside a scope that has opted in to collecting, it is parked in a list instead of tearing execution down — outside such a scope it behaves like any ordinary error, which is exactly what ValidateLine needs.

Hint 3

Decorate ValidateBatch with the correct [ErrorBehavior] and harvest the parked errors with GetCollectedErrors(true) — the true clears the collection, and anything left uncleared resurfaces as one big error the moment the procedure exits. One more trap: inside a collecting scope execution continues past a collected error, so chain ValidateLine's rules with else-if, or a line breaking several rules reports all of them instead of its first.

ALBusiness Central 28.5

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