bcquality/microsoft/knowledge/style/xmldoc-for-public-library-procedures.md
Jesper Schulz-Wedde a9f3c50863 Regenerate microsoft/knowledge from upstream BCApps instructions
The previous LLM-generated knowledge files contained factual
hallucinations. The most visible was the claim that `FindFirst` /
`FindLast` "forces a full-table scan" on an unfiltered record - it does
not; those APIs return a single row via the current key.

Other inaccuracies the audit found and fixed:

* `FindSet(true)` was described as "taking a LockTable". The correct
  upstream phrasing is that `FindSet(true)` sets
  `ReadIsolation::UpdLock` on the read. UpdLock and LockTable are
  related but distinct mechanisms.
* The list of production-scale tables had been invented beyond the
  upstream source (e.g. "Detailed Cust. Ledg. Entry") without a
  citation. The regenerated list matches the ten tables upstream lists
  with their P95 row counts.
* `SetLoadFields` guidance had been augmented with an extra mechanism
  claim ("the database resolves the filter using the index without
  hydrating the value") not present in upstream.

Approach: full regeneration of `microsoft/knowledge/` from the six
upstream BCApps Code Review instruction files, with Microsoft Learn /
the AL language reference as a secondary source. Every claim in every
regenerated file is anchored to a verbatim upstream quote (or a Learn
URL); the audit trail lives in artifacts/trace-<domain>.json on the
session workspace.

The PR #11 transaction/error-handling cluster is preserved verbatim:

* performance/understand-implicit-transaction-boundary.md
* performance/codeunit-run-as-atomic-sub-operation.{md,good.al,bad.al}
* performance/codeunit-run-requires-prior-commit-inside-transaction.{md,good.al,bad.al}
* performance/use-tryfunction-for-error-catching-not-rollback.{md,good.al,bad.al}
* performance/avoid-commit-inside-loops.{md,good.al,bad.al}
* security/commitbehavior-attribute-scopes-explicit-commits.{md,good.al,bad.al}
* testing/transactionmodel-attribute-governs-test-transactions.{md,good.al,bad.al}

These articles already cite Microsoft Learn and were carefully
cross-referenced; the regeneration skips their topics rather than
duplicating them.

File counts after regeneration:

  performance   35 .md  (5 preserved + 30 new)
  privacy       17 .md
  security      18 .md  (1 preserved + 17 new)
  style         33 .md
  testing        1 .md  (preserved)
  ui            19 .md
  upgrade       18 .md

Total 141 atomic knowledge files, each strictly one rule. All pass
.github/scripts/validate_frontmatter.py with 0 errors and 0 warnings.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
2026-05-21 09:53:09 +02:00

1.8 KiB

bc-version domain keywords technologies countries application-area
all
style
xmldoc
summary
param
returns
public-procedure
documentation
al
w1
all

Add XML documentation to public procedures on library/API codeunits

Description

XML documentation comments (/// <summary>…</summary>, /// <param>…</param>, /// <returns>…</returns>) are expected on procedures that form the public surface of a library — codeunits intended to be called from outside the current app: System App modules, AppSource library codeunits, Access = Public codeunits exposed for extension. The supported tags are <summary>, <param>, <returns>, <example>, <remarks>, and <paramref>. Active wording is preferred — 'Sets…', 'Gets…', 'Specifies…' — and the docs should list parameter preconditions and any exceptions the procedure may raise.

XML docs are NOT required on internal procedures, event subscribers, trigger implementations, page-part procedures, test procedures, or the object declarations themselves (tables, pages, codeunits). The reviewer signal is a procedure (not local procedure, not internal procedure) declared inside a codeunit whose role is "library" — those need XML docs; everything else is optional.

Best Practice

For every public procedure on a library codeunit, write a <summary> describing what the procedure does, one <param> per parameter naming its role and preconditions, and <returns> describing the return when applicable. Avoid placeholder text — <summary>Validates discount</summary> is no better than no doc at all.

Anti Pattern

A public procedure on a library codeunit with no XML doc, or a <summary> that restates the procedure name in three words. The first leaves consumers guessing at intent; the second wastes the slot a meaningful description should occupy.