bcquality/microsoft/knowledge/style/error-passes-parameters-directly-not-strsubstno.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
error
strsubstno
label
parameters
concatenation
aa0231
al
w1
all

Pass parameters directly to Error(), do not wrap with StrSubstNo

Description

Error() accepts a format string and a variable number of arguments — Error(SomeLabelErr, Arg1, Arg2). The platform performs the substitution itself, which is the path the translation pipeline understands. Wrapping the same call as Error(StrSubstNo(SomeLabelErr, Arg1, Arg2)) hides the placeholders from the platform and removes the format-string identity from the call-site, so analyzers cannot match the call to its label and translators lose the link between the formatted message and its template. The corresponding anti-pattern for hardcoded strings — Error('Customer ' + CustomerNo + ' not found') — is even worse: it builds an untranslatable, unanalyzable string at runtime.

Best Practice

Declare a Label with the Err suffix and the appropriate Comment for placeholders, then call Error(YourErr, arg1, arg2). The same rule applies to Message, Confirm, and other UI primitives: format string in, parameters as separate arguments, no StrSubstNo wrapper at the call site, no string concatenation. An Error('') (empty message) is acceptable when the calling code expects another layer to emit the actual diagnostic.

See sample: error-passes-parameters-directly-not-strsubstno.good.al.

Anti Pattern

Error(StrSubstNo(CustomerNotFoundErr, CustomerNo)) and Error(CustomerNotFoundErr + ': ' + CustomerNo) both defeat the translation and analysis machinery. Reviewers should treat StrSubstNo appearing as an argument to Error, Message, Confirm, or StrMenu as an unconditional signal to rewrite.

See sample: error-passes-parameters-directly-not-strsubstno.bad.al.