Fix ten focused correctness items plus sample links from Jesper's 2026-09-15 re-review

Six carried-over threads:
- api-page-least-privilege-write-access fixtures: added the mandatory
  EntityName/EntitySetName properties (AL0485).
- pages-must-not-contain-business-logic fixtures: Sales Line has no
  "Total Amount" field; replaced with the real "Line Amount" (field 103).
- test-feature-scenario-tags.good.al and test-one-when-per-test.good.al:
  CreatePriceHeader leaves a price list in Draft status, which price
  calculation ignores. Added Validate(Status, Active) + Modify before the
  sales line that depends on it. Verified Status field/enum against
  PriceListHeader.Table.al and PriceStatus.Enum.al in the BCApps clone.
- exposed-objects-must-be-in-a-permission-set.md: a published codeunit is
  a SOAP endpoint (SOAP is deprecated), not OData - Page/Query are the
  OData object types. Corrected and pointed new integrations at API
  pages/queries instead.
- al-error-handling-review.md: the log-writes-must-survive-rollback cue
  selected on Session.StartSession, which only appears in the compliant
  fix, never in the anti-pattern - the bad fixture could never be
  worklisted. Recued on the actual risk shape (log insert around a
  failed TryFunction/GetLastError* path, then raise/propagate), with
  StartSession as an explicit compliant discriminator instead.
- page-design-must-match-bc-page-type-conventions.md: the enum value is
  NavigatePage, not Navigate; noted the type list is a selected subset,
  not an exhaustive PageType catalogue (PromptDialog, ConfigurationDialog,
  UserControlHost, XmlPort also exist, out of this article's scope).

Four new correctness gaps:
- release-must-update-app-version.md: "the version is the only identity"
  was backwards - id is the app's stable identity, version identifies a
  release/code-state of it.
- defensive-vs-offensive-code-must-match-blast-radius.good.al: the "low
  blast radius" example had no else branch, so a failed Customer.Get()
  left the field at its prior/default value instead of the explicit
  chosen fallback the article claims to demonstrate. Added the else.
- bcpt-scenarios-must-be-app-specific.good.al: InitTest and both measured
  StartScenario/EndScenario sections were empty/comment-only, so the
  "app-specific" fixture measured no actual work. Filled in a real,
  self-contained header+line creation path.
- upgrade-tag-logic-must-not-nest-deeply.good.al: the flattened version
  dropped both safety conditions the bad fixture had (Discount % = 0,
  nonblank posting group), silently changing behavior instead of just
  removing nesting. Extracted the guarded update into a helper with both
  conditions preserved as early exits.

Also converted this PR's remaining plain-backtick "See sample:" sample
references (16 articles) to the READ-convention markdown-link form,
matching the fix already made on #156/#158.

Rebased onto upstream/main (conflicts in al-ui-review.md, al-style-review.md,
al-upgrade-review.md against merged upstream PRs - all additive, both
sides' worklist cues retained).
This commit is contained in:
Michael Dieringer 2026-09-21 22:44:17 +02:00
parent 3842ef7138
commit 67962727f6
27 changed files with 96 additions and 47 deletions

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@ -1,8 +1,12 @@
// Low blast radius: guard, with an explicit chosen fallback.
if Customer.Get(SalesHeader."Sell-to Customer No.") then
CustomerHomePage := Customer."Home Page";
CustomerHomePage := Customer."Home Page"
else
CustomerHomePage := '';
// Blank is an acceptable, deliberately-considered default here - the field
// is purely a display convenience and a reviewer sees it before the document ships.
// It is assigned explicitly, though, not left to whatever the variable
// happened to hold before this lookup ran.
// High blast radius: let it fail loud, because this feeds posted VAT.
SalesHeader.Get(SalesHeader."Document Type"::Order, DocumentNo);

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@ -17,10 +17,10 @@ Whether code should guard gracefully (defensive) or fail loudly (offensive/fail-
Trace what a silently-defaulted or skipped value actually reaches before deciding how to guard it. If it reaches a posted ledger amount, a tax/VAT calculation, a quantity or price actually used in a transaction, or a legally/compliance-facing output, code offensively: let the lookup fail loud (`TestField`, an unguarded `Get()` expected to always succeed, or an explicit `Error`) so a human sees the problem before anything posts. If it is cosmetic, informational, or easily corrected after the fact (a display field, an optional UI enhancement, a report not yet run), code defensively — but the fallback must be an explicit, deliberately-chosen, named business value, never a blank or zero that is merely the datatype default. When genuinely unsure which category a field falls into, that is a question to resolve explicitly with whoever owns the requirement, not a coin flip.
See sample: `defensive-vs-offensive-code-must-match-blast-radius.good.al`.
See sample: [`defensive-vs-offensive-code-must-match-blast-radius.good.al`](defensive-vs-offensive-code-must-match-blast-radius.good.al).
## Anti Pattern
Guarding two fields the same way purely out of habit, without analyzing what each one feeds. A low-blast-radius field, such as a customer's home page URL shown only for convenience on a printed document, and a high-blast-radius field, such as the VAT posting group that determines VAT actually applied to a posted transaction, are both wrapped in the same `if Header.Get(...) then ... else` pattern with a blank/zero fallback — leaving the posting-critical field free to post with a silently wrong value. A VAT registration number is not a safe stand-in for the low-risk side of this example: it is legally relevant, often validated, and can feed external VAT services or mandated document output, so it belongs on the offensive/fail-fast side alongside the posting group, not next to it as the "safe" contrast.
See sample: `defensive-vs-offensive-code-must-match-blast-radius.bad.al`.
See sample: [`defensive-vs-offensive-code-must-match-blast-radius.bad.al`](defensive-vs-offensive-code-must-match-blast-radius.bad.al).

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@ -17,10 +17,10 @@ Inserting a log record inside the same transaction as the operation it logs look
Write any log whose purpose includes capturing failures from a transaction that is independent of the operation being logged: start an isolated session (`Session.StartSession` on a `TableNo`-scoped codeunit that only inserts the log record and commits) so the entry persists regardless of what happens to the caller's transaction. `StartSession`'s only channel for getting data into that new session is its optional `Record` parameter, delivered to the target codeunit's `OnRun` trigger — a separate session gets a fresh instantiation of the codeunit, so calling a setter procedure on a local object variable before starting the session does not populate anything in the new session's instance. Capture duration and other telemetry values in the caller, place them into the `Record` passed to `StartSession`, and do the insert-and-commit entirely inside that session's own `OnRun`. Logs that only record successful, committed work can safely stay in the main transaction; this pattern targets error and diagnostic logs specifically.
See sample: `log-writes-must-survive-rollback.good.al`.
See sample: [`log-writes-must-survive-rollback.good.al`](log-writes-must-survive-rollback.good.al).
## Anti Pattern
Inserting the error-log record in the same transaction as the risky operation, so a rollback deletes the very entry meant to explain the failure. Adding a stray `Commit` before the risky call is not a fix either — it breaks the caller's atomicity and can violate posting-routine rules. Swallowing the error to keep the log alive (running a codeunit without checking or re-raising its result) is equally wrong: the log must observe the failure, not suppress it.
See sample: `log-writes-must-survive-rollback.bad.al`.
See sample: [`log-writes-must-survive-rollback.bad.al`](log-writes-must-survive-rollback.bad.al).