3 AL/BC patterns from CURABIS's internal automated-testing training material (#158)

* Add 3 more AL/BC patterns from CURABIS Academy testing course material

Third batch from CURABIS ApS: item-ledger-entry document-no lookup after Ship-and-Invoice posting, TestPage.Visible()/.Enabled() as the mechanism for verifying field UI state, and LibraryUtility.GenerateGUID() for collision-free test fixture values.

* Address Jesper Schulz-Wedde's review on PR #158

- use-generateguid-for-unique-test-fixture-values.md: GenerateGUID()
  is a Code[10] number-series value, not a real GUID; truncating it
  with CopyStr for a shorter field cuts off the changing digits. Point
  to GenerateRandomCode/GenerateRandomCodeWithLength/GenerateRandomXMLText
  instead, which verify uniqueness against the actual table.
- Split use-testpage-visible-enabled-to-verify-field-ui-state.md: drop
  its editability claim (the sample opens with OpenView() and asserts
  Enabled(), which verifies enabled state, not editability — Editable()
  and Enabled() are distinct TestField methods). New companion article
  use-testpage-editable-to-verify-field-editability.md covers Editable()
  with OpenEdit() specifically.
- Wire GenerateGUID/CopyStr and TestPage Visible/Enabled/Editable cues
  into al-testing-review.md, and the Item Ledger Entry/Last Shipping No.
  posting cue into al-data-modeling-review.md.

The Item Ledger Entry article itself was independently verified against
current BCApps source and needs no changes.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

* Address second round of Jesper Schulz-Wedde's review on PR #158

- use-generateguid-for-unique-test-fixture-values.md/.good.al: documented
  each LibraryUtility helper's actual behavior, verified against
  LibraryUtility.Codeunit.al. GenerateRandomCode opens the target table as
  a temporary RecordRef, so despite taking TableNo it never checks real
  data. GenerateRandomXMLText performs no table lookup at all. Only
  GenerateRandomCodeWithLength/GenerateRandomCode20 (capped at Code[10]/
  Code[20]) genuinely verify against the real table. Fixture switched to
  GenerateRandomCodeWithLength where the comment claims verified
  uniqueness.
- al-testing-review.md: rewired the cue to catch the actual anti-pattern
  (hardcoded literals, hand-built uniqueness, short-field GUID truncation)
  instead of only matching the compliant GenerateGUID()+CopyStr shape;
  broadened tokens to include TestPage, Library - Utility, and
  .Visible()/.Enabled()/.Editable().
- al-data-modeling-review.md: restricted the Item Ledger Entry
  Last-Shipping-No. cue to sales combined posting; purchase combined
  posting is Receive+Invoice and uses different fields entirely.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

* Fix remaining correctness issues from Jesper's 2026-09-15 re-review

- use-generateguid-for-unique-test-fixture-values.md: narrowed the
  collision rule to primary-key/unique-lookup fields - an ordinary
  descriptive field carries no uniqueness constraint, so a hardcoded
  or deterministic value there isn't the anti-pattern (the article and
  its al-testing-review.md worklist cue both said "primary-key or
  descriptive field"). Also corrected GenerateRandomCode: it opens its
  target table as a temporary RecordRef that starts and stays empty,
  so its repeat/until loop always exits after one iteration and never
  retries even within a single test run - the "non-colliding within a
  test run" claim was false. It's the rightmost N characters of
  GenerateGUID()'s sequential series, so a short field's value cycles
  (Code[1] repeats every 10 calls, Code[2] every 100). Verified against
  LibraryUtility.Codeunit.al in the BCApps reference clone.
- item-ledger-entry-document-no-follows-last-shipping-no: both
  fixtures called FindSet() without consuming its optional Boolean,
  which raises a runtime error on an empty result set - the opposite
  of the article's own claimed "silently matches zero rows, no error"
  behavior. Wrapped in `if ... then;` per the existing
  guard-database-reads.good.al idiom.
- al-data-modeling-review.md: widened both not-applicable scope
  clauses (intro and outcome) to include dimension wiring, posting-
  routine structure, and Item Ledger Entry document-number lookups -
  the leaf declared itself not-applicable outside setup/master/key/
  numbering/block/audit surfaces despite having a targeted cue for
  this PR's own new article.
- Converted this PR's 8 plain-backtick "See sample: `x.good.al`."
  references (across all 4 new articles) to the READ-convention
  markdown-link form required by Knowledge-Retrieval.ps1.

Rebased onto upstream/main (one conflict in al-data-modeling-review.md
intro wording, merged).

* Stop routing GenerateRandomCode20 as compliant for shorter fields

al-testing-review.md's cue presented GenerateRandomCodeWithLength and
GenerateRandomCode20 as interchangeable options for "a shorter field
needing real verified uniqueness." They aren't: verified against
LibraryUtility.Codeunit.al, GenerateRandomCode20 truncates
GenerateGUID()'s sequential value down to the target field's length by
keeping the leftmost (slowest-changing) characters via PadStr, so its
retry loop against a field shorter than 20 can churn through the same
truncated prefix for a long time. GenerateRandomCodeWithLength has no
such problem (it generates exactly the requested length of random
text). The knowledge article itself already scoped GenerateRandomCode20
to Code[20] correctly - only the skill cue needed narrowing to match.

---------

Co-authored-by: Claude Sonnet 5 <noreply@anthropic.com>
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---
bc-version: [all]
domain: testing
keywords: [generateguid, library-utility, test-fixtures, uniqueness, generaterandomcode, maxstrlen]
technologies: [al]
countries: [w1]
application-area: [all]
---
# Generate unique test fixture values with LibraryUtility helpers, not hardcoded literals
## Description
A fixture helper that assigns a hardcoded literal to a primary-key field, or to any field the test relies on as a unique lookup identifier, collides the moment two tests, or two runs of the same test, create that fixture without cleanup — and a literal longer than the field allows raises a truncation or insert error. An ordinary descriptive field carries no such constraint: two rows with the same description do not collide on insert, and a deterministic descriptive value is often exactly what an exact-match assertion needs, so none of this applies to it. `LibraryUtility.GenerateGUID()` is not a real GUID — it is a `Code[10]` number-series value (`GU00000000`–`GU99999999`) — and it returns the full 10 characters unshortened. Truncating it yourself with `CopyStr(..., 1, MaxStrLen(ShorterField))` for a field under 10 characters is unsafe: the changing digits sit at the right end and are exactly what gets cut off, so consecutive calls into a short field can produce the same truncated value. `GenerateGUID()` is only safe as-is for a field that holds the full 10 characters.
## Best Practice
For a field that holds the full 10 characters, assign `LibraryUtility.GenerateGUID()` directly. For a shorter field, do not truncate a GUID yourself — but also do not assume every `LibraryUtility` helper verifies uniqueness against the real table, because they don't all behave the same way:
- `GenerateRandomCode(FieldNo, TableNo)` opens the target table as a **temporary** `RecordRef`: the buffer starts and stays empty, so its `repeat...until RecRef.IsEmpty()` loop always exits after one iteration — despite taking `TableNo`, it never checks the real table, and it never retries even within its own call. Its value is the rightmost `FieldRef.Length` characters of `GenerateGUID()`'s sequential `GU00000000`–`GU99999999` series, so for a short field that window of digits cycles: a 1-character field repeats every 10 calls, a 2-character field every 100, and so on. It is a finite short-field namespace with a low collision *chance* within one test run — not a guarantee at any scope, unlike the table-checking helpers below.
- `GenerateRandomCodeWithLength(FieldNo, TableNo, CodeLength)` opens the real (non-temporary) table and loops until the generated value doesn't collide — a genuine verified-unique guarantee — but it returns `Code[10]` regardless of the requested `CodeLength`, so it's only useful for a field of 10 characters or fewer.
- `GenerateRandomCode20(FieldNo, TableNo)` is the same real, verified-against-the-table pattern as `GenerateRandomCodeWithLength`, sized for a `Code[20]` field.
- `GenerateRandomXMLText(Length)` performs no table lookup at all — it's a plain random-text generator, appropriate for a descriptive/incidental field where uniqueness doesn't matter, not for a value that needs to be collision-checked.
Pick `GenerateRandomCodeWithLength`/`GenerateRandomCode20` when the test genuinely needs a code verified unique against the table; use `GenerateRandomCode`/`GenerateGUID`/`GenerateRandomXMLText` for incidental values where a low collision *chance* is enough.
See sample: [`use-generateguid-for-unique-test-fixture-values.good.al`](use-generateguid-for-unique-test-fixture-values.good.al).
## Anti Pattern
Hardcoding a primary-key or unique-lookup fixture value such as `'TEST001'`, which collides across parallel or repeated test runs — a fixed descriptive value is not this anti-pattern, since the field carries no uniqueness constraint. Equally an anti-pattern: truncating `GenerateGUID()`'s result with `CopyStr(..., 1, MaxStrLen(Field))` for a field shorter than 10 characters — the truncation removes the part of the value that actually varies.
See sample: [`use-generateguid-for-unique-test-fixture-values.bad.al`](use-generateguid-for-unique-test-fixture-values.bad.al).