bcquality/microsoft/skills/review/al-testing-review.md
Michael Dieringer f63943dcfd
18 more AL/BC patterns: data-modeling, testing, style, security, error-handling, ui, upgrade, web-services, appsource (#157)
* Add 18 more community AL/BC patterns across appsource, data-modeling, error-handling, security, style, testing, ui, upgrade, and web-services

Second contribution from CURABIS ApS, generalized from patterns observed across real AppSource/PTE development. Cross-checked against the current microsoft/knowledge corpus before opening; several originally-drafted candidates were dropped as duplicates of existing files.

* Address Jesper Schulz-Wedde's review on PR #157

- release-must-update-app-version.md: reframe around AppSource's actual
  strict full-version-ordering requirement; scope branching-policy
  claims as team convention, not platform rule.
- pictures-must-use-media-not-blob.md: MediaSet is a collection of
  independent media objects, not automatic image variants/thumbnails.
- log-writes-must-survive-rollback.{md,good.al}: StartSession's only
  data channel into the new session is its Record parameter to a
  TableNo-scoped codeunit; a setter called on a local instance before
  starting the session populates nothing in the new session.
- exposed-objects-must-be-in-a-permission-set.md: correct the three
  exposure mechanisms (Web Services config, PageType/QueryType=API,
  ServiceEnabled as a method-only attribute).
- pages-must-not-contain-business-logic.md: scope to persisted
  mutations and cross-entry-point rules; presentation-only
  calculations and table-owned invariants are not violations.
- given-blocks-must-cover-full-precondition-chain.good.al: replace
  invented LibrarySales calls with the real API
  (CreateCustomer/CreateSalesOrderForCustomerNo/PostSalesDocument).
- test-feature-scenario-tags.{md,good.al}: move [SCENARIO] inside the
  test procedure body to match the current BCApps corpus; keep
  [FEATURE] at codeunit level per Microsoft's own documented option.
- ui-test-codeunit-naming.md: scope the _UT suffix and adjacent-ID
  pairing as an explicit team convention, not a BCApps-wide standard.
- page-design-must-match-bc-page-type-conventions.md /
  table-design-must-match-bc-table-type-conventions.md: Card's
  single-key primary-key claim is a contextual heuristic, not a
  mandatory constraint (Ship-to Address, Customer/Vendor Bank Account
  are real composite-key Card pages); a Subsidiary table with its own
  identity commonly gets List+Card, not Worksheet/Tabular.
- api-page-least-privilege-write-access.{md,good.al}: only page-placed
  fields are ever exposed; set InsertAllowed/DeleteAllowed=false in the
  good sample so a narrow field set can't still create/delete records.
- source-organized-by-feature-not-object-type.md,
  test-one-when-per-test.md: scope as team/testing-design conventions,
  not Microsoft platform requirements.
- upgrade-tag-logic-must-not-nest-deeply.md: add the Microsoft Learn
  citation that already backs the two-level nesting limit.
- Wire the new articles into the testing/data-modeling/error-handling/
  security/ui review skills' candidate-selection signals.

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

* Address second round of Jesper Schulz-Wedde's review on PR #157

- log-writes-must-survive-rollback.good.al: fixed invalid trigger
  OnRun(var Rec: ...) declaration; Rec is implicit when TableNo is set.
- exposed-objects-must-be-in-a-permission-set.md: distinguished the three
  exposure mechanisms (page/query web service or API, codeunit published
  as a web service, [ServiceEnabled] bound action on a page) and their
  actual permission targets (page/query "..." = X vs codeunit "..." = X).
- code-must-not-change-workdate.md: scoped from an absolute "never" to
  "not as a side effect of unrelated logic" - verified real WorkDate(x)
  setter usage in BCApps demo-data generators and test codeunits.
- bcpt-scenarios-must-be-app-specific.md: SingleInstance and
  StartScenario/EndScenario reframed as context-dependent patterns, not
  mandatory requirements - BCPT Create Customer uses neither.
- test-feature-scenario-tags.good.al/.bad.al: replaced the invented
  LibrarySales.CreateCustomerWithPrice/"Item Price Mgt." calls with a real,
  verified price-list-line test using Library - Sales/Library - Inventory/
  Library - Price Calculation.
- page-design-must-match-bc-page-type-conventions.md: scoped the missing
  UsageCategory anti-pattern to pages intended as searchable entry points.
- defensive-vs-offensive-code-must-match-blast-radius.md/.good.al/.bad.al:
  replaced the VAT registration number "low blast radius" example with a
  genuinely cosmetic field (customer home page URL).
- source-organized-by-feature-not-object-type.md: anti-pattern reframed as
  inconsistency with a repo's own convention, not the object-type scheme
  itself.
- pictures-must-use-media-not-blob.md: removed leftover "image variants"
  wording contradicting the already-corrected MediaSet description.

Proactively fixed while sweeping all fixtures for invented APIs:
- given-blocks-must-cover-full-precondition-chain.bad.al: PostSalesOrder
  called with wrong arity and referenced an undeclared variable.
- ui-test-codeunit-naming.good.al/.bad.al: replaced the same fake
  "Item Price Mgt."/TestPage "Item Price" with real Library - Sales calls
  and the real Customer Card TestPage.

Worklist completeness: added review-skill cues for the 12 of 18 new rules
that had none (al-appsource-review.md, al-data-modeling-review.md,
al-error-handling-review.md, al-security-review.md, al-style-review.md x3,
al-testing-review.md x2, al-ui-review.md, al-upgrade-review.md,
al-web-services-review.md), and fixed test-feature-scenario-tags' cue,
which only matched the compliant (tagged) shape instead of the anti-pattern
(untagged/generic-named test).

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

* 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).

* Fix four merge-critical issues from Jesper's 2026-09-22 review

- pages-must-not-contain-business-logic.good.al/.bad.al: the "good"
  codeunit still directly assigned real Sales Line."Line Amount" and
  called Modify(), bypassing the field's normal Validate cascade
  (discount, VAT, related-amount maintenance) - persisting inconsistent
  document lines regardless of which object the code lived in. Replaced
  the real Sales Line example with a self-contained "Sample Order Line"
  table and switched the codeunit to Validate()/Modify(true), so the
  fixture demonstrates the page-vs-codeunit separation without teaching
  unsafe direct field writes to a real BC document table.
- bcpt-scenarios-must-be-app-specific.good.al: Customer.FindFirst()
  assumed a pre-existing customer (fails against an empty environment),
  and a session-local NextNo counter for the header key collides across
  concurrent BCPT sessions and repeated runs. Creates its own customer
  when none exists, and generates keys from CreateGuid() instead of an
  in-memory counter.
- upgrade-tag-logic-must-not-nest-deeply: the rule conflated two
  different things - nesting one tag's existence check inside another
  (the real anti-pattern Microsoft's guidance warns against) with
  having business-data safety conditions inside a single tagged
  migration's own loop body (which Microsoft's own worked example does,
  and its own design guidance explicitly requires: "Implement extra
  safety checks to avoid data corruption, even though you're using
  upgrade tags"). Rewrote the Description/Best Practice/Anti Pattern to
  scope the rule to actual tag nesting and migrations blended under one
  tag, and rewrote both fixtures: good.al now shows two safety
  conditions correctly nested inside one migration's own loop plus a
  second, genuinely separate migration as its own flat tagged
  procedure; bad.al now shows the real anti-pattern, one tag's check
  nested inside another's guarded body.
- table-design-must-match-bc-table-type-conventions: the rule and its
  worklist cue fired on any new table with a keys block, forcing
  buffers, queues, logs, mapping tables, and staging tables into the
  nearest-looking one of nine business-record archetypes. Added an
  explicit scope note that these nine types aren't an exhaustive table
  catalogue, and narrowed the al-data-modeling-review.md cue to require
  positive evidence (a type-specific naming suffix, key shape, or
  usage) before worklisting, instead of a bare keys/primary-key
  declaration.

* Narrow upgrade-tag nesting cue to match revised article

Cue now flags only nested upgrade-tag checks or functionally unrelated
migrations under one tag, and explicitly excludes record loops and
business-data safety guards belonging to a single migration.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

---------

Co-authored-by: Claude Sonnet 5 <noreply@anthropic.com>
Co-authored-by: Jesper Schulz-Wedde <jesper.schulzwedde@microsoft.com>
Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>
2026-09-29 17:12:51 +02:00

18 KiB

kind id version title description inputs outputs bc-version technologies countries application-area
action-skill al-testing-review 1 AL testing review Performs an AL testing review against guidance from BCQuality.
pr-diff
file-path
folder-path
findings-report
all
al
w1
all

AL testing review

Reviews AL source changes against the testing knowledge domain in BCQuality and emits a findings report. This is a leaf action skill: it invokes no sub-skills. It is one of the skills composed by al-code-review.

An orchestrator invokes this skill with a pr-diff, file-path, or folder-path. Testing findings are narrow by design — they apply when the review scope contains test codeunits, test runners, test methods, handlers, assertions, or fixture construction. The skill returns not-applicable when none of those apply.

Source

Use READ's Bounded retrieval for review skills workflow with -Domain testing. Consume every catalog page across enabled layers before applying this leaf's Relevance and Worklist; preserve each exact catalog path and open complete bodies only for exact paths selected by the Worklist. If the helper or prepared index is unavailable or invalid, use READ's explicit path-discovery and bounded native-read fallback.

Relevance

Apply the frontmatter matching rules defined in READ (Frontmatter matching semantics) against the task context:

  • bc-version — the target BC version from the PR branch's app.json or the orchestrator-supplied version. If unavailable, the dimension is unknown.
  • technologies — [al].
  • countries — the countries declared in the consuming app's app.json. Default to the orchestrator's configured context; if absent, unknown.
  • application-area — the union of application areas declared by the changed objects. Pass the actual set; do not substitute [all]. If the area cannot be determined from the changes, the dimension is unknown.

Discard files that are not applicable. Retain conditionally applicable files (any dimension unknown) only when the orchestrator's configuration permits them; findings derived from those files MUST have confidence no higher than medium, AND the finding's message MUST name the dimension or dimensions that were unknown.

Worklist

Narrow the relevant files to the subset that applies to the changes under review. For each relevant file, compute overlap against:

  • The changed AL object names and types — especially codeunits with Subtype = Test, test runner codeunits with TestIsolation, test libraries, and codeunits that define UI handlers.
  • The changed methods and attributes, weighted toward [Test], [TransactionModel(...)], [TestPermissions(...)], [HandlerFunctions(...)], handler attributes, asserterror, ExpectedError, ExpectedErrorCode, fixture initialization, and test-library calls.
  • Tokens extracted from the diff that relate to testing (Subtype = Test, Subtype = TestRunner, TestIsolation, TestPermissions, Restrictive, NonRestrictive, Disabled, Permissions Mock, Library - Lower Permissions, TransactionModel, AutoRollback, AutoCommit, Commit, asserterror, ExpectedError, ExpectedErrorCode, HandlerFunctions, ConfirmHandler, MessageHandler, StrMenuHandler, ModalPageHandler, SendNotificationHandler, RecallNotificationHandler, Enqueue, Dequeue, AssertEmpty, Initialize, IsInitialized, OnTestInitialize, LibrarySetupStorage, Library Assert, LibraryVariableStorage, LibrarySales, LibraryPurchase, LibraryERM, LibraryInventory, LibraryRandom, Library - Utility, LibraryUtility, GenerateGUID, GenerateRandomCode, TestPage, .Visible(, .Enabled(, .Editable(, OpenNew, OpenView, OpenEdit, Init, Insert).

A file enters the candidate worklist when its keywords intersect the extracted tokens or its topic (derived from the index entry's path, title, and description) matches a changed object type. Read an article's full file — its ## Best Practice / ## Anti Pattern bodies — only after it makes the worklist; candidate selection uses the index alone. When the diff contains no testing-related changes by any of the above signals, return outcome: "not-applicable" without evaluating files.

The following targeted checks cover every current testing article. Treat each as a candidate-selection cue: when the signal appears in changed code, add the named article to the worklist and evaluate it in Action.

  • A method in a Subtype = Test codeunit adds or changes [TransactionModel(...)], exercises code that calls Commit under AutoRollback, defaults broadly to AutoCommit, or chooses None for a writing test — transactionmodel-attribute-governs-test-transactions.
  • A new or changed [Test] procedure is added, whether or not it already carries [FEATURE]/[SCENARIO]/[GIVEN]/[WHEN]/[THEN] tags — test-feature-scenario-tags. A procedure with no tags at all, or a generic name like Test1, is the anti-pattern signal; presence of the tags is the compliant shape, not the thing to search for.
  • A test codeunit calls TestPage methods (OpenNew, OpenView, OpenEdit) alongside [Test] procedures in the same codeunit that call business-logic procedures directly with no TestPage involved — ui-test-codeunit-naming. The anti-pattern signal is both kinds of test mixed into one codeunit (or, on a project using the _UT convention, a UI-layer codeunit missing the suffix); a codeunit containing only TestPage-driven tests is not itself a violation.
  • A [GIVEN]-tagged setup precedes a posting call or report execution and does not visibly set up posting-group/VAT setup records, an explicit date, or (for a report test) both an included and an excluded record — given-blocks-must-cover-full-precondition-chain.
  • A test procedure contains more than one [WHEN] block, or more than one distinct action not labelled [GIVEN], without the procedure name declaring a flow/defect-then-fix shape — test-one-when-per-test.
  • A BCPT* scenario codeunit is added and the PerformanceTest app's only other scenario codeunits are copies of Microsoft's shipped BCPT samples (BCPT Create Customer, BCPT Create Item Journal, BCPT Post GL Entries, etc.) with no scenario exercising the extension's own codeunits, FlowFields, or pages — bcpt-scenarios-must-be-app-specific.
  • An AutoCommit test runs under a Subtype = TestRunner codeunit that omits TestIsolation or sets it to Disabled, leaving committed data between tests — testisolation-belongs-on-the-test-runner. Require runner/repository context; a standalone test file cannot prove which runner executes it.
  • A permission-sensitive test uses TestPermissions = Disabled, claims to test a restricted user without "Permissions Mock"/"Library - Lower Permissions", or declares [TestPermissions(...)] without applying that context — permission-tests-must-lower-the-execution-context.
  • Test fixture code manually calls Init/Insert, invents keys or prerequisite records, or bypasses available LibrarySales, LibraryPurchase, LibraryERM, LibraryInventory, LibraryRandom, or equivalent library codeunits — use-library-codeunits-for-test-fixtures.
  • A test codeunit's Initialize procedure exits on IsInitialized before per-test reset such as LibraryVariableStorage.Clear, LibrarySetupStorage.Restore, or LibraryTestInitialize.OnTestInitialize, or a [Test] method in a codeunit using that pattern does not call Initialize() first — reset-per-test-state-before-the-isinitialized-guard.
  • asserterror is added or changed without a following Assert.ExpectedError, Assert.ExpectedErrorCode, or a purpose-built assertion such as ExpectedTestFieldError — asserterror-needs-expectederror-and-code.
  • Test fixture code assigns a hardcoded literal to a primary-key field or a field the test relies on as a unique lookup identifier, hand-builds a "unique" value for such a field (string concatenation, a counter, Format(CurrentDateTime)), or truncates LibraryUtility.GenerateGUID()'s result with CopyStr for such a field shorter than 10 characters — use-generateguid-for-unique-test-fixture-values. Calling GenerateGUID() untruncated into a full-length field, GenerateRandomCodeWithLength for a shorter field needing real verified uniqueness, or GenerateRandomCode20 specifically for a Code[20] field, is the compliant shape, not the signal to flag. GenerateRandomCode20 is not a substitute for GenerateRandomCodeWithLength on a shorter field — it truncates GenerateGUID()'s sequential value down to the field's length by keeping the leftmost characters, which change the slowest, so retries against a short field can churn through the same truncated prefix far longer than GenerateRandomCodeWithLength's equivalent. A hardcoded or deterministic value in an ordinary descriptive field is not this anti-pattern — that field carries no uniqueness constraint. Do not claim GenerateRandomCode (without WithLength/20) or GenerateRandomXMLText verify uniqueness against the real table, or that GenerateRandomCode is collision-free even within one test run for a short field — none of that is true.
  • A test asserts against a TestPage field's .Visible() or .Enabled() — use-testpage-visible-enabled-to-verify-field-ui-state. When the assertion is against .Editable(), or the page is opened with OpenEdit() specifically to check editability — use-testpage-editable-to-verify-field-editability.
  • A test path raises UI and [HandlerFunctions(...)] does not match the invoked handlers, or the test has no meaningful evidence of the UI result (for example, it treats a Boolean set before the action as proof of success) — ui-handlers-in-tests. A capture/reset/assert-after-RunModal pattern is valid. Enqueue/dequeue and AssertEmpty are required only when order, count, text, replies, or a scripted sequence is part of the contract. Only nonoptional handlers have to execute: a listed handler declared [SendNotificationHandler(true)] or [RecallNotificationHandler(true)] is optional by design, so do not treat it as unmatched when the run never raises the notification.
  • A test's [GIVEN]/setup looks up a hardcoded code/number/name assumed to already exist instead of creating it, leaves a mandatory field on a created record empty, uses a value that doesn't satisfy the scenario's own explicit length/format requirement (for example a truncation test whose value never exceeds the field), or a scenario-defining value (amount, quantity, percentage, date, threshold, rounding precision) is generated/randomized instead of an explicit chosen value — test-data-must-be-random-and-complete. Generating incidental fixture values (identifiers, names, descriptions) via the standard library codeunits is the compliant shape, not the signal to flag, and neither is a short-but-valid value in an otherwise-unremarkable field.

Once the candidate worklist is known, resolve layer-precedence conflicts per READ. Drop lower-precedence files whose normative guidance (## Best Practice or ## Anti Pattern) directly contradicts a higher-precedence candidate, and record each dropped file in suppressed with reason: "layer-precedence". Files that would have been candidates but are hidden because their layer is disabled in consumer configuration are recorded with reason: "configuration". Files that never became candidates are NOT recorded in suppressed.

When the post-conflict worklist is empty because no applicable testing knowledge exists, or because configuration suppressed every candidate, emit outcome: "no-knowledge". When the worklist is empty because no applicable testing knowledge matched the changes, emit outcome: "completed" with an empty findings array.

Action

For each worklist entry, evaluate the diff against the file's ## Best Practice and ## Anti Pattern sections. Emit findings as follows:

  • When the diff contains a clear match for an Anti Pattern, emit a finding with severity major or blocker, a message summarizing the anti-pattern, location pointing to the offending line or range, and a references entry pointing to the knowledge file. Use blocker only when the test can pass while verifying the wrong behavior or can leave committed data that contaminates later tests; otherwise the ceiling is major.
  • When the diff contains code that contradicts a Best Practice without being a full anti-pattern, emit minor with the same reference shape.
  • Applicability alone is not a finding. Emit info only for a concrete, non-actionable observation the article explicitly defines; otherwise emit nothing when no violation is present.

For ui-handlers-in-tests, use major when missing or incorrectly listed handlers make the test fail at runtime. Use minor when the test executes but lacks a meaningful semantic postcondition, including a pre-set Boolean used as proof. Do not escalate solely because a handler does not use queue storage or asserts inside the handler.

Set confidence to:

  • high when the detection is based on an unambiguous pattern match (attribute, handler declaration, assertion sequence, or fixture call).
  • medium when detection relies on heuristics or when any frontmatter dimension was unknown.
  • low when the finding is an advisory derived only from applicability.

After evaluating each worklist entry, also consider whether the diff exhibits a testing defect the agent recognises from its general AL knowledge that no knowledge file in the worklist covers. Such candidates are agent findings within this skill's domain — emit them with references: [], an id slug prefixed with agent:, confidence capped at medium, severity capped at minor (agent findings are advisory and non-gating), and a message that is self-contained (describing both the issue and a concrete recommendation, since there is no knowledge-file footer for the consumer to fall back on). Hold every candidate to the precision bar in skills/do.md (Agent findings): emit only a concrete, material testing defect a knowledgeable BC reviewer would agree is wrong — steelman it first and drop anything stylistic, speculative, dependent on code outside the diff, or merely a valid alternative; when in doubt, omit. The scope is strictly AL testing; defects outside this domain belong to other leaves and MUST NOT be emitted here. Before emitting, check the worklist for a knowledge file that matches the candidate — if one exists, upgrade the candidate to a knowledge-backed finding instead. See skills/do.md for the full contract.

For every emitted finding, decide whether the fix is mechanical. A fix is mechanical when it is small, local, and unambiguous from the diff context (for example: add the matching ExpectedError assertion after asserterror; add or remove a handler name in HandlerFunctions, except that a listed optional notification handler must never be proposed for removal; add LibraryVariableStorage.Clear or AssertEmpty when queue/LVS intentionally verifies interaction order, count, text, replies, or a scripted sequence; or replace hand-rolled fixture creation with an evident library call). For mechanical findings, emit findings[].suggested-code with the literal replacement for the source lines indicated by location. The payload must be a verbatim replacement — no diff markers, no fences, no commentary — that the consumer can render as a one-click suggestion. When a .good.al companion exists and the diff context matches the .bad.al shape, adapt the .good.al replacement into suggested-code.

Omit suggested-code only when the appropriate fix depends on context the skill cannot determine, when multiple defensible replacements exist, or when the fix spans non-contiguous code. If a finding is mechanical-looking but you omit suggested-code, set findings[].suggested-code-omission-reason to a short explanation. See skills/do.md for the full contract.

Outcome selection:

  • completed — the skill evaluated every worklist item.
  • no-knowledge — no applicable testing knowledge survived filtering.
  • not-applicable — the diff touches no test codeunit, runner, method, handler, assertion, or fixture surface.
  • partial — a budget was hit before the worklist was exhausted.
  • failed — an unrecoverable error occurred.

Output

Output conforms to the DO output contract. Every finding this skill emits MUST set findings[].domain to "Testing". A populated example:

{
  "skill": { "id": "al-testing-review", "version": 1 },
  "outcome": "completed",
  "summary": {
    "counts": { "blocker": 0, "major": 1, "minor": 0, "info": 0 },
    "coverage": { "worklist-size": 1, "items-evaluated": 1 }
  },
  "findings": [
    {
      "id": "microsoft/knowledge/testing/asserterror-needs-expectederror-and-code.md",
      "severity": "major",
      "message": "The negative test uses asserterror without checking the resulting message or error code, so any unrelated setup or permission error can make the test pass.",
      "location": {
        "file": "test/SalesPostingTests.Codeunit.al",
        "line": 42
      },
      "references": [
        { "path": "microsoft/knowledge/testing/asserterror-needs-expectederror-and-code.md" }
      ],
      "confidence": "high",
      "domain": "Testing",
      "suggested-code": "asserterror PostInvalidOrder();\nAssert.ExpectedError(ExpectedPostingErr);"
    }
  ],
  "suppressed": []
}

The empty-corpus case produces:

{
  "skill": { "id": "al-testing-review", "version": 1 },
  "outcome": "no-knowledge",
  "summary": {
    "counts": { "blocker": 0, "major": 0, "minor": 0, "info": 0 },
    "coverage": { "worklist-size": 0, "items-evaluated": 0 }
  },
  "findings": [],
  "suppressed": []
}