Microsoft Bcquality Assets Al Performance Review

AL performance review

Source: microsoft/skills/review/al-performance-review.md

> Bundled consumption note. This extension packages BCQuality as VS Code chat skills and chat instructions under assets/generated/microsoft-bcquality-assets. Do not probe an external clone, skills/entry.md, skills/read.md, skills/do.md, or knowledge-index.json when using this bundled copy. Treat this SKILL.md plus the bundled BCQuality instruction files whose Source: paths match the active domain as the packaged knowledge surface. This note overrides upstream clone-oriented path references preserved below for provenance.

AL performance review

Reviews AL source changes against the performance 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 either a pr-diff (the standard PR-review entry point) or a file-path (single-file review). The skill produces a single JSON document conforming to the DO output contract.

Source

Read the BCQuality knowledge index once, the knowledge-index.json BCQuality builds at the root of the knowledge checkout (Entry's preparation step regenerates it over the live, already-filtered clone, see skills/entry.md). It lists every article that survived layer and allow/deny filtering and carries, per article, its path, layer, domain, frontmatter dimensions, keywords, title, and a one-line description hint, exactly the fields Relevance and Worklist consume. Take the index entries whose domain is performance as this skill's candidate set across every enabled layer; do not open the individual article files at this step. Open an article's full body only once it enters the Worklist below, so a review reads the index plus the handful of worklisted articles instead of every file under */knowledge/performance/**.

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 tables, pages with SourceTable bindings, reports, queries, and codeunits performing record iteration.
• The changed procedures and triggers, weighted toward those that perform loops, Find/FindSet/FindFirst calls, CalcFields, SetAutoCalcFields, CalcSums, FlowField access, Commit calls, checkpoint helpers, record copying, RecordRef conversion, Modify/Delete calls, or cross-table navigation.
• Tokens extracted from the diff that relate to data access and hot-path costs (SetRange, SetFilter, SetLoadFields, SetCurrentKey, FindSet, ReadIsolation, LockTable, ModifyAll, DeleteAll, Modify, Delete, Commit, checkpoint, Copy, RecordRef, GetTable, TextBuilder, Dictionary, temporary, repeat, until, CalcFields, SetAutoCalcFields, CalcSums, FlowField, Visible).

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.

Apply these targeted cues even when simple token overlap would rank the article below the worklist cutoff:

• Worklist use-setautocalcfields-for-per-row-flowfields.md when a record loop calls CalcFields, or when every row reads the same FlowField for a comparison, branch, or per-record action. Worklist calcsums-instead-of-calcfields-in-loop.md instead when the loop only accumulates one set total.
• Worklist hidden-flowfields-still-calculate-before-bc26-opt-in.md when a page control directly sources a FlowField and sets Visible = false or a visibility expression. Suppress it when the target is known to have BC26's Calculate only visible FlowFields feature enabled, or when the FlowField is cheap and intentionally preloaded.
• Worklist avoid-commit-inside-loops.md only when Commit() is inside a record-iteration body or a helper invoked once per row. Do not match one Commit() after a bounded checkpoint helper returns, a Commit() outside iteration, or comments and documentation that merely mention commits.
• Worklist avoid-cloning-records-before-modify-delete-in-loops.md when an iteration calls Copy or RecordRef.GetTable before Modify/Delete, or passes the iterated record without var to a helper that writes that record. Do not worklist it from Modify, Delete, or RecordRef alone; exclude a direct write on the iterator, a read-only copy, a temporary record, a different target table, and a RecordRef opened and iterated directly.
• Worklist use-tryfunction-for-error-catching-not-rollback.md only when writes occur inside a try method and the code or surrounding flow expects an error to roll them back. A bare try-method call whose Boolean result is ignored belongs exclusively to error-handling/ignored-tryfunction-return-disables-try-semantics.md; do not worklist the performance article from that call shape alone.
• For LockTable in a pure read helper, select exactly one owner. Use do-not-locktable-in-read-only-procedure.md when the helper needs no stronger isolation and should remove the lock. Use prefer-readisolation-over-locktable-for-reads.md instead when the code explicitly requires committed-read semantics and ReadIsolation is the replacement. Never emit both findings for the same call.

These targeted inclusions and exclusions override generic token overlap. Do not retain an excluded article solely because the diff contains one of its keywords.

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 performance knowledge exists, or because configuration suppressed every candidate, emit outcome: "no-knowledge". When the worklist is empty because no applicable performance 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 knowledge file states the anti-pattern violates a platform-level guarantee (for example, documented query timeouts or transaction size limits). When the file does not make such a claim, 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.

Set confidence to:

• high when the detection is based on an unambiguous pattern match (identifier, syntax, object type).
• 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 performance 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 performance 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 performance; 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: delete unreachable lines; replace Count() > 0 with not IsEmpty(); move a local Label to object scope; add a missing ToolTip, OptionCaption, or DataClassification; replace a string-concatenated Error with a Label-backed call; change an over-broad permission token; or add an obvious else/guard branch). 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; default when the skill finishes normally, including when the resulting findings array is empty.
• no-knowledge, no applicable performance knowledge survived Source, Relevance, configuration filtering, and conflict resolution. findings is empty.
• not-applicable, the task context lacks an AL dimension (no AL changes in the diff, or technologies filter rejected the task).
• partial, a time or token budget was hit before the worklist was exhausted. summary.coverage reflects the evaluated subset; outcome-reason explains the cause.
• failed, an unrecoverable error occurred. outcome-reason is required.

Output

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

{
  "skill": { "id": "al-performance-review", "version": 1 },
  "outcome": "completed",
  "summary": {
    "counts": { "blocker": 0, "major": 1, "minor": 1, "info": 0 },
    "coverage": { "worklist-size": 2, "items-evaluated": 2 }
  },
  "findings": [
    {
      "id": "microsoft/knowledge/performance/apply-filters-before-iterating.md",
      "severity": "major",
      "message": "The Country/Region Code predicate is evaluated inside the loop instead of with SetRange before FindSet, so every row crosses the database boundary.",
      "location": {
        "file": "src/Sales/PostingRoutines.Codeunit.al",
        "line": 140,
        "range": { "start-line": 140, "end-line": 144 }
      },
      "references": [
        { "path": "microsoft/knowledge/performance/apply-filters-before-iterating.md" }
      ],
      "confidence": "high",
      "domain": "Performance"
    },
    {
      "id": "microsoft/knowledge/performance/use-setloadfields-for-partial-records.md",
      "severity": "minor",
      "message": "The loop reads only a small subset of fields from a wide table without SetLoadFields, transferring every column for each row.",
      "location": {
        "file": "src/Sales/PostingRoutines.Codeunit.al",
        "line": 152
      },
      "references": [
        { "path": "microsoft/knowledge/performance/use-setloadfields-for-partial-records.md" }
      ],
      "confidence": "high",
      "domain": "Performance"
    }
  ],
  "suppressed": []
}

The empty-corpus case, BCQuality's state until performance knowledge files land, produces:

{
  "skill": { "id": "al-performance-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": []
}

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: Louage
• Source: Louage/frw-agentic-coding
• License: MIT

Install and usage instructions live in the source repository linked above.