Spec 038 Phase 3 — Class-B rules + Margin/Padding API ergonomics by codemonkeychris · Pull Request #248 · microsoft/microsoft-ui-reactor

codemonkeychris · 2026-05-11T23:47:19Z

Summary

Three Class-B vocabulary-translation rules under the Phase-3 rule infrastructure, plus two Reactor API/skill fixes surfaced while authoring them.

Rules (Validation Gate; ready for review, not merge — bar #5 is human):

ThemeBackgroundSuffixRule — CS0117 on Theme.*Background → Theme.SolidBackground (cluster C0019, 16 events)
AlignmentShortcutRule — CS1061 on Reactor *Element receivers for HorizontalAlignment / VerticalAlignment → .HAlign(...) / .VAlign(...) (cluster C0017 + adjacent, ~22 events)
ButtonOnClickFactoryMoveRule — CS1061 on ButtonElement.OnClick → Button(..., onClick: ...), explicitly naming .OnTapped as the wrong sibling to keep agents from reaching for the gesture event

Reactor API fixes (driven by 525-run corpus signal):

Margin / Padding per-side overloads now default unspecified sides to 0.0, eliminating ~198 corpus build failures from .Margin(top: 12)-shaped calls
BREAKING (pre-1.0): Margin(double, double) and Padding(double, double) parameter order swapped from (horizontal, vertical) to (vertical, horizontal) to match CSS shorthand (top/bottom first). All repo callsites migrated to named-arg form (.Margin(horizontal: X, vertical: Y)) for layout preservation and reviewer clarity.

Skill updates (agent context):

reactor-getting-started cheatsheet shows named-arg Button("Save", onClick: handler) with explicit anti-pattern call-out
.OnTapped example re-anchored to non-Button surfaces

§3.1a residual: trace-channel rule_self_disabled row when a rule's declared target stops resolving against the live Reactor compilation; routed through TraceWriter.WriteRuleSelfDisabled, dedup'd per-invocation per-rule.

Test plan

dotnet test tests/Reactor.Tests — 7156 passed, 46 expected-skip, 0 failed
dotnet build Reactor.slnx -p:Platform=x64 — 0 errors, 29 warnings (all pre-existing in main: NU1903 CVE + a11y-showcase + stress_perf obsolete-API)
mur check --list-rules enumerates all three rules
CheckCommandTests 193/193
CSS-ordering regression test: .Margin(16, 14) → Thickness(14, 16, 14, 16)
Per-side regression test: .Margin(top: 12) → Thickness(0, 12, 0, 0)
Sample apps build clean (TodoApp, CommandingDemo verified individually)
Awaiting second-agent corpus drop (Validation Gate bar Adding Microsoft SECURITY.MD #2) to unblock Class-A rules in a follow-up PR

Review feedback addressed

9504cb0: RuleTargetResolutionTests.BuildLiveReactorCompilation force-loads Reactor.dll before enumerating AppDomain.CurrentDomain.GetAssemblies() — prevents false target-resolution failures on a cold xunit run where Reactor.dll wasn't already loaded.
docs/guide/* regeneration verified via mur docs compile: 4 of 5 files (styling, flex-layout, collections, animation) regenerate byte-identical to the committed content. getting-started.md has pre-existing pipeline drift (inlined snippets vs snippet= references) unrelated to this PR scope — the single Padding-line update is a targeted hand-edit; full regen pending a separate cleanup PR.

Deferred follow-ups

Class-A corpus-induced rules — blocked on cross-agent corpus drop
Optional REACTOR_* analyzer for positional 2-arg Margin / Padding (named-arg migration in this PR makes the order-footgun opt-in; analyzer would make it loud)
Reactor-touching integration fixture for the canonical Button.OnClick case (needs WindowsAppSDK restore on every test run)
docs/guide/getting-started.md pipeline-drift cleanup (collapse inlined snippets back into snippet= references)

🤖 Generated with Claude Code

…t ranker `mur check` grows two agent-visible behaviors on top of the Phase-1 Tier-2 suggester: MSBuild flag passthrough via the `--` separator with default-merging (`--nologo`, `-v:m`, `-p:Platform={host arch}` injected only when not named in passthrough), and a pre-emit ranker that suppresses cosmetic noise mid-iteration (CS1591 XML doc, CS0168 unused-var, IDE0xxx style, NU1701/NU1605, MSB3245/3270/3277, CS8600-8625 nullable warnings, REACTOR_* info-severity) while always emitting errors via a universal- error floor. New mode flags `--strict` / `--final` / `--quiet` and `--emit-threshold <float>` round-trip through ArgsParser. Trace output records the effective `dotnet build` argv as a `kind: "command"` header row so replays are bit-faithful. Suppress→error guardrail at tools/Reactor.MurCheckGuardrail audits an iter+final trace pair against PolicyTable's universal-error-floor invariant. Re-uses the live PolicyTable via InternalsVisibleTo so the two sources can never drift. Eight unit tests; the harness-side CI wiring is deferred behind the same WindowsAppSDK-fixture blocker as Phase-1 §1.6. Phase-2.x post-EC2 fixes: * Gate-input regression. CheckCommand.ShouldEmitSuggestions now counts the full parsed diagnostic list, not the post-ranker emittable list. EC2's 3-round preview measured Tier-2 firing collapse from EC1's 80% to 0% on kanban-mur because the ranker's nullable-warning suppression closed the gate on builds EC1 had left open. Regression test RankerTests.Suggest_gate_counts_full_parsed_list_not_post_ranker_emittable locks the behavior. * `--final` framing softened in both plugins/reactor/skills/reactor- build-and-check/SKILL.md and the legacy root SKILL.md. EC2's 3-round preview measured 0/6 production value across mandatory --final invocations; the framing now describes --final as an optional pre- merge sweep for human review / CI gates, explicitly not a task- completion requirement. * TraceWriter mode propagation fix. The diagnostic-row `mode` field used to be hardcoded to "iteration" even when invoked via --final. Now piped through TraceWriter.Open(path, root, mode); regression test TraceWriterTests.Diag_row_mode_matches_writer_invocation_mode locks it. EC2 5×N PASS by median (2026-05-11): * reactor-calc-mur-check beats base on every metric — cost −5.1%, tokens −5.8%, turns −5.1%, wall −7.9%; CV cost 1.9× tighter. * reactor-kanban-mur-check at cost median parity ($3.30 = $3.30); mean dragged to +5.7% by R2 outlier (R2-excluded mean −3.3%). * First-build OK 5/5 both variant arms. * --final invocation 0/10 across both projects (SKILL framing working as designed; the previous bugged-Phase-2 batch had 6/6 mandatory invocations). * Tier-2 firing 0/10 — gate correctly inhibits on small-batch iteration patterns; closing the kanban token gap is Phase-3's scope (rules > fuzzy match). * Criterion-2 guardrail audit deferred to a harness retrofit (post-run `mur check --final` against the final workspace state). Tests: 7102 / 7102 passing on the post-fix tree. CheckCommandTests grew from 120 to 148 tests across the Phase-2 surfaces (ArgsParser passthrough + mode flags, Ranker scoring + emit gates, Guardrail trace-pair audit, TraceWriter mode propagation, gate-input regression). Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Three Class-B vocabulary-translation rules under the Phase-3 rule infrastructure, plus two Reactor API/skill fixes surfaced while authoring them. Rules (Validation Gate; ready for review, not merge — bar #5 is human): - ThemeBackgroundSuffixRule: CS0117 on Theme.*Background → Theme.SolidBackground (cluster C0019, 16 events) - AlignmentShortcutRule: CS1061 on Reactor *Element receivers for HorizontalAlignment / VerticalAlignment → .HAlign(...) / .VAlign(...) (cluster C0017 + adjacent, ~22 events) - ButtonOnClickFactoryMoveRule: CS1061 on ButtonElement.OnClick → Button(..., onClick: ...), explicitly naming .OnTapped as the wrong sibling to keep agents from reaching for the gesture event Reactor API fixes (driven by 525-run corpus signal): - Margin / Padding per-side overloads now default unspecified sides to 0.0, eliminating ~198 corpus build failures from .Margin(top: 12)-shaped calls - BREAKING (pre-1.0): Margin(double, double) and Padding(double, double) parameter order swapped from (horizontal, vertical) to (vertical, horizontal) to match CSS shorthand (top/bottom first). All repo callsites migrated to named-arg form for layout preservation and reviewer clarity. Skill updates (agent context): - reactor-getting-started cheatsheet shows named-arg Button("Save", onClick: handler) with explicit anti-pattern call-out - .OnTapped example re-anchored to non-Button surfaces (Border, Image, ScrollView) §3.1a residual: trace-channel rule_self_disabled row when a rule's declared target stops resolving against the live Reactor compilation; routed through TraceWriter.WriteRuleSelfDisabled, dedup'd per-invocation per-rule. Tests: Reactor.Tests 7156/7202 (46 expected-skip); CheckCommandTests 193/193. Solution builds clean (no new C# / REACTOR_* warnings). Class-A rule PRs remain blocked on second-agent corpus drop (Validation Gate bar #2, cross-agent reproducibility). Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Copilot

Pull request overview

This PR advances Spec 038 by adding Phase-3 Tier-3 rule infrastructure + three initial Class‑B vocabulary-translation rules, and by improving Reactor layout ergonomics (Margin/Padding) with corresponding repo-wide callsite/doc updates. It also includes Phase‑2 mur check plumbing (modes, deterministic ranker, richer trace schema) and an offline guardrail tool.

Changes:

Add Tier‑3 rule system (IRulePattern, RuleRegistry, RuleSymbolResolver) and integrate it into mur check/Tier‑2 suggesting, including --disable-rule / --list-rules and trace telemetry for self-disabled rules.
Introduce deterministic pre-emit ranker + Phase‑2 argument parsing / passthrough behavior, plus an offline guardrail tool that audits iter vs final traces against PolicyTable.
Update ElementExtensions.Margin/Padding overload ergonomics (per-side defaults; 2‑arg order swap) and migrate callsites/docs/skills accordingly.

Show a summary per file

File	Description
tools/Reactor.MurCheckGuardrail/Reactor.MurCheckGuardrail.csproj	New offline guardrail tool project referencing Reactor.Cli PolicyTable
tools/Reactor.MurCheckGuardrail/Program.cs	Guardrail tool entrypoint
tools/Reactor.MurCheckGuardrail/GuardrailRunner.cs	Guardrail logic: parse trace JSONL + audit against PolicyTable invariants
tests/Reactor.Tests/Reactor.Tests.csproj	Reference guardrail tool from unit tests
tests/Reactor.Tests/ElementTests.cs	New Margin/Padding regression tests (per-side defaults, overload binding, CSS order)
tests/Reactor.Tests/ElementExtensionsCoverageTests.cs	Update 2-arg Margin/Padding tests to named args
tests/Reactor.Tests/ElementExtensionsAdditionalTests.cs	Update Margin overload test to named args
tests/Reactor.Tests/CheckCommandTests/TraceWriterTests.cs	Add tests for trace `mode` and rule-self-disabled schema
tests/Reactor.Tests/CheckCommandTests/SuggesterOrchestratorRuleTests.cs	New tests for Tier‑3 rule vs Tier‑2 precedence + disable/self-disable plumbing
tests/Reactor.Tests/CheckCommandTests/Rules/ThemeBackgroundSuffixRuleTests.cs	New fixture tests for Theme.*Background → Theme.SolidBackground rule
tests/Reactor.Tests/CheckCommandTests/Rules/RuleTargetResolutionTests.cs	New CI gate test intended to resolve all rule declared targets against live Reactor compilation
tests/Reactor.Tests/CheckCommandTests/Rules/RuleSymbolResolverTests.cs	New tests for resolver caching + type/member resolution
tests/Reactor.Tests/CheckCommandTests/Rules/RuleRegistryTests.cs	New tests for registry discovery, ordering, disable/self-disable, exception swallowing
tests/Reactor.Tests/CheckCommandTests/Rules/RuleContractTests.cs	New contract-shape tests for RuleContext/RuleSuggestion
tests/Reactor.Tests/CheckCommandTests/Rules/ButtonOnClickFactoryMoveRuleTests.cs	New fixture tests for ButtonElement.OnClick → Button(..., onClick: ...) rule
tests/Reactor.Tests/CheckCommandTests/Rules/AlignmentShortcutRuleTests.cs	New fixture tests for Horizontal/VerticalAlignment → HAlign/VAlign rule
tests/Reactor.Tests/CheckCommandTests/RankerTests.cs	New unit tests for deterministic ranker semantics and invariants
tests/Reactor.Tests/CheckCommandTests/GuardrailRunnerTests.cs	New unit tests for guardrail audit + trace parsing
tests/Reactor.Tests/CheckCommandTests/CheckCommandPipelineTests.cs	Add ranker/trace pipeline regression tests (stdout filter vs trace completeness, command rows)
tests/Reactor.Tests/CheckCommandTests/ArgsParserTests.cs	New tests for Phase‑2 args parsing, passthrough merging, modes, emit-threshold, rule flags
tests/Reactor.AppTests.Host/SelfTest/Fixtures/DataGridScrollFixtures.cs	Migrate Padding(…, …) callsites to named args
tests/Reactor.AppTests.Host/SelfTest/Fixtures/DataGridEditFixtures.cs	Migrate Padding(…, …) callsites to named args
tests/cmd_perf/CmdPerf.Reactor/Program.cs	Migrate Margin/Padding 2‑arg callsites to named args
src/Reactor/Hosting/Devtools/DevtoolsMenuFactory.cs	Migrate Padding(…, …) to named args
src/Reactor/Elements/ElementExtensions.cs	Margin/Padding API change: per-side defaults + 2‑arg overload order swap
src/Reactor/Controls/Editors/CellRenderers.cs	Migrate Padding(…, …) to named args
src/Reactor/Controls/DataGrid/DataGridComponent.cs	Migrate Padding(…, …) to named args
src/Reactor.Cli/Reactor.Cli.csproj	Add InternalsVisibleTo for guardrail tool assembly
src/Reactor.Cli/Check/TraceWriter.cs	Add trace mode plumbing + command rows + rule-self-disabled rows
src/Reactor.Cli/Check/SuggesterOrchestrator.cs	Integrate Tier‑3 rules alongside Tier‑2; allow non-Tier2 codes via rules
src/Reactor.Cli/Check/Rules/ThemeBackgroundSuffixRule.cs	New Class‑B vocab translation rule for Theme.*Background
src/Reactor.Cli/Check/Rules/RuleSymbolResolver.cs	New per-compilation symbol resolver (type/method/member) with caching
src/Reactor.Cli/Check/Rules/RuleRegistry.cs	New reflection-discovered registry + disable/self-disable/status reporting
src/Reactor.Cli/Check/Rules/IRulePattern.cs	New Tier‑3 rule contract + RuleContext/RuleSuggestion types
src/Reactor.Cli/Check/Rules/ButtonOnClickFactoryMoveRule.cs	New Class‑B rule for ButtonElement.OnClick → Button(..., onClick: ...)
src/Reactor.Cli/Check/Rules/AlignmentShortcutRule.cs	New Class‑B rule for *Alignment → HAlign/VAlign
src/Reactor.Cli/Check/Ranker/Ranker.cs	New Ranker wrapper over PolicyTable
src/Reactor.Cli/Check/Ranker/PolicyTable.cs	New deterministic policy table for per-mode scoring/thresholds
src/Reactor.Cli/Check/Mode.cs	New `mur check` invocation modes enum
src/Reactor.Cli/Check/CheckCommand.cs	Switch to ArgsParser, add list/disable rule flags, ranker stdout filtering, trace enhancements
src/Reactor.Cli/Check/CheckArgs.cs	Expand parsed args record + update help text; keep back-compat TryParse
src/Reactor.Cli/Check/ArgsParser.cs	New Phase‑2 parser: passthrough boundary + default-merging + modes + rule flags
skills/reactor.api.txt	Update API index for new Margin/Padding signatures
skills/design.md	Update design skill examples to named args for Margin(…, …)
SKILL.md	Update root skill guidance for `mur check` behavior + examples
samples/TodoApp/Program.cs	Migrate Padding(…, …) to named args
samples/ReactorHostControlDemo/MainWindow.xaml.cs	Migrate Margin(…, …) to named args
samples/ReactorHostControlDemo/CounterDemo.cs	Migrate Margin(…, …) to named args
samples/ReactorGallery/ControlPages/DesignGuidance/SpacingPage.cs	Update docs examples to named args for Margin/Padding 2‑arg form
samples/ReactorCharting.Gallery/Samples/DonutMixer.cs	Migrate Margin(…, …) to named args
samples/Reactor.TestApp/Demos/VirtualizationDemo.cs	Migrate Padding(…, …) to named args
samples/Reactor.TestApp/Demos/SlotsDemo.cs	Migrate Padding(…, …) to named args
samples/Reactor.TestApp/Demos/FlyoutDemo.cs	Migrate Padding(…, …) to named args
samples/Reactor.TestApp/Demos/DynamicListDemo.cs	Migrate Padding(…, …) to named args
samples/Reactor.TestApp/Demos/DataSystemDemo.cs	Migrate Margin(…, …) to named args
samples/Reactor.TestApp/Demos/ConditionalDemo.cs	Migrate Padding(…, …) to named args
samples/Reactor.TestApp/Demos/AsyncValueSamplesDemo.cs	Migrate Margin(…, …) to named args
samples/Reactor.TestApp/App.cs	Migrate Padding(…, …) to named args
samples/InteropFirst/Components/OrdersDataGrid.cs	Migrate Margin/Padding 2‑arg callsites to named args
samples/CommandingDemo/App.cs	Migrate Margin 2‑arg callsites to named args
samples/apps/monaco-editor/App.cs	Migrate Padding(…, …) to named args
samples/apps/headtrax/HeadTrax/Components/EmployeeGrid.cs	Migrate Padding(…, …) to named args
samples/apps/demo-script-tool/App/Components/InlineBanner.cs	Migrate Padding(…, …) to named args
Reactor.slnx	Add guardrail tool project to solution
plugins/reactor/skills/reactor-getting-started/SKILL.md	Update cheatsheet to emphasize Button onClick factory arg and avoid .OnTapped
plugins/reactor/skills/reactor-dsl/references/reactor.api.txt	Update embedded API reference for Margin/Padding signature changes
plugins/reactor/skills/reactor-design/SKILL.md	Update design skill examples to named args for Margin(…, …)
plugins/reactor/skills/reactor-build-and-check/SKILL.md	Update build-and-check skill to reflect `mur check` semantics and workflow
docs/specs/tasks/038-vocab-table.csv	Add vocab translation table entries used to justify Class‑B rules
docs/specs/tasks/038-mur-check-did-you-mean-implementation.md	Update spec task status and evaluation writeup with Phase‑2/3 progress
docs/specs/tasks/038-EC2-handoff.md	Add EC2 handoff doc for eval operator
docs/guide/styling.md	Update examples to named args for Padding(…, …) (but file is generated)
docs/guide/getting-started.md	Update examples to named args for Padding(…, …) (but file is generated)
docs/guide/flex-layout.md	Update examples to named args for Padding(…, …) (but file is generated)
docs/guide/collections.md	Update examples to named args for Padding(…, …) (but file is generated)
docs/guide/animation.md	Update examples to named args for Padding(…, …) (but file is generated)
docs/_pipeline/apps/styling/App.cs	Update snippet source to named args for Padding(…, …)
docs/_pipeline/apps/flex-layout/App.cs	Update snippet source to named args for Padding(…, …)
docs/_pipeline/apps/collections/App.cs	Update snippet source to named args for Padding(…, …)
docs/_pipeline/apps/calculator/App.cs	Update snippet source to named args for Padding(…, …)
docs/_pipeline/apps/animation/App.cs	Update snippet source to named args for Padding(…, …)
CHANGELOG.md	Document breaking Margin/Padding 2‑arg order change and Phase‑2/3 additions

Copilot's findings

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Files reviewed: 83/83 changed files
Comments generated: 6

Copilot review feedback on #248: BuildLiveReactorCompilation enumerated AppDomain.CurrentDomain.GetAssemblies() before the `typeof(...AsyncValue<int>).Assembly` force-load, so on a cold xunit run where Reactor.dll wasn't already loaded, the enumeration completed without Reactor in the reference list and target resolution failed for every rule. Moving the force-load to the head of the method guarantees Reactor.dll is in the AppDomain before enumeration begins. Spec 038 §3.1a. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

codemonkeychris · 2026-05-12T00:05:08Z

Thanks for the review @copilot. Both points addressed:

1. RuleTargetResolutionTests force-load order — real bug, fixed in 9504cb0. The typeof(...AsyncValue<int>).Assembly force-load now happens before AppDomain.CurrentDomain.GetAssemblies() enumeration, guaranteeing Reactor.dll is in the reference list on a cold xunit run.

2. docs/guide/* is generated output — acknowledged. The proper flow per docs/_pipeline/ai-author-skill.md is to edit docs/_pipeline/apps/<topic>/App.cs (source snippets) and let mur docs compile produce the docs/guide/*.md output. My initial sed pass edited both source and output in lockstep, which produced correct content but was procedurally wrong.

Verified by reverting and re-running the pipeline:

styling.md, flex-layout.md, collections.md, animation.md — mur docs compile --topic <each> --no-screenshots --no-ai --no-build produces byte-identical output to what's currently committed. ✓
getting-started.md — has pre-existing pipeline drift unrelated to this PR: regenerating it would also collapse ~170 lines of currently-inlined code into snippet="..." references. That's a separate semantic change that should land in its own PR (cleanup to bring the file back into pipeline-managed state). For this PR's scope, only the single .Padding(12, 8) → .Padding(horizontal: 12, vertical: 8) line is touched as a targeted hand-edit; full regen pending separate cleanup.

Future similar work will use the pipeline flow as the authoritative path.

codemonkeychris and others added 2 commits May 11, 2026 13:51

codemonkeychris requested a review from Copilot May 11, 2026 23:47

Copilot started reviewing on behalf of codemonkeychris May 11, 2026 23:48 View session

Copilot AI reviewed May 11, 2026

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Comment thread tests/Reactor.Tests/CheckCommandTests/Rules/RuleTargetResolutionTests.cs

Comment thread docs/guide/styling.md

Comment thread docs/guide/getting-started.md

Comment thread docs/guide/flex-layout.md

Comment thread docs/guide/collections.md

Comment thread docs/guide/animation.md

Copilot started work on behalf of codemonkeychris May 12, 2026 00:05 View session

Copilot AI changed the title ~~Spec 038 Phase 3 — Class-B rules + Margin/Padding API ergonomics~~ <empty> May 12, 2026

Copilot finished work on behalf of codemonkeychris May 12, 2026 00:06

codemonkeychris changed the title ~~<empty>~~ Spec 038 Phase 3 — Class-B rules + Margin/Padding API ergonomics May 12, 2026

codemonkeychris merged commit 2bec028 into main May 12, 2026
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codemonkeychris deleted the feat/spec-038-phase2 branch May 12, 2026 00:37

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Spec 038 Phase 3 — Class-B rules + Margin/Padding API ergonomics#248

Spec 038 Phase 3 — Class-B rules + Margin/Padding API ergonomics#248
codemonkeychris merged 3 commits into
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feat/spec-038-phase2

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codemonkeychris commented May 11, 2026 •

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