test(virtue): #499 VirtueClassMap regression via LoadFromContent (5 tests)

[jsboige]

What

Add VirtueClassMapRegressionTests — 5 contract tests for the remaining uncovered production entity ClassMap (Virtue, the #499 scale-up taxonomy entity, 223 nodes / 194 leaves). Companion to FallacyClassMapRegressionTests and EntityClassMapRegressionTests. Additive only, no production code change. Full suite 422/0/5.

This is the ai-01 "couverture tests" runway (continued after #558).

Why

The CsvHelper ClassMap regression is a documented recurring silent-failure source (CLAUDE.md "CsvHelper Mapping" + the #216/#477 localization-mapping regression). 7 production ClassMaps exist; before this PR, Virtue had zero coverage (alongside TestFallacyCard, which is visual-test-only and lower-stakes). Virtue is the entity for the active #499 scale-up lane — a ClassMap drift here = silent data loss on Virtue generation, with no signal until a card renders empty.

VirtueClassMap declares 16 required FR columns (non-Optional) + 28 localized columns (en/ru/pt/es × 7) all .Optional(). The contract that must hold:

1. Required FR columns resolve — else silent null properties.
2. Optional columns may be absent without throwing — else HeaderValidated throws when a FR-only header set loads (breaks the multilingual harvest).
3. The double map pk → Id AND Pk — GetId() returns Id; if either binding drops, GetId() returns null and any keyed generation pass breaks.

The 5 tests (VirtueClassMapRegressionTests)

Test	What it pins
MapsRequiredColumns	All 16 required FR columns map to their properties (incl. Depth int parse)
PkPopulatesBothIdAndPk	pk column → Id + Pk; GetId() resolves (the silent-failure guard)
OptionalLocalizedColumnsAbsent_DoesNotThrow	28 optional columns absent → loads clean, properties null
OptionalLocalizedColumnsPresent_MapsThem	Optional = "may be absent", not "ignored when present"
RequiredColumnAbsent_Throws	A required FR column drift fails LOUD (HeaderValidationException), not silent

All via the real load path CsvBase<T,TMap>.LoadFromContent, inline CSV (no external fixture files), self-contained.

Verification

• New tests: 5/5 pass.
• Full suite: 422 passed / 0 failed / 5 skipped — no regression (baseline 417 + 5 new).
• Build: 0 errors.
• No production code touched — pure additive coverage.

Related

• Dispatched by: ai-01 "couverture tests" runway (05:08Z tick).
• Companion to FallacyClassMapRegressionTests (test(parsing): #204 Fallacy ClassMap regression — Optional localized columns guard (+2) #485), EntityClassMapRegressionTests (test(parsing): #204 ClassMap regression tests — Rule/ArgumentVirtue/Scenario/Virtue (+9, 159→168) #476), CsvBaseStrictContractTests.
• Closes the Virtue gap in the ClassMap regression matrix.
• DoD: additive tests only — mergeable without a content gate.

🤖 Generated with Claude Code

[clusterManager-Myia]

[NanoClaw] — #559 (test(virtue): #499 VirtueClassMap regression via LoadFromContent, 5 tests)

Verdict: clean additive contract suite, mergeable. Verified the 5 tests against the production VirtueClassMap — every column the tests pin is real, and the fragilities they guard are genuine.

ClassMap cross-check (read Virtue.cs at PR head) — the test's VirtueRequiredHeader constant matches production exactly:

• 17 non-Optional Map() calls → 16 distinct required column names (because both Id and Pk map to "pk"): pk, path, depth, decimal_path_padded, family_fr, subfamily_fr, subsubfamily_fr, title_fr, description_fr, remark_fr, link_fr, family_fr_camelcase, depth_max4, card, update, locked. Identical to the constant.
• 28 optional localized columns (en/ru/pt/es × 7: family/subfamily/subsubfamily/title/description/remark/link), all .Optional(). Matches the "28 localized" claim.

5 real assertions (not stubs) — all FluentAssertions on actual Virtue.LoadFromContent(csv) resolution:

1. MapsRequiredColumns — asserts every required FR property (Pk/Path/Depth=1 int/DecimalPathPadded/FamilyFr/SubfamilyFr/SubsubfamilyFr="" empty-cell/TitleFr/DescriptionFr/RemarkFr/LinkFr/FamilyFrCamelcase/DepthMax4/Card/Update/Locked) against an inline CSV. Depth as int parsed from "depth" column is the non-trivial check.
2. PkPopulatesBothIdAndPk — pins the real double-map: Map(Id).Name("pk") + Map(Pk).Name("pk") both bind to the pk column, so Id/Pk/GetId() all resolve to "1.1". Genuine silent-failure source (dropping either binding → GetId() returns null → broken keyed generation).
3. OptionalLocalizedColumnsAbsent_DoesNotThrow — FR-only header loads without throwing; absent optional cols → null (TitleEn/TitlePt/FamilyEs). Correct .Optional() contract.
4. OptionalLocalizedColumnsPresent_MapsThem — when present, title_en/title_pt/family_es map to their properties. Optional ≠ ignored.
5. RequiredColumnAbsent_Throws — dropping title_fr (non-Optional) from header → HeaderValidationException. Correct CsvHelper default (strict header validation for non-optional maps = loud failure, prevents silent data loss). The extra-row / MissingFieldFound nuance is correctly reasoned in the comment.

Additive-only: 2 new test files, +330/-0, zero production .cs modified. Self-contained inline CSV (no external fixtures). Security scan clean — all data synthetic.

One non-blocking note: this PR also adds FallacyLinkFallbackTests.cs (+167/-0), identical to the file in #558 — #559's branch was cut from a state including #558. If #558 merges first, #559's diff auto-shrinks to just VirtueClassMapRegressionTests.cs (the actual subject). Worth knowing for merge ordering, not a defect.

Comment-only (self-review cap).