Feature: quickfiler-efc-home-controller-coverage

[drmoisan]

• Work Mode: full-feature

Problem / Why

Epic #136 requires every testable production file compiled by QuickFiler/QuickFiler.csproj to
reach at least 80% line coverage, measured per file rather than per assembly. Child F8 owns the
EfcHomeController partial-class family and its dependency-injection factories - six files
totalling approximately 1,411 lines:

File	Lines
QuickFiler/Controllers/EfcHomeController.cs	441
QuickFiler/Controllers/EfcHomeControllerDependencies.cs	428
QuickFiler/Controllers/EfcHomeControllerDependencyFactories.cs	268
QuickFiler/Controllers/EfcHomeController.ExecuteMoves.cs	144
QuickFiler/Controllers/EfcHomeController.Metrics.cs	87
QuickFiler/Controllers/EfcHomeController.Timing.cs	43

Existing test files cover parts of this surface (EfcHomeControllerTests.cs,
EfcHomeControllerLifecycleTests.cs, EfcHomeControllerSeamTests.cs,
EfcHomeControllerMetricsTests.cs, EfcHomeControllerExecuteMovesTests.cs,
EfcHomeControllerDependenciesTests.cs, EfcHomeControllerDependenciesProductionFactoryTests.cs),
but EfcHomeControllerDependencyFactories.cs has no dedicated test file and the actual per-file
line coverage of each of the six files is unmeasured. Aggregate assembly coverage does not satisfy
issue #136.

Proposed Behavior

No change to observable QuickFiler behavior. Add deterministic MSTest coverage - and, only where a
seam is genuinely required to reach otherwise-unreachable logic, add an additive injectable seam -
so that every file classified testable by F1's ledger reaches at least 80% line coverage,
verified with F1's per-file coverage harness and recorded as numeric evidence.

Acceptance Criteria

• Every file in the F8 set that F1's ledger classifies testable reaches >= 80% line coverage,
  verified with F1's per-file harness and recorded numerically under <FEATURE>/evidence/qa-gates/.
• Any file F1's ledger classifies ratified-exempt is excluded from the target set, citing the
  ledger entry as the authority.
• No production file in scope exceeds 500 lines.
• Tests use MSTest, Moq, and FluentAssertions; they are deterministic and isolated, and use no
  temporary files, external services, live forms, or popups.
• Per-file coverage spans the positive path plus invalid-input, boundary, and error-handling
  behavior.
• ExecuteMoves is covered through an injected move seam, never against a live Outlook store,
  including partial-failure and mid-batch-cancellation behavior.
• EfcHomeController.Timing.cs is covered through an injected clock; Thread.Sleep,
  Task.Delay, and real wall-clock waits are absent from the tests.
• The full C# toolchain passes in final form: csharpier, analyzer build, nullable build,
  coverage-enabled vstest.
• No behavior change to observable QuickFiler flows.

Constraints & Risks

• EfcHomeControllerDependencies and EfcHomeControllerDependencyFactories form the injection-seam
  contract for the whole EFC controller family, including EfcFormController and
  EfcItemController, which belong to sibling child F9. Any change to the dependency contract must
  be additive so F9 needs no edit. If an additive change is impossible, the required change is
  recorded in spec.md as a cross-child contract note rather than applied to F9's files.
• ExecuteMoves performs Outlook MailItem/MAPIFolder moves. It must be exercised only through
  an injected move seam.
• The move-execution and metrics paths carry ordering and state-transition invariants; partial
  failure and mid-batch cancellation must be covered explicitly.
• Seam hierarchy per .claude/rules/csharp.md: interface seam, then injectable delegate, then
  adapter. Never construct live forms in tests.
• This child must not modify coverage.config or any shared build property file, and must not edit
  files assigned to sibling children (see epic.md "Feature File Assignments").
• F1's outputs (harness and ledger) do not exist at preparation time; the plan consumes them as an
  upstream contract and F1 merges to the integration branch before F8 executes.

Test Conditions

• Per-file line coverage measurement for each of the six production files
• ExecuteMoves happy path, partial failure mid-batch, cancellation mid-batch, empty batch
• Metrics accumulation ordering and state transitions
• Timing behavior under an injected clock
• Dependency-factory construction, null-argument rejection, and lazy/cached resolution behavior
• Controller lifecycle: initialize, run, dispose, double-dispose

Source

From: docs/features/potential/2026-08-07-quickfiler-efc-home-controller-coverage.md