swift-core-worker

name	swift-core-worker
description	Builds shared Swift core logic in NetMonitorCore — models, services, renderers, serialization, and unit tests.

Swift Core Worker

NOTE: Startup and cleanup are handled by worker-base. This skill defines the WORK PROCEDURE.

When to Use This Skill

Use for features that involve:

• Shared data models in Packages/NetMonitorCore/
• Service protocols in ServiceProtocols.swift
• Shared computation (HeatmapRenderer, IDW interpolation)
• Shared actors/services (WiFiMeasurementEngine)
• File format serialization (.netmonsurvey bundle)
• Deleting/cleaning up old code across the monorepo
• Unit tests for any of the above

Work Procedure

Step 1: Understand the Feature

• Read the feature description, preconditions, expectedBehavior, and verificationSteps from features.json
• Read AGENTS.md for coding conventions and boundaries
• Read .factory/library/architecture.md for package placement and patterns
• If the feature touches existing code, read the relevant files first

Step 2: Write Tests First (TDD — Red Phase)

• Create test file(s) in Packages/NetMonitorCore/Tests/NetMonitorCoreTests/ or Tests/NetMonitor-macOSTests/ or Tests/NetMonitor-iOSTests/ as appropriate
• Use Swift Testing framework (@Suite, @Test, #expect)
• Write tests that cover ALL expectedBehavior items from the feature
• Tests must be compilable but failing (no implementation yet)
• For models: test Codable round-trip, Equatable, Sendable conformance
• For renderer: test IDW output values, color mapping, edge cases, performance
• For services: test with mock dependencies using protocols

Step 3: Implement (Green Phase)

• Create source files in the correct package paths (see architecture.md)
• Follow existing code style: 4-space indent, explicit public on API types
• All types: Sendable, Codable, Identifiable as appropriate
• Services: actor or Sendable protocol conformance
• Protocols: add to ServiceProtocols.swift following existing pattern
• Enums: add cases to existing enums in Enums.swift if needed

Step 4: Verify

• Run cd Packages/NetMonitorCore && swift build -c debug — must succeed with zero errors
• Run xcodebuild -scheme NetMonitor-macOS -configuration Debug build — must succeed
• Run xcodebuild -scheme NetMonitor-iOS -configuration Debug build — must succeed
• Run swiftlint lint --quiet — zero errors in new/modified files
• Run swiftformat . — zero violations
• If project.yml was modified, run xcodegen generate first
• Run tests via SSH: ssh mac-mini "cd ~/Projects/NetMonitor-2.0 && git pull && swift test -c debug --no-parallel --package-path Packages/NetMonitorCore 2>&1 | tail -30"
  • If mac-mini is unreachable, run tests locally as fallback: cd Packages/NetMonitorCore && swift test --no-parallel

Step 5: Update Shared State

• If you discovered architectural patterns or gotchas, update .factory/library/architecture.md
• If you found environment issues, update .factory/library/environment.md

Example Handoff

{
  "salientSummary": "Built SurveyProject, FloorPlan, MeasurementPoint, and 8 supporting model types in NetMonitorCore/Models/Heatmap/. All types are Sendable + Codable + Identifiable. Added WiFiMeasurementEngine actor in Services/Heatmap/ with passive/active/continuous measurement modes delegating to injected WiFiInfoServiceProtocol. Wrote 42 unit tests covering serialization round-trips, IDW interpolation correctness, color mapping for all 5 visualization types, and engine delegation. All tests pass, both targets build.",
  "whatWasImplemented": "Created 6 new files: HeatmapModels.swift (SurveyProject, FloorPlan, MeasurementPoint, HeatmapVisualization, SurveyMode, WiFiBand, CalibrationPoint, WallSegment, SurveyMetadata, FloorPlanOrigin), WiFiMeasurementEngine.swift (actor with passive/active/continuous modes), HeatmapRenderer.swift (IDW p=2.0, 5 color mappings, CGImage output), SurveyFileManager.swift (.netmonsurvey bundle save/load). Added HeatmapServiceProtocol to ServiceProtocols.swift. Added ToolType.wifiHeatmap to Enums.swift.",
  "whatWasLeftUndone": "",
  "verification": {
    "commandsRun": [
      {"command": "cd Packages/NetMonitorCore && swift build -c debug", "exitCode": 0, "observation": "Build succeeded, zero warnings"},
      {"command": "xcodebuild -scheme NetMonitor-macOS -configuration Debug build 2>&1 | tail -5", "exitCode": 0, "observation": "BUILD SUCCEEDED"},
      {"command": "xcodebuild -scheme NetMonitor-iOS -configuration Debug build 2>&1 | tail -5", "exitCode": 0, "observation": "BUILD SUCCEEDED"},
      {"command": "swiftlint lint --quiet 2>&1 | grep -c 'error'", "exitCode": 0, "observation": "0 errors"},
      {"command": "cd Packages/NetMonitorCore && swift test --no-parallel 2>&1 | tail -10", "exitCode": 0, "observation": "42 tests passed, 0 failures"}
    ],
    "interactiveChecks": []
  },
  "tests": {
    "added": [
      {"file": "Packages/NetMonitorCore/Tests/NetMonitorCoreTests/HeatmapModelsTests.swift", "cases": [
        {"name": "testSurveyProjectRoundTrip", "verifies": "Full SurveyProject serialization"},
        {"name": "testMeasurementPointAllFields", "verifies": "MeasurementPoint with all optional fields"},
        {"name": "testFloorPlanOriginCases", "verifies": "All FloorPlanOrigin cases round-trip"}
      ]},
      {"file": "Packages/NetMonitorCore/Tests/NetMonitorCoreTests/HeatmapRendererTests.swift", "cases": [
        {"name": "testIDWSinglePoint", "verifies": "Single point produces constant output"},
        {"name": "testIDWGradient", "verifies": "Two points produce correct gradient"},
        {"name": "testColorMappingSignalStrength", "verifies": "RSSI → green/yellow/red mapping"}
      ]}
    ]
  },
  "discoveredIssues": []
}

When to Return to Orchestrator

• Feature requires UI code (Views, ViewModels) — wrong worker type
• Platform-specific service implementation needed (CoreWLAN, NEHotspotNetwork, ARKit)
• project.yml changes that affect target configuration beyond simple additions
• Existing test infrastructure is broken and cannot be fixed
• Feature depends on code that doesn't exist yet (check preconditions)