TDD — Swift

Swift-specific TDD conventions for PurePoint.app (macOS desktop application).

Test Framework

• XCTest (built-in)
• Cmd+U in Xcode or swift test from command line
• Test targets in Xcode project

Test Organization

• Test files in the test target, mirroring source structure
• Name test classes as {ClassName}Tests
• Name test methods as test_{given}_{should} or testGiven{Situation}Should{Behavior}

Assert Format (Swift Adaptation)

func testGivenNewProjectShouldShowInSidebar() {
    // given
    let project = Project(path: "/tmp/test-repo")
    let sidebar = SidebarView()

    // when
    sidebar.addProject(project)

    // then
    XCTAssertEqual(sidebar.projects.count, 1)
    XCTAssertEqual(sidebar.projects.first?.path, "/tmp/test-repo")
}

SwiftTerm Testing

• Terminal views are hard to unit test — focus on the data layer
• Test DaemonClient JSON serialization/deserialization separately from UI
• Mock the Unix socket connection for client tests
• Use XCTest expectations for async IPC operations

UI Testing

• Use XCUITest for critical user journeys only (expensive to maintain)
• Prefer testing view models and controllers over views directly
• Mock WorkspaceService protocol and DaemonClient in view model tests

Daemon Client Testing

• Test NDJSON request/response serialization (encode request → JSON line, decode response → typed struct)
• Test attach-mode streaming (partial reads, multiple messages per chunk, connection drop mid-stream)
• Test error paths (connection lost, timeout, JSON parse error). No external dependencies — the protocol is plain JSON over Unix socket