Run tests in CI on Linux

Adds a Gitea Actions workflow running swift test in a swift:6.2 container.

The kit did not build without Apple frameworks, so the two files that need
them are wrapped in #if canImport, and the SwiftUI app target is added to
Package.swift only on macOS. Neither can exist in a Linux container.

This costs no coverage: all 43 tests are about file format and none touch
the Contacts or EventKit readers. The integration those readers represent
remains verifiable only on a Mac.

Co-Authored-By: Claude Opus 5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01C5X1tYo9oxAfvoiFMh1QQr

.gitea/workflows/test.yml

@@ -0,0 +1,28 @@
+name: Tests
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    container:
+      # Pinned rather than tracking latest: a toolchain bump should be a commit,
+      # not a surprise on an unrelated push.
+      image: swift:6.2
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Toolchain
+        run: swift --version
+
+      # This only covers IPodSyncKit — the format logic, which is where every
+      # test lives. The Contacts and EventKit readers are compiled out on Linux
+      # and can only be exercised on a Mac.
+      - name: Build
+        run: swift build --build-tests
+
+      - name: Test
+        run: swift test

Package.swift

@@ -1,18 +1,29 @@
 // swift-tools-version: 6.2
 import PackageDescription
 
+// The kit and its tests are Foundation-only and build anywhere. The app target
+// is SwiftUI driving Contacts and EventKit, none of which exist on Linux, so it
+// is added only on macOS — otherwise `swift test` in a Linux container would
+// fail trying to build an executable it can never link.
+var targets: [Target] = [
+    .target(name: "IPodSyncKit"),
+    .testTarget(
+        name: "IPodSyncKitTests",
+        dependencies: ["IPodSyncKit"]
+    ),
+]
+
+#if os(macOS)
+targets.append(
+    .executableTarget(
+        name: "iPodSyncApp",
+        dependencies: ["IPodSyncKit"]
+    )
+)
+#endif
+
 let package = Package(
     name: "iPodContactsAndCalendarSync",
     platforms: [.macOS(.v14)],
-    targets: [
-        .target(name: "IPodSyncKit"),
-        .executableTarget(
-            name: "iPodSyncApp",
-            dependencies: ["IPodSyncKit"]
-        ),
-        .testTarget(
-            name: "IPodSyncKitTests",
-            dependencies: ["IPodSyncKit"]
-        ),
-    ]
+    targets: targets
 )

README.md

@@ -92,6 +92,18 @@ swift test                       # run the test suite
 
 `Package.swift` opens directly in Xcode if you'd rather work there.
 
+### CI
+
+`.gitea/workflows/test.yml` runs `swift test` in a `swift:6.2` container on
+every push and pull request.
+
+It covers `IPodSyncKit` only. The Contacts and EventKit readers are compiled
+out on Linux via `#if canImport(…)`, and the SwiftUI app target is excluded
+from `Package.swift` on non-Apple platforms — neither can exist in a Linux
+container. No test coverage is lost by this: every test is about file format,
+and none of them touch the readers. What CI cannot tell you is whether reading
+from the real Contacts and Calendars databases still works; that needs a Mac.
+
 The bundle is **ad-hoc signed**, which is not the same as signed for
 distribution. Ad-hoc signing is required — Contacts and Calendars identify an
 app by its code signature, and an unsigned bundle gets denied or re-prompts

Sources/IPodSyncKit/CalendarReader.swift

@@ -1,3 +1,6 @@
+// EventKit has no Linux equivalent. See the note in ContactsReader.swift.
+#if canImport(EventKit)
+
 import EventKit
 import Foundation
 
@@ -125,3 +128,5 @@ public actor CalendarReader {
         return "\(String(safe).prefix(64))-\(stamp)@ipod-sync"
     }
 }
+
+#endif

Sources/IPodSyncKit/ContactsReader.swift

@@ -1,3 +1,8 @@
+// Contacts has no Linux equivalent. Guarding the whole file lets the kit
+// build in a Linux container so the format logic can be tested there;
+// nothing in this file is exercised by the test suite.
+#if canImport(Contacts)
+
 import Contacts
 import Foundation
 
@@ -131,3 +136,5 @@ public actor ContactsReader {
         }
     }
 }
+
+#endif