Parser: Support relative paths for --volume (apple#1013)

Author: dcantah

Sources/ContainerClient/Parser.swift

@@ -487,8 +487,8 @@ public struct Parser {
             let src = String(parts[0])
             let dst = String(parts[1])
 
-            // Check if it's an absolute directory path first
-            guard src.hasPrefix("/") else {
+            // Check if it's a filesystem path
+            guard src.contains("/") else {
                 // Named volume - validate name syntax only
                 guard VolumeStorage.isValidVolumeName(src) else {
                     throw ContainerizationError(.invalidArgument, message: "invalid volume name '\(src)': must match \(VolumeStorage.volumeNamePattern)")

Tests/ContainerClientTests/ParserTest.swift

@@ -382,6 +382,61 @@ struct ParserTest {
         }
     }
 
+    @Test
+    func testVolumeRelativePath() throws {
+        let tempDir = FileManager.default.temporaryDirectory.appendingPathComponent("test-volume-rel-\(UUID().uuidString)")
+        try FileManager.default.createDirectory(at: tempDir, withIntermediateDirectories: true)
+        defer {
+            try? FileManager.default.removeItem(at: tempDir)
+        }
+
+        let originalDir = FileManager.default.currentDirectoryPath
+        FileManager.default.changeCurrentDirectoryPath(tempDir.path)
+        defer {
+            FileManager.default.changeCurrentDirectoryPath(originalDir)
+        }
+
+        let result = try Parser.volume("./:/foo")
+
+        switch result {
+        case .filesystem(let fs):
+            let expectedPath = URL(filePath: ".").absoluteURL.path
+            // Normalize trailing slashes for comparison
+            #expect(fs.source.trimmingCharacters(in: CharacterSet(charactersIn: "/")) == expectedPath.trimmingCharacters(in: CharacterSet(charactersIn: "/")))
+            #expect(fs.destination == "/foo")
+        case .volume:
+            #expect(Bool(false), "Expected filesystem mount, got volume")
+        }
+    }
+
+    @Test
+    func testVolumeRelativePathNested() throws {
+        let tempDir = FileManager.default.temporaryDirectory.appendingPathComponent("test-volume-rel-nested-\(UUID().uuidString)")
+        let nestedDir = tempDir.appendingPathComponent("subdir")
+        try FileManager.default.createDirectory(at: nestedDir, withIntermediateDirectories: true)
+        defer {
+            try? FileManager.default.removeItem(at: tempDir)
+        }
+
+        let originalDir = FileManager.default.currentDirectoryPath
+        FileManager.default.changeCurrentDirectoryPath(tempDir.path)
+        defer {
+            FileManager.default.changeCurrentDirectoryPath(originalDir)
+        }
+
+        let result = try Parser.volume("./subdir:/foo")
+
+        switch result {
+        case .filesystem(let fs):
+            let expectedPath = URL(filePath: "./subdir").absoluteURL.path
+            // Normalize trailing slashes for comparison
+            #expect(fs.source.trimmingCharacters(in: CharacterSet(charactersIn: "/")) == expectedPath.trimmingCharacters(in: CharacterSet(charactersIn: "/")))
+            #expect(fs.destination == "/foo")
+        case .volume:
+            #expect(Bool(false), "Expected filesystem mount, got volume")
+        }
+    }
+
     @Test
     func testIsValidDomainNameOk() throws {
         let names = [