Fix relative path mount tests (#1168)

`make test` occasionally fails with:
```
✘ Test testHostDNSReinitialize() recorded an issue at HostDNSResolverTest.swift:132:45: Expectation failed: (error →    
  Error Domain=NSPOSIXErrorDomain Code=2 "No such file or directory") as? (ContainerizationError → NSError)
  ✘ Suite HostDNSResolverTest failed after 0.119 seconds with 1 issue.
```

Author: dkovba

Sources/Services/ContainerAPIService/Client/Parser.swift

@@ -316,18 +316,18 @@ public struct Parser {
         return result
     }
 
-    public static func mounts(_ rawMounts: [String]) throws -> [VolumeOrFilesystem] {
+    public static func mounts(_ rawMounts: [String], relativeTo basePath: URL? = nil) throws -> [VolumeOrFilesystem] {
         var mounts: [VolumeOrFilesystem] = []
         let rawMounts = rawMounts.dedupe()
         for mount in rawMounts {
-            let m = try Parser.mount(mount)
+            let m = try Parser.mount(mount, relativeTo: basePath)
             try validateMount(m)
             mounts.append(m)
         }
         return mounts
     }
 
-    public static func mount(_ mount: String) throws -> VolumeOrFilesystem {
+    public static func mount(_ mount: String, relativeTo basePath: URL? = nil) throws -> VolumeOrFilesystem {
         let parts = mount.split(separator: ",")
         if parts.count == 0 {
             throw ContainerizationError(.invalidArgument, message: "invalid mount format: \(mount)")
@@ -407,7 +407,7 @@ public struct Parser {
                 switch type {
                 case "virtiofs", "bind":
                     // For bind mounts, resolve both absolute and relative paths
-                    let url = URL(filePath: val)
+                    let url = basePath?.appending(path: val).standardizedFileURL ?? URL(filePath: val)
                     let absolutePath = url.absoluteURL.path
 
                     var isDirectory: ObjCBool = false
@@ -458,17 +458,17 @@ public struct Parser {
             ))
     }
 
-    public static func volumes(_ rawVolumes: [String]) throws -> [VolumeOrFilesystem] {
+    public static func volumes(_ rawVolumes: [String], relativeTo basePath: URL? = nil) throws -> [VolumeOrFilesystem] {
         var mounts: [VolumeOrFilesystem] = []
         for volume in rawVolumes {
-            let m = try Parser.volume(volume)
+            let m = try Parser.volume(volume, relativeTo: basePath)
             try Parser.validateMount(m)
             mounts.append(m)
         }
         return mounts
     }
 
-    public static func volume(_ volume: String) throws -> VolumeOrFilesystem {
+    public static func volume(_ volume: String, relativeTo basePath: URL? = nil) throws -> VolumeOrFilesystem {
         var vol = volume
         vol.trimLeft(char: ":")
 
@@ -508,7 +508,7 @@ public struct Parser {
                         options: options
                     ))
             }
-            let url = URL(filePath: src)
+            let url = basePath?.appending(path: src).standardizedFileURL ?? URL(filePath: src)
             let absolutePath = url.absoluteURL.path
 
             var isDirectory: ObjCBool = false

Tests/ContainerAPIClientTests/ParserTest.swift

@@ -329,20 +329,6 @@ struct ParserTest {
 
     @Test
     func testRelativePaths() throws {
-        let originalDir = FileManager.default.currentDirectoryPath
-        defer {
-            FileManager.default.changeCurrentDirectoryPath(originalDir)
-        }
-
-        func realpath(_ path: String) -> String {
-            let resolved = UnsafeMutablePointer<CChar>.allocate(capacity: Int(PATH_MAX))
-            defer { resolved.deallocate() }
-            guard let result = Darwin.realpath(path, resolved) else {
-                return path
-            }
-            return String(cString: result)
-        }
-
         // Test bind mount with relative path "."
         do {
             let tempDir = FileManager.default.temporaryDirectory.appendingPathComponent("test-bind-\(UUID().uuidString)")
@@ -351,12 +337,11 @@ struct ParserTest {
                 try? FileManager.default.removeItem(at: tempDir)
             }
 
-            FileManager.default.changeCurrentDirectoryPath(tempDir.path)
-            let result = try Parser.mount("type=bind,src=.,dst=/foo")
+            let result = try Parser.mount("type=bind,src=.,dst=/foo", relativeTo: tempDir)
 
             switch result {
             case .filesystem(let fs):
-                #expect(fs.source == realpath(tempDir.path))
+                #expect(fs.source == tempDir.standardizedFileURL.path)
                 #expect(fs.destination == "/foo")
                 #expect(!fs.isVolume)
             case .volume:
@@ -372,12 +357,11 @@ struct ParserTest {
                 try? FileManager.default.removeItem(at: tempDir)
             }
 
-            FileManager.default.changeCurrentDirectoryPath(tempDir.path)
-            let result = try Parser.volume("./:/foo")
+            let result = try Parser.volume("./:/foo", relativeTo: tempDir)
 
             switch result {
             case .filesystem(let fs):
-                let expectedPath = realpath(tempDir.path)
+                let expectedPath = tempDir.standardizedFileURL.path
                 // Normalize trailing slashes for comparison
                 #expect(fs.source.trimmingCharacters(in: CharacterSet(charactersIn: "/")) == expectedPath.trimmingCharacters(in: CharacterSet(charactersIn: "/")))
                 #expect(fs.destination == "/foo")
@@ -395,12 +379,11 @@ struct ParserTest {
                 try? FileManager.default.removeItem(at: tempDir)
             }
 
-            FileManager.default.changeCurrentDirectoryPath(tempDir.path)
-            let result = try Parser.volume("./subdir:/foo")
+            let result = try Parser.volume("./subdir:/foo", relativeTo: tempDir)
 
             switch result {
             case .filesystem(let fs):
-                let expectedPath = realpath(nestedDir.path)
+                let expectedPath = nestedDir.standardizedFileURL.path
                 // Normalize trailing slashes for comparison
                 #expect(fs.source.trimmingCharacters(in: CharacterSet(charactersIn: "/")) == expectedPath.trimmingCharacters(in: CharacterSet(charactersIn: "/")))
                 #expect(fs.destination == "/foo")