Tests: Fix relative path mount tests (apple#1028)

The tests are run in parallel on CI, and were split into three tests.
They change the cwd, so it's kind of a gamble whether some of them pass.
This just moves all the logic into one test mostly.

Author: dcantah

Tests/ContainerAPIClientTests/ParserTest.swift

@@ -280,30 +280,85 @@ struct ParserTest {
     }
 
     @Test
-    func testMountBindRelativePath() throws {
-
-        let tempDir = FileManager.default.temporaryDirectory.appendingPathComponent("test-bind-\(UUID().uuidString)")
-        try FileManager.default.createDirectory(at: tempDir, withIntermediateDirectories: true)
-        defer {
-            try? FileManager.default.removeItem(at: tempDir)
-        }
-
+    func testRelativePaths() throws {
         let originalDir = FileManager.default.currentDirectoryPath
-        FileManager.default.changeCurrentDirectoryPath(tempDir.path)
         defer {
             FileManager.default.changeCurrentDirectoryPath(originalDir)
         }
 
-        let result = try Parser.mount("type=bind,src=.,dst=/foo")
+        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)
+        }
 
-        switch result {
-        case .filesystem(let fs):
-            let expectedPath = URL(filePath: ".").absoluteURL.path
-            #expect(fs.source == expectedPath)
-            #expect(fs.destination == "/foo")
-            #expect(!fs.isVolume)
-        case .volume:
-            #expect(Bool(false), "Expected filesystem mount, got volume")
+        // Test bind mount with relative path "."
+        do {
+            let tempDir = FileManager.default.temporaryDirectory.appendingPathComponent("test-bind-\(UUID().uuidString)")
+            try FileManager.default.createDirectory(at: tempDir, withIntermediateDirectories: true)
+            defer {
+                try? FileManager.default.removeItem(at: tempDir)
+            }
+
+            FileManager.default.changeCurrentDirectoryPath(tempDir.path)
+            let result = try Parser.mount("type=bind,src=.,dst=/foo")
+
+            switch result {
+            case .filesystem(let fs):
+                #expect(fs.source == realpath(tempDir.path))
+                #expect(fs.destination == "/foo")
+                #expect(!fs.isVolume)
+            case .volume:
+                #expect(Bool(false), "Expected filesystem mount, got volume")
+            }
+        }
+
+        // Test volume with relative path "./"
+        do {
+            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)
+            }
+
+            FileManager.default.changeCurrentDirectoryPath(tempDir.path)
+            let result = try Parser.volume("./:/foo")
+
+            switch result {
+            case .filesystem(let fs):
+                let expectedPath = realpath(tempDir.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 volume with nested relative path "./subdir"
+        do {
+            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)
+            }
+
+            FileManager.default.changeCurrentDirectoryPath(tempDir.path)
+            let result = try Parser.volume("./subdir:/foo")
+
+            switch result {
+            case .filesystem(let fs):
+                let expectedPath = realpath(nestedDir.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")
+            }
         }
     }
 
@@ -382,61 +437,6 @@ 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 = [