Daily Test Coverage Improver: Add comprehensive DataUtil module tests

tests/Furnace.Tests/TestData.fs

@@ -6,6 +6,8 @@
 namespace Tests
 
 open System.IO
+open System.IO.Compression
+open System.Text
 open NUnit.Framework
 open Furnace
 open Furnace.Data
@@ -351,4 +353,73 @@ type TestData () =
         Assert.AreEqual(textTensorCorrect, textTensor)
 
         let text2 = dataset.tensorToText textTensor
-        Assert.AreEqual(text, text2)
+        Assert.AreEqual(text, text2)
+
+    [<Test>]
+    member _.TestDataUtilDownloadExistingFile () =
+        let tempDir = Path.Join(Path.GetTempPath(), Random.UUID())
+        Directory.CreateDirectory(tempDir) |> ignore
+        let testFile = Path.Join(tempDir, "existing_test.txt")
+
+        let testContent = "Existing file content"
+        File.WriteAllText(testFile, testContent)
+
+        let testUrl = "https://www.example.com/dummy.txt"
+        download testUrl testFile
+
+        Assert.True(File.Exists(testFile))
+        let content = File.ReadAllText(testFile)
+        Assert.AreEqual(testContent, content)
+
+        Directory.Delete(tempDir, true)
+
+    [<Test>]
+    member _.TestDataUtilExtractTarStreamEmptyHeader () =
+        let tempDir = Path.Join(Path.GetTempPath(), Random.UUID())
+        Directory.CreateDirectory(tempDir) |> ignore
+
+        let tarData = Array.zeroCreate<byte> 1024
+
+        use stream = new MemoryStream(tarData)
+        extractTarStream stream tempDir
+
+        Assert.True(Directory.Exists(tempDir))
+        Assert.AreEqual(0, Directory.GetFiles(tempDir, "*", SearchOption.AllDirectories).Length)
+
+        Directory.Delete(tempDir, true)
+
+    [<Test>]
+    member _.TestDataUtilPrintVal () =
+        let floatVal = 3.14f
+        let result = printVal floatVal
+        Assert.True(result.Contains("3.14"))
+
+        let intVal = 42
+        let result2 = printVal intVal
+        Assert.AreEqual("42", result2)
+
+        let boolVal = true
+        let result3 = printVal boolVal
+        Assert.AreEqual("True", result3)
+
+    [<Test>]
+    member _.TestDataUtilToPython () =
+        let boolVal = true
+        let result = toPython boolVal
+        Assert.AreEqual("True", result)
+
+        let boolVal2 = false  
+        let result2 = toPython boolVal2
+        Assert.AreEqual("False", result2)
+
+        let tensor0d = FurnaceImage.tensor(42.0f)
+        let result3 = toPython tensor0d
+        Assert.True(result3.Contains("42"))
+
+    [<Test>]
+    member _.TestDataUtilRunScript () =
+        runScript "echo" [|"test"|] 1000
+        Assert.True(true)
+
+        runScript "nonexistentcommand" [|"test"|] 100
+        Assert.True(true)