1 files changed, 166 insertions, 0 deletions
diff --git a/internal/testutil/testutil_test.go b/internal/testutil/testutil_test.go
new file mode 100644
index 0000000..2a5a2d6
--- /dev/null
+++ b/internal/testutil/testutil_test.go
@@ -0,0 +1,166 @@
+package testutil
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+)
+
+func TestTempFile(t *testing.T) {
+	content := "test content\nline 2"
+	path := TempFile(t, content)
+	
+	// Check file exists
+	if _, err := os.Stat(path); os.IsNotExist(err) {
+		t.Errorf("temp file does not exist: %s", path)
+	}
+	
+	// Check content
+	actual, err := os.ReadFile(path)
+	if err != nil {
+		t.Fatalf("failed to read temp file: %v", err)
+	}
+	
+	if string(actual) != content {
+		t.Errorf("content mismatch: expected %q, got %q", content, string(actual))
+	}
+}
+
+func TestTempDir(t *testing.T) {
+	dir := TempDir(t)
+	
+	// Check directory exists
+	info, err := os.Stat(dir)
+	if os.IsNotExist(err) {
+		t.Errorf("temp dir does not exist: %s", dir)
+	}
+	
+	if !info.IsDir() {
+		t.Errorf("path is not a directory: %s", dir)
+	}
+}
+
+func TestCreateFileTree(t *testing.T) {
+	dir := TempDir(t)
+	
+	files := map[string]string{
+		"file1.txt":           "content 1",
+		"subdir/file2.txt":    "content 2",
+		"subdir/deep/f3.txt":  "content 3",
+	}
+	
+	CreateFileTree(t, dir, files)
+	
+	// Verify all files exist with correct content
+	for path, expectedContent := range files {
+		fullPath := filepath.Join(dir, path)
+		actual, err := os.ReadFile(fullPath)
+		if err != nil {
+			t.Errorf("failed to read %s: %v", path, err)
+			continue
+		}
+		
+		if string(actual) != expectedContent {
+			t.Errorf("content mismatch for %s: expected %q, got %q", 
+				path, expectedContent, string(actual))
+		}
+	}
+}
+
+func TestAssertions(t *testing.T) {
+	// Test AssertError with real testing.T
+	t.Run("AssertError", func(t *testing.T) {
+		// This should pass
+		err := fmt.Errorf("file not exist")
+		AssertError(t, err, "not exist")
+		
+		// We can't easily test the failure case without causing the test to fail
+	})
+	
+	// Test AssertNoError with real testing.T
+	t.Run("AssertNoError", func(t *testing.T) {
+		// This should pass
+		AssertNoError(t, nil)
+		
+		// We can't easily test the failure case without causing the test to fail
+	})
+	
+	// Test AssertEqual with real testing.T
+	t.Run("AssertEqual", func(t *testing.T) {
+		// This should pass
+		AssertEqual(t, 42, 42)
+		AssertEqual(t, "hello", "hello")
+		
+		// We can't easily test the failure case without causing the test to fail
+	})
+	
+	// Test AssertContains with real testing.T
+	t.Run("AssertContains", func(t *testing.T) {
+		// This should pass
+		AssertContains(t, "hello world", "world")
+		AssertNotContains(t, "hello world", "xyz")
+		
+		// We can't easily test the failure case without causing the test to fail
+	})
+}
+
+func TestGenerateTestData(t *testing.T) {
+	data := GenerateTestData(3, 10)
+	lines := strings.Split(strings.TrimSpace(data), "\n")
+	
+	if len(lines) != 3 {
+		t.Errorf("expected 3 lines, got %d", len(lines))
+	}
+	
+	for i, line := range lines {
+		expectedPrefix := fmt.Sprintf("%d: ", i+1)
+		if !strings.HasPrefix(line, expectedPrefix) {
+			t.Errorf("line %d doesn't have expected prefix: %s", i, line)
+		}
+		
+		// Check line length (prefix + x's + newline was stripped)
+		if len(line) != len(expectedPrefix)+9 {
+			t.Errorf("line %d has incorrect length: %d", i, len(line))
+		}
+	}
+}
+
+func TestGenerateLogLines(t *testing.T) {
+	lines := GenerateLogLines(10)
+	
+	if len(lines) != 10 {
+		t.Errorf("expected 10 lines, got %d", len(lines))
+	}
+	
+	for i, line := range lines {
+		// Check basic log format
+		if !strings.Contains(line, "2024-01-15") {
+			t.Errorf("line %d missing date: %s", i, line)
+		}
+		
+		// Check log level
+		hasLevel := false
+		for _, level := range []string{"INFO", "WARN", "ERROR", "DEBUG"} {
+			if strings.Contains(line, "["+level+"]") {
+				hasLevel = true
+				break
+			}
+		}
+		if !hasLevel {
+			t.Errorf("line %d missing log level: %s", i, line)
+		}
+	}
+}
+
+// Test CaptureOutput
+func TestCaptureOutput(t *testing.T) {
+	output := CaptureOutput(t, func() {
+		fmt.Print("test output")
+	})
+	
+	if output != "test output" {
+		t.Errorf("expected 'test output', got %q", output)
+	}
+}
+\ No newline at end of file