diff --git a/internal/models/types_test.go b/internal/models/types_test.go
new file mode 100644
index 0000000..189682b
--- /dev/null
+++ b/internal/models/types_test.go
@@ -0,0 +1,93 @@
+package models
+
+import (
+	"testing"
+)
+
+func TestArchiveTypeConstants(t *testing.T) {
+	tests := []struct {
+		name     string
+		archType ArchiveType
+		expected string
+	}{
+		{"ZIP type", ZIP, "ZIP"},
+		{"TARGZ type", TARGZ, "TAR.GZ"},
+		{"TAR type", TAR, "TAR"},
+		{"GZIP type", GZIP, "GZIP"},
+		{"AUTO type", AUTO, "AUTO"},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if string(tt.archType) != tt.expected {
+				t.Errorf("ArchiveType = %q; want %q", tt.archType, tt.expected)
+			}
+		})
+	}
+}
+
+func TestCompressConfigValidation(t *testing.T) {
+	config := &CompressConfig{
+		SourcePath:       "/test/path",
+		OutputPath:       "/test/output.zip",
+		ArchiveType:      ZIP,
+		ExcludePaths:     []string{"*.log"},
+		IncludePaths:     []string{"*.go"},
+		VerifyIntegrity:  true,
+		CompressionLevel: 5,
+	}
+
+	if config.SourcePath != "/test/path" {
+		t.Errorf("SourcePath = %q; want %q", config.SourcePath, "/test/path")
+	}
+	if config.ArchiveType != ZIP {
+		t.Errorf("ArchiveType = %q; want %q", config.ArchiveType, ZIP)
+	}
+	if config.CompressionLevel != 5 {
+		t.Errorf("CompressionLevel = %d; want %d", config.CompressionLevel, 5)
+	}
+}
+
+func TestExtractConfigValidation(t *testing.T) {
+	config := &ExtractConfig{
+		ArchivePath:   "/test/archive.zip",
+		DestPath:      "/test/dest",
+		ArchiveType:   ZIP,
+		OverwriteAll:  true,
+		PreservePerms: true,
+	}
+
+	if config.ArchivePath != "/test/archive.zip" {
+		t.Errorf("ArchivePath = %q; want %q", config.ArchivePath, "/test/archive.zip")
+	}
+	if !config.OverwriteAll {
+		t.Error("OverwriteAll should be true")
+	}
+	if !config.PreservePerms {
+		t.Error("PreservePerms should be true")
+	}
+}
+
+func TestArchiveInfo(t *testing.T) {
+	info := &ArchiveInfo{
+		Type:             ZIP,
+		FileCount:        10,
+		TotalSize:        1024000,
+		CompressedSize:   512000,
+		CompressionRatio: 50.0,
+		Files: []FileInfo{
+			{Name: "test.txt", Size: 1024, IsDir: false, ModTime: "2024-01-01"},
+		},
+		Checksum: "abc123",
+	}
+
+	if info.FileCount != 10 {
+		t.Errorf("FileCount = %d; want %d", info.FileCount, 10)
+	}
+	if info.CompressionRatio != 50.0 {
+		t.Errorf("CompressionRatio = %f; want %f", info.CompressionRatio, 50.0)
+	}
+	if len(info.Files) != 1 {
+		t.Errorf("Files length = %d; want %d", len(info.Files), 1)
+	}
+}