diff --git a/utils/testutils.go b/utils/testutils.go
new file mode 100644
index 0000000..0cf2ce1
--- /dev/null
+++ b/utils/testutils.go
@@ -0,0 +1,34 @@
+package utils
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+
+	"go.viam.com/test"
+)
+
+// MockViamDirs replaces utils.ViamDirs entries with t.TempDir for duration of test.
+func MockViamDirs(t *testing.T) {
+	t.Helper()
+	old := ViamDirs
+	t.Cleanup(func() {
+		ViamDirs = old
+	})
+	td := t.TempDir()
+	ViamDirs = map[string]string{
+		"viam": td,
+	}
+	for _, subdir := range []string{"bin", "cache", "tmp", "etc"} {
+		ViamDirs[subdir] = filepath.Join(td, subdir)
+		err := os.Mkdir(ViamDirs[subdir], 0o750)
+		test.That(t, err, test.ShouldBeNil)
+	}
+}
+
+// Touch is equivalent to unix touch; creates an empty file at path.
+func Touch(t *testing.T, path string) {
+	f, err := os.Create(path) //nolint:gosec
+	test.That(t, err, test.ShouldBeNil)
+	f.Close() //nolint:gosec,errcheck
+}
diff --git a/utils/utils_test.go b/utils/utils_test.go
new file mode 100644
index 0000000..f813e75
--- /dev/null
+++ b/utils/utils_test.go
@@ -0,0 +1,96 @@
+package utils
+
+import (
+	"os/exec"
+	"path/filepath"
+	"testing"
+
+	"go.viam.com/test"
+)
+
+func TestDecompressFile(t *testing.T) {
+	MockViamDirs(t)
+	td := t.TempDir()
+	if _, err := exec.LookPath("xz"); err != nil {
+		t.Skip("no xz command")
+	}
+	orig := filepath.Join(td, "plaintext")
+
+	// compress an empty file
+	Touch(t, orig)
+	_, err := exec.Command("xz", orig).Output()
+	test.That(t, err, test.ShouldBeNil)
+
+	// decompress
+	path, err := DecompressFile(orig + ".xz")
+	test.That(t, err, test.ShouldBeNil)
+	test.That(t, path, test.ShouldResemble, filepath.Join(ViamDirs["cache"], "plaintext"))
+}
+
+func TestGetFileSum(t *testing.T) {
+	td := t.TempDir()
+	path := filepath.Join(td, "checkme")
+
+	Touch(t, path)
+
+	_, err := GetFileSum(path)
+	test.That(t, err, test.ShouldBeNil)
+}
+
+func TestCheckIfSame(t *testing.T) {
+	td := t.TempDir()
+
+	path1 := filepath.Join(td, "path1")
+	path2 := filepath.Join(td, "path2")
+	Touch(t, path1)
+	Touch(t, path2)
+
+	link := filepath.Join(td, "link")
+	test.That(t, ForceSymlink(path1, link), test.ShouldBeNil)
+
+	check := func(path1, path2 string, expected bool) {
+		same, err := CheckIfSame(path1, path2)
+		test.That(t, err, test.ShouldBeNil)
+		test.That(t, same == expected, test.ShouldBeTrue)
+	}
+
+	check(path1, path1, true)
+	check(path1, path2, false)
+	check(link, link, true)
+	check(link, path1, true)
+	check(link, path2, false)
+}
+
+func TestForceSymlink(t *testing.T) {
+	td := t.TempDir()
+	path := filepath.Join(td, "link")
+	target := filepath.Join(td, "target")
+
+	// test initial case
+	err := ForceSymlink(target, path)
+	test.That(t, err, test.ShouldBeNil)
+
+	// test already-exists case
+	err = ForceSymlink(target, path)
+	test.That(t, err, test.ShouldBeNil)
+}
+
+func TestWriteFileIfNew(t *testing.T) {
+	contents := []byte("hello")
+	path := filepath.Join(t.TempDir(), "writeme")
+
+	// write new
+	written, err := WriteFileIfNew(path, contents)
+	test.That(t, err, test.ShouldBeNil)
+	test.That(t, written, test.ShouldBeTrue)
+
+	// unchanged
+	written, err = WriteFileIfNew(path, contents)
+	test.That(t, err, test.ShouldBeNil)
+	test.That(t, written, test.ShouldBeFalse)
+
+	// changed
+	written, err = WriteFileIfNew(path, []byte("other contents"))
+	test.That(t, err, test.ShouldBeNil)
+	test.That(t, written, test.ShouldBeTrue)
+}