diff --git a/internal/shutils/decoder/decoder_test.go b/internal/shutils/decoder/decoder_test.go
new file mode 100644
index 0000000..1fbcc75
--- /dev/null
+++ b/internal/shutils/decoder/decoder_test.go
@@ -0,0 +1,206 @@
+package decoder_test
+
+import (
+	"bytes"
+	"context"
+	"errors"
+	"os"
+	"reflect"
+	"strings"
+	"testing"
+
+	"go.arsenm.dev/lure/distro"
+	"go.arsenm.dev/lure/internal/shutils/decoder"
+	"mvdan.cc/sh/v3/interp"
+	"mvdan.cc/sh/v3/syntax"
+)
+
+type BuildVars struct {
+	Name          string   `sh:"name,required"`
+	Version       string   `sh:"version,required"`
+	Release       int      `sh:"release,required"`
+	Epoch         uint     `sh:"epoch"`
+	Description   string   `sh:"desc"`
+	Homepage      string   `sh:"homepage"`
+	Maintainer    string   `sh:"maintainer"`
+	Architectures []string `sh:"architectures"`
+	Licenses      []string `sh:"license"`
+	Provides      []string `sh:"provides"`
+	Conflicts     []string `sh:"conflicts"`
+	Depends       []string `sh:"deps"`
+	BuildDepends  []string `sh:"build_deps"`
+	Replaces      []string `sh:"replaces"`
+}
+
+const testScript = `
+	name='test'
+	version='0.0.1'
+	release=1
+	epoch=2
+	desc="Test package"
+	homepage='https://lure.arsenm.dev'
+	maintainer='Arsen Musayelyan <arsen@arsenm.dev>'
+	architectures=('arm64' 'amd64')
+	license=('GPL-3.0-or-later')
+	provides=('test')
+	conflicts=('test')
+	replaces=('test-old')
+	replaces_test_os=('test-legacy')
+
+	deps=('sudo')
+
+	build_deps=('golang')
+	build_deps_arch=('go')
+
+	test() {
+		echo "Test"
+	}
+
+	package() {
+		install-binary test
+	}
+`
+
+var osRelease = &distro.OSRelease{
+	ID:   "test_os",
+	Like: []string{"arch"},
+}
+
+func TestDecodeVars(t *testing.T) {
+	ctx := context.Background()
+
+	fl, err := syntax.NewParser().Parse(strings.NewReader(testScript), "lure.sh")
+	if err != nil {
+		t.Fatalf("Expected no error, got %s", err)
+	}
+
+	runner, err := interp.New()
+	if err != nil {
+		t.Fatalf("Expected no error, got %s", err)
+	}
+
+	err = runner.Run(ctx, fl)
+	if err != nil {
+		t.Fatalf("Expected no error, got %s", err)
+	}
+
+	dec := decoder.New(osRelease, runner)
+
+	var bv BuildVars
+	err = dec.DecodeVars(&bv)
+	if err != nil {
+		t.Fatalf("Expected no error, got %s", err)
+	}
+
+	expected := BuildVars{
+		Name:          "test",
+		Version:       "0.0.1",
+		Release:       1,
+		Epoch:         2,
+		Description:   "Test package",
+		Homepage:      "https://lure.arsenm.dev",
+		Maintainer:    "Arsen Musayelyan <arsen@arsenm.dev>",
+		Architectures: []string{"arm64", "amd64"},
+		Licenses:      []string{"GPL-3.0-or-later"},
+		Provides:      []string{"test"},
+		Conflicts:     []string{"test"},
+		Replaces:      []string{"test-legacy"},
+		Depends:       []string{"sudo"},
+		BuildDepends:  []string{"go"},
+	}
+
+	if !reflect.DeepEqual(bv, expected) {
+		t.Errorf("Expected %v, got %v", expected, bv)
+	}
+}
+
+func TestDecodeVarsMissing(t *testing.T) {
+	ctx := context.Background()
+
+	const testScript = `
+		name='test'
+		epoch=2
+		desc="Test package"
+		homepage='https://lure.arsenm.dev'
+		maintainer='Arsen Musayelyan <arsen@arsenm.dev>'
+		architectures=('arm64' 'amd64')
+		license=('GPL-3.0-or-later')
+		provides=('test')
+		conflicts=('test')
+		replaces=('test-old')
+		replaces_test_os=('test-legacy')
+
+		deps=('sudo')
+
+		build_deps=('golang')
+		build_deps_arch=('go')
+
+		test() {
+			echo "Test"
+		}
+
+		package() {
+			install-binary test
+		}
+	`
+
+	fl, err := syntax.NewParser().Parse(strings.NewReader(testScript), "lure.sh")
+	if err != nil {
+		t.Fatalf("Expected no error, got %s", err)
+	}
+
+	runner, err := interp.New()
+	if err != nil {
+		t.Fatalf("Expected no error, got %s", err)
+	}
+
+	err = runner.Run(ctx, fl)
+	if err != nil {
+		t.Fatalf("Expected no error, got %s", err)
+	}
+
+	dec := decoder.New(osRelease, runner)
+
+	var bv BuildVars
+	err = dec.DecodeVars(&bv)
+
+	var notFoundErr decoder.VarNotFoundError
+	if !errors.As(err, &notFoundErr) {
+		t.Fatalf("Expected VarNotFoundError, got %T %v", err, err)
+	}
+}
+
+func TestGetFunc(t *testing.T) {
+	ctx := context.Background()
+
+	fl, err := syntax.NewParser().Parse(strings.NewReader(testScript), "lure.sh")
+	if err != nil {
+		t.Fatalf("Expected no error, got %s", err)
+	}
+
+	runner, err := interp.New()
+	if err != nil {
+		t.Fatalf("Expected no error, got %s", err)
+	}
+
+	err = runner.Run(ctx, fl)
+	if err != nil {
+		t.Fatalf("Expected no error, got %s", err)
+	}
+
+	dec := decoder.New(osRelease, runner)
+	fn, ok := dec.GetFunc("test")
+	if !ok {
+		t.Fatalf("Expected test() function to exist")
+	}
+
+	buf := &bytes.Buffer{}
+	err = fn(ctx, interp.StdIO(os.Stdin, buf, buf))
+	if err != nil {
+		t.Fatalf("Expected no error, got %s", err)
+	}
+
+	if buf.String() != "Test\n" {
+		t.Fatalf(`Expected "Test\n", got %#v`, buf.String())
+	}
+}
diff --git a/internal/shutils/exec_test.go b/internal/shutils/exec_test.go
new file mode 100644
index 0000000..e7597b2
--- /dev/null
+++ b/internal/shutils/exec_test.go
@@ -0,0 +1,106 @@
+package shutils_test
+
+import (
+	"context"
+	"strings"
+	"testing"
+
+	"go.arsenm.dev/lure/distro"
+	"go.arsenm.dev/lure/internal/shutils"
+	"go.arsenm.dev/lure/internal/shutils/decoder"
+	"mvdan.cc/sh/v3/interp"
+	"mvdan.cc/sh/v3/syntax"
+)
+
+const testScript = `
+	name='test'
+	version='0.0.1'
+	release=1
+	epoch=2
+	desc="Test package"
+	homepage='https://lure.arsenm.dev'
+	maintainer='Arsen Musayelyan <arsen@arsenm.dev>'
+	architectures=('arm64' 'amd64')
+	license=('GPL-3.0-or-later')
+	provides=('test')
+	conflicts=('test')
+	replaces=('test-old')
+	replaces_test_os=('test-legacy')
+
+	deps=('sudo')
+
+	build_deps=('golang')
+	build_deps_arch=('go')
+
+	test() {
+		test-cmd "Hello, World"
+		test-fb
+	}
+
+	package() {
+		install-binary test
+	}
+`
+
+var osRelease = &distro.OSRelease{
+	ID:   "test_os",
+	Like: []string{"arch"},
+}
+
+func TestExecFuncs(t *testing.T) {
+	ctx := context.Background()
+
+	fl, err := syntax.NewParser().Parse(strings.NewReader(testScript), "lure.sh")
+	if err != nil {
+		t.Fatalf("Expected no error, got %s", err)
+	}
+
+	runner, err := interp.New()
+	if err != nil {
+		t.Fatalf("Expected no error, got %s", err)
+	}
+
+	err = runner.Run(ctx, fl)
+	if err != nil {
+		t.Fatalf("Expected no error, got %s", err)
+	}
+
+	dec := decoder.New(osRelease, runner)
+	fn, ok := dec.GetFunc("test")
+	if !ok {
+		t.Fatalf("Expected test() function to exist")
+	}
+
+	eh := shutils.ExecFuncs{
+		"test-cmd": func(hc interp.HandlerContext, name string, args []string) error {
+			if name != "test-cmd" {
+				t.Errorf("Expected name to be 'test-cmd', got '%s'", name)
+			}
+
+			if len(args) < 1 {
+				t.Fatalf("Expected at least one argument, got %d", len(args))
+			}
+
+			if args[0] != "Hello, World" {
+				t.Errorf("Expected first argument to be 'Hello, World', got '%s'", args[0])
+			}
+
+			return nil
+		},
+	}
+
+	fbInvoked := false
+	fbHandler := func(context.Context, []string) error {
+		fbInvoked = true
+		return nil
+	}
+
+	err = fn(ctx, interp.ExecHandler(eh.ExecHandler(fbHandler)))
+	if err != nil {
+		t.Errorf("Expected no error, got %s", err)
+	}
+
+	if !fbInvoked {
+		t.Errorf("Expected fallback handler to be invoked")
+	}
+}
diff --git a/internal/shutils/nop_test.go b/internal/shutils/nop_test.go
new file mode 100644
index 0000000..bcea3cf
--- /dev/null
+++ b/internal/shutils/nop_test.go
@@ -0,0 +1,40 @@
+package shutils_test
+
+import (
+	"bytes"
+	"context"
+	"os"
+	"strings"
+	"testing"
+
+	"go.arsenm.dev/lure/internal/shutils"
+	"mvdan.cc/sh/v3/interp"
+	"mvdan.cc/sh/v3/syntax"
+)
+
+func TestNopExec(t *testing.T) {
+	ctx := context.Background()
+
+	fl, err := syntax.NewParser().Parse(strings.NewReader(`/bin/echo test`), "lure.sh")
+	if err != nil {
+		t.Fatalf("Expected no error, got %s", err)
+	}
+
+	buf := &bytes.Buffer{}
+	runner, err := interp.New(
+		interp.ExecHandler(shutils.NopExec),
+		interp.StdIO(os.Stdin, buf, buf),
+	)
+	if err != nil {
+		t.Fatalf("Expected no error, got %s", err)
+	}
+
+	err = runner.Run(ctx, fl)
+	if err != nil {
+		t.Fatalf("Expected no error, got %s", err)
+	}
+
+	if buf.String() != "" {
+		t.Fatalf("Expected empty string, got %#v", buf.String())
+	}
+}