1 files changed, 130 insertions, 0 deletions
diff --git a/parse_test.go b/parse_test.go
new file mode 100644
index 0000000..9ad5944
--- /dev/null
+++ b/parse_test.go
@@ -0,0 +1,130 @@
+package arg
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func split(s string) []string {
+	return strings.Split(s, " ")
+}
+
+func TestStringSingle(t *testing.T) {
+	var args struct {
+		Foo string
+	}
+	err := ParseFrom(split("--foo bar"), &args)
+	require.NoError(t, err)
+	assert.Equal(t, "bar", args.Foo)
+}
+
+func TestMixed(t *testing.T) {
+	var args struct {
+		Foo  string `arg:"-f"`
+		Bar  int
+		Baz  uint `arg:"positional"`
+		Ham  bool
+		Spam float32
+	}
+	args.Bar = 3
+	err := ParseFrom(split("123 -spam=1.2 -ham -f xyz"), &args)
+	require.NoError(t, err)
+	assert.Equal(t, "xyz", args.Foo)
+	assert.Equal(t, 3, args.Bar)
+	assert.Equal(t, uint(123), args.Baz)
+	assert.Equal(t, true, args.Ham)
+	assert.Equal(t, 1.2, args.Spam)
+}
+
+func TestRequired(t *testing.T) {
+	var args struct {
+		Foo string `arg:"required"`
+	}
+	err := ParseFrom(nil, &args)
+	require.Error(t, err, "--foo is required")
+}
+
+func TestShortFlag(t *testing.T) {
+	var args struct {
+		Foo string `arg:"-f"`
+	}
+
+	err := ParseFrom(split("-f xyz"), &args)
+	require.NoError(t, err)
+	assert.Equal(t, "xyz", args.Foo)
+
+	err = ParseFrom(split("-foo xyz"), &args)
+	require.NoError(t, err)
+	assert.Equal(t, "xyz", args.Foo)
+
+	err = ParseFrom(split("--foo xyz"), &args)
+	require.NoError(t, err)
+	assert.Equal(t, "xyz", args.Foo)
+}
+
+func TestCaseSensitive(t *testing.T) {
+	var args struct {
+		Lower bool `arg:"-v"`
+		Upper bool `arg:"-V"`
+	}
+
+	err := ParseFrom(split("-v"), &args)
+	require.NoError(t, err)
+	assert.True(t, args.Lower)
+	assert.False(t, args.Upper)
+}
+
+func TestCaseSensitive2(t *testing.T) {
+	var args struct {
+		Lower bool `arg:"-v"`
+		Upper bool `arg:"-V"`
+	}
+
+	err := ParseFrom(split("-V"), &args)
+	require.NoError(t, err)
+	assert.False(t, args.Lower)
+	assert.True(t, args.Upper)
+}
+
+func TestPositional(t *testing.T) {
+	var args struct {
+		Input  string `arg:"positional"`
+		Output string `arg:"positional"`
+	}
+	err := ParseFrom(split("foo"), &args)
+	require.NoError(t, err)
+	assert.Equal(t, "foo", args.Input)
+	assert.Equal(t, "", args.Output)
+}
+
+func TestRequiredPositional(t *testing.T) {
+	var args struct {
+		Input  string `arg:"positional"`
+		Output string `arg:"positional,required"`
+	}
+	err := ParseFrom(split("foo"), &args)
+	assert.Error(t, err)
+}
+
+func TestTooManyPositional(t *testing.T) {
+	var args struct {
+		Input  string `arg:"positional"`
+		Output string `arg:"positional"`
+	}
+	err := ParseFrom(split("foo bar baz"), &args)
+	assert.Error(t, err)
+}
+
+func TestMultiple(t *testing.T) {
+	var args struct {
+		Foo []int
+		Bar []string
+	}
+	err := ParseFrom(split("--foo 1 2 3 --bar x y z"), &args)
+	require.NoError(t, err)
+	assert.Equal(t, []int{1, 2, 3}, args.Foo)
+	assert.Equal(t, []string{"x", "y", "z"}, args.Bar)
+}