1 files changed, 219 insertions, 0 deletions
diff --git a/opts_test.go b/opts_test.go
new file mode 100644
index 0000000..a972867
--- /dev/null
+++ b/opts_test.go
@@ -0,0 +1,219 @@
+package opts
+
+import (
+	"fmt"
+	"testing"
+)
+
+func die(t *testing.T, name string, want, got any) {
+	t.Fatalf("Expected %s to be ‘%s’ but got ‘%s’", name, want, got)
+}
+
+func assertGet(t *testing.T, args []string, fw, ow int, ew error) []Flag {
+	flags, optind, err := Get(args, "abλc:dß")
+	if err != ew {
+		die(t, "err", ew, err)
+	}
+	if optind != ow {
+		die(t, "optind", ow, optind)
+	}
+	if len(flags) != fw {
+		die(t, "flags", fw, flags)
+	}
+	return flags
+}
+
+func TestNoArg(t *testing.T) {
+	args := []string{}
+	assertGet(t, args, 0, 0, nil)
+}
+
+func TestNoFlag(t *testing.T) {
+	args := []string{"foo"}
+	assertGet(t, args, 0, 1, nil)
+}
+
+func TestCNoArg(t *testing.T) {
+	args := []string{"foo", "-c"}
+	assertGet(t, args, 0, 0, ErrNoArgument('c'))
+}
+
+func TestCWithArg(t *testing.T) {
+	args := []string{"foo", "-c", "bar"}
+	flags := assertGet(t, args, 1, 3, nil)
+	if flags[0].Key != 'c' {
+		die(t, "flags[0].Key", 'c', flags[0].Key)
+	}
+	if flags[0].Value != "bar" {
+		die(t, "flags[0].Value", "bar", flags[0].Value)
+	}
+}
+
+func TestCWithArgNoSpace(t *testing.T) {
+	args := []string{"foo", "-cbar"}
+	flags := assertGet(t, args, 1, 2, nil)
+	if flags[0].Key != 'c' {
+		die(t, "flags[0].Key", 'c', flags[0].Key)
+	}
+	if flags[0].Value != "bar" {
+		die(t, "flags[0].Value", "bar", flags[0].Value)
+	}
+}
+
+func TestANoArg(t *testing.T) {
+	args := []string{"foo", "-a"}
+	flags := assertGet(t, args, 1, 2, nil)
+	if flags[0].Key != 'a' {
+		die(t, "flags[0].Key", 'a', flags[0].Key)
+	}
+	if flags[0].Value != "" {
+		die(t, "flags[0].Value", "", flags[0].Value)
+	}
+}
+
+func TestAWithArg(t *testing.T) {
+	args := []string{"foo", "-a", "bar"}
+	flags := assertGet(t, args, 1, 2, nil)
+	if flags[0].Key != 'a' {
+		die(t, "flags[0].Key", 'a', flags[0].Key)
+	}
+	if flags[0].Value != "" {
+		die(t, "flags[0].Value", "", flags[0].Value)
+	}
+}
+
+func TestAAndCWithArg(t *testing.T) {
+	args := []string{"foo", "-a", "-c", "bar"}
+	flags := assertGet(t, args, 2, 4, nil)
+	if flags[0].Key != 'a' {
+		die(t, "flags[0].Key", 'a', flags[0].Key)
+	}
+	if flags[0].Value != "" {
+		die(t, "flags[0].Value", "", flags[0].Value)
+	}
+	if flags[1].Key != 'c' {
+		die(t, "flags[0].Key", 'c', flags[1].Key)
+	}
+	if flags[1].Value != "bar" {
+		die(t, "flags[0].Value", "bar", flags[1].Value)
+	}
+}
+
+func TestACWithArg(t *testing.T) {
+	args := []string{"foo", "-ac", "bar"}
+	flags := assertGet(t, args, 2, 3, nil)
+	if flags[0].Key != 'a' {
+		die(t, "flags[0].Key", 'a', flags[0].Key)
+	}
+	if flags[0].Value != "" {
+		die(t, "flags[0].Value", "", flags[0].Value)
+	}
+	if flags[1].Key != 'c' {
+		die(t, "flags[0].Key", 'c', flags[1].Key)
+	}
+	if flags[1].Value != "bar" {
+		die(t, "flags[0].Value", "bar", flags[1].Value)
+	}
+}
+
+func TestCAWithArg(t *testing.T) {
+	args := []string{"foo", "-ca", "bar"}
+	flags := assertGet(t, args, 1, 2, nil)
+	if flags[0].Key != 'c' {
+		die(t, "flags[0].Key", 'c', flags[0].Key)
+	}
+	if flags[0].Value != "a" {
+		die(t, "flags[0].Value", "a", flags[0].Value)
+	}
+}
+
+func TestBAfterDashDash(t *testing.T) {
+	args := []string{"foo", "--", "-b"}
+	assertGet(t, args, 0, 2, nil)
+}
+
+func TestCWithArgAfterDashDash(t *testing.T) {
+	args := []string{"foo", "--", "-c", "bar", "baz"}
+	assertGet(t, args, 0, 2, nil)
+}
+
+func TestCWithArgThenDAfterDashDash(t *testing.T) {
+	args := []string{"foo", "-c", "bar", "baz", "--", "-d"}
+	flags := assertGet(t, args, 1, 3, nil)
+	if flags[0].Key != 'c' {
+		die(t, "flags[0].Key", 'c', flags[0].Key)
+	}
+	if flags[0].Value != "bar" {
+		die(t, "flags[0].Value", "bar", flags[0].Value)
+	}
+}
+
+func TestCWithArgThenDAfterEmpty(t *testing.T) {
+	args := []string{"foo", "-c", "bar", "baz", "", "-d"}
+	flags := assertGet(t, args, 1, 3, nil)
+	if flags[0].Key != 'c' {
+		die(t, "flags[0].Key", 'c', flags[0].Key)
+	}
+	if flags[0].Value != "bar" {
+		die(t, "flags[0].Value", "bar", flags[0].Value)
+	}
+}
+
+func TestBChainedThrice(t *testing.T) {
+	args := []string{"foo", "-bbb"}
+	flags := assertGet(t, args, 3, 2, nil)
+	for i := 0; i < 3; i++ {
+		s := fmt.Sprintf("flags[%d].", i)
+		if flags[i].Key != 'b' {
+			die(t, s+"Key", 'b', flags[i].Key)
+		}
+		if flags[i].Value != "" {
+			die(t, s+"Value", "", flags[i].Value)
+		}
+	}
+}
+
+func TestẞChainedTwice(t *testing.T) {
+	args := []string{"foo", "-ßß"}
+	flags := assertGet(t, args, 2, 2, nil)
+	for i := 0; i < 2; i++ {
+		s := fmt.Sprintf("flags[%d].", i)
+		if flags[i].Key != 'ß' {
+			die(t, s+"Key", 'ß', flags[i].Key)
+		}
+		if flags[i].Value != "" {
+			die(t, s+"Value", "", flags[i].Value)
+		}
+	}
+}
+
+func TestΛAsArgToC(t *testing.T) {
+	args := []string{"foo", "-c", "-λ"}
+	flags := assertGet(t, args, 1, 3, nil)
+	if flags[0].Key != 'c' {
+		die(t, "flags[0].Key", 'c', flags[0].Key)
+	}
+	if flags[0].Value != "-λ" {
+		die(t, "flags[0].Value", "-λ", flags[0].Value)
+	}
+}
+
+func TestInvalidFlag(t *testing.T) {
+	args := []string{"foo", "-X"}
+	assertGet(t, args, 0, 0, ErrBadOption('X'))
+}
+
+func TestInvalidFlagWithArg(t *testing.T) {
+	args := []string{"foo", "-X", "bar"}
+	assertGet(t, args, 0, 0, ErrBadOption('X'))
+}
+
+func TestAAfterArg(t *testing.T) {
+	args := []string{"foo", "bar", "-a"}
+	assertGet(t, args, 0, 1, nil)
+}
+
+func TestXAfterDash(t *testing.T) {
+	args := []string{"foo", "-", "-x"}
+	assertGet(t, args, 0, 1, nil)
+}