1 files changed, 36 insertions, 0 deletions
diff --git a/flag_test.go b/flag_test.go
index 0fb83c7..5b0df0e 100644
--- a/flag_test.go
+++ b/flag_test.go
@@ -143,6 +143,42 @@ func TestInitFlagSet(s *testing.T) {
 	})
 }
 
+func TestParseProtobufEnum(s *testing.T) {
+	t := &core.T{T: s}
+
+	// That type and map emulate code generated by protoc.
+	type fakeEnum int32
+	values := map[string]int32{
+		"FAKE_UNKNOWN": 0,
+		"FOO":          1,
+		"BAR":          2,
+	}
+	parse := core.ParseProtobufEnum[fakeEnum](values)
+
+	t.Run("Match", func(t *core.T) {
+		val, err := parse("FOO")
+		t.AssertErrorIs(nil, err)
+		t.AssertEqual(fakeEnum(1), val)
+	})
+
+	t.Run("MatchCase", func(t *core.T) {
+		val, err := parse("Foo")
+		t.AssertErrorIs(nil, err)
+		t.AssertEqual(fakeEnum(1), val)
+	})
+
+	t.Run("UnknownValue", func(t *core.T) {
+		val, err := parse("BAZ")
+		var exp core.UnknownEnumValueError
+		if t.AssertErrorAs(&exp, err) {
+			t.AssertEqual("BAZ", exp.Actual)
+			sort.Strings(exp.Expected)
+			t.AssertEqual([]string{"BAR", "FAKE_UNKNOWN", "FOO"}, exp.Expected)
+		}
+		t.AssertEqual(fakeEnum(0), val)
+	})
+}
+
 func TestParseStringEnum(s *testing.T) {
 	t := &core.T{T: s}
 	parse := core.ParseStringEnum("foo", "bar")