test: add comprehensive tests for IRCMessageType API

Cover Name(), String(), Code(), Int(), FromInt() for known and unknown
numerics, plus the deprecated Name() package-level function.
100% statement coverage on pkg/irc.

pkg/irc/numerics_test.go

@@ -0,0 +1,163 @@
+package irc_test
+
+import (
+	"errors"
+	"testing"
+
+	"git.eeqj.de/sneak/neoirc/pkg/irc"
+)
+
+func TestName(t *testing.T) {
+	t.Parallel()
+
+	tests := []struct {
+		numeric irc.IRCMessageType
+		want    string
+	}{
+		{irc.RplWelcome, "RPL_WELCOME"},
+		{irc.RplBounce, "RPL_BOUNCE"},
+		{irc.RplLuserOp, "RPL_LUSEROP"},
+		{irc.ErrCannotSendToChan, "ERR_CANNOTSENDTOCHAN"},
+		{irc.ErrNicknameInUse, "ERR_NICKNAMEINUSE"},
+	}
+
+	for _, tc := range tests {
+		if got := tc.numeric.Name(); got != tc.want {
+			t.Errorf("IRCMessageType(%d).Name() = %q, want %q", tc.numeric.Int(), got, tc.want)
+		}
+	}
+}
+
+func TestString(t *testing.T) {
+	t.Parallel()
+
+	tests := []struct {
+		numeric irc.IRCMessageType
+		want    string
+	}{
+		{irc.RplWelcome, "RPL_WELCOME <001>"},
+		{irc.RplBounce, "RPL_BOUNCE <005>"},
+		{irc.RplLuserOp, "RPL_LUSEROP <252>"},
+		{irc.ErrCannotSendToChan, "ERR_CANNOTSENDTOCHAN <404>"},
+	}
+
+	for _, tc := range tests {
+		if got := tc.numeric.String(); got != tc.want {
+			t.Errorf("IRCMessageType(%d).String() = %q, want %q", tc.numeric.Int(), got, tc.want)
+		}
+	}
+}
+
+func TestCode(t *testing.T) {
+	t.Parallel()
+
+	tests := []struct {
+		numeric irc.IRCMessageType
+		want    string
+	}{
+		{irc.RplWelcome, "001"},
+		{irc.RplBounce, "005"},
+		{irc.RplLuserOp, "252"},
+		{irc.ErrCannotSendToChan, "404"},
+	}
+
+	for _, tc := range tests {
+		if got := tc.numeric.Code(); got != tc.want {
+			t.Errorf("IRCMessageType(%d).Code() = %q, want %q", tc.numeric.Int(), got, tc.want)
+		}
+	}
+}
+
+func TestInt(t *testing.T) {
+	t.Parallel()
+
+	tests := []struct {
+		numeric irc.IRCMessageType
+		want    int
+	}{
+		{irc.RplWelcome, 1},
+		{irc.RplBounce, 5},
+		{irc.RplLuserOp, 252},
+		{irc.ErrCannotSendToChan, 404},
+	}
+
+	for _, tc := range tests {
+		if got := tc.numeric.Int(); got != tc.want {
+			t.Errorf("IRCMessageType(%d).Int() = %d, want %d", tc.want, got, tc.want)
+		}
+	}
+}
+
+func TestFromInt_Known(t *testing.T) {
+	t.Parallel()
+
+	tests := []struct {
+		code int
+		want irc.IRCMessageType
+	}{
+		{1, irc.RplWelcome},
+		{5, irc.RplBounce},
+		{252, irc.RplLuserOp},
+		{404, irc.ErrCannotSendToChan},
+		{433, irc.ErrNicknameInUse},
+	}
+
+	for _, test := range tests {
+		got, err := irc.FromInt(test.code)
+		if err != nil {
+			t.Errorf("FromInt(%d) returned unexpected error: %v", test.code, err)
+
+			continue
+		}
+
+		if got != test.want {
+			t.Errorf("FromInt(%d) = %v, want %v", test.code, got, test.want)
+		}
+	}
+}
+
+func TestFromInt_Unknown(t *testing.T) {
+	t.Parallel()
+
+	unknowns := []int{0, 999, 600, -1}
+	for _, code := range unknowns {
+		_, err := irc.FromInt(code)
+		if err == nil {
+			t.Errorf("FromInt(%d) expected error, got nil", code)
+
+			continue
+		}
+
+		if !errors.Is(err, irc.ErrUnknownNumeric) {
+			t.Errorf("FromInt(%d) error = %v, want ErrUnknownNumeric", code, err)
+		}
+	}
+}
+
+func TestUnknownNumeric_Name(t *testing.T) {
+	t.Parallel()
+
+	unknown := irc.IRCMessageType(999)
+	if got := unknown.Name(); got != "" {
+		t.Errorf("IRCMessageType(999).Name() = %q, want empty string", got)
+	}
+}
+
+func TestUnknownNumeric_String(t *testing.T) {
+	t.Parallel()
+
+	unknown := irc.IRCMessageType(999)
+	want := "UNKNOWN <999>"
+
+	if got := unknown.String(); got != want {
+		t.Errorf("IRCMessageType(999).String() = %q, want %q", got, want)
+	}
+}
+
+func TestDeprecatedNameFunc(t *testing.T) {
+	t.Parallel()
+
+	if got := irc.Name(irc.RplYourHost); got != "RPL_YOURHOST" {
+		t.Errorf("Name(RplYourHost) = %q, want %q", got, "RPL_YOURHOST")
+	}
+}