fix #1074

Make snomask add/remove behavior match other ircds

irc/sno/constants.go

@@ -7,6 +7,8 @@ package sno
 // Mask is a type of server notice mask.
 type Mask rune
 
+type Masks []Mask
+
 // Notice mask types
 const (
 	LocalAnnouncements Mask = 'a'
@@ -18,8 +20,8 @@ const (
 	LocalQuits         Mask = 'q'
 	Stats              Mask = 't'
 	LocalAccounts      Mask = 'u'
-	LocalXline         Mask = 'x'
 	LocalVhosts        Mask = 'v'
+	LocalXline         Mask = 'x'
 )
 
 var (
@@ -39,17 +41,17 @@ var (
 	}
 
 	// ValidMasks contains the snomasks that we support.
-	ValidMasks = map[Mask]bool{
-		LocalAnnouncements: true,
-		LocalConnects:      true,
-		LocalChannels:      true,
-		LocalKills:         true,
-		LocalNicks:         true,
-		LocalOpers:         true,
-		LocalQuits:         true,
-		Stats:              true,
-		LocalAccounts:      true,
-		LocalXline:         true,
-		LocalVhosts:        true,
+	ValidMasks = []Mask{
+		LocalAnnouncements,
+		LocalConnects,
+		LocalChannels,
+		LocalKills,
+		LocalNicks,
+		LocalOpers,
+		LocalQuits,
+		Stats,
+		LocalAccounts,
+		LocalVhosts,
+		LocalXline,
 	}
 )

irc/sno/utils.go

@@ -0,0 +1,87 @@
+// Copyright (c) 2020 Shivaram Lingamneni
+// released under the MIT license
+
+package sno
+
+import (
+	"strings"
+)
+
+func IsValidMask(r rune) bool {
+	for _, m := range ValidMasks {
+		if m == Mask(r) {
+			return true
+		}
+	}
+	return false
+}
+
+func (masks Masks) String() string {
+	var buf strings.Builder
+	buf.Grow(len(masks))
+	for _, m := range masks {
+		buf.WriteRune(rune(m))
+	}
+	return buf.String()
+}
+
+func (masks Masks) Contains(mask Mask) bool {
+	for _, m := range masks {
+		if mask == m {
+			return true
+		}
+	}
+	return false
+}
+
+// Evaluate changes to snomasks made with MODE. There are several cases:
+// adding snomasks with `/mode +s a` or `/mode +s +a`, removing them with `/mode +s -a`,
+// adding all with `/mode +s *` or `/mode +s +*`, removing all with `/mode +s -*` or `/mode -s`
+func EvaluateSnomaskChanges(add bool, arg string, currentMasks Masks) (addMasks, removeMasks Masks, newArg string) {
+	if add {
+		if len(arg) == 0 {
+			return
+		}
+		add := true
+		switch arg[0] {
+		case '+':
+			arg = arg[1:]
+		case '-':
+			add = false
+			arg = arg[1:]
+		default:
+			// add
+		}
+		if strings.IndexByte(arg, '*') != -1 {
+			if add {
+				for _, mask := range ValidMasks {
+					if !currentMasks.Contains(mask) {
+						addMasks = append(addMasks, mask)
+					}
+				}
+			} else {
+				removeMasks = currentMasks
+			}
+		} else {
+			for _, r := range arg {
+				if IsValidMask(r) {
+					m := Mask(r)
+					if add && !currentMasks.Contains(m) {
+						addMasks = append(addMasks, m)
+					} else if !add && currentMasks.Contains(m) {
+						removeMasks = append(removeMasks, m)
+					}
+				}
+			}
+		}
+		if len(addMasks) != 0 {
+			newArg = "+" + addMasks.String()
+		} else if len(removeMasks) != 0 {
+			newArg = "-" + removeMasks.String()
+		}
+	} else {
+		removeMasks = currentMasks
+		newArg = ""
+	}
+	return
+}

irc/sno/utils_test.go

@@ -0,0 +1,53 @@
+// Copyright (c) 2020 Shivaram Lingamneni
+// released under the MIT license
+
+package sno
+
+import (
+	"fmt"
+	"reflect"
+	"testing"
+)
+
+func assertEqual(supplied, expected interface{}, t *testing.T) {
+	if !reflect.DeepEqual(supplied, expected) {
+		panic(fmt.Sprintf("expected %#v but got %#v", expected, supplied))
+	}
+}
+
+func TestEvaluateSnomaskChanges(t *testing.T) {
+	add, remove, newArg := EvaluateSnomaskChanges(true, "*", nil)
+	assertEqual(add, Masks{'a', 'c', 'j', 'k', 'n', 'o', 'q', 't', 'u', 'v', 'x'}, t)
+	assertEqual(len(remove), 0, t)
+	assertEqual(newArg, "+acjknoqtuvx", t)
+
+	add, remove, newArg = EvaluateSnomaskChanges(true, "*", Masks{'a', 'u'})
+	assertEqual(add, Masks{'c', 'j', 'k', 'n', 'o', 'q', 't', 'v', 'x'}, t)
+	assertEqual(len(remove), 0, t)
+	assertEqual(newArg, "+cjknoqtvx", t)
+
+	add, remove, newArg = EvaluateSnomaskChanges(true, "-a", Masks{'a', 'u'})
+	assertEqual(len(add), 0, t)
+	assertEqual(remove, Masks{'a'}, t)
+	assertEqual(newArg, "-a", t)
+
+	add, remove, newArg = EvaluateSnomaskChanges(true, "-*", Masks{'a', 'u'})
+	assertEqual(len(add), 0, t)
+	assertEqual(remove, Masks{'a', 'u'}, t)
+	assertEqual(newArg, "-au", t)
+
+	add, remove, newArg = EvaluateSnomaskChanges(true, "+c", Masks{'a', 'u'})
+	assertEqual(add, Masks{'c'}, t)
+	assertEqual(len(remove), 0, t)
+	assertEqual(newArg, "+c", t)
+
+	add, remove, newArg = EvaluateSnomaskChanges(false, "", Masks{'a', 'u'})
+	assertEqual(len(add), 0, t)
+	assertEqual(remove, Masks{'a', 'u'}, t)
+	assertEqual(newArg, "", t)
+
+	add, remove, newArg = EvaluateSnomaskChanges(false, "*", Masks{'a', 'u'})
+	assertEqual(len(add), 0, t)
+	assertEqual(remove, Masks{'a', 'u'}, t)
+	assertEqual(newArg, "", t)
+}