feat: allow single letter user id (#3991)

* Allow single letter user id.

They do work - I use one and login using Authelia, but then I am not able to update the profile to update avatar or add comment because "Invalid username: r" errors

* Add test for the util with uid matcher

* Move the test to separate directory

* Use goimports on the test file

* Rename the test for a mroe matching name, add failing test

* Update the regexp so that two letter work

---------

Co-authored-by: Roman Kamyk <roman@kamyk.me>

internal/util/resource_name.go

@@ -3,5 +3,5 @@ package util
 import "regexp"
 
 var (
-	UIDMatcher = regexp.MustCompile("^[a-zA-Z0-9]([a-zA-Z0-9-]{1,30}[a-zA-Z0-9])$")
+	UIDMatcher = regexp.MustCompile("^[a-zA-Z0-9]([a-zA-Z0-9-]{0,30}[a-zA-Z0-9])?$")
 )

test/util/resource_name_test.go

@@ -0,0 +1,37 @@
+package util_test
+
+import (
+	"testing"
+
+	"github.com/usememos/memos/internal/util"
+)
+
+func TestUIDMatcher(t *testing.T) {
+	tests := []struct {
+		input    string
+		expected bool
+	}{
+		{"", false},
+		{"-abc123", false},
+		{"012345678901234567890123456789", true},
+		{"1abc-123", true},
+		{"A123B456C789", true},
+		{"a", true},
+		{"ab", true},
+		{"a*b&c", false},
+		{"a--b", true},
+		{"a-1b-2c", true},
+		{"a1234567890123456789012345678901", true},
+		{"abc123", true},
+		{"abc123-", false},
+	}
+
+	for _, test := range tests {
+		t.Run(test.input, func(t *testing.T) {
+			result := util.UIDMatcher.MatchString(test.input)
+			if result != test.expected {
+				t.Errorf("For input '%s', expected %v but got %v", test.input, test.expected, result)
+			}
+		})
+	}
+}