diff --git a/models/forgefed/federationinfo_test.go b/models/forgefed/federationinfo_test.go
new file mode 100644
index 0000000000..b6185dddeb
--- /dev/null
+++ b/models/forgefed/federationinfo_test.go
@@ -0,0 +1,24 @@
+// Copyright 2024 The forgejo Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package forgefed
+
+import (
+	"testing"
+
+	"code.gitea.io/gitea/modules/timeutil"
+	"code.gitea.io/gitea/modules/validation"
+)
+
+func Test_ValidateMaxLen(t *testing.T) {
+	sut := FederationInfo{
+		HostFqdn: "host.do.main",
+		NodeInfo: NodeInfo{
+			Source: "forgejo",
+		},
+		LatestActivity: timeutil.TimeStampNow(),
+	}
+	if res, err := validation.IsValid(sut); !res {
+		t.Errorf("sut should be valid but was %q", err)
+	}
+}
diff --git a/modules/validation/validateable.go b/modules/validation/validatable.go
similarity index 100%
rename from modules/validation/validateable.go
rename to modules/validation/validatable.go
diff --git a/modules/validation/validatable_test.go b/modules/validation/validatable_test.go
new file mode 100644
index 0000000000..2a0c46aad5
--- /dev/null
+++ b/modules/validation/validatable_test.go
@@ -0,0 +1,44 @@
+// Copyright 2024 The forgejo Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package validation
+
+import (
+	"testing"
+
+	"code.gitea.io/gitea/modules/timeutil"
+)
+
+func Test_ValidateNotEmpty_ForString(t *testing.T) {
+	sut := ""
+	if len(ValidateNotEmpty(sut, "dummyField")) == 0 {
+		t.Errorf("sut should be invalid")
+	}
+	sut = "not empty"
+	if res := ValidateNotEmpty(sut, "dummyField"); len(res) > 0 {
+		t.Errorf("sut should be valid but was %q", res)
+	}
+}
+
+func Test_ValidateNotEmpty_ForTimestamp(t *testing.T) {
+	sut := timeutil.TimeStamp(0)
+	if res := ValidateNotEmpty(sut, "dummyField"); len(res) == 0 {
+		t.Errorf("sut should be invalid")
+	}
+	sut = timeutil.TimeStampNow()
+	if res := ValidateNotEmpty(sut, "dummyField"); len(res) > 0 {
+		t.Errorf("sut should be valid but was %q", res)
+	}
+
+}
+
+func Test_ValidateMaxLen(t *testing.T) {
+	sut := "0123456789"
+	if len(ValidateMaxLen(sut, 9, "dummyField")) == 0 {
+		t.Errorf("sut should be invalid")
+	}
+	sut = "0123456789"
+	if res := ValidateMaxLen(sut, 11, "dummyField"); len(res) > 0 {
+		t.Errorf("sut should be valid but was %q", res)
+	}
+}