From 5e61f0ad50c6309d10502ffa1f5783b35dc72b08 Mon Sep 17 00:00:00 2001
From: Robin Krahl <robin@nitrokey.com>
Date: Mon, 8 Jun 2026 12:10:21 +0200
Subject: [PATCH] Add tests for enum counts and conversions

---
 Cargo.toml            |  1 +
 src/ctap2/get_info.rs | 38 ++++++++++++++++++++++++++++++++++++++
 src/webauthn.rs       | 11 +++++++++++
 3 files changed, 50 insertions(+)

diff --git a/Cargo.toml b/Cargo.toml
index ddae0a6..c6a496e 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -27,6 +27,7 @@ ciborium = "0.2"
 hex = "0.4"
 hex-literal = "0.4.1"
 serde_test = "1.0.176"
+strum = { version = "0.28", features = ["derive"] }
 
 [features]
 std = []
diff --git a/src/ctap2/get_info.rs b/src/ctap2/get_info.rs
index 90e1229..857048a 100644
--- a/src/ctap2/get_info.rs
+++ b/src/ctap2/get_info.rs
@@ -258,6 +258,7 @@ impl ResponseBuilder {
 }
 
 #[derive(Copy, Clone, Debug, Eq, PartialEq, Serialize, Deserialize)]
+#[cfg_attr(test, derive(strum::EnumCount, strum::VariantArray))]
 #[non_exhaustive]
 #[serde(into = "&str", try_from = "&str")]
 pub enum Version {
@@ -308,6 +309,7 @@ impl TryFrom<&str> for Version {
 pub const EXTENSION_COUNT: usize = 7;
 
 #[derive(Copy, Clone, Debug, Eq, PartialEq, Serialize, Deserialize)]
+#[cfg_attr(test, derive(strum::EnumCount, strum::VariantArray))]
 #[non_exhaustive]
 #[serde(into = "&str", try_from = "&str")]
 pub enum Extension {
@@ -364,6 +366,7 @@ impl TryFrom<&str> for Extension {
 pub const TRANSPORT_COUNT: usize = 3;
 
 #[derive(Copy, Clone, Debug, Eq, PartialEq, Serialize, Deserialize)]
+#[cfg_attr(test, derive(strum::EnumCount, strum::VariantArray))]
 #[non_exhaustive]
 #[serde(into = "&str", try_from = "&str")]
 pub enum Transport {
@@ -526,7 +529,42 @@ pub struct Certifications {
 #[cfg(test)]
 mod tests {
     use super::*;
+    use core::fmt::Debug;
     use serde_test::{assert_ser_tokens, assert_tokens, Token};
+    use strum::{EnumCount, VariantArray};
+
+    fn test_enum<T>(count: usize)
+    where
+        T: EnumCount
+            + VariantArray
+            + Into<&'static str>
+            + for<'a> TryFrom<&'a str>
+            + PartialEq
+            + Debug
+            + Copy,
+    {
+        assert_eq!(count, T::COUNT);
+
+        for variant in T::VARIANTS {
+            let variant_str: &str = (*variant).into();
+            assert_eq!(Some(*variant), T::try_from(variant_str).ok());
+        }
+    }
+
+    #[test]
+    fn test_version() {
+        test_enum::<Version>(VERSION_COUNT);
+    }
+
+    #[test]
+    fn test_transport() {
+        test_enum::<Transport>(TRANSPORT_COUNT);
+    }
+
+    #[test]
+    fn test_extension() {
+        test_enum::<Extension>(EXTENSION_COUNT);
+    }
 
     #[test]
     fn test_serde_version() {
diff --git a/src/webauthn.rs b/src/webauthn.rs
index ec9eb37..59a908c 100644
--- a/src/webauthn.rs
+++ b/src/webauthn.rs
@@ -137,6 +137,7 @@ impl PublicKeyCredentialUserEntity {
 
 #[derive(Clone, Copy, Debug, Eq, PartialEq)]
 #[cfg_attr(feature = "arbitrary", derive(arbitrary::Arbitrary))]
+#[cfg_attr(test, derive(strum::EnumCount, strum::VariantArray))]
 #[non_exhaustive]
 pub enum KnownPublicKeyCredentialParameters {
     ES256,
@@ -289,6 +290,16 @@ pub struct PublicKeyCredentialDescriptorRef<'a> {
 #[cfg(test)]
 mod tests {
     use super::*;
+    use strum::{EnumCount as _, VariantArray as _};
+
+    #[test]
+    fn test_known_cred_params() {
+        assert_eq!(KnownPublicKeyCredentialParameters::COUNT, COUNT_KNOWN_ALGS);
+        assert_eq!(
+            KnownPublicKeyCredentialParameters::ALL,
+            KnownPublicKeyCredentialParameters::VARIANTS
+        );
+    }
 
     #[test]
     fn test_truncate() {