tests: simplify and rename test_private_key_from_bytes

* Rename to `test_private_key_from_der`.
* Rewrite to be table-driven.

src/lib.rs

@@ -766,54 +766,52 @@ mod non_std_tests {
     use super::*;
 
     #[test]
-    fn test_private_key_from_bytes() {
-        let key = include_bytes!("test_keys/eddsakey.der");
-        let key = PrivateKeyDer::try_from(&key[..]).unwrap();
-
-        assert!(matches!(key, PrivateKeyDer::Pkcs8(_)));
-
-        let key = include_bytes!("test_keys/nistp256key.der");
-        let key = PrivateKeyDer::try_from(&key[..]).unwrap();
-
-        assert!(matches!(key, PrivateKeyDer::Sec1(_)));
-
-        let key = include_bytes!("test_keys/nistp256key.pkcs8.der");
-        let key = PrivateKeyDer::try_from(&key[..]).unwrap();
-
-        assert!(matches!(key, PrivateKeyDer::Pkcs8(_)));
-
-        let key = include_bytes!("test_keys/nistp384key.der");
-        let key = PrivateKeyDer::try_from(&key[..]).unwrap();
-        assert!(matches!(key, PrivateKeyDer::Sec1(_)));
-
-        let key = include_bytes!("test_keys/nistp384key.pkcs8.der");
-        let key = PrivateKeyDer::try_from(&key[..]).unwrap();
-
-        assert!(matches!(key, PrivateKeyDer::Pkcs8(_)));
-
-        let key = include_bytes!("test_keys/nistp521key.der");
-        let key = PrivateKeyDer::try_from(&key[..]).unwrap();
-
-        assert!(matches!(key, PrivateKeyDer::Sec1(_)));
-
-        let key = include_bytes!("test_keys/nistp521key.pkcs8.der");
-        let key = PrivateKeyDer::try_from(&key[..]).unwrap();
-
-        assert!(matches!(key, PrivateKeyDer::Pkcs8(_)));
-
-        let key = include_bytes!("test_keys/rsa2048key.pkcs1.der");
-        let key = PrivateKeyDer::try_from(&key[..]).unwrap();
-
-        assert!(matches!(key, PrivateKeyDer::Pkcs1(_)));
-
-        let key = include_bytes!("test_keys/rsa2048key.pkcs8.der");
-        let key = PrivateKeyDer::try_from(&key[..]).unwrap();
-
-        assert!(matches!(key, PrivateKeyDer::Pkcs8(_)));
-
-        let key = include_bytes!("test_keys/rsa4096key.pkcs8.der");
-        let key = PrivateKeyDer::try_from(&key[..]).unwrap();
+    fn test_private_key_from_der() {
+        fn is_pkcs8(key: &PrivateKeyDer<'_>) -> bool {
+            matches!(key, PrivateKeyDer::Pkcs8(_))
+        }
+        fn is_pkcs1(key: &PrivateKeyDer<'_>) -> bool {
+            matches!(key, PrivateKeyDer::Pkcs1(_))
+        }
+        fn is_sec1(key: &PrivateKeyDer<'_>) -> bool {
+            matches!(key, PrivateKeyDer::Sec1(_))
+        }
 
-        assert!(matches!(key, PrivateKeyDer::Pkcs8(_)));
+        let test_cases: &[(&[u8], fn(&PrivateKeyDer<'_>) -> bool); 10] = &[
+            (&include_bytes!("test_keys/eddsakey.der")[..], is_pkcs8),
+            (&include_bytes!("test_keys/nistp256key.der")[..], is_sec1),
+            (
+                &include_bytes!("test_keys/nistp256key.pkcs8.der")[..],
+                is_pkcs8,
+            ),
+            (&include_bytes!("test_keys/nistp384key.der")[..], is_sec1),
+            (
+                &include_bytes!("test_keys/nistp384key.pkcs8.der")[..],
+                is_pkcs8,
+            ),
+            (&include_bytes!("test_keys/nistp521key.der")[..], is_sec1),
+            (
+                &include_bytes!("test_keys/nistp521key.pkcs8.der")[..],
+                is_pkcs8,
+            ),
+            (
+                &include_bytes!("test_keys/rsa2048key.pkcs1.der")[..],
+                is_pkcs1,
+            ),
+            (
+                &include_bytes!("test_keys/rsa2048key.pkcs8.der")[..],
+                is_pkcs8,
+            ),
+            (
+                &include_bytes!("test_keys/rsa4096key.pkcs8.der")[..],
+                is_pkcs8,
+            ),
+        ];
+
+        for (key_bytes, expected_check_fn) in test_cases.iter() {
+            assert!(expected_check_fn(
+                &PrivateKeyDer::try_from(*key_bytes).unwrap()
+            ));
+        }
     }
 }