chore: [MR-591] Trim canonical state framework (#2539)

This removes exceptions for unsupported certification versions and trims
down the testing framework accordingly.

---------

Co-authored-by: Alin Sinpalean <58422065+alin-at-dfinity@users.noreply.github.com>

Author: stiegerc

rs/canonical_state/certification_version/src/lib.rs

@@ -2,43 +2,6 @@ use strum_macros::{EnumCount, EnumIter};
 
 #[derive(Copy, Clone, Eq, PartialEq, Ord, PartialOrd, Debug, EnumCount, EnumIter)]
 pub enum CertificationVersion {
-    /// Initial version.
-    V0 = 0,
-    /// Added canister module hash and controller.
-    V1 = 1,
-    /// Added support for multiple canister controllers.
-    V2 = 2,
-    /// Added subnet to canister ID ranges routing tables.
-    V3 = 3,
-    /// Added optional `Request::cycles_payment` and `Response::cycles_refund`
-    /// fields that are not yet populated.
-    V4 = 4,
-    /// Added support for canister metadata custom sections.
-    V5 = 5,
-    /// Encoding of canister metadata custom sections.
-    V6 = 6,
-    /// Support for decoding of `StreamHeader::reject_signals`.
-    /// Support for `done` ingress history status.
-    V7 = 7,
-    /// Encoding of `StreamHeader::reject_signals`.
-    /// Producing `done` ingress history statuses.
-    V8 = 8,
-    /// Producing non-empty `StreamHeader::reject_signals`.
-    V9 = 9,
-    /// Dropped `SystemMetadata::id_counter`.
-    V10 = 10,
-    /// Producing `error_code` field in `request_status` subtree.
-    V11 = 11,
-    /// Added `/subnet/<own_subnet_id>/node` subtree, with node public keys.
-    V12 = 12,
-    /// Dropped `/canister/<canister_id>/controller`.
-    V13 = 13,
-    /// Define optional `Request::metadata` field.
-    V14 = 14,
-    /// Added subnet metrics in `subnet` subtree.
-    V15 = 15,
-    /// Added `/api_boundary_nodes` subtree with domain, ipv4_address and ipv6_address for each API boundary node.
-    V16 = 16,
     /// Added `flags` to `StreamHeader`. Defined `StreamHeaderFlagBits::ResponsesOnly` flag.
     V17 = 17,
     /// Added `deadline` fields to `Request` and `Response`.
@@ -69,9 +32,8 @@ impl std::convert::TryFrom<u32> for CertificationVersion {
     type Error = UnsupportedCertificationVersion;
 
     fn try_from(n: u32) -> Result<Self, Self::Error> {
-        use strum::IntoEnumIterator;
-        CertificationVersion::iter()
-            .nth(n as usize)
+        all_supported_versions()
+            .find(|v| *v as u32 == n)
             .ok_or(UnsupportedCertificationVersion(n))
     }
 }
@@ -92,7 +54,8 @@ pub const MIN_SUPPORTED_CERTIFICATION_VERSION: CertificationVersion = Certificat
 /// this.
 pub const MAX_SUPPORTED_CERTIFICATION_VERSION: CertificationVersion = CertificationVersion::V19;
 
-/// Returns a list of all certification versions up to [MAX_SUPPORTED_CERTIFICATION_VERSION].
+/// Returns a list of all certification versions from `MIN_SUPPORTED_CERTIFICATION_VERSION`
+/// up to `MAX_SUPPORTED_CERTIFICATION_VERSION`.
 pub fn all_supported_versions() -> impl std::iter::Iterator<Item = CertificationVersion> {
     use strum::IntoEnumIterator;
     CertificationVersion::iter().filter(|v| {
@@ -105,3 +68,21 @@ fn version_constants_consistent() {
     assert!(MIN_SUPPORTED_CERTIFICATION_VERSION <= CURRENT_CERTIFICATION_VERSION);
     assert!(CURRENT_CERTIFICATION_VERSION <= MAX_SUPPORTED_CERTIFICATION_VERSION);
 }
+
+#[test]
+fn convert_from_u32_succeeds_for_all_supported_certification_versions() {
+    use strum::IntoEnumIterator;
+    assert!(all_supported_versions().all(|v| (v as u32).try_into() == Ok(v)));
+    // Old unsupported version should fail.
+    let v = CertificationVersion::iter().next().unwrap() as u32 - 1;
+    assert_eq!(
+        CertificationVersion::try_from(v),
+        Err(UnsupportedCertificationVersion(v))
+    );
+    // Non-existent version should fail.
+    let v = CertificationVersion::iter().last().unwrap() as u32 + 1;
+    assert_eq!(
+        CertificationVersion::try_from(v),
+        Err(UnsupportedCertificationVersion(v))
+    );
+}