test(client): inline retry hint compatibility cases

Signed-off-by: WenyXu <wenymedia@gmail.com>

Cargo.lock

@@ -2115,7 +2115,6 @@ dependencies = [
  "prost 0.14.1",
  "query",
  "rand 0.9.4",
- "serde",
  "serde_json",
  "snafu 0.8.6",
  "store-api",

src/client/Cargo.toml

@@ -46,6 +46,3 @@ tokio.workspace = true
 tokio-stream = { workspace = true, features = ["net"] }
 tonic.workspace = true
 tonic-prost.workspace = true
-
-[dev-dependencies]
-serde.workspace = true

src/client/src/region.rs

@@ -666,19 +666,25 @@ mod tests {
 
     #[test]
     fn test_retry_hint_wire_compatibility() {
-        #[derive(serde::Deserialize)]
-        struct Fixture {
-            name: String,
-            wire_hint: Option<String>,
-            expected_hint: String,
-        }
-
-        let fixtures: Vec<Fixture> = serde_json::from_str(include_str!(
-            "../../../tests/compatibility/wire/write_retry/retry_hints.json"
-        ))
-        .unwrap();
-        assert_eq!(fixtures.len(), 5);
-        for fixture in fixtures {
+        for (name, wire_hint, expected_hint) in [
+            ("legacy_missing", None, RetryHint::NonRetryable),
+            ("legacy_retryable", Some("retryable"), RetryHint::Retryable),
+            (
+                "legacy_non_retryable",
+                Some("non_retryable"),
+                RetryHint::NonRetryable,
+            ),
+            (
+                "route_refresh",
+                Some("retry_after_route_refresh"),
+                RetryHint::RetryAfterRouteRefresh,
+            ),
+            (
+                "unknown_future_hint",
+                Some("future_retry_hint"),
+                RetryHint::NonRetryable,
+            ),
+        ] {
             let mut status = Status::failed_precondition("region unavailable");
             status.metadata_mut().insert(
                 common_error::GREPTIME_DB_HEADER_ERROR_CODE,
@@ -687,30 +693,19 @@ mod tests {
                     .parse()
                     .unwrap(),
             );
-            if let Some(hint) = fixture.wire_hint {
+            if let Some(hint) = wire_hint {
                 status.metadata_mut().insert(
                     common_error::GREPTIME_DB_HEADER_ERROR_RETRY_HINT,
                     hint.parse().unwrap(),
                 );
             }
             let error: error::Error = status.into();
-            assert_eq!(
-                error.retry_hint().as_str(),
-                fixture.expected_hint,
-                "{}",
-                fixture.name
-            );
-            assert_eq!(
-                error.status_code(),
-                StatusCode::RegionNotReady,
-                "{}",
-                fixture.name
-            );
+            assert_eq!(error.retry_hint(), expected_hint, "{name}");
+            assert_eq!(error.status_code(), StatusCode::RegionNotReady, "{name}");
             assert_eq!(
                 error.tonic_code(),
                 Some(tonic::Code::FailedPrecondition),
-                "{}",
-                fixture.name
+                "{name}"
             );
         }
     }

tests/compatibility/README.md

@@ -6,7 +6,7 @@ SQL restart tests are run via `cargo sqlness compat` and reuse the sqlness-runne
 
 ## Wire fixtures
 
-Frozen wire fixtures are exercised by the Rust tests that own their context
+Frozen protobuf fixtures are exercised by the Rust tests that own their context
 conversion, not by SQLness case discovery. The
 [legacy query-context fixture](wire/read_preference/README.md) checks omitted
 read-preference defaulting and unrelated metadata preservation:
@@ -15,13 +15,6 @@ read-preference defaulting and unrelated metadata preservation:
 cargo nextest run -p session -E 'test(test_legacy_query_context_wire_defaults_to_leader)'
 ```
 
-The [write-retry metadata fixture](wire/write_retry/README.md) checks legacy,
-route-refresh, missing, and unknown retry-hint decoding in the client:
-
-```shell
-cargo nextest run -p client -E 'test(test_retry_hint_wire_compatibility)'
-```
-
 ## Quick Start
 
 ```shell

tests/compatibility/wire/write_retry/README.md

@@ -1,25 +0,0 @@
-# Write-retry metadata compatibility
-
-`retry_hints.json` freezes gRPC `x-greptime-err-retry-hint` metadata values
-and the expected current client decoding. These are constructed protocol fixtures,
-not captures from released binaries.
-
-The client test converts real `tonic::Status` metadata through the production
-error decoder. Missing and unknown values default to `NonRetryable`; existing
-`retryable` and `non_retryable` values retain their meaning; the new
-`retry_after_route_refresh` value preserves its distinct hint. The application
-status code and gRPC status code remain unchanged.
-
-```shell
-cargo nextest run -p client -E 'test(test_retry_hint_wire_compatibility)'
-```
-
-`test_transport_error_parity_and_datanode_mapping` separately exercises these
-recognized values over an actual gRPC client/server connection.
-
-An older decoder that recognizes only the two legacy strings treats the new
-string as unknown and uses its existing `NonRetryable` fallback. This is a source
-compatibility observation, not a claim that an old binary was run. These tests do
-not promise that an old client will refresh routing or perform automatic retries.
-
-The fixture is hand-authored and must not be regenerated from test output.

tests/compatibility/wire/write_retry/retry_hints.json

@@ -1,7 +0,0 @@
-[
-  {"name": "legacy_missing", "wire_hint": null, "expected_hint": "non_retryable"},
-  {"name": "legacy_retryable", "wire_hint": "retryable", "expected_hint": "retryable"},
-  {"name": "legacy_non_retryable", "wire_hint": "non_retryable", "expected_hint": "non_retryable"},
-  {"name": "route_refresh", "wire_hint": "retry_after_route_refresh", "expected_hint": "retry_after_route_refresh"},
-  {"name": "unknown_future_hint", "wire_hint": "future_retry_hint", "expected_hint": "non_retryable"}
-]