restore core gRPC server tests & add testing framework for gateway handlers

crates/defguard_common/src/config.rs

@@ -230,7 +230,48 @@ impl DefGuardConfig {
     // this is an ugly workaround to avoid `cargo test` args being captured by `clap`
     #[must_use]
     pub fn new_test_config() -> Self {
-        Self::parse_from::<[_; 0], String>([])
+        #[expect(
+            deprecated,
+            reason = "Test config still initializes compatibility-only deprecated fields"
+        )]
+        let config = Self {
+            log_level: "info".to_string(),
+            log_file: None,
+            secret_key: None,
+            database_host: "localhost".to_string(),
+            database_port: 5432,
+            database_name: "defguard".to_string(),
+            database_user: "defguard".to_string(),
+            database_password: SecretString::from(String::new()),
+            http_port: 8000,
+            grpc_port: 50055,
+            grpc_cert: None,
+            grpc_key: None,
+            openid_signing_key: None,
+            url: None,
+            disable_stats_purge: None,
+            stats_purge_frequency: None,
+            stats_purge_threshold: None,
+            enrollment_url: None,
+            enrollment_token_timeout: None,
+            mfa_code_timeout: None,
+            session_timeout: None,
+            password_reset_token_timeout: None,
+            enrollment_session_timeout: None,
+            password_reset_session_timeout: None,
+            cookie_domain: None,
+            cookie_insecure: false,
+            cmd: None,
+            check_period: std::time::Duration::from_secs(12 * 3600).into(),
+            check_period_no_license: std::time::Duration::from_secs(24 * 3600).into(),
+            check_period_renewal_window: std::time::Duration::from_secs(3600).into(),
+            http_bind_address: None,
+            grpc_bind_address: None,
+            adopt_gateway: None,
+            adopt_edge: None,
+        };
+
+        config
     }
 
     /// Validate that the auto-adoption flags are consistent.

crates/defguard_common/src/db/models/gateway.rs

@@ -34,6 +34,12 @@ impl<I> Gateway<I> {
             self.connected_at.is_some()
         }
     }
+
+    /// Return address and port as URL with HTTP scheme.
+    #[must_use]
+    pub fn url(&self) -> String {
+        format!("http://{}:{}", self.address, self.port)
+    }
 }
 
 impl Gateway {
@@ -168,12 +174,6 @@ impl Gateway<Id> {
         Ok(record)
     }
 
-    /// Return address and port as URL with HTTP scheme.
-    #[must_use]
-    pub fn url(&self) -> String {
-        format!("http://{}:{}", self.address, self.port)
-    }
-
     /// Disable all Gateways except one. Used for expired licence.
     pub async fn leave_one_enabled<'e, E>(executor: E) -> sqlx::Result<()>
     where

crates/defguard_core/Cargo.toml

@@ -87,6 +87,7 @@ async-stream = "0.3"
 
 [dev-dependencies]
 claims.workspace = true
+hyper-util = "0.1"
 matches.workspace = true
 reqwest = { version = "0.12", features = [
     "cookies",

crates/defguard_core/src/grpc/mod.rs

@@ -96,7 +96,7 @@ pub async fn run_grpc_server(
     Ok(())
 }
 
-pub(crate) async fn build_grpc_service_router(
+pub async fn build_grpc_service_router(
     server: Server,
     pool: PgPool,
     worker_state: Arc<Mutex<WorkerState>>,
@@ -114,6 +114,9 @@ pub(crate) async fn build_grpc_service_router(
     health_reporter
         .set_serving::<AuthServiceServer<AuthServer>>()
         .await;
+    health_reporter
+        .set_serving::<WorkerServiceServer<WorkerServer>>()
+        .await;
 
     let router = server
         .http2_keepalive_interval(Some(TEN_SECS))