feat: Add get_ext() helper method on WorkerContext

crates/ctx/src/lib.rs

@@ -1,3 +1,5 @@
+use std::fmt::Debug;
+
 use getset::Getters;
 use graphile_worker_extensions::ReadOnlyExtensions;
 use graphile_worker_job::Job;
@@ -7,14 +9,20 @@ use sqlx::PgPool;
 #[derive(Getters, Clone, Debug)]
 #[getset(get = "pub")]
 pub struct WorkerContext {
+    /// The payload of the job.
     payload: Value,
+    /// The postgres pool.
     pg_pool: PgPool,
+    /// The job.
     job: Job,
+    /// The worker id.
     worker_id: String,
+    /// Extensions (for providing custom app state)
     extensions: ReadOnlyExtensions,
 }
 
 impl WorkerContext {
+    /// Creates a new WorkerContext.
     pub fn new(
         payload: Value,
         pg_pool: PgPool,
@@ -30,4 +38,9 @@ impl WorkerContext {
             extensions,
         }
     }
+
+    /// Returns the extension value associated with the specified type.
+    pub fn get_ext<T: Send + Sync + 'static>(&self) -> Option<&T> {
+        self.extensions.get()
+    }
 }