Introduce MonoFromFutureAsyncLoadingCacheGetAll Refaster rule (#1551)

PicnicSupermarket · Feb 18, 2025 · c2a26ed · c2a26ed
1 parent 2419dad
commit c2a26ed
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diff --git a/error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/ReactorRules.java b/error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/ReactorRules.java
@@ -2174,6 +2174,22 @@ Mono<V> after(AsyncLoadingCache<K, V> cache, K key) {
     }
   }
 
+  /**
+   * Don't propagate {@link Mono} cancellations to upstream cache value computations, as completion
+   * of such computations may benefit concurrent or subsequent cache usages.
+   */
+  static final class MonoFromFutureAsyncLoadingCacheGetAll<K1, K2 extends K1, V> {
+    @BeforeTemplate
+    Mono<Map<K1, V>> before(AsyncLoadingCache<K1, V> cache, Iterable<K2> keys) {
+      return Mono.fromFuture(() -> cache.getAll(keys));
+    }
+
+    @AfterTemplate
+    Mono<Map<K1, V>> after(AsyncLoadingCache<K1, V> cache, Iterable<K2> keys) {
+      return Mono.fromFuture(() -> cache.getAll(keys), /* suppressCancel= */ true);
+    }
+  }
+
   /**
    * Prefer {@link Flux#fromStream(Supplier)} over {@link Flux#fromStream(Stream)}, as the former
    * yields a {@link Flux} that is more likely to behave as expected when subscribed to more than

diff --git a/...ontrib/src/test/resources/tech/picnic/errorprone/refasterrules/ReactorRulesTestInput.java b/...ontrib/src/test/resources/tech/picnic/errorprone/refasterrules/ReactorRulesTestInput.java
@@ -20,6 +20,7 @@
 import java.util.Collection;
 import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
 import java.util.Optional;
 import java.util.concurrent.Callable;
 import java.util.concurrent.CompletableFuture;
@@ -745,6 +746,11 @@ Mono<String> testMonoFromFutureAsyncLoadingCacheGet() {
     return Mono.fromFuture(() -> ((AsyncLoadingCache<Integer, String>) null).get(0));
   }
 
+  Mono<Map<Integer, String>> testMonoFromFutureAsyncLoadingCacheGetAll() {
+    return Mono.fromFuture(
+        () -> ((AsyncLoadingCache<Integer, String>) null).getAll(ImmutableSet.of()));
+  }
+
   Flux<Integer> testFluxFromStreamSupplier() {
     return Flux.fromStream(Stream.of(1));
   }

diff --git a/...ntrib/src/test/resources/tech/picnic/errorprone/refasterrules/ReactorRulesTestOutput.java b/...ntrib/src/test/resources/tech/picnic/errorprone/refasterrules/ReactorRulesTestOutput.java
@@ -22,6 +22,7 @@
 import java.util.Collection;
 import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
 import java.util.Optional;
 import java.util.concurrent.Callable;
 import java.util.concurrent.CompletableFuture;
@@ -719,6 +720,11 @@ Mono<String> testMonoFromFutureAsyncLoadingCacheGet() {
     return Mono.fromFuture(() -> ((AsyncLoadingCache<Integer, String>) null).get(0), true);
   }
 
+  Mono<Map<Integer, String>> testMonoFromFutureAsyncLoadingCacheGetAll() {
+    return Mono.fromFuture(
+        () -> ((AsyncLoadingCache<Integer, String>) null).getAll(ImmutableSet.of()), true);
+  }
+
   Flux<Integer> testFluxFromStreamSupplier() {
     return Flux.fromStream(() -> Stream.of(1));
   }