From 60ba1ab80bb09ecb1cff8618589710b4fea9cab7 Mon Sep 17 00:00:00 2001
From: cpovirk <cpovirk@google.com>
Date: Thu, 20 Feb 2025 09:59:57 -0800
Subject: [PATCH] Reduce scope of suppressions in `Abstract*Future` classes,
 and make the classes look slightly more similar to one another.

RELNOTES=n/a
PiperOrigin-RevId: 729152015
---
 .../concurrent/AbstractCatchingFuture.java    | 62 +++++++++----------
 .../concurrent/AbstractTransformFuture.java   | 20 +++---
 .../concurrent/AbstractCatchingFuture.java    | 62 +++++++++----------
 .../concurrent/AbstractTransformFuture.java   | 20 +++---
 4 files changed, 78 insertions(+), 86 deletions(-)

diff --git a/android/guava/src/com/google/common/util/concurrent/AbstractCatchingFuture.java b/android/guava/src/com/google/common/util/concurrent/AbstractCatchingFuture.java
index c15f6cb658e2..9482e213eeb4 100644
--- a/android/guava/src/com/google/common/util/concurrent/AbstractCatchingFuture.java
+++ b/android/guava/src/com/google/common/util/concurrent/AbstractCatchingFuture.java
@@ -34,11 +34,8 @@
 
 /** Implementations of {@code Futures.catching*}. */
 @GwtCompatible
-@SuppressWarnings({
-  // Whenever both tests are cheap and functional, it's faster to use &, | instead of &&, ||
-  "ShortCircuitBoolean",
-  "nullness", // TODO(b/147136275): Remove once our checker understands & and |.
-})
+// Whenever both tests are cheap and functional, it's faster to use &, | instead of &&, ||
+@SuppressWarnings("ShortCircuitBoolean")
 abstract class AbstractCatchingFuture<
         V extends @Nullable Object, X extends Throwable, F, T extends @Nullable Object>
     extends FluentFuture.TrustedFuture<V> implements Runnable {
@@ -47,9 +44,9 @@ abstract class AbstractCatchingFuture<
       Class<X> exceptionType,
       Function<? super X, ? extends V> fallback,
       Executor executor) {
-    CatchingFuture<V, X> future = new CatchingFuture<>(input, exceptionType, fallback);
-    input.addListener(future, rejectionPropagatingExecutor(executor, future));
-    return future;
+    CatchingFuture<V, X> output = new CatchingFuture<>(input, exceptionType, fallback);
+    input.addListener(output, rejectionPropagatingExecutor(executor, output));
+    return output;
   }
 
   static <X extends Throwable, V extends @Nullable Object> ListenableFuture<V> createAsync(
@@ -57,9 +54,9 @@ abstract class AbstractCatchingFuture<
       Class<X> exceptionType,
       AsyncFunction<? super X, ? extends V> fallback,
       Executor executor) {
-    AsyncCatchingFuture<V, X> future = new AsyncCatchingFuture<>(input, exceptionType, fallback);
-    input.addListener(future, rejectionPropagatingExecutor(executor, future));
-    return future;
+    AsyncCatchingFuture<V, X> output = new AsyncCatchingFuture<>(input, exceptionType, fallback);
+    input.addListener(output, rejectionPropagatingExecutor(executor, output));
+    return output;
   }
 
   /*
@@ -78,6 +75,7 @@ abstract class AbstractCatchingFuture<
   }
 
   @Override
+  @SuppressWarnings("nullness") // TODO(b/147136275): Remove once our checker understands & and |.
   public final void run() {
     @RetainedLocalRef ListenableFuture<? extends V> localInputFuture = inputFuture;
     @RetainedLocalRef Class<X> localExceptionType = exceptionType;
@@ -148,6 +146,24 @@ public final void run() {
     setResult(fallbackResult);
   }
 
+  /** Template method for subtypes to actually run the fallback. */
+  @ForOverride
+  @ParametricNullness
+  abstract T doFallback(F fallback, X throwable) throws Exception;
+
+  /** Template method for subtypes to actually set the result. */
+  @ForOverride
+  abstract void setResult(@ParametricNullness T result);
+
+  @Override
+  protected final void afterDone() {
+    @RetainedLocalRef ListenableFuture<? extends V> localInputFuture = inputFuture;
+    maybePropagateCancellationTo(localInputFuture);
+    this.inputFuture = null;
+    this.exceptionType = null;
+    this.fallback = null;
+  }
+
   @Override
   protected @Nullable String pendingToString() {
     @RetainedLocalRef ListenableFuture<? extends V> localInputFuture = inputFuture;
@@ -171,24 +187,6 @@ public final void run() {
     return null;
   }
 
-  /** Template method for subtypes to actually run the fallback. */
-  @ForOverride
-  @ParametricNullness
-  abstract T doFallback(F fallback, X throwable) throws Exception;
-
-  /** Template method for subtypes to actually set the result. */
-  @ForOverride
-  abstract void setResult(@ParametricNullness T result);
-
-  @Override
-  protected final void afterDone() {
-    @RetainedLocalRef ListenableFuture<? extends V> localInputFuture = inputFuture;
-    maybePropagateCancellationTo(localInputFuture);
-    this.inputFuture = null;
-    this.exceptionType = null;
-    this.fallback = null;
-  }
-
   /**
    * An {@link AbstractCatchingFuture} that delegates to an {@link AsyncFunction} and {@link
    * #setFuture(ListenableFuture)}.
@@ -206,13 +204,13 @@ private static final class AsyncCatchingFuture<V extends @Nullable Object, X ext
     @Override
     ListenableFuture<? extends V> doFallback(
         AsyncFunction<? super X, ? extends V> fallback, X cause) throws Exception {
-      ListenableFuture<? extends V> replacement = fallback.apply(cause);
+      ListenableFuture<? extends V> output = fallback.apply(cause);
       checkNotNull(
-          replacement,
+          output,
           "AsyncFunction.apply returned null instead of a Future. "
               + "Did you mean to return immediateFuture(null)? %s",
           fallback);
-      return replacement;
+      return output;
     }
 
     @Override
diff --git a/android/guava/src/com/google/common/util/concurrent/AbstractTransformFuture.java b/android/guava/src/com/google/common/util/concurrent/AbstractTransformFuture.java
index 5a078eb48901..a455f7d24140 100644
--- a/android/guava/src/com/google/common/util/concurrent/AbstractTransformFuture.java
+++ b/android/guava/src/com/google/common/util/concurrent/AbstractTransformFuture.java
@@ -31,11 +31,8 @@
 
 /** Implementations of {@code Futures.transform*}. */
 @GwtCompatible
-@SuppressWarnings({
-  // Whenever both tests are cheap and functional, it's faster to use &, | instead of &&, ||
-  "ShortCircuitBoolean",
-  "nullness", // TODO(b/147136275): Remove once our checker understands & and |.
-})
+// Whenever both tests are cheap and functional, it's faster to use &, | instead of &&, ||
+@SuppressWarnings("ShortCircuitBoolean")
 abstract class AbstractTransformFuture<
         I extends @Nullable Object, O extends @Nullable Object, F, T extends @Nullable Object>
     extends FluentFuture.TrustedFuture<O> implements Runnable {
@@ -43,7 +40,6 @@ abstract class AbstractTransformFuture<
       ListenableFuture<I> input,
       AsyncFunction<? super I, ? extends O> function,
       Executor executor) {
-    checkNotNull(executor);
     AsyncTransformFuture<I, O> output = new AsyncTransformFuture<>(input, function);
     input.addListener(output, rejectionPropagatingExecutor(executor, output));
     return output;
@@ -51,7 +47,6 @@ abstract class AbstractTransformFuture<
 
   static <I extends @Nullable Object, O extends @Nullable Object> ListenableFuture<O> create(
       ListenableFuture<I> input, Function<? super I, ? extends O> function, Executor executor) {
-    checkNotNull(function);
     TransformFuture<I, O> output = new TransformFuture<>(input, function);
     input.addListener(output, rejectionPropagatingExecutor(executor, output));
     return output;
@@ -70,7 +65,10 @@ abstract class AbstractTransformFuture<
   }
 
   @Override
-  @SuppressWarnings("CatchingUnchecked") // sneaky checked exception
+  @SuppressWarnings({
+    "CatchingUnchecked", // sneaky checked exception
+    "nullness", // TODO(b/147136275): Remove once our checker understands & and |.
+  })
   public final void run() {
     @RetainedLocalRef ListenableFuture<? extends I> localInputFuture = inputFuture;
     @RetainedLocalRef F localFunction = function;
@@ -225,13 +223,13 @@ private static final class AsyncTransformFuture<
     ListenableFuture<? extends O> doTransform(
         AsyncFunction<? super I, ? extends O> function, @ParametricNullness I input)
         throws Exception {
-      ListenableFuture<? extends O> outputFuture = function.apply(input);
+      ListenableFuture<? extends O> output = function.apply(input);
       checkNotNull(
-          outputFuture,
+          output,
           "AsyncFunction.apply returned null instead of a Future. "
               + "Did you mean to return immediateFuture(null)? %s",
           function);
-      return outputFuture;
+      return output;
     }
 
     @Override
diff --git a/guava/src/com/google/common/util/concurrent/AbstractCatchingFuture.java b/guava/src/com/google/common/util/concurrent/AbstractCatchingFuture.java
index c15f6cb658e2..9482e213eeb4 100644
--- a/guava/src/com/google/common/util/concurrent/AbstractCatchingFuture.java
+++ b/guava/src/com/google/common/util/concurrent/AbstractCatchingFuture.java
@@ -34,11 +34,8 @@
 
 /** Implementations of {@code Futures.catching*}. */
 @GwtCompatible
-@SuppressWarnings({
-  // Whenever both tests are cheap and functional, it's faster to use &, | instead of &&, ||
-  "ShortCircuitBoolean",
-  "nullness", // TODO(b/147136275): Remove once our checker understands & and |.
-})
+// Whenever both tests are cheap and functional, it's faster to use &, | instead of &&, ||
+@SuppressWarnings("ShortCircuitBoolean")
 abstract class AbstractCatchingFuture<
         V extends @Nullable Object, X extends Throwable, F, T extends @Nullable Object>
     extends FluentFuture.TrustedFuture<V> implements Runnable {
@@ -47,9 +44,9 @@ abstract class AbstractCatchingFuture<
       Class<X> exceptionType,
       Function<? super X, ? extends V> fallback,
       Executor executor) {
-    CatchingFuture<V, X> future = new CatchingFuture<>(input, exceptionType, fallback);
-    input.addListener(future, rejectionPropagatingExecutor(executor, future));
-    return future;
+    CatchingFuture<V, X> output = new CatchingFuture<>(input, exceptionType, fallback);
+    input.addListener(output, rejectionPropagatingExecutor(executor, output));
+    return output;
   }
 
   static <X extends Throwable, V extends @Nullable Object> ListenableFuture<V> createAsync(
@@ -57,9 +54,9 @@ abstract class AbstractCatchingFuture<
       Class<X> exceptionType,
       AsyncFunction<? super X, ? extends V> fallback,
       Executor executor) {
-    AsyncCatchingFuture<V, X> future = new AsyncCatchingFuture<>(input, exceptionType, fallback);
-    input.addListener(future, rejectionPropagatingExecutor(executor, future));
-    return future;
+    AsyncCatchingFuture<V, X> output = new AsyncCatchingFuture<>(input, exceptionType, fallback);
+    input.addListener(output, rejectionPropagatingExecutor(executor, output));
+    return output;
   }
 
   /*
@@ -78,6 +75,7 @@ abstract class AbstractCatchingFuture<
   }
 
   @Override
+  @SuppressWarnings("nullness") // TODO(b/147136275): Remove once our checker understands & and |.
   public final void run() {
     @RetainedLocalRef ListenableFuture<? extends V> localInputFuture = inputFuture;
     @RetainedLocalRef Class<X> localExceptionType = exceptionType;
@@ -148,6 +146,24 @@ public final void run() {
     setResult(fallbackResult);
   }
 
+  /** Template method for subtypes to actually run the fallback. */
+  @ForOverride
+  @ParametricNullness
+  abstract T doFallback(F fallback, X throwable) throws Exception;
+
+  /** Template method for subtypes to actually set the result. */
+  @ForOverride
+  abstract void setResult(@ParametricNullness T result);
+
+  @Override
+  protected final void afterDone() {
+    @RetainedLocalRef ListenableFuture<? extends V> localInputFuture = inputFuture;
+    maybePropagateCancellationTo(localInputFuture);
+    this.inputFuture = null;
+    this.exceptionType = null;
+    this.fallback = null;
+  }
+
   @Override
   protected @Nullable String pendingToString() {
     @RetainedLocalRef ListenableFuture<? extends V> localInputFuture = inputFuture;
@@ -171,24 +187,6 @@ public final void run() {
     return null;
   }
 
-  /** Template method for subtypes to actually run the fallback. */
-  @ForOverride
-  @ParametricNullness
-  abstract T doFallback(F fallback, X throwable) throws Exception;
-
-  /** Template method for subtypes to actually set the result. */
-  @ForOverride
-  abstract void setResult(@ParametricNullness T result);
-
-  @Override
-  protected final void afterDone() {
-    @RetainedLocalRef ListenableFuture<? extends V> localInputFuture = inputFuture;
-    maybePropagateCancellationTo(localInputFuture);
-    this.inputFuture = null;
-    this.exceptionType = null;
-    this.fallback = null;
-  }
-
   /**
    * An {@link AbstractCatchingFuture} that delegates to an {@link AsyncFunction} and {@link
    * #setFuture(ListenableFuture)}.
@@ -206,13 +204,13 @@ private static final class AsyncCatchingFuture<V extends @Nullable Object, X ext
     @Override
     ListenableFuture<? extends V> doFallback(
         AsyncFunction<? super X, ? extends V> fallback, X cause) throws Exception {
-      ListenableFuture<? extends V> replacement = fallback.apply(cause);
+      ListenableFuture<? extends V> output = fallback.apply(cause);
       checkNotNull(
-          replacement,
+          output,
           "AsyncFunction.apply returned null instead of a Future. "
               + "Did you mean to return immediateFuture(null)? %s",
           fallback);
-      return replacement;
+      return output;
     }
 
     @Override
diff --git a/guava/src/com/google/common/util/concurrent/AbstractTransformFuture.java b/guava/src/com/google/common/util/concurrent/AbstractTransformFuture.java
index 5a078eb48901..a455f7d24140 100644
--- a/guava/src/com/google/common/util/concurrent/AbstractTransformFuture.java
+++ b/guava/src/com/google/common/util/concurrent/AbstractTransformFuture.java
@@ -31,11 +31,8 @@
 
 /** Implementations of {@code Futures.transform*}. */
 @GwtCompatible
-@SuppressWarnings({
-  // Whenever both tests are cheap and functional, it's faster to use &, | instead of &&, ||
-  "ShortCircuitBoolean",
-  "nullness", // TODO(b/147136275): Remove once our checker understands & and |.
-})
+// Whenever both tests are cheap and functional, it's faster to use &, | instead of &&, ||
+@SuppressWarnings("ShortCircuitBoolean")
 abstract class AbstractTransformFuture<
         I extends @Nullable Object, O extends @Nullable Object, F, T extends @Nullable Object>
     extends FluentFuture.TrustedFuture<O> implements Runnable {
@@ -43,7 +40,6 @@ abstract class AbstractTransformFuture<
       ListenableFuture<I> input,
       AsyncFunction<? super I, ? extends O> function,
       Executor executor) {
-    checkNotNull(executor);
     AsyncTransformFuture<I, O> output = new AsyncTransformFuture<>(input, function);
     input.addListener(output, rejectionPropagatingExecutor(executor, output));
     return output;
@@ -51,7 +47,6 @@ abstract class AbstractTransformFuture<
 
   static <I extends @Nullable Object, O extends @Nullable Object> ListenableFuture<O> create(
       ListenableFuture<I> input, Function<? super I, ? extends O> function, Executor executor) {
-    checkNotNull(function);
     TransformFuture<I, O> output = new TransformFuture<>(input, function);
     input.addListener(output, rejectionPropagatingExecutor(executor, output));
     return output;
@@ -70,7 +65,10 @@ abstract class AbstractTransformFuture<
   }
 
   @Override
-  @SuppressWarnings("CatchingUnchecked") // sneaky checked exception
+  @SuppressWarnings({
+    "CatchingUnchecked", // sneaky checked exception
+    "nullness", // TODO(b/147136275): Remove once our checker understands & and |.
+  })
   public final void run() {
     @RetainedLocalRef ListenableFuture<? extends I> localInputFuture = inputFuture;
     @RetainedLocalRef F localFunction = function;
@@ -225,13 +223,13 @@ private static final class AsyncTransformFuture<
     ListenableFuture<? extends O> doTransform(
         AsyncFunction<? super I, ? extends O> function, @ParametricNullness I input)
         throws Exception {
-      ListenableFuture<? extends O> outputFuture = function.apply(input);
+      ListenableFuture<? extends O> output = function.apply(input);
       checkNotNull(
-          outputFuture,
+          output,
           "AsyncFunction.apply returned null instead of a Future. "
               + "Did you mean to return immediateFuture(null)? %s",
           function);
-      return outputFuture;
+      return output;
     }
 
     @Override