From 1f564eb74a5d9b7495d82bd98110d25a6664ea82 Mon Sep 17 00:00:00 2001
From: Googler <noreply@google.com>
Date: Mon, 27 Nov 2023 12:26:13 -0800
Subject: [PATCH] Implement Optional.ifPresentOrElse.

PiperOrigin-RevId: 585727393
---
 jre/java/java/util/Optional.java              |  8 +++++
 .../j2cl/jre/java8/util/OptionalTest.java     | 32 +++++++++++++++++++
 2 files changed, 40 insertions(+)

diff --git a/jre/java/java/util/Optional.java b/jre/java/java/util/Optional.java
index aed531be1d..c4342a00de 100644
--- a/jre/java/java/util/Optional.java
+++ b/jre/java/java/util/Optional.java
@@ -72,6 +72,14 @@ public void ifPresent(Consumer<? super T> consumer) {
     }
   }
 
+  public void ifPresentOrElse(Consumer<? super T> consumer, Runnable emptyConsumer) {
+    if (isPresent()) {
+      consumer.accept(ref);
+    } else {
+      emptyConsumer.run();
+    }
+  }
+
   public Optional<T> filter(Predicate<? super T> predicate) {
     checkNotNull(predicate);
     if (!isPresent() || predicate.test(ref)) {
diff --git a/jre/javatests/com/google/j2cl/jre/java8/util/OptionalTest.java b/jre/javatests/com/google/j2cl/jre/java8/util/OptionalTest.java
index 55f49b2d33..65934c8896 100644
--- a/jre/javatests/com/google/j2cl/jre/java8/util/OptionalTest.java
+++ b/jre/javatests/com/google/j2cl/jre/java8/util/OptionalTest.java
@@ -107,6 +107,38 @@ public void testIfPresent() {
     assertTrue("Consumer not executed", mutableFlag[0]);
   }
 
+  public void testIfPresentOrElse() {
+    if (isWasm()) {
+      // TODO(b/183769034): Re-enable when NPE on dereference is supported
+      return;
+    }
+
+    // empty case
+    empty.ifPresentOrElse(null, () -> {}); // should not fail as per JavaDoc
+    empty.ifPresentOrElse(wrapped -> fail("Empty Optional should not execute consumer"), () -> {});
+
+    // non-empty case
+    try {
+      present.ifPresentOrElse(null, () -> {});
+      fail("Non-Empty Optional must throw NullPointerException if consumer is null");
+    } catch (NullPointerException e) {
+      // expected
+    }
+
+    present.ifPresentOrElse(
+        (wrapped) -> {
+          assertSame(REFERENCE, wrapped);
+          mutableFlag[0] = true;
+        },
+        () -> fail("Non-Empty Optional should not call empty consumer"));
+    assertTrue("Consumer not executed", mutableFlag[0]);
+    mutableFlag[0] = false;
+    empty.ifPresentOrElse(
+        (wrapped) -> fail("Empty Optional should not call non-empty consumer"),
+        () -> mutableFlag[0] = true);
+    assertTrue("Consumer not executed", mutableFlag[0]);
+  }
+
   public void testFilter() {
     if (isWasm()) {
       // TODO(b/183769034): Re-enable when NPE on dereference is supported