From fcc1fb76907331d1a622a3b4d5e0700337af681b Mon Sep 17 00:00:00 2001
From: Ivan Hetman <Ihromant@users.noreply.github.com>
Date: Tue, 8 Sep 2020 19:02:45 +0300
Subject: [PATCH] Fix Stream.min and Stream.max (#520)

---
 .../util/stream/impl/TSimpleStreamImpl.java   |  4 ++--
 .../classlib/java/util/stream/StreamTest.java | 22 +++++++++++++++++++
 2 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/classlib/src/main/java/org/teavm/classlib/java/util/stream/impl/TSimpleStreamImpl.java b/classlib/src/main/java/org/teavm/classlib/java/util/stream/impl/TSimpleStreamImpl.java
index 3adc07282..07ed91145 100644
--- a/classlib/src/main/java/org/teavm/classlib/java/util/stream/impl/TSimpleStreamImpl.java
+++ b/classlib/src/main/java/org/teavm/classlib/java/util/stream/impl/TSimpleStreamImpl.java
@@ -226,12 +226,12 @@ public abstract class TSimpleStreamImpl<T> implements TStream<T> {
 
     @Override
     public Optional<T> min(Comparator<? super T> comparator) {
-        return reduce((a, b) -> comparator.compare(a, b) < 0 ? a : b);
+        return reduce((a, b) -> comparator.compare(a, b) <= 0 ? a : b);
     }
 
     @Override
     public Optional<T> max(Comparator<? super T> comparator) {
-        return reduce((a, b) -> comparator.compare(a, b) > 0 ? a : b);
+        return reduce((a, b) -> comparator.compare(a, b) >= 0 ? a : b);
     }
 
     @Override
diff --git a/tests/src/test/java/org/teavm/classlib/java/util/stream/StreamTest.java b/tests/src/test/java/org/teavm/classlib/java/util/stream/StreamTest.java
index 996b5c1d7..16d5dd24e 100644
--- a/tests/src/test/java/org/teavm/classlib/java/util/stream/StreamTest.java
+++ b/tests/src/test/java/org/teavm/classlib/java/util/stream/StreamTest.java
@@ -18,12 +18,15 @@ package org.teavm.classlib.java.util.stream;
 import static org.junit.Assert.assertArrayEquals;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertSame;
 import static org.junit.Assert.assertTrue;
 import static org.teavm.classlib.java.util.stream.Helper.appendNumbersTo;
 import static org.teavm.classlib.java.util.stream.Helper.testDoubleStream;
 import static org.teavm.classlib.java.util.stream.Helper.testIntStream;
 import static org.teavm.classlib.java.util.stream.Helper.testIntegerStream;
 import static org.teavm.classlib.java.util.stream.Helper.testLongStream;
+import java.util.Arrays;
+import java.util.Collections;
 import java.util.Comparator;
 import java.util.Iterator;
 import java.util.Spliterator;
@@ -287,6 +290,25 @@ public class StreamTest {
 
         assertFalse(Stream.<Integer>empty().min(Comparator.comparing(x -> x)).isPresent());
         assertFalse(Stream.<Integer>empty().max(Comparator.comparing(x -> x)).isPresent());
+
+        IntPair first = new IntPair(0, 0);
+        IntPair second = new IntPair(0, 1);
+
+        Comparator<IntPair> comp = Comparator.comparingInt(p -> p.number);
+        assertEquals(0, Stream.of(first, second).max(comp).get().id);
+        assertEquals(0, Stream.of(first, second).min(comp).get().id);
+        assertSame(Collections.max(Arrays.asList(first, second), comp), Stream.of(first, second).max(comp).get());
+        assertSame(Collections.min(Arrays.asList(first, second), comp), Stream.of(first, second).min(comp).get());
+    }
+
+    private static class IntPair {
+        private final int number;
+        private final int id;
+
+        private IntPair(int number, int id) {
+            this.number = number;
+            this.id = id;
+        }
     }
 
     @Test