Simplify TopKSelectorTest.testExceedMaxIteration()

Fixes #5698 PiperOrigin-RevId: 394579757
google · Sep 3, 2021 · f28b8db · f28b8db
1 parent 54c174a
commit f28b8db
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diff --git a/android/guava-tests/test/com/google/common/collect/TopKSelectorTest.java b/android/guava-tests/test/com/google/common/collect/TopKSelectorTest.java
@@ -17,23 +17,22 @@
 package com.google.common.collect;
 
 import static com.google.common.truth.Truth.assertThat;
-import static java.util.Collections.sort;
 
+import com.google.common.annotations.GwtCompatible;
 import com.google.common.math.IntMath;
 import com.google.common.primitives.Ints;
 import java.math.RoundingMode;
-import java.util.ArrayList;
 import java.util.Collections;
 import java.util.Comparator;
 import java.util.List;
-import java.util.Random;
 import junit.framework.TestCase;
 
 /**
  * Tests for {@code TopKSelector}.
  *
  * @author Louis Wasserman
  */
+@GwtCompatible
 public class TopKSelectorTest extends TestCase {
 
   public void testNegativeK() {
@@ -125,33 +124,10 @@ public int compare(Integer o1, Integer o2) {
 
   public void testExceedMaxIteration() {
     /*
-     * Bug #5692 occurred when TopKSelector called Arrays.sort incorrectly. Test data that would
-     * trigger a problematic call to Arrays.sort is hard to construct by hand, so we searched for
-     * one among randomly generated inputs. To reach the Arrays.sort call, we need to pass an input
-     * that requires many iterations of partitioning inside trim(). So, to construct our random
-     * inputs, we concatenated 10 sorted lists together.
+     * Bug #5692 occurred when TopKSelector called Arrays.sort incorrectly.
      */
-
-    int k = 10000;
-    Random random = new Random(1629833645599L);
-
-    // target list to be sorted using TopKSelector
-    List<Integer> target = new ArrayList<>();
-    for (int i = 0; i < 9; i++) {
-      List<Integer> sortedArray = new ArrayList();
-      for (int j = 0; j < 10000; j++) {
-        sortedArray.add(random.nextInt());
-      }
-      sort(sortedArray, Ordering.natural());
-      target.addAll(sortedArray);
-    }
-
-    TopKSelector<Integer> top = TopKSelector.least(k, Ordering.natural());
-    for (int value : target) {
-      top.offer(value);
-    }
-
-    sort(target, Ordering.natural());
-    assertEquals(top.topK(), target.subList(0, k));
+    TopKSelector<Integer> top = TopKSelector.least(7);
+    top.offerAll(Ints.asList(5, 7, 6, 2, 4, 3, 1, 0, 0, 0, 0, 0, 0, 0));
+    assertThat(top.topK()).isEqualTo(Ints.asList(0, 0, 0, 0, 0, 0, 0));
   }
 }
diff --git a/guava-tests/test/com/google/common/collect/TopKSelectorTest.java b/guava-tests/test/com/google/common/collect/TopKSelectorTest.java
@@ -17,23 +17,22 @@
 package com.google.common.collect;
 
 import static com.google.common.truth.Truth.assertThat;
-import static java.util.Collections.sort;
 
+import com.google.common.annotations.GwtCompatible;
 import com.google.common.math.IntMath;
 import com.google.common.primitives.Ints;
 import java.math.RoundingMode;
-import java.util.ArrayList;
 import java.util.Collections;
 import java.util.Comparator;
 import java.util.List;
-import java.util.Random;
 import junit.framework.TestCase;
 
 /**
  * Tests for {@code TopKSelector}.
  *
  * @author Louis Wasserman
  */
+@GwtCompatible
 public class TopKSelectorTest extends TestCase {
 
   public void testNegativeK() {
@@ -125,33 +124,10 @@ public int compare(Integer o1, Integer o2) {
 
   public void testExceedMaxIteration() {
     /*
-     * Bug #5692 occurred when TopKSelector called Arrays.sort incorrectly. Test data that would
-     * trigger a problematic call to Arrays.sort is hard to construct by hand, so we searched for
-     * one among randomly generated inputs. To reach the Arrays.sort call, we need to pass an input
-     * that requires many iterations of partitioning inside trim(). So, to construct our random
-     * inputs, we concatenated 10 sorted lists together.
+     * Bug #5692 occurred when TopKSelector called Arrays.sort incorrectly.
      */
-
-    int k = 10000;
-    Random random = new Random(1629833645599L);
-
-    // target list to be sorted using TopKSelector
-    List<Integer> target = new ArrayList<>();
-    for (int i = 0; i < 9; i++) {
-      List<Integer> sortedArray = new ArrayList();
-      for (int j = 0; j < 10000; j++) {
-        sortedArray.add(random.nextInt());
-      }
-      sort(sortedArray, Ordering.natural());
-      target.addAll(sortedArray);
-    }
-
-    TopKSelector<Integer> top = TopKSelector.least(k, Ordering.natural());
-    for (int value : target) {
-      top.offer(value);
-    }
-
-    sort(target, Ordering.natural());
-    assertEquals(top.topK(), target.subList(0, k));
+    TopKSelector<Integer> top = TopKSelector.least(7);
+    top.offerAll(Ints.asList(5, 7, 6, 2, 4, 3, 1, 0, 0, 0, 0, 0, 0, 0));
+    assertThat(top.topK()).isEqualTo(Ints.asList(0, 0, 0, 0, 0, 0, 0));
   }
 }