Merge commit '4196569' into merge-2.11-to-2.12-june-1

1 files changed, 48 insertions, 0 deletions

diff --git a/test/junit/scala/collection/immutable/HashMapTest.scala b/test/junit/scala/collection/immutable/HashMapTest.scala
new file mode 100644
index 0000000000..a970786455
--- /dev/null
+++ b/test/junit/scala/collection/immutable/HashMapTest.scala
@@ -0,0 +1,48 @@
+package scala.collection.immutable
+
+import org.junit.Assert.assertEquals
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.junit.runners.JUnit4
+
+@RunWith(classOf[JUnit4])
+class HashMapTest {
+
+  private val computeHashF = {
+    HashMap.empty.computeHash _
+  }
+
+  @Test
+  def canMergeIdenticalHashMap1sWithNullKvs() {
+    def m = new HashMap.HashMap1(1, computeHashF(1), 1, null)
+    val merged = m.merged(m)(null)
+    assertEquals(m, merged)
+  }
+
+  @Test
+  def canMergeIdenticalHashMap1sWithNullKvsCustomMerge() {
+    def m = new HashMap.HashMap1(1, computeHashF(1), 1, null)
+    val merged = m.merged(m) {
+      case ((k1, v1), (k2, v2)) =>
+        (k1, v1 + v2)
+    }
+    assertEquals(new HashMap.HashMap1(1, computeHashF(1), 2, null), merged)
+  }
+
+  @Test
+  def canMergeHashMap1sWithNullKvsHashCollision() {
+    val key1 = 1000L * 1000 * 1000 * 10
+    val key2 = key1.##.toLong
+    assert(key1.## == key2.##)
+
+    val m1 = new HashMap.HashMap1(key1, computeHashF(key1.##), 1, null)
+    val m2 = new HashMap.HashMap1(key2, computeHashF(key2.##), 1, null)
+    val expected = HashMap(key1 -> 1, key2 -> 1)
+    val merged = m1.merged(m2)(null)
+    assertEquals(expected, merged)
+    val mergedWithMergeFunction = m1.merged(m2) { (kv1, kv2) =>
+      throw new RuntimeException("Should not be reached.")
+    }
+    assertEquals(expected, mergedWithMergeFunction)
+  }
+}
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