BUG: Lucene.Net.Tests.Queries.TermsFilterTest::TestSingleFieldEquals(): Hash code collision provided in Lucene won't necessarily be a collision in .NET. Generate the collision at runtime so the test will pass (the test wouldn't have passed if the assert hadn't been commented). (#259)
diff --git a/src/Lucene.Net.Tests.Queries/TermsFilterTest.cs b/src/Lucene.Net.Tests.Queries/TermsFilterTest.cs
index 45b1add..7627f18 100644
--- a/src/Lucene.Net.Tests.Queries/TermsFilterTest.cs
+++ b/src/Lucene.Net.Tests.Queries/TermsFilterTest.cs
@@ -339,13 +339,50 @@
[Test]
public void TestSingleFieldEquals()
{
- // Two terms with the same hash code
+ //// Two terms with the same hash code
//assertEquals("AaAaBB".GetHashCode(), "BBBBBB".GetHashCode());
- TermsFilter left = TermsFilter(true, new Term("id", "AaAaAa"), new Term("id", "AaAaBB"));
- TermsFilter right = TermsFilter(true, new Term("id", "AaAaAa"), new Term("id", "BBBBBB"));
+ //TermsFilter left = TermsFilter(true, new Term("id", "AaAaAa"), new Term("id", "AaAaBB"));
+ //TermsFilter right = TermsFilter(true, new Term("id", "AaAaAa"), new Term("id", "BBBBBB"));
+ //assertFalse(left.Equals(right));
+
+ // LUCENENET specific - since in .NET the hash code is dependent on the underlying
+ // target framework, we need to generate a collision at runtime.
+ GenerateHashCollision(out string theString, out string stringWithCollision);
+ assertEquals(theString.GetHashCode(), stringWithCollision.GetHashCode());
+ TermsFilter left = TermsFilter(true, new Term("id", "AaAaAa"), new Term("id", theString));
+ TermsFilter right = TermsFilter(true, new Term("id", "AaAaAa"), new Term("id", stringWithCollision));
assertFalse(left.Equals(right));
}
+ // LUCENENET specific - since in .NET the hash code is dependent on the underlying
+ // target framework, we need to generate a collision at runtime.
+ // Source: https://stackoverflow.com/a/32027473
+ private static void GenerateHashCollision(out string theString, out string stringWithCollision)
+ {
+ var words = new Dictionary<int, string>();
+
+ int i = 0;
+ string teststring;
+ while (true)
+ {
+ i++;
+ teststring = i.ToString();
+ try
+ {
+ words.Add(teststring.GetHashCode(), teststring);
+ }
+ catch (Exception)
+ {
+ break;
+ }
+ }
+
+ var collisionHash = teststring.GetHashCode();
+
+ theString = teststring;
+ stringWithCollision = words[collisionHash];
+ }
+
[Test]
public void TestNoTerms()
{
