add test for LRUHashDict

nano-dhall/src/main/scala/io/chymyst/nanodhall/LRUHashDict.scala

@@ -17,7 +17,6 @@ class LRUHashDict[A](maxSize: Int) extends HashDict[A] {
 
   override def store(value: A): Int = {
     val key = keyDict.computeIfAbsent(value, _ => valueDict.size + 1)
-    assert(!valueDict.containsKey(key))
     valueDict.put(key, value)
     key
   }

nano-dhall/src/test/scala/io/chymyst/nanodhall/unit/LRUHashDictTest.scala

@@ -0,0 +1,19 @@
+package io.chymyst.nanodhall.unit
+
+import com.eed3si9n.expecty.Expecty.expect
+import io.chymyst.dhall.LRUHashDict
+import munit.FunSuite
+
+class LRUHashDictTest extends FunSuite {
+  test("hash strings") {
+    val dict = new LRUHashDict[String](10)
+    val abc  = dict.store("abc")
+    val cde  = dict.store("cde")
+    expect(abc != cde)
+    expect(dict.store("abc") == abc)
+    expect(dict.store("cde") == cde)
+    expect(dict.lookup(abc) == Some("abc"))
+    expect(dict.lookup(cde) == Some("cde"))
+    expect(dict.lookup(0) == None)
+  }
+}