Fix a type mapping bug

src/main/kotlin/org/openrewrite/kotlin/KotlinTypeMapping.kt

@@ -84,10 +84,13 @@ class KotlinTypeMapping(
             return Unknown.getInstance()
         }
         val signature = signatureBuilder.signature(type, parent)
-        val existing = typeCache.get<JavaType>(signature)
-        if (existing != null) {
-            return existing
+        if (signature.isNotEmpty()) {
+            val existing = typeCache.get<JavaType>(signature)
+            if (existing != null) {
+                return existing
+            }
         }
+
         return type(type, parent, signature)
     }
 

src/test/java/org/openrewrite/kotlin/tree/ObjectExpressionTest.java

@@ -69,4 +69,21 @@ interface B
           )
         );
     }
+
+    @Issue("https://github.com/openrewrite/rewrite-kotlin/issues/373")
+    @Test
+    void anonymousObject2() {
+        rewriteRun(
+          kotlin(
+            """
+              open class Object<T>
+              class Test(name: String, any: Any)
+              
+              fun <T> foo(name: String) =
+                  Test(name, object : Object<T>() {
+                  })
+              """
+          )
+        );
+    }
 }