Fixed wrong targets for virtual invokes (#925)

Author: Damtev

utbot-framework-test/src/test/kotlin/org/utbot/examples/stream/BaseStreamExampleTest.kt

@@ -343,14 +343,13 @@ class BaseStreamExampleTest : UtValueTestCaseChecker(
     }
 
     @Test
-    @Disabled("TODO unsat type constraints https://github.com/UnitTestBot/UTBotJava/issues/253")
     fun testCustomCollectionStreamExample() {
         check(
             BaseStreamExample::customCollectionStreamExample,
             ignoreExecutionsNumber,
             { c, r -> c.isEmpty() && r == 0L },
             { c, r -> c.isNotEmpty() && c.size.toLong() == r },
-            coverage = DoNotCalculate
+            coverage = DoNotCalculate // TODO failed coverage calculation
         )
     }
 

utbot-framework/src/main/kotlin/org/utbot/engine/Traverser.kt

@@ -2346,8 +2346,15 @@ class Traverser(
         // for objects (especially objects with type equals to type parameter of generic)
         // better than engine.
         val types = instanceOfConstraint?.typeStorage?.possibleConcreteTypes ?: instance.possibleConcreteTypes
-        val methodInvocationTargets = findLibraryTargets(instance.type, methodSubSignature)
-            ?: findMethodInvocationTargets(types, methodSubSignature)
+
+        val allPossibleConcreteTypes = typeResolver
+            .constructTypeStorage(instance.type, useConcreteType = false)
+            .possibleConcreteTypes
+
+        val methodInvocationTargets = findLibraryTargets(instance.type, methodSubSignature)?.takeIf {
+            // we have no specified types, so we can take only library targets (if present) for optimization purposes
+            types.size == allPossibleConcreteTypes.size
+        } ?: findMethodInvocationTargets(types, methodSubSignature)
 
         return methodInvocationTargets
             .map { (method, implementationClass, possibleTypes) ->

utbot-sample/src/main/java/org/utbot/examples/stream/BaseStreamExample.java

@@ -410,21 +410,16 @@ long closedStreamExample(List<Integer> values) {
     }
 
     @SuppressWarnings({"ReplaceInefficientStreamCount", "ConstantConditions"})
+    // TODO wrong generic type for data field https://github.com/UnitTestBot/UTBotJava/issues/730
     long customCollectionStreamExample(CustomCollection<Integer> customCollection) {
         UtMock.assume(customCollection != null && customCollection.data != null);
 
-        if (customCollection.isEmpty()) {
-            return customCollection.stream().count();
+        final Stream<Integer> stream = customCollection.stream();
 
-            // simplified example, does not generate branch too
-            /*customCollection.removeIf(Objects::isNull);
-            return customCollection.toArray().length;*/
+        if (customCollection.isEmpty()) {
+            return stream.count();
         } else {
-            return customCollection.stream().count();
-
-            // simplified example, does not generate branch too
-            /*customCollection.removeIf(Objects::isNull);
-            return customCollection.toArray().length;*/
+            return stream.count();
         }
     }