Added a test with a path diversion because of jdk statics

utbot-framework-test/src/test/kotlin/org/utbot/examples/stdlib/StaticsPathDiversionTest.kt

@@ -0,0 +1,41 @@
+package org.utbot.examples.stdlib
+
+import org.junit.jupiter.api.Disabled
+import org.junit.jupiter.api.Test
+import org.utbot.framework.plugin.api.CodegenLanguage
+import org.utbot.framework.plugin.api.util.id
+import org.utbot.testcheckers.ge
+import org.utbot.testing.FullWithAssumptions
+import org.utbot.testing.UtValueTestCaseChecker
+import java.io.File
+
+internal class StaticsPathDiversionTest : UtValueTestCaseChecker(
+    testClass = StaticsPathDiversion::class,
+    testCodeGeneration = true,
+    pipelines = listOf(
+        TestLastStage(CodegenLanguage.JAVA),
+        TestLastStage(CodegenLanguage.KOTLIN)
+    )
+) {
+    @Test
+    @Disabled("See https://github.com/UnitTestBot/UTBotJava/issues/716")
+    fun testJavaIOFile() {
+        // TODO Here we have a path diversion example - the static field `java.io.File#separator` is considered as not meaningful,
+        //  so it is not passed to the concrete execution because of absence in the `stateBefore` models.
+        //  So, the symbolic engine has 2 results - true and false, as expected, but the concrete executor may produce 1 or 2,
+        //  depending on the model for the argument of the MUT produced by the solver.
+        //  Such diversion was predicted to some extent - see `org.utbot.common.WorkaroundReason.IGNORE_STATICS_FROM_TRUSTED_LIBRARIES`
+        //  and the corresponding issue https://github.com/UnitTestBot/UTBotJava/issues/716
+        check(
+            StaticsPathDiversion::separatorEquality,
+            ge(2), // We cannot guarantee the exact number of branches without minimization
+
+            // In the matchers below we check that the symbolic does not change the static field `File.separator` - we should
+            // change the parameter, not the static field
+            { s, separator -> separator == File.separator && s == separator },
+            { s, separator -> separator == File.separator && s != separator },
+            additionalMockAlwaysClasses = setOf(java.io.File::class.id), // From the use-case
+            coverage = FullWithAssumptions(assumeCallsNumber = 1)
+        )
+    }
+}

utbot-sample/src/main/java/org/utbot/examples/stdlib/StaticsPathDiversion.java

@@ -0,0 +1,21 @@
+package org.utbot.examples.stdlib;
+
+import org.utbot.api.mock.UtMock;
+
+import java.io.File;
+
+public class StaticsPathDiversion {
+    @SuppressWarnings({"IfStatementWithIdenticalBranches"})
+    // In this test we check that the symbolic engine does not change the static field `File.separator`
+    public String separatorEquality(String s) {
+        // Ignore this case to make sure we will have not more than 2 executions even without minimization
+        UtMock.assume(s != null);
+
+        // We use if-else here instead of a simple return to get executions for both return values
+        if (File.separator.equals(s)) {
+            return File.separator;
+        } else {
+            return File.separator;
+        }
+    }
+}