diff --git a/analysis/low-level-api-fir/tests/org/jetbrains/kotlin/analysis/low/level/api/fir/diagnostic/compiler/based/DiagnosticCompilerTestFE10TestdataTestGenerated.java b/analysis/low-level-api-fir/tests/org/jetbrains/kotlin/analysis/low/level/api/fir/diagnostic/compiler/based/DiagnosticCompilerTestFE10TestdataTestGenerated.java
index 2c6bc42c71b..f2a672e1c6b 100644
--- a/analysis/low-level-api-fir/tests/org/jetbrains/kotlin/analysis/low/level/api/fir/diagnostic/compiler/based/DiagnosticCompilerTestFE10TestdataTestGenerated.java
+++ b/analysis/low-level-api-fir/tests/org/jetbrains/kotlin/analysis/low/level/api/fir/diagnostic/compiler/based/DiagnosticCompilerTestFE10TestdataTestGenerated.java
@@ -42435,12 +42435,6 @@ public class DiagnosticCompilerTestFE10TestdataTestGenerated extends AbstractDia
       runTest("compiler/testData/diagnostics/testsWithStdLib/shadowingInDestructuring.kt");
     }
 
-    @Test
-    @TestMetadata("streams.kt")
-    public void testStreams() {
-      runTest("compiler/testData/diagnostics/testsWithStdLib/streams.kt");
-    }
-
     @Nested
     @TestMetadata("compiler/testData/diagnostics/testsWithStdLib/annotations")
     @TestDataPath("$PROJECT_ROOT")
@@ -47057,6 +47051,28 @@ public class DiagnosticCompilerTestFE10TestdataTestGenerated extends AbstractDia
       }
     }
 
+    @Nested
+    @TestMetadata("compiler/testData/diagnostics/testsWithStdLib/streams")
+    @TestDataPath("$PROJECT_ROOT")
+    public class Streams {
+      @Test
+      public void testAllFilesPresentInStreams() {
+        KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/diagnostics/testsWithStdLib/streams"), Pattern.compile("^(.+)\\.(kt|kts)$"), Pattern.compile("^(.+)\\.(reversed|fir|ll)\\.kts?$"), true);
+      }
+
+      @Test
+      @TestMetadata("basic.kt")
+      public void testBasic() {
+        runTest("compiler/testData/diagnostics/testsWithStdLib/streams/basic.kt");
+      }
+
+      @Test
+      @TestMetadata("wrongNullability.kt")
+      public void testWrongNullability() {
+        runTest("compiler/testData/diagnostics/testsWithStdLib/streams/wrongNullability.kt");
+      }
+    }
+
     @Nested
     @TestMetadata("compiler/testData/diagnostics/testsWithStdLib/targetedBuiltIns")
     @TestDataPath("$PROJECT_ROOT")
diff --git a/analysis/low-level-api-fir/tests/org/jetbrains/kotlin/analysis/low/level/api/fir/diagnostic/compiler/based/LLFirPreresolvedReversedDiagnosticCompilerFE10TestDataTestGenerated.java b/analysis/low-level-api-fir/tests/org/jetbrains/kotlin/analysis/low/level/api/fir/diagnostic/compiler/based/LLFirPreresolvedReversedDiagnosticCompilerFE10TestDataTestGenerated.java
index dda9c9135e9..1f0574488e8 100644
--- a/analysis/low-level-api-fir/tests/org/jetbrains/kotlin/analysis/low/level/api/fir/diagnostic/compiler/based/LLFirPreresolvedReversedDiagnosticCompilerFE10TestDataTestGenerated.java
+++ b/analysis/low-level-api-fir/tests/org/jetbrains/kotlin/analysis/low/level/api/fir/diagnostic/compiler/based/LLFirPreresolvedReversedDiagnosticCompilerFE10TestDataTestGenerated.java
@@ -42435,12 +42435,6 @@ public class LLFirPreresolvedReversedDiagnosticCompilerFE10TestDataTestGenerated
       runTest("compiler/testData/diagnostics/testsWithStdLib/shadowingInDestructuring.kt");
     }
 
-    @Test
-    @TestMetadata("streams.kt")
-    public void testStreams() {
-      runTest("compiler/testData/diagnostics/testsWithStdLib/streams.kt");
-    }
-
     @Nested
     @TestMetadata("compiler/testData/diagnostics/testsWithStdLib/annotations")
     @TestDataPath("$PROJECT_ROOT")
@@ -47057,6 +47051,28 @@ public class LLFirPreresolvedReversedDiagnosticCompilerFE10TestDataTestGenerated
       }
     }
 
+    @Nested
+    @TestMetadata("compiler/testData/diagnostics/testsWithStdLib/streams")
+    @TestDataPath("$PROJECT_ROOT")
+    public class Streams {
+      @Test
+      public void testAllFilesPresentInStreams() {
+        KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/diagnostics/testsWithStdLib/streams"), Pattern.compile("^(.+)\\.(kt|kts)$"), Pattern.compile("^(.+)\\.(reversed|fir|ll)\\.kts?$"), true);
+      }
+
+      @Test
+      @TestMetadata("basic.kt")
+      public void testBasic() {
+        runTest("compiler/testData/diagnostics/testsWithStdLib/streams/basic.kt");
+      }
+
+      @Test
+      @TestMetadata("wrongNullability.kt")
+      public void testWrongNullability() {
+        runTest("compiler/testData/diagnostics/testsWithStdLib/streams/wrongNullability.kt");
+      }
+    }
+
     @Nested
     @TestMetadata("compiler/testData/diagnostics/testsWithStdLib/targetedBuiltIns")
     @TestDataPath("$PROJECT_ROOT")
diff --git a/compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirLightTreeOldFrontendDiagnosticsTestGenerated.java b/compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirLightTreeOldFrontendDiagnosticsTestGenerated.java
index 81ff14587bf..0df6a78ec51 100644
--- a/compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirLightTreeOldFrontendDiagnosticsTestGenerated.java
+++ b/compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirLightTreeOldFrontendDiagnosticsTestGenerated.java
@@ -40007,12 +40007,6 @@ public class FirLightTreeOldFrontendDiagnosticsTestGenerated extends AbstractFir
       runTest("compiler/testData/diagnostics/testsWithStdLib/shadowingInDestructuring.kt");
     }
 
-    @Test
-    @TestMetadata("streams.kt")
-    public void testStreams() {
-      runTest("compiler/testData/diagnostics/testsWithStdLib/streams.kt");
-    }
-
     @Nested
     @TestMetadata("compiler/testData/diagnostics/testsWithStdLib/annotations")
     @TestDataPath("$PROJECT_ROOT")
@@ -44687,6 +44681,28 @@ public class FirLightTreeOldFrontendDiagnosticsTestGenerated extends AbstractFir
       }
     }
 
+    @Nested
+    @TestMetadata("compiler/testData/diagnostics/testsWithStdLib/streams")
+    @TestDataPath("$PROJECT_ROOT")
+    public class Streams {
+      @Test
+      public void testAllFilesPresentInStreams() {
+        KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/diagnostics/testsWithStdLib/streams"), Pattern.compile("^(.+)\\.kt$"), Pattern.compile("^(.+)\\.(reversed|fir|ll)\\.kts?$"), true);
+      }
+
+      @Test
+      @TestMetadata("basic.kt")
+      public void testBasic() {
+        runTest("compiler/testData/diagnostics/testsWithStdLib/streams/basic.kt");
+      }
+
+      @Test
+      @TestMetadata("wrongNullability.kt")
+      public void testWrongNullability() {
+        runTest("compiler/testData/diagnostics/testsWithStdLib/streams/wrongNullability.kt");
+      }
+    }
+
     @Nested
     @TestMetadata("compiler/testData/diagnostics/testsWithStdLib/targetedBuiltIns")
     @TestDataPath("$PROJECT_ROOT")
diff --git a/compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirPsiOldFrontendDiagnosticsTestGenerated.java b/compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirPsiOldFrontendDiagnosticsTestGenerated.java
index 1b5a645f55f..0f9101c25fc 100644
--- a/compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirPsiOldFrontendDiagnosticsTestGenerated.java
+++ b/compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirPsiOldFrontendDiagnosticsTestGenerated.java
@@ -40145,12 +40145,6 @@ public class FirPsiOldFrontendDiagnosticsTestGenerated extends AbstractFirPsiDia
       runTest("compiler/testData/diagnostics/testsWithStdLib/shadowingInDestructuring.kt");
     }
 
-    @Test
-    @TestMetadata("streams.kt")
-    public void testStreams() {
-      runTest("compiler/testData/diagnostics/testsWithStdLib/streams.kt");
-    }
-
     @Nested
     @TestMetadata("compiler/testData/diagnostics/testsWithStdLib/annotations")
     @TestDataPath("$PROJECT_ROOT")
@@ -44825,6 +44819,28 @@ public class FirPsiOldFrontendDiagnosticsTestGenerated extends AbstractFirPsiDia
       }
     }
 
+    @Nested
+    @TestMetadata("compiler/testData/diagnostics/testsWithStdLib/streams")
+    @TestDataPath("$PROJECT_ROOT")
+    public class Streams {
+      @Test
+      public void testAllFilesPresentInStreams() {
+        KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/diagnostics/testsWithStdLib/streams"), Pattern.compile("^(.+)\\.kt$"), Pattern.compile("^(.+)\\.(reversed|fir|ll)\\.kts?$"), true);
+      }
+
+      @Test
+      @TestMetadata("basic.kt")
+      public void testBasic() {
+        runTest("compiler/testData/diagnostics/testsWithStdLib/streams/basic.kt");
+      }
+
+      @Test
+      @TestMetadata("wrongNullability.kt")
+      public void testWrongNullability() {
+        runTest("compiler/testData/diagnostics/testsWithStdLib/streams/wrongNullability.kt");
+      }
+    }
+
     @Nested
     @TestMetadata("compiler/testData/diagnostics/testsWithStdLib/targetedBuiltIns")
     @TestDataPath("$PROJECT_ROOT")
diff --git a/compiler/testData/diagnostics/testsWithStdLib/streams.txt b/compiler/testData/diagnostics/testsWithStdLib/streams.txt
deleted file mode 100644
index f8a8fa2235a..00000000000
--- a/compiler/testData/diagnostics/testsWithStdLib/streams.txt
+++ /dev/null
@@ -1,3 +0,0 @@
-package
-
-public fun testStreams(/*0*/ list: java.util.ArrayList<kotlin.String>): kotlin.Unit
diff --git a/compiler/testData/diagnostics/testsWithStdLib/streams.kt b/compiler/testData/diagnostics/testsWithStdLib/streams/basic.kt
similarity index 100%
rename from compiler/testData/diagnostics/testsWithStdLib/streams.kt
rename to compiler/testData/diagnostics/testsWithStdLib/streams/basic.kt
diff --git a/compiler/testData/diagnostics/testsWithStdLib/streams/wrongNullability.fir.kt b/compiler/testData/diagnostics/testsWithStdLib/streams/wrongNullability.fir.kt
new file mode 100644
index 00000000000..6fb17a78eb0
--- /dev/null
+++ b/compiler/testData/diagnostics/testsWithStdLib/streams/wrongNullability.fir.kt
@@ -0,0 +1,24 @@
+// FULL_JDK
+// JVM_TARGET: 1.8
+
+import java.util.function.IntPredicate
+import java.util.stream.Stream
+import kotlin.streams.toList
+
+class IntLongPair(val i: Int, val l: Long)
+
+interface Process {
+    fun pid(): Int
+
+    fun totalCpuDuration(): Long?
+}
+
+fun run(filter: IntPredicate, allProcesses: Stream<Process>): List<IntLongPair> {
+    return allProcesses.filter {
+        filter.test(it.pid())
+    }.map<IntLongPair?> {
+        val duration = it.totalCpuDuration()
+        if (duration != null) IntLongPair(it.pid(), duration)
+        else null
+    }.toList()
+}
diff --git a/compiler/testData/diagnostics/testsWithStdLib/streams/wrongNullability.kt b/compiler/testData/diagnostics/testsWithStdLib/streams/wrongNullability.kt
new file mode 100644
index 00000000000..3f321c79605
--- /dev/null
+++ b/compiler/testData/diagnostics/testsWithStdLib/streams/wrongNullability.kt
@@ -0,0 +1,24 @@
+// FULL_JDK
+// JVM_TARGET: 1.8
+
+import java.util.function.IntPredicate
+import java.util.stream.Stream
+import kotlin.streams.toList
+
+class IntLongPair(val i: Int, val l: Long)
+
+interface Process {
+    fun pid(): Int
+
+    fun totalCpuDuration(): Long?
+}
+
+fun run(filter: IntPredicate, allProcesses: Stream<Process>): List<IntLongPair> {
+    return allProcesses.filter {
+        filter.test(it.pid())
+    }.map<IntLongPair?> {
+        val duration = it.totalCpuDuration()
+        if (duration != null) IntLongPair(it.pid(), <!DEBUG_INFO_SMARTCAST!>duration<!>)
+        else null
+    }.toList()
+}
diff --git a/compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/DiagnosticTestGenerated.java b/compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/DiagnosticTestGenerated.java
index 0a5e41f05f5..dbe5cf5da96 100644
--- a/compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/DiagnosticTestGenerated.java
+++ b/compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/DiagnosticTestGenerated.java
@@ -42435,12 +42435,6 @@ public class DiagnosticTestGenerated extends AbstractDiagnosticTest {
       runTest("compiler/testData/diagnostics/testsWithStdLib/shadowingInDestructuring.kt");
     }
 
-    @Test
-    @TestMetadata("streams.kt")
-    public void testStreams() {
-      runTest("compiler/testData/diagnostics/testsWithStdLib/streams.kt");
-    }
-
     @Nested
     @TestMetadata("compiler/testData/diagnostics/testsWithStdLib/annotations")
     @TestDataPath("$PROJECT_ROOT")
@@ -47115,6 +47109,28 @@ public class DiagnosticTestGenerated extends AbstractDiagnosticTest {
       }
     }
 
+    @Nested
+    @TestMetadata("compiler/testData/diagnostics/testsWithStdLib/streams")
+    @TestDataPath("$PROJECT_ROOT")
+    public class Streams {
+      @Test
+      public void testAllFilesPresentInStreams() {
+        KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/diagnostics/testsWithStdLib/streams"), Pattern.compile("^(.+)\\.kt$"), Pattern.compile("^(.+)\\.(reversed|fir|ll)\\.kts?$"), true);
+      }
+
+      @Test
+      @TestMetadata("basic.kt")
+      public void testBasic() {
+        runTest("compiler/testData/diagnostics/testsWithStdLib/streams/basic.kt");
+      }
+
+      @Test
+      @TestMetadata("wrongNullability.kt")
+      public void testWrongNullability() {
+        runTest("compiler/testData/diagnostics/testsWithStdLib/streams/wrongNullability.kt");
+      }
+    }
+
     @Nested
     @TestMetadata("compiler/testData/diagnostics/testsWithStdLib/targetedBuiltIns")
     @TestDataPath("$PROJECT_ROOT")