From 5b7611c45ecb19601d5912a98607e4996d6669ea Mon Sep 17 00:00:00 2001
From: Mikhail Pyltsin <Mikhail.Pyltsin@jetbrains.com>
Date: Thu, 21 Nov 2024 10:25:34 +0100
Subject: [PATCH] [java-inspection] IDEA-310567 'Constant values' false
 positive for switch expression

- skip 'constant values' for switch expressions if they contain always failed methods

GitOrigin-RevId: 1207911bd11f94f37293254fa609e47b42aa96e1
---
 .../dataFlow/ConstantValueInspection.java      |  9 ++++++++-
 .../fixture/SkipSwitchExpressionWithThrow.java | 18 ++++++++++++++++++
 2 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/java/java-impl-inspections/src/com/intellij/codeInspection/dataFlow/ConstantValueInspection.java b/java/java-impl-inspections/src/com/intellij/codeInspection/dataFlow/ConstantValueInspection.java
index 29bbcd23c5e3..08a0b46c4cfc 100644
--- a/java/java-impl-inspections/src/com/intellij/codeInspection/dataFlow/ConstantValueInspection.java
+++ b/java/java-impl-inspections/src/com/intellij/codeInspection/dataFlow/ConstantValueInspection.java
@@ -1,4 +1,4 @@
-// Copyright 2000-2023 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
+// Copyright 2000-2024 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
 package com.intellij.codeInspection.dataFlow;
 
 import com.intellij.codeInsight.daemon.impl.quickfix.SimplifyBooleanExpressionFix;
@@ -400,6 +400,13 @@ public final class ConstantValueInspection extends AbstractBaseJavaLocalInspecti
         ref.set(true);
         return false;
       }
+      if (element instanceof PsiMethodCallExpression methodCallExpression) {
+        List<? extends MethodContract> contracts = JavaMethodContractUtil.getMethodCallContracts(methodCallExpression);
+        if (ContainerUtil.exists(contracts, contract -> contract.isTrivial() && contract.getReturnValue().isFail())) {
+          ref.set(true);
+          return false;
+        }
+      }
       return true;
     });
     return ref.get();
diff --git a/java/java-tests/testData/inspection/dataFlow/fixture/SkipSwitchExpressionWithThrow.java b/java/java-tests/testData/inspection/dataFlow/fixture/SkipSwitchExpressionWithThrow.java
index 6297b6690a57..2c3378260a90 100644
--- a/java/java-tests/testData/inspection/dataFlow/fixture/SkipSwitchExpressionWithThrow.java
+++ b/java/java-tests/testData/inspection/dataFlow/fixture/SkipSwitchExpressionWithThrow.java
@@ -1,3 +1,5 @@
+import org.jetbrains.annotations.Nullable;
+
 class SkipSwitchExpressionWithThrow {
   static boolean test(int x) {
     return switch (x) {
@@ -7,4 +9,20 @@ class SkipSwitchExpressionWithThrow {
       default -> throw new IllegalStateException();
     };
   }
+
+  public enum Foo {
+    A, B
+  }
+
+  public static <R> R exception() {
+    throw new RuntimeException();
+  }
+
+  @Nullable
+  public static Object test2(Foo foo) {
+    return switch (foo) {
+      case A -> null;
+      case B -> exception();
+    };
+  }
 }
\ No newline at end of file