From 16eafc89c2cdf8c0a370ab98d979d41d5d799540 Mon Sep 17 00:00:00 2001
From: Andreas Dangel <andreas.dangel@pmd-code.org>
Date: Sun, 27 Oct 2024 16:24:05 +0100
Subject: [PATCH 1/2] [java] TooFewBranchesForSwitch - allow list of case
 constants

Fixes #5287
---
 docs/pages/release_notes.md                   |  2 +
 .../resources/category/java/performance.xml   |  2 +-
 .../xml/TooFewBranchesForSwitch.xml           | 42 +++++++++++++++++++
 3 files changed, 45 insertions(+), 1 deletion(-)

diff --git a/docs/pages/release_notes.md b/docs/pages/release_notes.md
index bc1a36ec7a..68f3742003 100644
--- a/docs/pages/release_notes.md
+++ b/docs/pages/release_notes.md
@@ -15,6 +15,8 @@ This is a {{ site.pmd.release_type }} release.
 ### 🚀 New and noteworthy
 
 ### 🐛 Fixed Issues
+* java-performance
+  * [#5287](https://github.com/pmd/pmd/issues/5287): \[java] TooFewBranchesForSwitch false-positive with switch using list of case constants
 
 ### 🚨 API Changes
 
diff --git a/pmd-java/src/main/resources/category/java/performance.xml b/pmd-java/src/main/resources/category/java/performance.xml
index a8e4c37142..8b2d4e20c5 100644
--- a/pmd-java/src/main/resources/category/java/performance.xml
+++ b/pmd-java/src/main/resources/category/java/performance.xml
@@ -629,7 +629,7 @@ Note: This rule was named TooFewBranchesForASwitchStatement before PMD 7.7.0.
                 <value>
 <![CDATA[
 //(SwitchStatement | SwitchExpression)
-  [ (count(*) - 1) < $minimumNumberCaseForASwitch ]
+  [ (count(*/SwitchLabel/*) + count(*/SwitchLabel[@Default = true()])) < $minimumNumberCaseForASwitch ]
   (: only consider if no pattern matching is used :)
   [*/SwitchLabel[@PatternLabel = false()]]
 ]]>
diff --git a/pmd-java/src/test/resources/net/sourceforge/pmd/lang/java/rule/performance/xml/TooFewBranchesForSwitch.xml b/pmd-java/src/test/resources/net/sourceforge/pmd/lang/java/rule/performance/xml/TooFewBranchesForSwitch.xml
index e603390ec6..2da0d99a82 100644
--- a/pmd-java/src/test/resources/net/sourceforge/pmd/lang/java/rule/performance/xml/TooFewBranchesForSwitch.xml
+++ b/pmd-java/src/test/resources/net/sourceforge/pmd/lang/java/rule/performance/xml/TooFewBranchesForSwitch.xml
@@ -136,6 +136,48 @@ public class SwitchWithRecordPattern {
         }
     }
 }
+]]></code>
+    </test-code>
+
+    <test-code>
+        <description>#5287 [java] TooFewBranchesForSwitch false-positive with switch using list of case constants</description>
+        <rule-property name="minimumNumberCaseForASwitch">3</rule-property>
+        <expected-problems>0</expected-problems>
+        <code><![CDATA[
+enum SomeEnum { A, B, C, D }
+class Tester {
+    int checkSwitchExpression(SomeEnum someEnumValue) {
+        return switch(someEnumValue) {
+            case A, B, C -> 1;
+            default -> 0;
+        };
+    }
+
+    int checkSwitchStatement(SomeEnum someEnumValue) {
+        int result;
+        switch(someEnumValue) {
+            case A, B, C -> { result = 1; }
+            default -> { result = 0; }
+        }
+        return result;
+    }
+
+    int checkSwitchExpressionGroup(SomeEnum someEnumValue) {
+        return switch(someEnumValue) {
+            case A, B, C: yield 1;
+            default: yield 0;
+        };
+    }
+
+    int checkSwitchStatementGroup(SomeEnum someEnumValue) {
+        int result;
+        switch(someEnumValue) {
+            case A, B, C: result = 1; break;
+            default: result = 0; break;
+        }
+        return result;
+    }
+}
 ]]></code>
     </test-code>
 </test-data>

From ee7d6fed3e4795f4fcb8827d8fc6a6851bf191dc Mon Sep 17 00:00:00 2001
From: Andreas Dangel <andreas.dangel@pmd-code.org>
Date: Thu, 7 Nov 2024 19:50:29 +0100
Subject: [PATCH 2/2] [java] TooFewBranchesForSwitch - add test case from
 comment on #5311

---
 .../xml/TooFewBranchesForSwitch.xml           | 20 +++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/pmd-java/src/test/resources/net/sourceforge/pmd/lang/java/rule/performance/xml/TooFewBranchesForSwitch.xml b/pmd-java/src/test/resources/net/sourceforge/pmd/lang/java/rule/performance/xml/TooFewBranchesForSwitch.xml
index 2da0d99a82..4cbc9893c7 100644
--- a/pmd-java/src/test/resources/net/sourceforge/pmd/lang/java/rule/performance/xml/TooFewBranchesForSwitch.xml
+++ b/pmd-java/src/test/resources/net/sourceforge/pmd/lang/java/rule/performance/xml/TooFewBranchesForSwitch.xml
@@ -178,6 +178,26 @@ class Tester {
         return result;
     }
 }
+]]></code>
+    </test-code>
+
+    <test-code>
+        <description>From #5311: Another example for list of case constants</description>
+        <expected-problems>0</expected-problems>
+        <code><![CDATA[
+public class Foo {
+
+  String foo(Bar bar) {
+    return switch (bar) {
+      case A, B, C, D -> "Hello";
+      case E, F, G -> "World";
+    };
+  }
+
+  enum Bar {
+    A, B, C, D, E, F, G
+  }
+}
 ]]></code>
     </test-code>
 </test-data>