SONARJAVA-4617 S1226 - Fix CFG construction inside "return switch" ex…

…pression for yield without break cases (#4533)
SonarSource · Nov 21, 2023 · 751ab82 · 751ab82
1 parent cf2b33d
commit 751ab82
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Showing 4 changed files with 44 additions and 2 deletions.
diff --git a/...es/checks/ParameterReassignedToCheck.java → ...ng/checks/ParameterReassignedToCheck.java b/...es/checks/ParameterReassignedToCheck.java → ...ng/checks/ParameterReassignedToCheck.java
@@ -1,6 +1,41 @@
 import java.util.function.Supplier;
 
 class A {
+
+  public String foo(int dt, String myString) {
+    dt = 1; // Noncompliant
+    myString = switch (dt) { // Compliant - FN
+      case 1 -> {
+        yield myString + "";
+      }
+      default -> null;
+    };
+    return myString;
+  }
+
+  public String foo3(int dt, String myString) {
+    dt = 1; // Noncompliant
+    myString = switch (dt) { // Noncompliant
+      case 1 -> {
+        yield "";
+      }
+      default -> null;
+    };
+    return myString;
+  }
+
+  public String foo2(int dt, String myString2) {
+    String str = switch (dt) { // Compliant
+      case 1 -> {
+        try {
+          yield myString2 + "";
+        } catch (Exception e) {
+          yield "Exc";
+        }
+      }
+      default -> null;
+    };
+  }
   public void f() {
   }
   abstract void method();

diff --git a/java-checks/src/test/java/org/sonar/java/checks/ParameterReassignedToCheckTest.java b/java-checks/src/test/java/org/sonar/java/checks/ParameterReassignedToCheckTest.java
@@ -22,12 +22,14 @@
 import org.junit.jupiter.api.Test;
 import org.sonar.java.checks.verifier.CheckVerifier;
 
+import static org.sonar.java.checks.verifier.TestUtils.nonCompilingTestSourcesPath;
+
 class ParameterReassignedToCheckTest {
 
   @Test
   void test() {
     CheckVerifier.newVerifier()
-      .onFile("src/test/files/checks/ParameterReassignedToCheck.java")
+      .onFile(nonCompilingTestSourcesPath("checks/ParameterReassignedToCheck.java"))
       .withCheck(new ParameterReassignedToCheck())
       .verifyIssues();
   }

diff --git a/java-frontend/src/main/java/org/sonar/java/cfg/CFG.java b/java-frontend/src/main/java/org/sonar/java/cfg/CFG.java
@@ -923,7 +923,7 @@ private void buildBreakStatement(BreakStatementTree tree) {
   }
 
   private void buildYieldStatement(YieldStatementTree tree) {
-    currentBlock = createUnconditionalJump(tree, breakTargets.getLast(), currentBlock);
+    currentBlock = createUnconditionalJump(tree, breakTargets.isEmpty() ? null : breakTargets.getLast(), currentBlock);
     build(tree.expression());
     currentBlock.exitBlock = null;
   }

diff --git a/java-frontend/src/test/java/org/sonar/java/model/declaration/MethodTreeImplTest.java b/java-frontend/src/test/java/org/sonar/java/model/declaration/MethodTreeImplTest.java
@@ -204,6 +204,11 @@ void compute_cfg() {
     cfg = method.cfg();
     assertThat(cfg).isNotNull();
     assertThat(method.cfg()).isSameAs(cfg);
+
+    MethodTree methodWithSwitchAndYield = getUniqueMethod("class A { String foo(int arg) {return switch (arg) {case 1: yield \"Got a 1\"; case 2: yield \"Got a 2\"; default: yield \"More than 2\";};}}");
+    cfg = methodWithSwitchAndYield.cfg();
+    assertThat(cfg).isNotNull();
+    assertThat(methodWithSwitchAndYield.cfg()).isSameAs(cfg);
   }
 
   @Test