From dc8ca06f05acde6ff0dd7d0a63c5517531e34460 Mon Sep 17 00:00:00 2001
From: Mikhail Pyltsin <Mikhail.Pyltsin@jetbrains.com>
Date: Thu, 5 Jun 2025 11:19:28 +0200
Subject: [PATCH] [java-highlighting] IDEA-374019 Don't show error about 'main'
 method if there is an error with braces

GitOrigin-RevId: 38e303a7ace428d45c6e869fce3acc655dba1a6d
---
 .../codeserver/highlighting/ClassChecker.java | 19 ++++++++++++++++++-
 .../BrokenClassToImplicitClass.java           |  4 ++--
 .../BrokenFileNoHighlighting.java             |  8 ++++++++
 .../daemon/ImplicitClassHighlightingTest.kt   |  6 +++++-
 4 files changed, 33 insertions(+), 4 deletions(-)
 create mode 100644 java/java-tests/testData/codeInsight/daemonCodeAnalyzer/implicitClass/BrokenFileNoHighlighting.java

diff --git a/java/codeserver/highlighting/src/com/intellij/java/codeserver/highlighting/ClassChecker.java b/java/codeserver/highlighting/src/com/intellij/java/codeserver/highlighting/ClassChecker.java
index f617ec0a4c4c..6293e6db36b5 100644
--- a/java/codeserver/highlighting/src/com/intellij/java/codeserver/highlighting/ClassChecker.java
+++ b/java/codeserver/highlighting/src/com/intellij/java/codeserver/highlighting/ClassChecker.java
@@ -15,6 +15,7 @@ import com.intellij.openapi.roots.ModuleFileIndex;
 import com.intellij.openapi.roots.ModuleRootManager;
 import com.intellij.openapi.util.Comparing;
 import com.intellij.openapi.util.Pair;
+import com.intellij.openapi.util.Ref;
 import com.intellij.openapi.vfs.VirtualFile;
 import com.intellij.pom.java.JavaFeature;
 import com.intellij.psi.*;
@@ -402,10 +403,24 @@ final class ClassChecker {
     PsiMethod[] methods = implicitClass.getMethods();
     boolean hasMainMethod = ContainerUtil.exists(methods, method -> "main".equals(method.getName()) && PsiMethodUtil.isMainMethod(method));
     if (!hasMainMethod) {
+      //don't show errors if the file contains broken {}
+      if(hasErrorElementWithBraces(file)) return;
       myVisitor.report(JavaErrorKinds.CLASS_IMPLICIT_NO_MAIN_METHOD.create(file, implicitClass));
     }
   }
 
+  private static boolean hasErrorElementWithBraces(@NotNull PsiElement parentElement) {
+    Ref<Boolean> result = new Ref<>(false);
+    PsiWalkingState.processAll(parentElement, el -> {
+      if (el instanceof PsiErrorElement element &&
+          (element.getText().contains("}") || element.getText().contains("{"))) {
+        result.set(true);
+        return false;
+      } else return true;
+    });
+    return result.get();
+  }
+
   void checkImplicitClassMember(@NotNull PsiMember member) {
     if (!(member.getContainingClass() instanceof PsiImplicitClass)) return;
 
@@ -448,7 +463,9 @@ final class ClassChecker {
   }
 
   void checkPackageNotAllowedInImplicitClass(@NotNull PsiPackageStatement statement) {
-    if (myVisitor.isApplicable(JavaFeature.IMPLICIT_CLASSES) && JavaImplicitClassUtil.isFileWithImplicitClass(myVisitor.file())) {
+    if (myVisitor.isApplicable(JavaFeature.IMPLICIT_CLASSES) &&
+        JavaImplicitClassUtil.isFileWithImplicitClass(myVisitor.file()) &&
+        !hasErrorElementWithBraces(myVisitor.file())) {
       myVisitor.report(JavaErrorKinds.CLASS_IMPLICIT_PACKAGE.create(statement));
     }
   }
diff --git a/java/java-tests/testData/codeInsight/daemonCodeAnalyzer/advFixture/BrokenClassToImplicitClass.java b/java/java-tests/testData/codeInsight/daemonCodeAnalyzer/advFixture/BrokenClassToImplicitClass.java
index 6ce23e6cd7d1..9b6e3daa9d3b 100644
--- a/java/java-tests/testData/codeInsight/daemonCodeAnalyzer/advFixture/BrokenClassToImplicitClass.java
+++ b/java/java-tests/testData/codeInsight/daemonCodeAnalyzer/advFixture/BrokenClassToImplicitClass.java
@@ -1,4 +1,4 @@
-<error descr="Implicitly declared class contains no 'main' method"><error descr="Package statement is not allowed for implicitly declared class">package p1;</error>
+package p1;
 
 class <warning descr="Class 'Demo' is never used">Demo</warning>{
   public static void  <warning descr="Method 't1()' is never used">t1</warning>(){}
@@ -9,4 +9,4 @@ class <warning descr="Class 'Demo' is never used">Demo</warning>{
 }
 public static void  <warning descr="Method 't5()' is never used">t5</warning>(){}
 public static void  <warning descr="Method 't6()' is never used">t6</warning>(){}
-<error descr="'class' or 'interface' expected">}</error></error>
\ No newline at end of file
+<error descr="'class' or 'interface' expected">}</error>
\ No newline at end of file
diff --git a/java/java-tests/testData/codeInsight/daemonCodeAnalyzer/implicitClass/BrokenFileNoHighlighting.java b/java/java-tests/testData/codeInsight/daemonCodeAnalyzer/implicitClass/BrokenFileNoHighlighting.java
new file mode 100644
index 000000000000..6797823e7aaa
--- /dev/null
+++ b/java/java-tests/testData/codeInsight/daemonCodeAnalyzer/implicitClass/BrokenFileNoHighlighting.java
@@ -0,0 +1,8 @@
+package com.example;
+
+public class A {
+}
+
+<error descr="'class' or 'interface' expected">}</error>
+
+int a = 1;
diff --git a/java/java-tests/testSrc/com/intellij/java/codeInsight/daemon/ImplicitClassHighlightingTest.kt b/java/java-tests/testSrc/com/intellij/java/codeInsight/daemon/ImplicitClassHighlightingTest.kt
index 49bba34d7f8e..69efd80f2510 100644
--- a/java/java-tests/testSrc/com/intellij/java/codeInsight/daemon/ImplicitClassHighlightingTest.kt
+++ b/java/java-tests/testSrc/com/intellij/java/codeInsight/daemon/ImplicitClassHighlightingTest.kt
@@ -13,7 +13,7 @@ import com.intellij.testFramework.fixtures.LightJavaCodeInsightFixtureTestCase
 import org.jetbrains.plugins.groovy.intentions.style.inference.resolve
 
 class ImplicitClassHighlightingTest : LightJavaCodeInsightFixtureTestCase() {
-  override fun getProjectDescriptor() = JAVA_21
+  override fun getProjectDescriptor() = JAVA_23
   override fun getBasePath() = JavaTestUtil.getRelativeJavaTestDataPath() + "/codeInsight/daemonCodeAnalyzer/implicitClass"
 
   fun testHighlightInsufficientLevel() {
@@ -172,6 +172,10 @@ class ImplicitClassHighlightingTest : LightJavaCodeInsightFixtureTestCase() {
     doTest()
   }
 
+  fun testBrokenFileNoHighlighting() {
+    doTest()
+  }
+
   private fun doTest() {
     myFixture.configureByFile(getTestName(false) + ".java")
     myFixture.checkHighlighting()