[java-highlighting] IJ-CR-165049 IDEA-374019 Don't show error about 'main' method if there is an error with braces

- don't highlight if there is package statement
- skip duplicated nested class for implicit classes

GitOrigin-RevId: eadb287b7e52bfedd04340b8841597b9d6839ee5

java/codeserver/highlighting/src/com/intellij/java/codeserver/highlighting/ClassChecker.java

@@ -197,7 +197,10 @@ final class ClassChecker {
       }
       parent = element;
 
-      if (element instanceof PsiDeclarationStatement) element = PsiTreeUtil.getChildOfType(element, PsiClass.class);
+      if (element instanceof PsiDeclarationStatement){ element = PsiTreeUtil.getChildOfType(element, PsiClass.class);}
+
+      if (element instanceof PsiImplicitClass) return;
+
       if (element instanceof PsiClass psiClass && name.equals(psiClass.getName())) {
         myVisitor.report(JavaErrorKinds.CLASS_DUPLICATE.create(aClass, psiClass));
       }
@@ -403,6 +406,8 @@ 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 there is a package, this package will be highlighted
+      if (file.getPackageStatement() != null) return;
       //don't show errors if the file contains broken {}
       if(hasErrorElementWithBraces(file)) return;
       myVisitor.report(JavaErrorKinds.CLASS_IMPLICIT_NO_MAIN_METHOD.create(file, implicitClass));

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/implicitClass/BrokenFileNoHighlighting.java

@@ -1,5 +1,3 @@
-package com.example;
-
 public class A {
 }
 

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/implicitClass/BrokenFileNoHighlightingWithPackage.java

@@ -0,0 +1,7 @@
+<error descr="Package statement is not allowed for implicitly declared class">package a;</error>
+
+int ab;
+
+class AB {
+
+}

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/implicitClass/SameNameInnerClass.java

@@ -0,0 +1,5 @@
+<error descr="Implicitly declared class contains no 'main' method">public class SameNameInnerClass {
+
+}
+
+int a = 1;</error>

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/implicitClass/WithPackageStatement.java

@@ -1,5 +1,5 @@
-<error descr="Implicitly declared class contains no 'main' method"><error descr="Package statement is not allowed for implicitly declared class">package pack.bar;</error>
+<error descr="Package statement is not allowed for implicitly declared class">package pack.bar;</error>
 
 void foo() {
 
-}</error>
+}

java/java-tests/testSrc/com/intellij/java/codeInsight/daemon/ImplicitClassHighlightingTest.kt

@@ -176,6 +176,14 @@ class ImplicitClassHighlightingTest : LightJavaCodeInsightFixtureTestCase() {
     doTest()
   }
 
+  fun testBrokenFileNoHighlightingWithPackage() {
+    doTest()
+  }
+
+  fun testSameNameInnerClass() {
+    doTest()
+  }
+
   private fun doTest() {
     myFixture.configureByFile(getTestName(false) + ".java")
     myFixture.checkHighlighting()