IDEA-247122 Variable initialization completion adds semicolon which breaks the code

GitOrigin-RevId: 61fb7454dbf3a62be2f9250e2f5e46f329b35e53

java/java-impl/src/com/intellij/codeInsight/ExpectedTypesProvider.java

@@ -552,7 +552,9 @@ public final class ExpectedTypesProvider {
     @Override
     public void visitVariable(@NotNull PsiVariable variable) {
       PsiType type = variable.getType();
-      TailType tail = variable instanceof PsiResourceVariable ? TailType.NONE : TailType.SEMICOLON;
+      TailType tail = variable instanceof PsiResourceVariable ? TailType.NONE :
+                      PsiUtilCore.getElementType(PsiTreeUtil.nextCodeLeaf(variable)) == JavaTokenType.COMMA ? CommaTailType.INSTANCE :
+                      TailType.SEMICOLON;
       myResult.add(createInfoImpl(type, ExpectedTypeInfo.TYPE_OR_SUBTYPE, type, tail, null, getPropertyName(variable)));
     }
 

java/java-tests/testData/codeInsight/completion/smartType/NoSemicolonAfterNonLastVariableInitializer-out.java

@@ -0,0 +1,5 @@
+class C {
+    int x = nextInt(), <caret>y = 0;
+
+    int nextInt() {}
+}

java/java-tests/testData/codeInsight/completion/smartType/NoSemicolonAfterNonLastVariableInitializer.java

@@ -0,0 +1,5 @@
+class C {
+    int x = nex<caret>, y = 0;
+
+    int nextInt() {}
+}

java/java-tests/testSrc/com/intellij/java/codeInsight/completion/SmartTypeCompletionTest.java

@@ -1476,4 +1476,7 @@ public class SmartTypeCompletionTest extends LightFixtureCompletionTestCase {
     myFixture.complete(CompletionType.SMART);
     checkResultByFile("second/MethodAsQualifier-out.java");
   }
+
+  public void testNoSemicolonAfterNonLastVariableInitializer() { doTest(); }
+
 }

platform/core-api/src/com/intellij/psi/util/PsiTreeUtil.java

@@ -1103,6 +1103,30 @@ public class PsiTreeUtil {
     return nextLeaf;
   }
 
+  /**
+   * @return closest leaf (not necessarily a sibling) before the given element
+   * which has non-empty range and is neither a whitespace nor a comment
+   */
+  public static @Nullable PsiElement prevCodeLeaf(@NotNull PsiElement element) {
+    PsiElement prevLeaf = prevLeaf(element, true);
+    while (prevLeaf != null && isNonCodeLeaf(prevLeaf)) prevLeaf = prevLeaf(prevLeaf, true);
+    return prevLeaf;
+  }
+
+  /**
+   * @return closest leaf (not necessarily a sibling) after the given element
+   * which has non-empty range and is neither a whitespace nor a comment
+   */
+  public static @Nullable PsiElement nextCodeLeaf(@NotNull PsiElement element) {
+    PsiElement nextLeaf = nextLeaf(element, true);
+    while (nextLeaf != null && isNonCodeLeaf(nextLeaf)) nextLeaf = nextLeaf(nextLeaf, true);
+    return nextLeaf;
+  }
+
+  private static boolean isNonCodeLeaf(PsiElement leaf) {
+    return StringUtil.isEmptyOrSpaces(leaf.getText()) || getNonStrictParentOfType(leaf, PsiComment.class) != null;
+  }
+
   public static @Nullable PsiElement nextLeaf(@NotNull PsiElement element, final boolean skipEmptyElements) {
     PsiElement nextLeaf = nextLeaf(element);
     while (skipEmptyElements && nextLeaf != null && nextLeaf.getTextLength() == 0) nextLeaf = nextLeaf(nextLeaf);

platform/lang-impl/src/com/intellij/psi/filters/FilterPositionUtil.java

@@ -1,11 +1,7 @@
 // Copyright 2000-2020 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
 package com.intellij.psi.filters;
 
-import com.intellij.lang.ASTNode;
-import com.intellij.psi.PsiComment;
 import com.intellij.psi.PsiElement;
-import com.intellij.psi.TokenType;
-import com.intellij.psi.impl.source.tree.TreeUtil;
 import com.intellij.psi.util.PsiTreeUtil;
 import org.jetbrains.annotations.Nullable;
 
@@ -15,20 +11,6 @@ import org.jetbrains.annotations.Nullable;
 public final class FilterPositionUtil {
   @Nullable
   public static PsiElement searchNonSpaceNonCommentBack(PsiElement element) {
-    return searchNonSpaceNonCommentBack(element, false);
-  }
-
-  @Nullable
-  public static PsiElement searchNonSpaceNonCommentBack(PsiElement element, final boolean strict) {
-    if (element == null || element.getNode() == null) return null;
-    ASTNode leftNeighbour = TreeUtil.prevLeaf(element.getNode());
-    if (!strict) {
-      while (leftNeighbour != null &&
-             (leftNeighbour.getElementType() == TokenType.WHITE_SPACE ||
-              PsiTreeUtil.getNonStrictParentOfType(leftNeighbour.getPsi(), PsiComment.class) != null)) {
-        leftNeighbour = TreeUtil.prevLeaf(leftNeighbour);
-      }
-    }
-    return leftNeighbour != null ? leftNeighbour.getPsi() : null;
+    return element == null ? null : PsiTreeUtil.prevCodeLeaf(element);
   }
 }