[java-completion] Insert comma automatically when completing a new annotation attribute

Fixes IDEA-336370 Autocompletion should be smarter for annotations

GitOrigin-RevId: aa6efeb2b35f6ea242ed43cc1cb05aeceefe6d5c

java/java-impl/src/com/intellij/codeInsight/completion/JavaCompletionContributor.java

@@ -20,6 +20,7 @@ import com.intellij.lang.jvm.types.JvmPrimitiveTypeKind;
 import com.intellij.openapi.actionSystem.IdeActions;
 import com.intellij.openapi.editor.Document;
 import com.intellij.openapi.editor.Editor;
+import com.intellij.openapi.editor.ex.util.LexerEditorHighlighter;
 import com.intellij.openapi.keymap.KeymapUtil;
 import com.intellij.openapi.module.Module;
 import com.intellij.openapi.module.ModuleUtilCore;
@@ -39,6 +40,7 @@ import com.intellij.patterns.PsiJavaElementPattern;
 import com.intellij.patterns.PsiNameValuePairPattern;
 import com.intellij.psi.*;
 import com.intellij.psi.codeStyle.CodeStyleManager;
+import com.intellij.psi.codeStyle.CommonCodeStyleSettings;
 import com.intellij.psi.filters.*;
 import com.intellij.psi.filters.classes.AnnotationTypeFilter;
 import com.intellij.psi.filters.classes.AssignableFromContextFilter;
@@ -1014,7 +1016,8 @@ public final class JavaCompletionContributor extends CompletionContributor imple
   private static LookupElementBuilder createAnnotationAttributeElement(@NotNull PsiMethod annoMethod,
                                                                        @Nullable String value,
                                                                        @NotNull PsiElement position) {
-    String space = ReferenceExpressionCompletionContributor.getSpace(CodeStyle.getLanguageSettings(annoMethod.getContainingFile()).SPACE_AROUND_ASSIGNMENT_OPERATORS);
+    CommonCodeStyleSettings styleSettings = CodeStyle.getLanguageSettings(annoMethod.getContainingFile());
+    String space = ReferenceExpressionCompletionContributor.getSpace(styleSettings.SPACE_AROUND_ASSIGNMENT_OPERATORS);
     String lookupString = annoMethod.getName() + (value == null ? "" : space + "=" + space + value);
     return LookupElementBuilder.create(annoMethod, lookupString).withIcon(annoMethod.getIcon(0))
       .withStrikeoutness(JavaDeprecationUtils.isDeprecated(annoMethod, position))
@@ -1028,14 +1031,34 @@ public final class JavaCompletionContributor extends CompletionContributor imple
         context.commitDocument();
         PsiAnnotationParameterList paramList =
           PsiTreeUtil.findElementOfClassAtOffset(context.getFile(), context.getStartOffset(), PsiAnnotationParameterList.class, false);
+        Document document = context.getDocument();
         if (paramList != null && paramList.getAttributes().length > 0 && paramList.getAttributes()[0].getName() == null) {
           int valueOffset = paramList.getAttributes()[0].getTextRange().getStartOffset();
-          context.getDocument().insertString(valueOffset, PsiAnnotation.DEFAULT_REFERENCED_METHOD_NAME);
+          document.insertString(valueOffset, PsiAnnotation.DEFAULT_REFERENCED_METHOD_NAME);
           EqTailType.INSTANCE.processTail(editor, valueOffset + PsiAnnotation.DEFAULT_REFERENCED_METHOD_NAME.length());
         }
+        int offset = editor.getCaretModel().getOffset();
+        CharSequence sequence = document.getCharsSequence();
+        if (hasAttributeNameAt(sequence, offset)) {
+          document.insertString(offset, styleSettings.SPACE_AFTER_COMMA ? ", " : ",");
+        }
       });
   }
 
+  private static boolean hasAttributeNameAt(@NotNull CharSequence sequence, int offset) {
+    int length = sequence.length();
+    if (length <= offset) return false;
+    char nextChar = sequence.charAt(offset);
+    if (!StringUtil.isJavaIdentifierStart(nextChar)) return false;
+    while (offset < length - 1 && StringUtil.isJavaIdentifierPart(sequence.charAt(offset + 1))) {
+      offset++;
+    }
+    while (offset < length - 1 && StringUtil.isWhiteSpace(sequence.charAt(offset + 1))) {
+      offset++;
+    }
+    return offset < length - 1 && sequence.charAt(offset + 1) == '=';
+  }
+
   @Override
   public String advertise(@NotNull CompletionParameters parameters) {
     if (!(parameters.getOriginalFile() instanceof PsiJavaFile)) return null;

java/java-tests/testData/codeInsight/completion/normal/AnnotationAttrBeforeExisting.java

@@ -0,0 +1,9 @@
+@interface Anno {
+  String attr();
+  int existing();
+}
+
+@Anno(att<caret>existing = 2)
+class Cls {
+  
+}

java/java-tests/testData/codeInsight/completion/normal/AnnotationAttrBeforeExistingBool.java

@@ -0,0 +1,9 @@
+@interface Anno {
+  boolean attr() default true;
+  int existing();
+}
+
+@Anno(att<caret>existing = 2)
+class Cls {
+  
+}

java/java-tests/testData/codeInsight/completion/normal/AnnotationAttrBeforeExistingBool_after.java

@@ -0,0 +1,9 @@
+@interface Anno {
+  boolean attr() default true;
+  int existing();
+}
+
+@Anno(attr = false<caret>, existing = 2)
+class Cls {
+  
+}

java/java-tests/testData/codeInsight/completion/normal/AnnotationAttrBeforeExisting_after.java

@@ -0,0 +1,9 @@
+@interface Anno {
+  String attr();
+  int existing();
+}
+
+@Anno(attr = <caret>, existing = 2)
+class Cls {
+  
+}

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

@@ -342,6 +342,14 @@ public class NormalCompletionTest extends NormalCompletionTestCase {
     selectItem(myItems[0]);
     checkResultByFile("Annotation7_after.java");
   }
+  
+  public void testAnnotationAttrBeforeExisting() {
+    doTest("\n");
+  }
+  
+  public void testAnnotationAttrBeforeExistingBool() {
+    doTest("\n");
+  }
 
   public void testEnumInAnnotation() {
     configureByFile("Annotation4.java");