[javadoc] IDEA-285556 Support language injection into snippet

Implement updating the content of a snippet tag with the help from a method implementer. A snippet might invoke overriding a method though a completion and when a parent method is inserted it might contain javadoc. In this case it's impossible to recreate a snippet tag because the new text for the tag contains "/**" and "*/" that come from the parent method's javadoc. The implemented method implementer helps to strip a method's javadoc if it's present.

Signed-off-by: Nikita Eshkeev <nikita.eshkeev@jetbrains.com>

GitOrigin-RevId: 42b315ed2670701e50574a383f0442df69accd35

java/java-impl/src/com/intellij/codeInsight/generation/OverrideImplementUtil.java

@@ -163,7 +163,7 @@ public final class OverrideImplementUtil extends OverrideImplementExploreUtil {
   }
 
   @NotNull
-  private static PsiMethod decorateMethod(@NotNull PsiClass aClass,
+  public static PsiMethod decorateMethod(@NotNull PsiClass aClass,
                                           @NotNull PsiMethod method,
                                           boolean toCopyJavaDoc,
                                           boolean insertOverrideIfPossible,
@@ -292,7 +292,7 @@ public final class OverrideImplementUtil extends OverrideImplementExploreUtil {
     for (MethodImplementor implementor : getImplementors()) {
       final GenerationInfo info = implementor.createGenerationInfo(s, mergeIfExists);
       if (info instanceof PsiGenerationInfo) {
-        @SuppressWarnings({"unchecked"}) final PsiGenerationInfo<PsiMethod> psiGenerationInfo = (PsiGenerationInfo<PsiMethod>)info;
+        @SuppressWarnings("unchecked") final PsiGenerationInfo<PsiMethod> psiGenerationInfo = (PsiGenerationInfo<PsiMethod>)info;
         return psiGenerationInfo;
       }
     }

java/java-impl/src/com/intellij/codeInsight/javadoc/SnippetDocTagMethodImplementor.java

@@ -0,0 +1,61 @@
+// Copyright 2000-2022 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
+package com.intellij.codeInsight.javadoc;
+
+import com.intellij.codeInsight.MethodImplementor;
+import com.intellij.codeInsight.generation.GenerateMembersUtil;
+import com.intellij.codeInsight.generation.GenerationInfo;
+import com.intellij.codeInsight.generation.OverrideImplementUtil;
+import com.intellij.codeInsight.generation.PsiGenerationInfo;
+import com.intellij.lang.injection.InjectedLanguageManager;
+import com.intellij.psi.PsiClass;
+import com.intellij.psi.PsiLanguageInjectionHost;
+import com.intellij.psi.PsiMethod;
+import com.intellij.psi.PsiSubstitutor;
+import com.intellij.psi.javadoc.PsiSnippetDocTag;
+import com.intellij.psi.util.TypeConversionUtil;
+import com.intellij.util.Consumer;
+import com.intellij.util.IncorrectOperationException;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+public class SnippetDocTagMethodImplementor implements MethodImplementor {
+  @Override
+  public PsiMethod @NotNull [] getMethodsToImplement(PsiClass aClass) {
+    return PsiMethod.EMPTY_ARRAY;
+  }
+
+  @Override
+  public PsiMethod @NotNull [] createImplementationPrototypes(PsiClass inClass,
+                                                              PsiMethod method) throws IncorrectOperationException {
+    final PsiLanguageInjectionHost injectionHost = InjectedLanguageManager.getInstance(inClass.getProject()).getInjectionHost(inClass);
+    if (!(injectionHost instanceof PsiSnippetDocTag)) {
+      return PsiMethod.EMPTY_ARRAY;
+    }
+
+    final PsiClass containingClass = method.getContainingClass();
+    if (containingClass == null) {
+      return PsiMethod.EMPTY_ARRAY;
+    }
+
+    final PsiSubstitutor substitutor = inClass.isInheritor(containingClass, true)
+                                       ? TypeConversionUtil.getSuperClassSubstitutor(containingClass, inClass, PsiSubstitutor.EMPTY)
+                                       : PsiSubstitutor.EMPTY;
+    final PsiMethod result = GenerateMembersUtil.substituteGenericMethod(method, substitutor, inClass);
+
+    return new PsiMethod[]{result};
+  }
+
+  @Override
+  public @Nullable GenerationInfo createGenerationInfo(PsiMethod method,
+                                                       boolean mergeIfExists) {
+    return null;
+  }
+
+  @Override
+  public @NotNull Consumer<PsiMethod> createDecorator(PsiClass targetClass,
+                                                      final PsiMethod baseMethod,
+                                                      boolean toCopyJavaDoc,
+                                                      boolean insertOverrideIfPossible) {
+    return result -> OverrideImplementUtil.decorateMethod(targetClass, baseMethod, false, insertOverrideIfPossible, result);
+  }
+}

java/java-impl/src/com/intellij/psi/impl/source/tree/injected/JavadocInjector.java

@@ -22,6 +22,8 @@ import java.util.List;
 public class JavadocInjector implements MultiHostInjector {
 
   private static final String LANG_ATTR_KEY = "lang";
+  private static final String SNIPPET_INJECTION_JAVA_HEADER = "class ___JavadocSnippetPlaceholder {\n" +
+                                                              "  void ___JavadocSnippetPlaceholderMethod() throws Throwable {\n";
 
   @Override
   public void getLanguagesToInject(@NotNull MultiHostRegistrar registrar,
@@ -32,8 +34,8 @@ public class JavadocInjector implements MultiHostInjector {
 
     final Language language = getLanguage(snippet);
 
-    final String prefix = language == JavaLanguage.INSTANCE ? "class ___JavadocSnippetPlaceholder { " : null;
-    final String suffix = language == JavaLanguage.INSTANCE ? " }" : null;
+    final String prefix = language == JavaLanguage.INSTANCE ? SNIPPET_INJECTION_JAVA_HEADER : null;
+    final String suffix = language == JavaLanguage.INSTANCE ? " }}" : null;
 
     registrar.startInjecting(language)
       .addPlace(prefix, suffix, snippet, innerRangeStrippingQuotes(snippet))

java/java-psi-impl/src/META-INF/JavaPsiPlugin.xml

@@ -121,6 +121,7 @@
                              implementationClass="com.intellij.psi.impl.source.resolve.reference.impl.manipulators.StringLiteralManipulator"/>
     <lang.elementManipulator forClass="com.intellij.psi.impl.source.javadoc.PsiSnippetDocTagImpl"
                              implementationClass="com.intellij.psi.impl.source.javadoc.SnippetDocTagManipulator"/>
+    <methodImplementor implementation="com.intellij.codeInsight.javadoc.SnippetDocTagMethodImplementor"/>
     <superMethodsSearch implementation="com.intellij.psi.impl.search.MethodSuperSearcher"/>
     <lang.psiAugmentProvider implementation="com.intellij.psi.impl.source.JShellPsiAugmentProvider"/>
     <codeInsight.containerProvider implementation="com.intellij.codeInsight.JavaContainerProvider" id="JAVA"/>

java/java-psi-impl/src/com/intellij/psi/impl/source/javadoc/SnippetDocTagManipulator.java

@@ -7,9 +7,15 @@ import com.intellij.psi.AbstractElementManipulator;
 import com.intellij.psi.JavaDocTokenType;
 import com.intellij.psi.PsiElement;
 import com.intellij.psi.impl.source.tree.TreeUtil;
+import com.intellij.psi.*;
+import com.intellij.psi.codeStyle.JavaFileCodeStyleFacade;
+import com.intellij.psi.javadoc.PsiDocComment;
+import com.intellij.psi.javadoc.PsiSnippetDocTag;
 import com.intellij.psi.javadoc.PsiSnippetDocTagBody;
 import com.intellij.psi.javadoc.PsiSnippetDocTagValue;
+import com.intellij.psi.util.PsiTreeUtil;
 import com.intellij.util.IncorrectOperationException;
+import org.jetbrains.annotations.Contract;
 import org.jetbrains.annotations.NotNull;
 
 public final class SnippetDocTagManipulator extends AbstractElementManipulator<PsiSnippetDocTagImpl> {
@@ -18,7 +24,41 @@ public final class SnippetDocTagManipulator extends AbstractElementManipulator<P
   public PsiSnippetDocTagImpl handleContentChange(@NotNull PsiSnippetDocTagImpl element,
                                                   @NotNull TextRange range,
                                                   String newContent) throws IncorrectOperationException {
-    throw new UnsupportedOperationException("Not implemented");
+    final PsiElementFactory factory = JavaPsiFacade.getElementFactory(element.getProject());
+
+    final JavaFileCodeStyleFacade codeStyleFacade = JavaFileCodeStyleFacade.forContext(element.getContainingFile());
+    final String newSnippetTagContent = codeStyleFacade.isJavaDocLeadingAsterisksEnabled()
+                                        ? prependAbsentAsterisks(newContent)
+                                        : newContent;
+
+    final PsiDocComment text = factory.createDocCommentFromText("/**\n" + newSnippetTagContent + "\n*/");
+    final PsiSnippetDocTag snippet = PsiTreeUtil.findChildOfType(text, PsiSnippetDocTag.class);
+    if (snippet == null) {
+      return element;
+    }
+    return (PsiSnippetDocTagImpl)element.replace(snippet);
+  }
+
+  @Contract(pure = true)
+  private static @NotNull String prependAbsentAsterisks(@NotNull String input) {
+    final StringBuilder builder = new StringBuilder();
+    boolean afterNewLine = false;
+    for (char c : input.toCharArray()) {
+      if (c == '\n') {
+        afterNewLine = true;
+      }
+      else if (afterNewLine) {
+        if (c == '*') {
+          afterNewLine = false;
+        }
+        else if (!Character.isWhitespace(c)) {
+          builder.append("* ");
+          afterNewLine = false;
+        }
+      }
+      builder.append(c);
+    }
+    return builder.toString();
   }
 
   @Override

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/javaDoc/Snippet.java

@@ -1,5 +1,5 @@
 /** {<warning descr="'@snippet' tag is not available at this language level">@snippet</warning> :
- *  Body<EOLError descr="Identifier expected"></EOLError>
+ *  Body
  * }
  */
 class A {

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/javaDoc/SnippetInstructions.java

@@ -1,11 +1,9 @@
 /** {<warning descr="'@snippet' tag is not available at this language level">@snippet</warning> :
- * {
  *   Optional<Integer> v = null;
  *   if (v.isPresent()) {
  *      System.out.println("v: " + v.get());
  *   }
  * }
- * }
  */
 class A {
 }

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/javaDoc/SnippetInstructionsWithUnhandledThrowable.java

@@ -0,0 +1,7 @@
+/** {<warning descr="'@snippet' tag is not available at this language level">@snippet</warning> :
+ * FileInputStream is = new FileInputStream("hello.world");
+ * int r = is.read();
+ * }
+ */
+class A {
+}

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/javaDoc/SnippetMethod.java

@@ -1,5 +1,5 @@
 /** {<warning descr="'@snippet' tag is not available at this language level">@snippet</warning> :
- * void f() {}
+ * void f<error descr="';' expected">(</error><error descr="Expression expected">)</error> {}
  * }
  */
 class A {

java/java-tests/testData/codeInsight/javadoc/snippet/completion/afterOverrideMethod.java

@@ -0,0 +1,14 @@
+class Main {
+  /**
+   * A simple program.
+   * {@snippet:
+   * class HelloWorld {
+   *  @Override
+   * public boolean equals(Object obj) {
+   * return super.equals(obj);
+   * }void f() {}
+   * }
+   *}
+   */
+  void f() {}
+}

java/java-tests/testData/codeInsight/javadoc/snippet/completion/beforeOverrideMethod.java

@@ -0,0 +1,12 @@
+class Main {
+  /**
+   * A simple program.
+   * {@snippet :
+   * class HelloWorld {
+   *  equal<caret>
+   *   void f() {}
+   * }
+   *}
+   */
+  void f() {}
+}

java/java-tests/testData/codeInsight/javadoc/snippet/enterhandler/afterEnterInMethodJavadoc.java

@@ -5,7 +5,7 @@ class Main {
    * A simple program.
    * {@snippet :
    * class HelloWorld {
-   *    <caret>
+   *       <caret>
    * }
    * }
    */

java/java-tests/testSrc/com/intellij/java/codeInsight/daemon/JavadocHighlightingTest.java

@@ -131,7 +131,7 @@ public class JavadocHighlightingTest extends LightDaemonAnalyzerTestCase {
   public void testSnippetInstructions() { doTest(); }
   public void testEmptySnippet() { doTest(); }
   public void testOnlyEmptyLinesInSnippet() { doTest(); }
-
+  public void testSnippetInstructionsWithUnhandledThrowable() { doTest(); }
 
   public void testIssueLinksInJavaDoc() {
     IssueNavigationConfiguration navigationConfiguration = IssueNavigationConfiguration.getInstance(getProject());
@@ -182,4 +182,4 @@ public class JavadocHighlightingTest extends LightDaemonAnalyzerTestCase {
   private void doTest(String testFileName) {
     doTest(testFileName, true, false);
   }
-}
+}

java/java-tests/testSrc/com/intellij/java/codeInsight/javadoc/JavadocCompletionInSnippetTest.java

@@ -0,0 +1,35 @@
+// Copyright 2000-2021 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
+package com.intellij.java.codeInsight.javadoc;
+
+import com.intellij.testFramework.LightProjectDescriptor;
+import com.intellij.testFramework.PlatformTestUtil;
+import com.intellij.testFramework.fixtures.BasePlatformTestCase;
+import org.jetbrains.annotations.NotNull;
+
+import java.io.File;
+
+import static com.intellij.testFramework.fixtures.LightJavaCodeInsightFixtureTestCase.JAVA_17;
+
+public class JavadocCompletionInSnippetTest extends BasePlatformTestCase {
+
+  public void testOverrideMethod() {
+    doTest();
+  }
+
+  private void doTest() {
+    myFixture.configureByFile("before" + getTestName(false) + ".java");
+    myFixture.completeBasic();
+    myFixture.checkResultByFile("after" + getTestName(false) + ".java");
+  }
+
+  @Override
+  protected String getTestDataPath() {
+    return PlatformTestUtil.getCommunityPath().replace(File.separatorChar, '/') + "/java/java-tests/testData/codeInsight/javadoc/snippet/completion/";
+  }
+
+  @NotNull
+  @Override
+  protected LightProjectDescriptor getProjectDescriptor() {
+    return JAVA_17;
+  }
+}

java/java-tests/testSrc/com/intellij/java/codeInsight/javadoc/JavadocSnippetInjectionTest.java

@@ -6,7 +6,6 @@ import com.intellij.codeInsight.daemon.quickFix.LightQuickFixParameterizedTestCa
 import com.intellij.lang.Language;
 import com.intellij.lang.injection.InjectedLanguageManager;
 import com.intellij.psi.PsiElement;
-import com.intellij.psi.impl.source.tree.injected.MyTestInjector;
 import com.intellij.psi.javadoc.PsiSnippetDocTag;
 import com.intellij.psi.util.PsiTreeUtil;
 import com.intellij.psi.util.PsiUtilCore;

platform/core-impl/src/com/intellij/psi/impl/smartPointers/SmartPsiElementPointerImpl.java

@@ -142,11 +142,16 @@ class SmartPsiElementPointerImpl<E extends PsiElement> implements SmartPointerEx
                                                                                   boolean forInjected) {
     SmartPointerElementInfo elementInfo = doCreateElementInfo(manager.getProject(), element, containingFile, forInjected);
     if (ApplicationManager.getApplication().isUnitTestMode() && !ApplicationManagerEx.isInStressTest()) {
-      PsiElement restored = elementInfo.restoreElement(manager);
-      if (!element.equals(restored)) {
+      PsiElement restoredElement = elementInfo.restoreElement(manager);
+      if (restoredElement == null) {
+        // The problem might be with injection. It's a questionable solution, requires more discussion.
+        elementInfo = doCreateElementInfo(manager.getProject(), element, containingFile, !forInjected);
+        restoredElement = elementInfo.restoreElement(manager);
+      }
+      if (!element.equals(restoredElement)) {
         // likely cause: PSI having isPhysical==true, but which can't be restored by containing file and range. To fix, make isPhysical return false
         LOG.error("Cannot restore " + element + " of " + element.getClass() + " from " + elementInfo +
-                  "; restored=" + restored + (restored == null ? "" : " of "+restored.getClass())+" in " + element.getProject());
+                  "; restored=" + restoredElement + (restoredElement == null ? "" : " of " + restoredElement.getClass()) + " in " + element.getProject());
       }
     }
     return elementInfo;