[javadoc][snippet] IDEA-285783 Add snippet to allowed javadoc tags

GitOrigin-RevId: 326a6039748ff843277f9731853d06e6ac9cc417

java/java-psi-api/src/com/intellij/pom/java/LanguageLevel.java

@@ -40,6 +40,7 @@ public enum LanguageLevel {
   JDK_16_PREVIEW(JavaPsiBundle.messagePointer("jdk.16.preview.language.level.description"), 16),
   JDK_17(JavaPsiBundle.messagePointer("jdk.17.language.level.description"), 17),
   JDK_17_PREVIEW(JavaPsiBundle.messagePointer("jdk.17.preview.language.level.description"), 17),
+  // TODO please notify nikita.eshkeev@jetbrains.com after having JDK_18 added, he need to update the "snippet" tag in JavadocManagerImpl.java:49
   JDK_X(JavaPsiBundle.messagePointer("jdk.X.language.level.description"), 18);
 
   public static final LanguageLevel HIGHEST = JDK_17;

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

@@ -45,6 +45,8 @@ public class JavadocManagerImpl implements JavadocManager {
     myInfos.add(new SimpleDocTagInfo("index", LanguageLevel.JDK_1_9, true, PsiElement.class));
     myInfos.add(new SimpleDocTagInfo("summary", LanguageLevel.JDK_10, true, PsiElement.class));
     myInfos.add(new SimpleDocTagInfo("systemProperty", LanguageLevel.JDK_12, true, PsiElement.class));
+    // TODO nikita.eshkeev@jetbrains.com, please change the language level to LanguageLevel.JDK_18 when it's available
+    myInfos.add(new SimpleDocTagInfo("snippet", LanguageLevel.JDK_17, true, PsiElement.class));
 
     // not a standard tag, used by IDEA for suppressing inspections
     myInfos.add(new SimpleDocTagInfo(SuppressionUtilCore.SUPPRESS_INSPECTIONS_TAG_NAME, LanguageLevel.JDK_1_3, false, PsiElement.class));

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

@@ -0,0 +1,15 @@
+/**
+ * {@snippet lang=JAVA :
+ *   public class ShowOptional {
+ *     void show(Optional<String> v) {
+ *         // @start region="example"
+ *         if (v.isPresent()) {
+ *             System.out.println("v: " + v.get());
+ *         }
+ *         // @end
+ *     }
+ *   }
+ * }
+ */
+class Main {
+}

java/java-tests/testSrc/com/intellij/java/codeInsight/completion/JavadocCompletionTest.groovy

@@ -160,7 +160,7 @@ class JavadocCompletionTest extends LightFixtureCompletionTestCase {
 
   void testInlineLookup() {
     configureByFile("InlineTagName.java")
-    assertStringItems("code", "docRoot", "index", "inheritDoc", "link", "linkplain", "literal", "summary", "systemProperty", "value")
+    assertStringItems("code", "docRoot", "index", "inheritDoc", "link", "linkplain", "literal", "snippet", "summary", "systemProperty", "value")
   }
 
   @NeedsIndex.ForStandardLibrary
@@ -775,7 +775,7 @@ interface Bar<T> extends Foo<T> {
   void "test tags at top level inline"() {
     myFixture.configureByText 'a.java', "interface Foo { /** Hello <caret> */void foo(int a); }"
     myFixture.completeBasic()
-    assert myFixture.lookupElementStrings == ['{@code}', '{@docRoot}', '{@index}', '{@inheritDoc}', '{@linkplain}', '{@link}', '{@literal}', '{@summary}', '{@systemProperty}', '{@value}']
+    assert myFixture.lookupElementStrings == ['{@code}', '{@docRoot}', '{@index}', '{@inheritDoc}', '{@linkplain}', '{@link}', '{@literal}', '{@snippet}', '{@summary}', '{@systemProperty}', '{@value}']
     def element = myFixture.lookupElements[5]
     assert element.lookupString == "{@link}"
     selectItem(element)
@@ -785,7 +785,7 @@ interface Bar<T> extends Foo<T> {
   void "test tags after return"() {
     myFixture.configureByText 'a.java', "interface Foo { /** @return <caret> */int foo(int a); }"
     myFixture.completeBasic()
-    assert myFixture.lookupElementStrings == ['{@code}', '{@docRoot}', '{@index}', '{@inheritDoc}', '{@linkplain}', '{@link}', '{@literal}', '{@return}', '{@summary}', '{@systemProperty}', '{@value}']
+    assert myFixture.lookupElementStrings == ['{@code}', '{@docRoot}', '{@index}', '{@inheritDoc}', '{@linkplain}', '{@link}', '{@literal}', '{@return}', '{@snippet}', '{@summary}', '{@systemProperty}', '{@value}']
     def element = myFixture.lookupElements[5]
     assert element.lookupString == "{@link}"
     selectItem(element)
@@ -795,7 +795,7 @@ interface Bar<T> extends Foo<T> {
   void "test tags at top level inline in brace"() {
     myFixture.configureByText 'a.java', "interface Foo { /** Hello {<caret>} */void foo(int a); }"
     myFixture.completeBasic()
-    assert myFixture.lookupElementStrings == ['@code', '@docRoot', '@index', '@inheritDoc', '@link', '@linkplain', '@literal', '@summary', '@systemProperty', '@value']
+    assert myFixture.lookupElementStrings == ['@code', '@docRoot', '@index', '@inheritDoc', '@link', '@linkplain', '@literal', '@snippet', '@summary', '@systemProperty', '@value']
     def element = myFixture.lookupElements[4]
     assert element.lookupString == "@link"
     selectItem(element)

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

@@ -125,6 +125,7 @@ public class JavadocHighlightingTest extends LightDaemonAnalyzerTestCase {
   public void testIgnoreAccessors() { myInspection.setIgnoreSimpleAccessors(true); doTest(); }
   public void testAuthoredMethod() { doTest(); }
   public void testThrowsInheritDoc() { doTest(); }
+  public void testSnippetInlineTag() {  doTest(); }
 
   public void testIssueLinksInJavaDoc() {
     IssueNavigationConfiguration navigationConfiguration = IssueNavigationConfiguration.getInstance(getProject());