Merge pull request #2035 from dlsniper/add-const-folding

Added const folding option (fixes #2015)

Author: zolotov

src/com/goide/editor/GoFoldingBuilder.java

@@ -82,6 +82,13 @@ protected void buildLanguageFoldRegions(@NotNull final List<FoldingDescriptor> r
       }
     }
 
+    for (GoConstDeclaration constDeclaration : PsiTreeUtil.findChildrenOfType(file, GoConstDeclaration.class)) {
+      TextRange range = processList(constDeclaration.getLparen(), constDeclaration.getRparen(), constDeclaration.getConstSpecList().size());
+      if (range != null) {
+        result.add(new FoldingDescriptor(constDeclaration, range));
+      }
+    }
+
     for (GoTypeDeclaration typeDeclaration : PsiTreeUtil.findChildrenOfType(file, GoTypeDeclaration.class)) {
       TextRange range = processList(typeDeclaration.getLparen(), typeDeclaration.getRparen(), typeDeclaration.getTypeSpecList().size());
       if (range != null) {
@@ -172,7 +179,8 @@ private static void addCommentFolds(@NotNull PsiElement comment,
     }
 
     if (end != null) {
-      foldElements.add(new FoldingDescriptor(comment, new TextRange(comment.getTextRange().getStartOffset(), end.getTextRange().getEndOffset())));
+      foldElements
+        .add(new FoldingDescriptor(comment, new TextRange(comment.getTextRange().getStartOffset(), end.getTextRange().getEndOffset())));
     }
   }
 
@@ -182,8 +190,13 @@ protected String getLanguagePlaceholderText(@NotNull ASTNode node, @NotNull Text
     PsiElement psi = node.getPsi();
     IElementType type = node.getElementType();
     if (psi instanceof GoBlock || psi instanceof GoStructType ||
-        psi instanceof GoInterfaceType || psi instanceof GoLiteralValue) return "{...}";
-    if (psi instanceof GoVarDeclaration || psi instanceof GoTypeDeclaration) return "(...)";
+        psi instanceof GoInterfaceType || psi instanceof GoLiteralValue) {
+      return "{...}";
+    }
+    if (psi instanceof GoVarDeclaration || psi instanceof GoConstDeclaration
+        || psi instanceof GoTypeDeclaration) {
+      return "(...)";
+    }
     if (psi instanceof GoImportDeclaration) return "...";
     if (GoParserDefinition.LINE_COMMENT == type) return "/.../";
     if (GoParserDefinition.MULTILINE_COMMENT == type) return "/*...*/";

testData/folding/constDeclaration.go

@@ -0,0 +1,6 @@
+package foo
+
+const <fold text='(...)'>(
+	demo = 1
+	dem = "2"
+)</fold>

tests/com/goide/editor/GoFoldingBuilderTest.java

@@ -37,6 +37,7 @@ protected String getBasePath() {
   public void testImportListWithNewLineAfterKeyword()             { doTest(); }
   public void testImportListWithOnlyThreeSymbolsToFold()          { doTest(); }
   public void testVarDeclaration()                                { doTest(); }
+  public void testConstDeclaration()                              { doTest(); }
   public void testTypeDeclaration()                               { doTest(); }
   public void testCompositeLiteral()                              { doTest(); }
 }