#16: Trailing comments formatting issue

Fixed #16

Author: kshchepanovskyi

src/main/java/io/protostuff/jetbrains/plugin/formatter/ProtoFileBlock.java

@@ -15,6 +15,9 @@
 import java.util.List;
 
 import static io.protostuff.jetbrains.plugin.formatter.BlockFactory.createBlock;
+import static io.protostuff.jetbrains.plugin.formatter.StatementBlock.COMMENT;
+import static io.protostuff.jetbrains.plugin.formatter.StatementBlock.LINE_COMMENT;
+import static io.protostuff.jetbrains.plugin.formatter.StatementBlock.SPACE_OR_NEW_LINE;
 
 /**
  * @author Kostiantyn Shchepanovskyi
@@ -65,6 +68,16 @@ public Spacing getSpacing(@Nullable Block child1, @NotNull Block child2) {
         if (child1 == null) {
             return StatementBlock.NONE;
         }
+        if (child2 instanceof ASTBlock) {
+            ASTBlock block = (ASTBlock) child2;
+            IElementType elementType = block.getNode().getElementType();
+
+            // Do not move trailing comments to new line.
+            if (LINE_COMMENT.equals(elementType)
+                    || COMMENT.equals(elementType)) {
+                return SPACE_OR_NEW_LINE;
+            }
+        }
         return StatementBlock.NEW_LINE;
     }
 

src/test/java/io/protostuff/jetbrains/plugin/formatter/FormatterTest.java

@@ -21,6 +21,10 @@ protected String getTestDataPath() {
         return "src/test/resources/formatting";
     }
 
+    private void run(String test) {
+       run(test, commonCodeStyleSettings -> {});
+    }
+
     private void run(String test, Consumer<CommonCodeStyleSettings> settings) {
         myFixture.configureByFiles(test + "/Source.proto");
         CodeStyleSettings codeStyleSettings = CodeStyleSettingsManager.getSettings(getProject());
@@ -36,7 +40,7 @@ protected void run() throws Throwable {
     }
 
     public void testDefaultFormatter() {
-       run("default", settings -> {});
+       run("default");
     }
 
     public void testTab() {
@@ -53,10 +57,7 @@ public void testCustomIndent() {
         });
     }
 
-//    public void testDisableSpaceAroundAssignmentOperator() {
-//        run("disable_space_around_assignment_operator", settings -> {
-//            settings.SPACE_AROUND_ASSIGNMENT_OPERATORS = false;
-//        });
-//    }
-
+    public void testTrailingComments() {
+        run("trailing_line_comments");
+    }
 }

src/test/resources/formatting/trailing_line_comments/Expected.proto

@@ -0,0 +1,5 @@
+syntax = "proto2"; // trailing comments should stay one the same line
+
+message TestMessage {
+    optional int32 x = 1; // trailing comments should stay one the same line
+}

src/test/resources/formatting/trailing_line_comments/Source.proto

@@ -0,0 +1,5 @@
+syntax = "proto2";// trailing comments should stay one the same line
+
+message TestMessage {
+    optional int32 x = 1;// trailing comments should stay one the same line
+}